diff --git a/toolchain/check/testdata/array/basics.carbon b/toolchain/check/testdata/array/basics.carbon
index d6a48ab4d325..7905c55ed1c7 100644
--- a/toolchain/check/testdata/array/basics.carbon
+++ b/toolchain/check/testdata/array/basics.carbon
@@ -226,7 +226,7 @@ var a: array(1, 1);
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- array_vs_tuple.carbon
 // CHECK:STDOUT:
@@ -285,9 +285,9 @@ var a: array(1, 1);
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %tuple.type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc7(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc7(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- assign_return_value.carbon
 // CHECK:STDOUT:
@@ -344,9 +344,9 @@ var a: array(1, 1);
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8_27(%self.param: %tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8_27(%self.param: ref %tuple.type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8_3(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8_3(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- nine_elements.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/array/import.carbon b/toolchain/check/testdata/array/import.carbon
index f91810f99b92..f81c8f50efc2 100644
--- a/toolchain/check/testdata/array/import.carbon
+++ b/toolchain/check/testdata/array/import.carbon
@@ -109,7 +109,7 @@ fn F() -> array(i32, 1) {
 // CHECK:STDOUT:   return %Int.as.Copy.impl.Op.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_todo_import_symbolic_decl.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/array/index_not_literal.carbon b/toolchain/check/testdata/array/index_not_literal.carbon
index f9e17db36ed1..04855648b871 100644
--- a/toolchain/check/testdata/array/index_not_literal.carbon
+++ b/toolchain/check/testdata/array/index_not_literal.carbon
@@ -174,7 +174,7 @@ fn F(a: array({}, 3)) -> {} {
 // CHECK:STDOUT:   return %F.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- index_non_literal.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/array/init_dependent_bound.carbon b/toolchain/check/testdata/array/init_dependent_bound.carbon
index 954be793bae4..90a9e8c8b3cc 100644
--- a/toolchain/check/testdata/array/init_dependent_bound.carbon
+++ b/toolchain/check/testdata/array/init_dependent_bound.carbon
@@ -129,7 +129,7 @@ fn H() { G(3); }
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type.70a) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type.70a) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @G(constants.%T) {
 // CHECK:STDOUT:   %T.loc4_6.1 => constants.%T
diff --git a/toolchain/check/testdata/as/basics.carbon b/toolchain/check/testdata/as/basics.carbon
index 95120e608804..e3f5e77ccd36 100644
--- a/toolchain/check/testdata/as/basics.carbon
+++ b/toolchain/check/testdata/as/basics.carbon
@@ -258,7 +258,7 @@ let n: {.x: ()} = {.x = ()} as {.x = ()};
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: %X) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: ref %X) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @Var() {
 // CHECK:STDOUT: !entry:
@@ -293,7 +293,7 @@ let n: {.x: ()} = {.x = ()} as {.x = ()};
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc20(%self.param: %tuple.type.2de) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc20(%self.param: ref %tuple.type.2de) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- identity.carbon
 // CHECK:STDOUT:
@@ -360,7 +360,7 @@ let n: {.x: ()} = {.x = ()} as {.x = ()};
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %X) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %X) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- overloaded.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/as/const.carbon b/toolchain/check/testdata/as/const.carbon
index c7baa43b9317..703aaf3cfef1 100644
--- a/toolchain/check/testdata/as/const.carbon
+++ b/toolchain/check/testdata/as/const.carbon
@@ -181,7 +181,7 @@ fn Use() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %const) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %const) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
@@ -234,7 +234,7 @@ fn Use() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %X) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %X) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/as/maybe_unformed.carbon b/toolchain/check/testdata/as/maybe_unformed.carbon
index ae538c0c12c8..048988f13705 100644
--- a/toolchain/check/testdata/as/maybe_unformed.carbon
+++ b/toolchain/check/testdata/as/maybe_unformed.carbon
@@ -279,7 +279,7 @@ fn Use() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %MaybeUnformed.b49) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %MaybeUnformed.b49) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/as/partial.carbon b/toolchain/check/testdata/as/partial.carbon
index 9fd3d260bebd..185fede367e2 100644
--- a/toolchain/check/testdata/as/partial.carbon
+++ b/toolchain/check/testdata/as/partial.carbon
@@ -217,7 +217,7 @@ fn Use() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %.4b5) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %.4b5) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
@@ -289,7 +289,7 @@ fn Use() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %X) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %X) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- unsafe_remove_partial.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/as/var_init.carbon b/toolchain/check/testdata/as/var_init.carbon
index 2ed4a5b0ae0f..9150314b67db 100644
--- a/toolchain/check/testdata/as/var_init.carbon
+++ b/toolchain/check/testdata/as/var_init.carbon
@@ -72,5 +72,5 @@ fn Convert(t: ()) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %X) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %X) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/basics/dump_sem_ir_ranges.carbon b/toolchain/check/testdata/basics/dump_sem_ir_ranges.carbon
index eaa13d973673..cc5e9cf1a6f9 100644
--- a/toolchain/check/testdata/basics/dump_sem_ir_ranges.carbon
+++ b/toolchain/check/testdata/basics/dump_sem_ir_ranges.carbon
@@ -251,7 +251,7 @@ library "[[@TEST_NAME]]";
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- file_without_ranges.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/basics/duplicate_name_same_line.carbon b/toolchain/check/testdata/basics/duplicate_name_same_line.carbon
index a89aba88cf03..9a13cf3b1215 100644
--- a/toolchain/check/testdata/basics/duplicate_name_same_line.carbon
+++ b/toolchain/check/testdata/basics/duplicate_name_same_line.carbon
@@ -71,5 +71,5 @@ fn A() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/builtins/int/and_assign.carbon b/toolchain/check/testdata/builtins/int/and_assign.carbon
index 95f9a2c5321d..3da7448bddd9 100644
--- a/toolchain/check/testdata/builtins/int/and_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/and_assign.carbon
@@ -67,7 +67,7 @@ fn MixedTypes(ref a: i32, b: i64) = "int.and_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/left_shift_assign.carbon b/toolchain/check/testdata/builtins/int/left_shift_assign.carbon
index a883b6bf7da8..126a770aeea1 100644
--- a/toolchain/check/testdata/builtins/int/left_shift_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/left_shift_assign.carbon
@@ -67,7 +67,7 @@ fn NotRef(a: i32, b: i32) = "int.left_shift_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
@@ -77,7 +77,7 @@ fn NotRef(a: i32, b: i32) = "int.left_shift_assign";
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @CallMixed(%a.param: %i32, %b.param: %i64) {
+// CHECK:STDOUT: fn @CallMixed(%a.param: ref %i32, %b.param: %i64) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %MixedTypes.ref: %MixedTypes.type = name_ref MixedTypes, file.%MixedTypes.decl [concrete = constants.%MixedTypes]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/or_assign.carbon b/toolchain/check/testdata/builtins/int/or_assign.carbon
index 59dd3079c324..1ddb0a20a74f 100644
--- a/toolchain/check/testdata/builtins/int/or_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/or_assign.carbon
@@ -61,7 +61,7 @@ fn MixedTypes(ref a: i32, b: i64) = "int.or_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/right_shift_assign.carbon b/toolchain/check/testdata/builtins/int/right_shift_assign.carbon
index 1ef1bd312797..923e27bedbf1 100644
--- a/toolchain/check/testdata/builtins/int/right_shift_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/right_shift_assign.carbon
@@ -67,7 +67,7 @@ fn NotRef(a: i32, b: i32) = "int.right_shift_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
@@ -77,7 +77,7 @@ fn NotRef(a: i32, b: i32) = "int.right_shift_assign";
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @CallMixed(%a.param: %i32, %b.param: %i64) {
+// CHECK:STDOUT: fn @CallMixed(%a.param: ref %i32, %b.param: %i64) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %MixedTypes.ref: %MixedTypes.type = name_ref MixedTypes, file.%MixedTypes.decl [concrete = constants.%MixedTypes]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/sdiv_assign.carbon b/toolchain/check/testdata/builtins/int/sdiv_assign.carbon
index 2de8167b26cf..a4970c579524 100644
--- a/toolchain/check/testdata/builtins/int/sdiv_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/sdiv_assign.carbon
@@ -61,7 +61,7 @@ fn MixedTypes(ref a: i32, b: i64) = "int.sdiv_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/smod_assign.carbon b/toolchain/check/testdata/builtins/int/smod_assign.carbon
index eeed753adc7c..d1e802f8f6dc 100644
--- a/toolchain/check/testdata/builtins/int/smod_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/smod_assign.carbon
@@ -61,7 +61,7 @@ fn MixedTypes(ref a: i32, b: i64) = "int.smod_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/smul_assign.carbon b/toolchain/check/testdata/builtins/int/smul_assign.carbon
index 55e201f7f300..89c92174b8eb 100644
--- a/toolchain/check/testdata/builtins/int/smul_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/smul_assign.carbon
@@ -61,7 +61,7 @@ fn MixedTypes(ref a: i32, b: i64) = "int.smul_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/ssub_assign.carbon b/toolchain/check/testdata/builtins/int/ssub_assign.carbon
index 6b89ed1106e5..b162f4b565ae 100644
--- a/toolchain/check/testdata/builtins/int/ssub_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/ssub_assign.carbon
@@ -61,7 +61,7 @@ fn MixedTypes(ref a: i32, b: i64) = "int.ssub_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/uadd_assign.carbon b/toolchain/check/testdata/builtins/int/uadd_assign.carbon
index 655dca412218..e93b2c57ba05 100644
--- a/toolchain/check/testdata/builtins/int/uadd_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/uadd_assign.carbon
@@ -61,7 +61,7 @@ fn MixedTypes(ref a: i32, b: i64) = "int.uadd_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/udiv_assign.carbon b/toolchain/check/testdata/builtins/int/udiv_assign.carbon
index 7ed7f7f304ca..d70c6ab7c35b 100644
--- a/toolchain/check/testdata/builtins/int/udiv_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/udiv_assign.carbon
@@ -61,7 +61,7 @@ fn MixedTypes(ref a: i32, b: i64) = "int.udiv_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/umod_assign.carbon b/toolchain/check/testdata/builtins/int/umod_assign.carbon
index 4bcd417be6bf..c583e3919ec2 100644
--- a/toolchain/check/testdata/builtins/int/umod_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/umod_assign.carbon
@@ -61,7 +61,7 @@ fn MixedTypes(ref a: i32, b: i64) = "int.umod_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/umul_assign.carbon b/toolchain/check/testdata/builtins/int/umul_assign.carbon
index 1adb10d2bc17..4e3bbc05d811 100644
--- a/toolchain/check/testdata/builtins/int/umul_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/umul_assign.carbon
@@ -61,7 +61,7 @@ fn MixedTypes(ref a: i32, b: i64) = "int.umul_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/usub_assign.carbon b/toolchain/check/testdata/builtins/int/usub_assign.carbon
index f3a94a1f4751..3045472d5db0 100644
--- a/toolchain/check/testdata/builtins/int/usub_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/usub_assign.carbon
@@ -61,7 +61,7 @@ fn MixedTypes(ref a: i32, b: i64) = "int.usub_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/builtins/int/xor_assign.carbon b/toolchain/check/testdata/builtins/int/xor_assign.carbon
index 460cd0a42043..51e707b98948 100644
--- a/toolchain/check/testdata/builtins/int/xor_assign.carbon
+++ b/toolchain/check/testdata/builtins/int/xor_assign.carbon
@@ -61,7 +61,7 @@ fn MixedTypes(ref a: i32, b: i64) = "int.xor_assign";
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%a.param: %i32, %b.param: %i32) {
+// CHECK:STDOUT: fn @Call(%a.param: ref %i32, %b.param: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Builtin.ref: %Builtin.type = name_ref Builtin, file.%Builtin.decl [concrete = constants.%Builtin]
 // CHECK:STDOUT:   %a.ref: ref %i32 = name_ref a, %a
diff --git a/toolchain/check/testdata/class/access_modifers.carbon b/toolchain/check/testdata/class/access_modifers.carbon
index 4508769a3a87..7db75046a3a7 100644
--- a/toolchain/check/testdata/class/access_modifers.carbon
+++ b/toolchain/check/testdata/class/access_modifers.carbon
@@ -342,7 +342,7 @@ class A {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Circle) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Circle) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_protected_field_access.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/adapter/adapt_copy.carbon b/toolchain/check/testdata/class/adapter/adapt_copy.carbon
index ebc247d03de7..c9841debe835 100644
--- a/toolchain/check/testdata/class/adapter/adapt_copy.carbon
+++ b/toolchain/check/testdata/class/adapter/adapt_copy.carbon
@@ -291,7 +291,7 @@ fn InTuple(c: (AdaptStruct, u32)) -> (AdaptStruct, u32) {
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: %AdaptCopyable) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: ref %AdaptCopyable) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @InTuple(%c.param: %tuple.type.d78) -> out %return.param: %tuple.type.d78 {
 // CHECK:STDOUT: !entry:
@@ -319,7 +319,7 @@ fn InTuple(c: (AdaptStruct, u32)) -> (AdaptStruct, u32) {
 // CHECK:STDOUT:   return <error> to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc35(%self.param: %tuple.type.d78) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc35(%self.param: ref %tuple.type.d78) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- adapt_copyable_tuple.carbon
 // CHECK:STDOUT:
@@ -517,7 +517,7 @@ fn InTuple(c: (AdaptStruct, u32)) -> (AdaptStruct, u32) {
 // CHECK:STDOUT:   return %.loc10_11.9 to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: %AdaptTuple) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: ref %AdaptTuple) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @InTuple(%c.param: %tuple.type.3c7) -> out %return.param: %tuple.type.3c7 {
 // CHECK:STDOUT: !entry:
@@ -611,7 +611,7 @@ fn InTuple(c: (AdaptStruct, u32)) -> (AdaptStruct, u32) {
 // CHECK:STDOUT:   return %.loc15_11 to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc14(%self.param: %tuple.type.3c7) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc14(%self.param: ref %tuple.type.3c7) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_adapt_not_copyable.carbon
 // CHECK:STDOUT:
@@ -705,7 +705,7 @@ fn InTuple(c: (AdaptStruct, u32)) -> (AdaptStruct, u32) {
 // CHECK:STDOUT:   return <error> to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %AdaptNoncopyable) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %AdaptNoncopyable) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_adapt_not_copyable_indirect.carbon
 // CHECK:STDOUT:
@@ -850,7 +850,7 @@ fn InTuple(c: (AdaptStruct, u32)) -> (AdaptStruct, u32) {
 // CHECK:STDOUT:   return <error> to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %AdaptNoncopyableIndirect) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %AdaptNoncopyableIndirect) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- adapt_copyable_struct.carbon
 // CHECK:STDOUT:
@@ -1046,7 +1046,7 @@ fn InTuple(c: (AdaptStruct, u32)) -> (AdaptStruct, u32) {
 // CHECK:STDOUT:   return %.loc10_11.13 to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: %AdaptStruct) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: ref %AdaptStruct) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @InTuple(%c.param: %tuple.type.691) -> out %return.param: %tuple.type.691 {
 // CHECK:STDOUT: !entry:
@@ -1140,5 +1140,5 @@ fn InTuple(c: (AdaptStruct, u32)) -> (AdaptStruct, u32) {
 // CHECK:STDOUT:   return %.loc15_11 to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc14(%self.param: %tuple.type.691) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc14(%self.param: ref %tuple.type.691) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/base_method.carbon b/toolchain/check/testdata/class/base_method.carbon
index 41647f3f9bdc..2889e63ddeec 100644
--- a/toolchain/check/testdata/class/base_method.carbon
+++ b/toolchain/check/testdata/class/base_method.carbon
@@ -151,7 +151,7 @@ fn Call(p: Derived*) {
 // CHECK:STDOUT:   extend %Base.ref
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Base.F(%self.param.loc21: %Base) {
+// CHECK:STDOUT: fn @Base.F(%self.param.loc21: ref %Base) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %self.ref: ref %Base = name_ref self, %self.loc21
 // CHECK:STDOUT:   %a.ref: %Base.elem = name_ref a, @Base.%.loc16 [concrete = @Base.%.loc16]
diff --git a/toolchain/check/testdata/class/base_method_shadow.carbon b/toolchain/check/testdata/class/base_method_shadow.carbon
index 5dcdf006c895..740748a41f3b 100644
--- a/toolchain/check/testdata/class/base_method_shadow.carbon
+++ b/toolchain/check/testdata/class/base_method_shadow.carbon
@@ -208,11 +208,11 @@ fn Call(a: A*, b: B*, c: C*, d: D*) {
 // CHECK:STDOUT:   extend %B.ref
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @A.F(%self.param: %A);
+// CHECK:STDOUT: fn @A.F(%self.param: ref %A);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @B.F(%self.param: %B);
+// CHECK:STDOUT: fn @B.F(%self.param: ref %B);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @C.F(%self.param: %C);
+// CHECK:STDOUT: fn @C.F(%self.param: ref %C);
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @Call(%a.param: %ptr.643, %b.param: %ptr.27c, %c.param: %ptr.31e, %d.param: %ptr.805) {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/class/derived_to_base.carbon b/toolchain/check/testdata/class/derived_to_base.carbon
index 4e5b79d8fc1f..3593947aa3b2 100644
--- a/toolchain/check/testdata/class/derived_to_base.carbon
+++ b/toolchain/check/testdata/class/derived_to_base.carbon
@@ -426,7 +426,7 @@ fn PassConstB(p: const B) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- qualified.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/destroy_calls.carbon b/toolchain/check/testdata/class/destroy_calls.carbon
index 9ea824e36ad0..ea70a10eacad 100644
--- a/toolchain/check/testdata/class/destroy_calls.carbon
+++ b/toolchain/check/testdata/class/destroy_calls.carbon
@@ -147,11 +147,11 @@ fn G() { F({}); }
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: %B) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: ref %B) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: %A) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: ref %A) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- nested_scope.carbon
 // CHECK:STDOUT:
@@ -220,11 +220,11 @@ fn G() { F({}); }
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: %B) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: ref %B) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: %A) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: ref %A) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- temp.carbon
 // CHECK:STDOUT:
@@ -282,11 +282,11 @@ fn G() { F({}); }
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc14(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc14(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: %B) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: ref %B) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: %A) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: ref %A) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- generic_class.carbon
 // CHECK:STDOUT:
@@ -328,7 +328,7 @@ fn G() { F({}); }
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %D.213) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %D.213) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- generic_use_inside_generic.carbon
 // CHECK:STDOUT:
@@ -408,7 +408,7 @@ fn G() { F({}); }
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C.850) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C.850) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%T) {
 // CHECK:STDOUT:   %T.loc6_15.1 => constants.%T
diff --git a/toolchain/check/testdata/class/fail_abstract.carbon b/toolchain/check/testdata/class/fail_abstract.carbon
index e50aa8dfb901..8d8daf20f034 100644
--- a/toolchain/check/testdata/class/fail_abstract.carbon
+++ b/toolchain/check/testdata/class/fail_abstract.carbon
@@ -351,7 +351,7 @@ fn CallReturnAbstract() {
 // CHECK:STDOUT:   .Self = constants.%Abstract
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @F(%p.param: <error>) {
+// CHECK:STDOUT: fn @F(%p.param: ref <error>) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
diff --git a/toolchain/check/testdata/class/fail_ref_self.carbon b/toolchain/check/testdata/class/fail_ref_self.carbon
index 6551580ba52f..ef6ba3f99aa1 100644
--- a/toolchain/check/testdata/class/fail_ref_self.carbon
+++ b/toolchain/check/testdata/class/fail_ref_self.carbon
@@ -119,7 +119,7 @@ fn F(c: Class, p: Class*) {
 // CHECK:STDOUT:   .F = %Class.F.decl
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Class.F(%self.param: %Class);
+// CHECK:STDOUT: fn @Class.F(%self.param: ref %Class);
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @Make() -> out %return.param: %Class;
 // CHECK:STDOUT:
@@ -146,5 +146,5 @@ fn F(c: Class, p: Class*) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Class) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Class) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/field_access.carbon b/toolchain/check/testdata/class/field_access.carbon
index 9cab74691461..1c70efa785b9 100644
--- a/toolchain/check/testdata/class/field_access.carbon
+++ b/toolchain/check/testdata/class/field_access.carbon
@@ -206,7 +206,7 @@ fn Run() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc25(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc25(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc21(%self.param: %Class) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc21(%self.param: ref %Class) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/field_access_in_value.carbon b/toolchain/check/testdata/class/field_access_in_value.carbon
index c84fa22dc0c1..909c294cfb8d 100644
--- a/toolchain/check/testdata/class/field_access_in_value.carbon
+++ b/toolchain/check/testdata/class/field_access_in_value.carbon
@@ -214,7 +214,7 @@ fn Test() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc26(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc26(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc21(%self.param: %Class) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc21(%self.param: ref %Class) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/generic/basic.carbon b/toolchain/check/testdata/class/generic/basic.carbon
index 057dd53dec1e..e0e2714ad5f0 100644
--- a/toolchain/check/testdata/class/generic/basic.carbon
+++ b/toolchain/check/testdata/class/generic/basic.carbon
@@ -198,7 +198,7 @@ class Declaration(T:! type);
 // CHECK:STDOUT:   %impl.elem0.loc7_12.2: @Class.GetAddr.%.loc7_12.2 (%.f11) = impl_witness_access %Copy.lookup_impl_witness, element0 [symbolic = %impl.elem0.loc7_12.2 (constants.%impl.elem0.a55)]
 // CHECK:STDOUT:   %specific_impl_fn.loc7_12.2: <specific function> = specific_impl_function %impl.elem0.loc7_12.2, @Copy.Op(%Copy.facet) [symbolic = %specific_impl_fn.loc7_12.2 (constants.%specific_impl_fn.0df)]
 // CHECK:STDOUT:
-// CHECK:STDOUT:   fn(%self.param: @Class.GetAddr.%Class (%Class)) -> out %return.param: @Class.GetAddr.%ptr.loc6_36.1 (%ptr.e7d) {
+// CHECK:STDOUT:   fn(%self.param: ref @Class.GetAddr.%Class (%Class)) -> out %return.param: @Class.GetAddr.%ptr.loc6_36.1 (%ptr.e7d) {
 // CHECK:STDOUT:   !entry:
 // CHECK:STDOUT:     %self.ref: ref @Class.GetAddr.%Class (%Class) = name_ref self, %self
 // CHECK:STDOUT:     %k.ref: @Class.GetAddr.%Class.elem (%Class.elem) = name_ref k, @Class.%.loc14_8 [concrete = @Class.%.loc14_8]
diff --git a/toolchain/check/testdata/class/generic/import.carbon b/toolchain/check/testdata/class/generic/import.carbon
index 9b993847988b..08c1027c9204 100644
--- a/toolchain/check/testdata/class/generic/import.carbon
+++ b/toolchain/check/testdata/class/generic/import.carbon
@@ -618,7 +618,7 @@ class Class(U:! type) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @F [from "foo.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %CompleteClass.d85) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %CompleteClass.d85) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @UseField() -> out %return.param: %i32 {
 // CHECK:STDOUT: !entry:
@@ -803,7 +803,7 @@ class Class(U:! type) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @F [from "foo.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %CompleteClass.582) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %CompleteClass.582) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @CompleteClass(constants.%T) {
 // CHECK:STDOUT:   %T => constants.%T
diff --git a/toolchain/check/testdata/class/generic/init.carbon b/toolchain/check/testdata/class/generic/init.carbon
index 76a9e2eba7dc..0e8218674d4f 100644
--- a/toolchain/check/testdata/class/generic/init.carbon
+++ b/toolchain/check/testdata/class/generic/init.carbon
@@ -277,7 +277,7 @@ fn InitFromAdaptedSpecific(x: i32) -> i32 {
 // CHECK:STDOUT:   return %Int.as.Copy.impl.Op.call.loc16
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Class.805) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Class.805) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @InitFromStructGeneric(constants.%T.035) {
 // CHECK:STDOUT:   %T.loc9_26.1 => constants.%T.035
diff --git a/toolchain/check/testdata/class/generic/member_access.carbon b/toolchain/check/testdata/class/generic/member_access.carbon
index d262b8269bfc..da1d459a581a 100644
--- a/toolchain/check/testdata/class/generic/member_access.carbon
+++ b/toolchain/check/testdata/class/generic/member_access.carbon
@@ -204,7 +204,7 @@ fn StaticMemberFunctionCall(T:! type) -> Class(T) {
 // CHECK:STDOUT:   %impl.elem0.loc15_12.2: @Class.GetAddr.%.loc15_12.2 (%.f11) = impl_witness_access %Copy.lookup_impl_witness, element0 [symbolic = %impl.elem0.loc15_12.2 (constants.%impl.elem0.a55)]
 // CHECK:STDOUT:   %specific_impl_fn.loc15_12.2: <specific function> = specific_impl_function %impl.elem0.loc15_12.2, @Copy.Op(%Copy.facet) [symbolic = %specific_impl_fn.loc15_12.2 (constants.%specific_impl_fn.0df)]
 // CHECK:STDOUT:
-// CHECK:STDOUT:   fn(%self.param: @Class.GetAddr.%Class (%Class.847)) -> out %return.param: @Class.GetAddr.%ptr.loc13_36.1 (%ptr.e7d) {
+// CHECK:STDOUT:   fn(%self.param: ref @Class.GetAddr.%Class (%Class.847)) -> out %return.param: @Class.GetAddr.%ptr.loc13_36.1 (%ptr.e7d) {
 // CHECK:STDOUT:   !entry:
 // CHECK:STDOUT:     %self.ref: ref @Class.GetAddr.%Class (%Class.847) = name_ref self, %self
 // CHECK:STDOUT:     %x.ref: @Class.GetAddr.%Class.elem (%Class.elem.05d) = name_ref x, @Class.%.loc5_8 [concrete = @Class.%.loc5_8]
diff --git a/toolchain/check/testdata/class/generic/member_type.carbon b/toolchain/check/testdata/class/generic/member_type.carbon
index c4d8c3d6f4f5..b9edf4830ed4 100644
--- a/toolchain/check/testdata/class/generic/member_type.carbon
+++ b/toolchain/check/testdata/class/generic/member_type.carbon
@@ -345,7 +345,7 @@ fn Test() -> i32 {
 // CHECK:STDOUT:   return %Int.as.Copy.impl.Op.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Inner.74c) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Inner.74c) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Outer(constants.%T.035) {
 // CHECK:STDOUT:   %T.loc4_13.1 => constants.%T.035
@@ -793,7 +793,7 @@ fn Test() -> i32 {
 // CHECK:STDOUT:   return %C.as.Inner.impl.F.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C.d3f) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C.d3f) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Outer(constants.%T) {
 // CHECK:STDOUT:   %T.loc4_13.1 => constants.%T
diff --git a/toolchain/check/testdata/class/generic/method_deduce.carbon b/toolchain/check/testdata/class/generic/method_deduce.carbon
index b47b9c28c553..8539e9762866 100644
--- a/toolchain/check/testdata/class/generic/method_deduce.carbon
+++ b/toolchain/check/testdata/class/generic/method_deduce.carbon
@@ -315,7 +315,7 @@ fn CallGenericMethodWithNonDeducedParam(c: Class(A)) -> (A, B) {
 // CHECK:STDOUT:   return %Class.GetNoDeduce.call to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %A) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %A) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Class(constants.%T) {
 // CHECK:STDOUT:   %T.loc18_13.1 => constants.%T
diff --git a/toolchain/check/testdata/class/import.carbon b/toolchain/check/testdata/class/import.carbon
index 6f29a795b079..35aa1cc97306 100644
--- a/toolchain/check/testdata/class/import.carbon
+++ b/toolchain/check/testdata/class/import.carbon
@@ -151,7 +151,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @ForwardDeclared.F(%self.param: %ForwardDeclared);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @ForwardDeclared.G(%self.param: %ForwardDeclared);
+// CHECK:STDOUT: fn @ForwardDeclared.G(%self.param: ref %ForwardDeclared);
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- b.carbon
 // CHECK:STDOUT:
@@ -425,13 +425,13 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @ForwardDeclared.G [from "a.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc18(%self.param: %ptr.8c3) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc18(%self.param: ref %ptr.8c3) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: %ptr.006) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: ref %ptr.006) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: %ForwardDeclared.20f323.1) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: ref %ForwardDeclared.20f323.1) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: %Field) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: ref %Field) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc7(%self.param: %Empty) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc7(%self.param: ref %Empty) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/import_base.carbon b/toolchain/check/testdata/class/import_base.carbon
index 87fde58250cf..5706d465d86a 100644
--- a/toolchain/check/testdata/class/import_base.carbon
+++ b/toolchain/check/testdata/class/import_base.carbon
@@ -309,5 +309,5 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @Base.F [from "a.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Child) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Child) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/import_member_cycle.carbon b/toolchain/check/testdata/class/import_member_cycle.carbon
index 96656a9528ab..d4146a226f4d 100644
--- a/toolchain/check/testdata/class/import_member_cycle.carbon
+++ b/toolchain/check/testdata/class/import_member_cycle.carbon
@@ -134,5 +134,5 @@ fn Run() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %ptr) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %ptr) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/init_as.carbon b/toolchain/check/testdata/class/init_as.carbon
index 48974014f696..8c89e40d7bc3 100644
--- a/toolchain/check/testdata/class/init_as.carbon
+++ b/toolchain/check/testdata/class/init_as.carbon
@@ -171,5 +171,5 @@ fn F() -> i32 {
 // CHECK:STDOUT:   return %Int.as.Copy.impl.Op.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Class) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Class) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/local.carbon b/toolchain/check/testdata/class/local.carbon
index 65e94dec3d6c..61d658379f63 100644
--- a/toolchain/check/testdata/class/local.carbon
+++ b/toolchain/check/testdata/class/local.carbon
@@ -200,5 +200,5 @@ class A {
 // CHECK:STDOUT:   return %b to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %B) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %B) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/method.carbon b/toolchain/check/testdata/class/method.carbon
index 20357386bd41..667c7dc4d457 100644
--- a/toolchain/check/testdata/class/method.carbon
+++ b/toolchain/check/testdata/class/method.carbon
@@ -367,7 +367,7 @@ fn CallGOnInitializingExpr() -> i32 {
 // CHECK:STDOUT:   return %Int.as.Copy.impl.Op.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Class.G(%self.param: %Class) -> out %return.param: %i32;
+// CHECK:STDOUT: fn @Class.G(%self.param: ref %Class) -> out %return.param: %i32;
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @Call(%c.param: %Class) -> out %return.param: %i32 {
 // CHECK:STDOUT: !entry:
@@ -413,7 +413,7 @@ fn CallGOnInitializingExpr() -> i32 {
 // CHECK:STDOUT:   return %Class.F.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Class) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Class) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @CallWithRef() -> out %return.param: %i32 {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/class/nested.carbon b/toolchain/check/testdata/class/nested.carbon
index 83ffe2343ef8..f6916da3503a 100644
--- a/toolchain/check/testdata/class/nested.carbon
+++ b/toolchain/check/testdata/class/nested.carbon
@@ -259,9 +259,9 @@ fn F(a: Outer*) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: %Inner) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: ref %Inner) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc18(%self.param: %Outer) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc18(%self.param: ref %Outer) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @F(%a.param: %ptr.56b) {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/class/nested_name.carbon b/toolchain/check/testdata/class/nested_name.carbon
index 39c70ad886fd..a8e43bd01159 100644
--- a/toolchain/check/testdata/class/nested_name.carbon
+++ b/toolchain/check/testdata/class/nested_name.carbon
@@ -170,5 +170,5 @@ fn G(o: Outer) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Inner) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Inner) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/partial.carbon b/toolchain/check/testdata/class/partial.carbon
index 56e823aca1a0..9112015bcd0a 100644
--- a/toolchain/check/testdata/class/partial.carbon
+++ b/toolchain/check/testdata/class/partial.carbon
@@ -261,7 +261,7 @@ fn F[T:! type](p: partial T*);
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @A(%p.param: %.e97);
+// CHECK:STDOUT: fn @A(%p.param: ref %.e97);
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_partial_nondynamic.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/raw_self.carbon b/toolchain/check/testdata/class/raw_self.carbon
index fd081145ff53..8502b9cc1ea8 100644
--- a/toolchain/check/testdata/class/raw_self.carbon
+++ b/toolchain/check/testdata/class/raw_self.carbon
@@ -183,7 +183,7 @@ fn Class.G[self: Self](r#self: i32) -> (i32, i32) {
 // CHECK:STDOUT:   .n = %.loc18
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Class.F(%self.param.loc21_20: %Class, %self.param.loc21_34: %i32) {
+// CHECK:STDOUT: fn @Class.F(%self.param.loc21_20: ref %Class, %self.param.loc21_34: %i32) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %self.ref.loc22_3: ref %Class = name_ref self, %self.loc21_16
 // CHECK:STDOUT:   %n.ref: %Class.elem = name_ref n, @Class.%.loc18 [concrete = @Class.%.loc18]
diff --git a/toolchain/check/testdata/class/raw_self_type.carbon b/toolchain/check/testdata/class/raw_self_type.carbon
index 61ee69f7e332..263be23c22cf 100644
--- a/toolchain/check/testdata/class/raw_self_type.carbon
+++ b/toolchain/check/testdata/class/raw_self_type.carbon
@@ -176,7 +176,7 @@ fn MemberNamedSelf.F(x: Self, y: r#Self) {}
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %ptr.8e5) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %ptr.8e5) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @MemberNamedSelf.F(%x.param.loc28: %MemberNamedSelf, %y.param.loc28: %Self.0d4) {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/class/reorder_qualified.carbon b/toolchain/check/testdata/class/reorder_qualified.carbon
index 0b75980a0b70..0207c49f8d8c 100644
--- a/toolchain/check/testdata/class/reorder_qualified.carbon
+++ b/toolchain/check/testdata/class/reorder_qualified.carbon
@@ -355,11 +355,11 @@ class A {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @A.AF();
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc36(%self.param: %D) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc36(%self.param: ref %D) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc35(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc35(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc34(%self.param: %B) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc34(%self.param: ref %B) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc33(%self.param: %A) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc33(%self.param: ref %A) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/scope.carbon b/toolchain/check/testdata/class/scope.carbon
index cf1c4a47c98e..9119b388363a 100644
--- a/toolchain/check/testdata/class/scope.carbon
+++ b/toolchain/check/testdata/class/scope.carbon
@@ -212,5 +212,5 @@ fn Run() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/self.carbon b/toolchain/check/testdata/class/self.carbon
index 51fe8707f216..5a0886790679 100644
--- a/toolchain/check/testdata/class/self.carbon
+++ b/toolchain/check/testdata/class/self.carbon
@@ -187,7 +187,7 @@ class Class {
 // CHECK:STDOUT:   return %Int.as.Copy.impl.Op.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Class.G(%self.param.loc15: %Class) -> out %return.param.loc15: %i32 {
+// CHECK:STDOUT: fn @Class.G(%self.param.loc15: ref %Class) -> out %return.param.loc15: %i32 {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %self.ref: ref %Class = name_ref self, %self.loc15
 // CHECK:STDOUT:   %n.ref: %Class.elem = name_ref n, @Class.%.loc8 [concrete = @Class.%.loc8]
diff --git a/toolchain/check/testdata/class/self_conversion.carbon b/toolchain/check/testdata/class/self_conversion.carbon
index 9369dc4c04f3..80770c49f8bf 100644
--- a/toolchain/check/testdata/class/self_conversion.carbon
+++ b/toolchain/check/testdata/class/self_conversion.carbon
@@ -228,7 +228,7 @@ fn Call(p: Derived*) -> i32 {
 // CHECK:STDOUT:   return %Int.as.Copy.impl.Op.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Derived.RefSelfBase(%self.param.loc30: %Base) {
+// CHECK:STDOUT: fn @Derived.RefSelfBase(%self.param.loc30: ref %Base) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %self.ref: ref %Base = name_ref self, %self.loc30
 // CHECK:STDOUT:   %a.ref: %Base.elem = name_ref a, @Base.%.loc16 [concrete = @Base.%.loc16]
diff --git a/toolchain/check/testdata/class/static_method.carbon b/toolchain/check/testdata/class/static_method.carbon
index 4abaa864b8da..2b3366dd066e 100644
--- a/toolchain/check/testdata/class/static_method.carbon
+++ b/toolchain/check/testdata/class/static_method.carbon
@@ -115,5 +115,5 @@ fn Run() -> i32 {
 // CHECK:STDOUT:   return %Class.F.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Class) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Class) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/class/syntactic_merge.carbon b/toolchain/check/testdata/class/syntactic_merge.carbon
index 919f67465128..706be12df31f 100644
--- a/toolchain/check/testdata/class/syntactic_merge.carbon
+++ b/toolchain/check/testdata/class/syntactic_merge.carbon
@@ -1180,9 +1180,9 @@ fn Base.F[ref self: Base]() {
 // CHECK:STDOUT:   .Base = <poisoned>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Base.F.loc7(%self.param: %Base);
+// CHECK:STDOUT: fn @Base.F.loc7(%self.param: ref %Base);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Base.F.loc17(%self.param: %Base) {
+// CHECK:STDOUT: fn @Base.F.loc17(%self.param: ref %Base) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %self.ref: ref %Base = name_ref self, %self
 // CHECK:STDOUT:   %a.ref: %Base.elem = name_ref a, @Base.%.loc5_8 [concrete = @Base.%.loc5_8]
diff --git a/toolchain/check/testdata/class/virtual_modifiers.carbon b/toolchain/check/testdata/class/virtual_modifiers.carbon
index 1ad77cae5033..5223884053b1 100644
--- a/toolchain/check/testdata/class/virtual_modifiers.carbon
+++ b/toolchain/check/testdata/class/virtual_modifiers.carbon
@@ -751,7 +751,7 @@ class T2(G2:! type) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Derived) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Derived) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- todo_fail_later_base.carbon
 // CHECK:STDOUT:
@@ -938,7 +938,7 @@ class T2(G2:! type) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: virtual fn @Base.H [from "modifiers.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Base) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Base) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- impl_abstract.carbon
 // CHECK:STDOUT:
@@ -1262,11 +1262,11 @@ class T2(G2:! type) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc21(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc21(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc20(%self.param: %B2) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc20(%self.param: ref %B2) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: %B1) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: ref %B1) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_modifiers.carbon
 // CHECK:STDOUT:
@@ -1549,9 +1549,9 @@ class T2(G2:! type) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc14(%self.param: %Base) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc14(%self.param: ref %Base) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_impl_without_base_declaration.carbon
 // CHECK:STDOUT:
@@ -2628,7 +2628,7 @@ class T2(G2:! type) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: virtual fn @T1.F1(%self.param: %T1);
 // CHECK:STDOUT:
-// CHECK:STDOUT: override fn @T2.F1(%self.param: %T2);
+// CHECK:STDOUT: override fn @T2.F1(%self.param: ref %T2);
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_generic_virtual.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/deduce/array.carbon b/toolchain/check/testdata/deduce/array.carbon
index 2580fe73a252..42fea8d668dc 100644
--- a/toolchain/check/testdata/deduce/array.carbon
+++ b/toolchain/check/testdata/deduce/array.carbon
@@ -312,7 +312,7 @@ fn G() {
 // CHECK:STDOUT:   return %F.call to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type.931) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type.931) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%T) {
 // CHECK:STDOUT:   %T.loc6_6.1 => constants.%T
@@ -545,7 +545,7 @@ fn G() {
 // CHECK:STDOUT:   return %F.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type.931) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type.931) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%N) {
 // CHECK:STDOUT:   %N.loc6_6.1 => constants.%N
@@ -718,7 +718,7 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type.931) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type.931) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%T, constants.%N) {
 // CHECK:STDOUT:   %T.loc6_6.1 => constants.%T
@@ -910,7 +910,7 @@ fn G() {
 // CHECK:STDOUT:   return %F.call to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type.931) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type.931) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%T) {
 // CHECK:STDOUT:   %T.loc6_6.1 => constants.%T
@@ -1156,7 +1156,7 @@ fn G() {
 // CHECK:STDOUT:   return %F.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type.b6d) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type.b6d) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%N) {
 // CHECK:STDOUT:   %N.loc7_6.1 => constants.%N
@@ -1390,7 +1390,7 @@ fn G() {
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type.931) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type.931) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%N.5de) {
 // CHECK:STDOUT:   %N.loc6_6.1 => constants.%N.5de
diff --git a/toolchain/check/testdata/deduce/generic_type.carbon b/toolchain/check/testdata/deduce/generic_type.carbon
index e29b9d4a6abb..aa5c35b2a143 100644
--- a/toolchain/check/testdata/deduce/generic_type.carbon
+++ b/toolchain/check/testdata/deduce/generic_type.carbon
@@ -924,7 +924,7 @@ fn G() -> i32 {
 // CHECK:STDOUT:   return %F.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %WithNontype.6bb) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %WithNontype.6bb) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @WithNontype(constants.%N.5de) {
 // CHECK:STDOUT:   %N.loc4_19.1 => constants.%N.5de
diff --git a/toolchain/check/testdata/deduce/value_with_type_through_access.carbon b/toolchain/check/testdata/deduce/value_with_type_through_access.carbon
index 9390fed8eb1e..8af83e6e7515 100644
--- a/toolchain/check/testdata/deduce/value_with_type_through_access.carbon
+++ b/toolchain/check/testdata/deduce/value_with_type_through_access.carbon
@@ -282,9 +282,9 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13_30(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13_30(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13_6(%self.param: %HoldsType.a31) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13_6(%self.param: ref %HoldsType.a31) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @HoldsType(constants.%T) {
 // CHECK:STDOUT:   %T.loc4_17.1 => constants.%T
@@ -483,9 +483,9 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13_33(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13_33(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13_6(%self.param: %HoldsType.673) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13_6(%self.param: ref %HoldsType.673) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @HoldsType(constants.%T) {
 // CHECK:STDOUT:   %T.loc4_17.1 => constants.%T
@@ -748,7 +748,7 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Class) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Class) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @HoldsType(constants.%T.d7d) {
 // CHECK:STDOUT:   %T.loc8_17.1 => constants.%T.d7d
@@ -976,7 +976,7 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @HoldsType(constants.%T.9b7) {
 // CHECK:STDOUT:   %T.loc4_17.1 => constants.%T.9b7
diff --git a/toolchain/check/testdata/facet/call_combined_impl_witness.carbon b/toolchain/check/testdata/facet/call_combined_impl_witness.carbon
index 7b5a1191fe9c..435ed313714a 100644
--- a/toolchain/check/testdata/facet/call_combined_impl_witness.carbon
+++ b/toolchain/check/testdata/facet/call_combined_impl_witness.carbon
@@ -375,7 +375,7 @@ fn F() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @A.AA(constants.%Self.c51) {}
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/facet/convert_class_type_to_generic_facet_value.carbon b/toolchain/check/testdata/facet/convert_class_type_to_generic_facet_value.carbon
index 5975cad5862b..25ff53f7615a 100644
--- a/toolchain/check/testdata/facet/convert_class_type_to_generic_facet_value.carbon
+++ b/toolchain/check/testdata/facet/convert_class_type_to_generic_facet_value.carbon
@@ -566,7 +566,7 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %GenericParam) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %GenericParam) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Generic(constants.%Scalar) {
 // CHECK:STDOUT:   %Scalar.loc4_19.1 => constants.%Scalar
diff --git a/toolchain/check/testdata/facet/convert_class_value_to_facet_value_value.carbon b/toolchain/check/testdata/facet/convert_class_value_to_facet_value_value.carbon
index 314d2f82c2a8..b29ee835a964 100644
--- a/toolchain/check/testdata/facet/convert_class_value_to_facet_value_value.carbon
+++ b/toolchain/check/testdata/facet/convert_class_value_to_facet_value_value.carbon
@@ -160,7 +160,7 @@ fn F() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Goat) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Goat) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @WalkAnimal(constants.%T) {
 // CHECK:STDOUT:   %T.loc17_15.1 => constants.%T
diff --git a/toolchain/check/testdata/facet/convert_class_value_to_generic_facet_value_value.carbon b/toolchain/check/testdata/facet/convert_class_value_to_generic_facet_value_value.carbon
index c84b5384c6af..912515a8385a 100644
--- a/toolchain/check/testdata/facet/convert_class_value_to_generic_facet_value_value.carbon
+++ b/toolchain/check/testdata/facet/convert_class_value_to_generic_facet_value_value.carbon
@@ -350,9 +350,9 @@ fn B() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc20_42(%self.param: %GenericParam) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc20_42(%self.param: ref %GenericParam) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc20_22(%self.param: %ImplsGeneric) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc20_22(%self.param: ref %ImplsGeneric) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Generic(constants.%Scalar) {
 // CHECK:STDOUT:   %Scalar.loc4_19.1 => constants.%Scalar
@@ -610,7 +610,7 @@ fn B() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @I(constants.%V, constants.%W) {
 // CHECK:STDOUT:   %V.loc3_13.1 => constants.%V
@@ -843,7 +843,7 @@ fn B() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @I(constants.%V, constants.%W) {
 // CHECK:STDOUT:   %V.loc3_13.1 => constants.%V
@@ -1052,7 +1052,7 @@ fn B() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C.9f1) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C.9f1) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @C(constants.%V, constants.%W) {
 // CHECK:STDOUT:   %V.loc5_9.1 => constants.%V
diff --git a/toolchain/check/testdata/facet/convert_facet_value_as_type_knows_original_type.carbon b/toolchain/check/testdata/facet/convert_facet_value_as_type_knows_original_type.carbon
index ac6a84b4a6ac..358a61414086 100644
--- a/toolchain/check/testdata/facet/convert_facet_value_as_type_knows_original_type.carbon
+++ b/toolchain/check/testdata/facet/convert_facet_value_as_type_knows_original_type.carbon
@@ -222,7 +222,7 @@ fn F[A:! J, B:! A](x: C(A, B)) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Goat) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Goat) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- facet_access_type_converts_back_to_original_facet_value.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/facet/convert_facet_value_value_to_generic_facet_value_value.carbon b/toolchain/check/testdata/facet/convert_facet_value_value_to_generic_facet_value_value.carbon
index 5aed5fe6282c..9a19a895611a 100644
--- a/toolchain/check/testdata/facet/convert_facet_value_value_to_generic_facet_value_value.carbon
+++ b/toolchain/check/testdata/facet/convert_facet_value_value_to_generic_facet_value_value.carbon
@@ -435,9 +435,9 @@ fn F() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc35_29(%self.param: %Grass) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc35_29(%self.param: ref %Grass) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc35_17(%self.param: %Goat) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc35_17(%self.param: ref %Goat) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Eats(constants.%Food.67d) {
 // CHECK:STDOUT:   %Food.loc21_16.1 => constants.%Food.67d
diff --git a/toolchain/check/testdata/facet/convert_facet_value_value_to_itself.carbon b/toolchain/check/testdata/facet/convert_facet_value_value_to_itself.carbon
index 604b9cfacab3..80b5cf048ac9 100644
--- a/toolchain/check/testdata/facet/convert_facet_value_value_to_itself.carbon
+++ b/toolchain/check/testdata/facet/convert_facet_value_value_to_itself.carbon
@@ -206,7 +206,7 @@ fn F() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Goat) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Goat) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @FeedAnimal(constants.%T) {
 // CHECK:STDOUT:   %T.loc17_15.1 => constants.%T
diff --git a/toolchain/check/testdata/facet/fail_deduction_uses_runtime_type_conversion.carbon b/toolchain/check/testdata/facet/fail_deduction_uses_runtime_type_conversion.carbon
index 4d78022b93fc..ec4a8bd7ec17 100644
--- a/toolchain/check/testdata/facet/fail_deduction_uses_runtime_type_conversion.carbon
+++ b/toolchain/check/testdata/facet/fail_deduction_uses_runtime_type_conversion.carbon
@@ -286,7 +286,7 @@ fn G(holds_to: HoldsType((RuntimeConvertTo, )), from:! RuntimeConvertFrom) {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %RuntimeConvertTo) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %RuntimeConvertTo) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @HoldsType(constants.%T) {
 // CHECK:STDOUT:   %T.loc17_17.1 => constants.%T
diff --git a/toolchain/check/testdata/for/actual.carbon b/toolchain/check/testdata/for/actual.carbon
index 103b49cd5c7f..93a3d439ca7c 100644
--- a/toolchain/check/testdata/for/actual.carbon
+++ b/toolchain/check/testdata/for/actual.carbon
@@ -1051,7 +1051,7 @@ fn Read(y:! Core.IntLiteral()) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @Range [from "lib.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %IntRange.a89) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %IntRange.a89) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Read(constants.%y) {
 // CHECK:STDOUT:   %y.loc4_9.1 => constants.%y
diff --git a/toolchain/check/testdata/for/basic.carbon b/toolchain/check/testdata/for/basic.carbon
index fa8eb5b3a9af..bfab474796bc 100644
--- a/toolchain/check/testdata/for/basic.carbon
+++ b/toolchain/check/testdata/for/basic.carbon
@@ -188,9 +188,9 @@ fn Run() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc18_35.1(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc18_35.1(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc18_35.2(%self.param: %Optional.311) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc18_35.2(%self.param: ref %Optional.311) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc18_18(%self.param: %TrivialRange) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc18_18(%self.param: ref %TrivialRange) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/for/pattern.carbon b/toolchain/check/testdata/for/pattern.carbon
index 85a23b8c1074..503327c64694 100644
--- a/toolchain/check/testdata/for/pattern.carbon
+++ b/toolchain/check/testdata/for/pattern.carbon
@@ -271,13 +271,13 @@ fn Run() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_36.1(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_36.1(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_36.2(%self.param: %Optional.0f3) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_36.2(%self.param: ref %Optional.0f3) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_36.3(%self.param: %empty_struct_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_36.3(%self.param: ref %empty_struct_type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_35(%self.param: %EmptyRange.77b) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_35(%self.param: ref %EmptyRange.77b) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- var.carbon
 // CHECK:STDOUT:
@@ -436,13 +436,13 @@ fn Run() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_8(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_8(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_40.1(%self.param: %Optional.0f3) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_40.1(%self.param: ref %Optional.0f3) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_40.2(%self.param: %empty_struct_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_40.2(%self.param: ref %empty_struct_type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_39(%self.param: %EmptyRange.77b) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_39(%self.param: ref %EmptyRange.77b) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- tuple.carbon
 // CHECK:STDOUT:
@@ -627,13 +627,13 @@ fn Run() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_61.1(%self.param: %tuple.type.784) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_61.1(%self.param: ref %tuple.type.784) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_61.2(%self.param: %Optional.0cc) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_61.2(%self.param: ref %Optional.0cc) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_61.3(%self.param: %empty_struct_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_61.3(%self.param: ref %empty_struct_type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_60(%self.param: %EmptyRange.717) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_60(%self.param: ref %EmptyRange.717) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- tuple_class.carbon
 // CHECK:STDOUT:
@@ -810,11 +810,11 @@ fn Run() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_49.1(%self.param: %tuple.type.d23) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_49.1(%self.param: ref %tuple.type.d23) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_49.2(%self.param: %Optional.fce) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_49.2(%self.param: ref %Optional.fce) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_49.3(%self.param: %empty_struct_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_49.3(%self.param: ref %empty_struct_type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10_48(%self.param: %EmptyRange.849) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10_48(%self.param: ref %EmptyRange.849) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/call/alias.carbon b/toolchain/check/testdata/function/call/alias.carbon
index a8102d9bf742..bf3254ddecf0 100644
--- a/toolchain/check/testdata/function/call/alias.carbon
+++ b/toolchain/check/testdata/function/call/alias.carbon
@@ -96,5 +96,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/call/fail_return_type_mismatch.carbon b/toolchain/check/testdata/function/call/fail_return_type_mismatch.carbon
index d35ec06942cb..efb31e0efea0 100644
--- a/toolchain/check/testdata/function/call/fail_return_type_mismatch.carbon
+++ b/toolchain/check/testdata/function/call/fail_return_type_mismatch.carbon
@@ -136,5 +136,5 @@ fn Run() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/call/i32.carbon b/toolchain/check/testdata/function/call/i32.carbon
index 0f14c56c0501..915956bd070f 100644
--- a/toolchain/check/testdata/function/call/i32.carbon
+++ b/toolchain/check/testdata/function/call/i32.carbon
@@ -153,5 +153,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/call/more_param_ir.carbon b/toolchain/check/testdata/function/call/more_param_ir.carbon
index aecf6d6537ae..2eab1d7ae8cf 100644
--- a/toolchain/check/testdata/function/call/more_param_ir.carbon
+++ b/toolchain/check/testdata/function/call/more_param_ir.carbon
@@ -160,5 +160,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %tuple.type.a1c) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %tuple.type.a1c) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/call/ref.carbon b/toolchain/check/testdata/function/call/ref.carbon
index 1384cc6d7209..7ed21394e01d 100644
--- a/toolchain/check/testdata/function/call/ref.carbon
+++ b/toolchain/check/testdata/function/call/ref.carbon
@@ -151,7 +151,7 @@ fn G() {
 // CHECK:STDOUT:   %G.decl: %G.type = fn_decl @G [concrete = constants.%G] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @F(%x.param: %i32);
+// CHECK:STDOUT: fn @F(%x.param: ref %i32);
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @G() {
 // CHECK:STDOUT: !entry:
@@ -182,7 +182,7 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- class.carbon
 // CHECK:STDOUT:
@@ -225,7 +225,7 @@ fn G() {
 // CHECK:STDOUT:   .F = %C.F.decl
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @C.F(%self.param: %C);
+// CHECK:STDOUT: fn @C.F(%self.param: ref %C);
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @G() {
 // CHECK:STDOUT: !entry:
@@ -245,5 +245,5 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/call/return_implicit.carbon b/toolchain/check/testdata/function/call/return_implicit.carbon
index 9b24009800a9..f85cc551d0bf 100644
--- a/toolchain/check/testdata/function/call/return_implicit.carbon
+++ b/toolchain/check/testdata/function/call/return_implicit.carbon
@@ -79,5 +79,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/declaration/fail_import_incomplete_return.carbon b/toolchain/check/testdata/function/declaration/fail_import_incomplete_return.carbon
index 7f709204d273..4d0a45957726 100644
--- a/toolchain/check/testdata/function/declaration/fail_import_incomplete_return.carbon
+++ b/toolchain/check/testdata/function/declaration/fail_import_incomplete_return.carbon
@@ -294,5 +294,5 @@ fn CallFAndGIncomplete() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @ReturnDUsed [from "fail_incomplete_return.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %D) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %D) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/definition/fail_local_decl.carbon b/toolchain/check/testdata/function/definition/fail_local_decl.carbon
index 8cddeb278df6..baf8bbdaa780 100644
--- a/toolchain/check/testdata/function/definition/fail_local_decl.carbon
+++ b/toolchain/check/testdata/function/definition/fail_local_decl.carbon
@@ -155,5 +155,5 @@ fn F() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_struct_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_struct_type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/function/generic/deduce.carbon b/toolchain/check/testdata/function/generic/deduce.carbon
index 25a81ba53e70..dba3a82159f5 100644
--- a/toolchain/check/testdata/function/generic/deduce.carbon
+++ b/toolchain/check/testdata/function/generic/deduce.carbon
@@ -653,7 +653,7 @@ fn F() {
 // CHECK:STDOUT:   return %ExplicitAndAlsoDeduced.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %A) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %A) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @ExplicitAndAlsoDeduced(constants.%T) {
 // CHECK:STDOUT:   %T.loc6_27.1 => constants.%T
diff --git a/toolchain/check/testdata/function/generic/resolve_used.carbon b/toolchain/check/testdata/function/generic/resolve_used.carbon
index eb165e3f29b8..f38a5c32e79e 100644
--- a/toolchain/check/testdata/function/generic/resolve_used.carbon
+++ b/toolchain/check/testdata/function/generic/resolve_used.carbon
@@ -157,7 +157,7 @@ fn CallNegative() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i0) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i0) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @ErrorIfNIsZero(constants.%N) {
 // CHECK:STDOUT:   %N.loc4_19.1 => constants.%N
diff --git a/toolchain/check/testdata/function/generic/return_slot.carbon b/toolchain/check/testdata/function/generic/return_slot.carbon
index 9180c66433cd..cf1185a47581 100644
--- a/toolchain/check/testdata/function/generic/return_slot.carbon
+++ b/toolchain/check/testdata/function/generic/return_slot.carbon
@@ -243,11 +243,11 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc24(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc24(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc23(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc23(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Wrap(constants.%T) {
 // CHECK:STDOUT:   %T.loc15_12.1 => constants.%T
diff --git a/toolchain/check/testdata/generic/complete_type.carbon b/toolchain/check/testdata/generic/complete_type.carbon
index a2f2d3322196..2f110abc14e0 100644
--- a/toolchain/check/testdata/generic/complete_type.carbon
+++ b/toolchain/check/testdata/generic/complete_type.carbon
@@ -316,7 +316,7 @@ fn G() { F(B); }
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %ptr.27c) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %ptr.27c) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%T) {
 // CHECK:STDOUT:   %T.loc6_6.1 => constants.%T
@@ -448,7 +448,7 @@ fn G() { F(B); }
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %ptr.27c) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %ptr.27c) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%T) {
 // CHECK:STDOUT:   %T.loc6_6.1 => constants.%T
diff --git a/toolchain/check/testdata/generic/local.carbon b/toolchain/check/testdata/generic/local.carbon
index 21602ee4055a..9c4f400dc029 100644
--- a/toolchain/check/testdata/generic/local.carbon
+++ b/toolchain/check/testdata/generic/local.carbon
@@ -185,7 +185,7 @@ class C(C:! type) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C.d45) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C.d45) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @C(constants.%T) {
 // CHECK:STDOUT:   %T.loc5_11.1 => constants.%T
diff --git a/toolchain/check/testdata/generic/template/unimplemented.carbon b/toolchain/check/testdata/generic/template/unimplemented.carbon
index 3e89cbab4a67..0fd3edf638e1 100644
--- a/toolchain/check/testdata/generic/template/unimplemented.carbon
+++ b/toolchain/check/testdata/generic/template/unimplemented.carbon
@@ -376,7 +376,7 @@ fn F[template T:! Core.Destroy](x: T) {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @F(constants.%T.765) {
 // CHECK:STDOUT:   %T.loc4_15.1 => constants.%T.765
diff --git a/toolchain/check/testdata/if_expr/basic.carbon b/toolchain/check/testdata/if_expr/basic.carbon
index e1ea4a93297d..1c9f51d3375e 100644
--- a/toolchain/check/testdata/if_expr/basic.carbon
+++ b/toolchain/check/testdata/if_expr/basic.carbon
@@ -196,5 +196,5 @@ fn F(b: bool, n: i32, m: i32) -> i32 {
 // CHECK:STDOUT:   return %Int.as.Copy.impl.Op.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/if_expr/constant_condition.carbon b/toolchain/check/testdata/if_expr/constant_condition.carbon
index d123142722ee..6f986ec356b3 100644
--- a/toolchain/check/testdata/if_expr/constant_condition.carbon
+++ b/toolchain/check/testdata/if_expr/constant_condition.carbon
@@ -381,9 +381,9 @@ fn PartiallyConstant(t: type) -> i32 {
 // CHECK:STDOUT:   return %Int.as.Copy.impl.Op.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc28(%self.param: %ptr.235) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc28(%self.param: ref %ptr.235) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc27(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc27(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @PartiallyConstant(%t.param: type) -> out %return.param: %i32 {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/if_expr/struct.carbon b/toolchain/check/testdata/if_expr/struct.carbon
index 2756853eae73..e64be08dd670 100644
--- a/toolchain/check/testdata/if_expr/struct.carbon
+++ b/toolchain/check/testdata/if_expr/struct.carbon
@@ -188,5 +188,5 @@ fn F(cond: bool) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %struct_type.a.b.501) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %struct_type.a.b.501) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/extend_impl_generic.carbon b/toolchain/check/testdata/impl/extend_impl_generic.carbon
index 7ec18a5a18e8..6b138bd31495 100644
--- a/toolchain/check/testdata/impl/extend_impl_generic.carbon
+++ b/toolchain/check/testdata/impl/extend_impl_generic.carbon
@@ -345,9 +345,9 @@ class X(U:! type) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc22_20(%self.param: %Param) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc22_20(%self.param: ref %Param) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc22_3(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc22_3(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @HasF(constants.%T.67d) {
 // CHECK:STDOUT:   %T.loc4_16.1 => constants.%T.67d
diff --git a/toolchain/check/testdata/impl/fail_extend_impl_scope.carbon b/toolchain/check/testdata/impl/fail_extend_impl_scope.carbon
index 94ccac2fb3ba..e9ef703e6c34 100644
--- a/toolchain/check/testdata/impl/fail_extend_impl_scope.carbon
+++ b/toolchain/check/testdata/impl/fail_extend_impl_scope.carbon
@@ -313,7 +313,7 @@ fn F() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Point) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Point) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Z.Zero(constants.%Self.c59) {}
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/fail_impl_as_scope.carbon b/toolchain/check/testdata/impl/fail_impl_as_scope.carbon
index 1696f2f8bb77..460f8f0f00cc 100644
--- a/toolchain/check/testdata/impl/fail_impl_as_scope.carbon
+++ b/toolchain/check/testdata/impl/fail_impl_as_scope.carbon
@@ -450,7 +450,7 @@ class X {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Point) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Point) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Z.Zero(constants.%Self.c59) {}
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/impl_as.carbon b/toolchain/check/testdata/impl/impl_as.carbon
index 2f4eab4d1238..15524d68cea4 100644
--- a/toolchain/check/testdata/impl/impl_as.carbon
+++ b/toolchain/check/testdata/impl/impl_as.carbon
@@ -130,7 +130,7 @@ class C {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Simple.F(constants.%Self.af2) {}
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/impl_thunk.carbon b/toolchain/check/testdata/impl/impl_thunk.carbon
index c2fdcfd9f794..9f43f724816a 100644
--- a/toolchain/check/testdata/impl/impl_thunk.carbon
+++ b/toolchain/check/testdata/impl/impl_thunk.carbon
@@ -412,7 +412,7 @@ impl () as I({}) {
 // CHECK:STDOUT:   return %.loc10_48.12 to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %struct_type.d.c.b36) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %struct_type.d.c.b36) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- inheritance_conversion.carbon
 // CHECK:STDOUT:
@@ -488,9 +488,9 @@ impl () as I({}) {
 // CHECK:STDOUT:   witness = %X.impl_witness
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @B.as.X.impl.F.loc14_37.1(%self.param: %A, %other.param: %ptr.643) -> out %return.param: %ptr.31e;
+// CHECK:STDOUT: fn @B.as.X.impl.F.loc14_37.1(%self.param: ref %A, %other.param: %ptr.643) -> out %return.param: %ptr.31e;
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @B.as.X.impl.F.loc14_37.2(%self.param: %B, %other.param: %ptr.27c) -> out %return.param: %ptr.27c [thunk @B.as.X.impl.%B.as.X.impl.F.decl.loc14_37.1] {
+// CHECK:STDOUT: fn @B.as.X.impl.F.loc14_37.2(%self.param: ref %B, %other.param: %ptr.27c) -> out %return.param: %ptr.27c [thunk @B.as.X.impl.%B.as.X.impl.F.decl.loc14_37.1] {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %F.ref: %B.as.X.impl.F.type.421a66.1 = name_ref F, @B.as.X.impl.%B.as.X.impl.F.decl.loc14_37.1 [concrete = constants.%B.as.X.impl.F.8ec460.1]
 // CHECK:STDOUT:   <elided>
@@ -640,9 +640,9 @@ impl () as I({}) {
 // CHECK:STDOUT:   witness = %X.impl_witness
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @B.as.X.impl.F.loc14_37.1(%self.param: %A, %other.param: %ptr.643) -> out %return.param: %ptr.31e;
+// CHECK:STDOUT: fn @B.as.X.impl.F.loc14_37.1(%self.param: ref %A, %other.param: %ptr.643) -> out %return.param: %ptr.31e;
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @B.as.X.impl.F.loc14_37.2(%self.param: %B, %other.param: %ptr.27c) -> out %return.param: %ptr.27c [thunk @B.as.X.impl.%B.as.X.impl.F.decl.loc14_37.1] {
+// CHECK:STDOUT: fn @B.as.X.impl.F.loc14_37.2(%self.param: ref %B, %other.param: %ptr.27c) -> out %return.param: %ptr.27c [thunk @B.as.X.impl.%B.as.X.impl.F.decl.loc14_37.1] {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %F.ref: %B.as.X.impl.F.type.421a66.1 = name_ref F, @B.as.X.impl.%B.as.X.impl.F.decl.loc14_37.1 [concrete = constants.%B.as.X.impl.F.8ec460.1]
 // CHECK:STDOUT:   <elided>
@@ -737,9 +737,9 @@ impl () as I({}) {
 // CHECK:STDOUT:   witness = %X.impl_witness
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @B.as.X.impl.F.loc14_37.1(%self.param: %A, %other.param: %ptr.643) -> out %return.param: %ptr.31e;
+// CHECK:STDOUT: fn @B.as.X.impl.F.loc14_37.1(%self.param: ref %A, %other.param: %ptr.643) -> out %return.param: %ptr.31e;
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @B.as.X.impl.F.loc14_37.2(%self.param: %B, %other.param: %ptr.27c) -> out %return.param: %ptr.27c [thunk @B.as.X.impl.%B.as.X.impl.F.decl.loc14_37.1] {
+// CHECK:STDOUT: fn @B.as.X.impl.F.loc14_37.2(%self.param: ref %B, %other.param: %ptr.27c) -> out %return.param: %ptr.27c [thunk @B.as.X.impl.%B.as.X.impl.F.decl.loc14_37.1] {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %F.ref: %B.as.X.impl.F.type.421a66.1 = name_ref F, @B.as.X.impl.%B.as.X.impl.F.decl.loc14_37.1 [concrete = constants.%B.as.X.impl.F.8ec460.1]
 // CHECK:STDOUT:   <elided>
@@ -820,7 +820,7 @@ impl () as I({}) {
 // CHECK:STDOUT:   return <error> to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %B) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %B) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- generic_function.carbon
 // CHECK:STDOUT:
@@ -1230,5 +1230,5 @@ impl () as I({}) {
 // CHECK:STDOUT:   return %.loc10_29.12 to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %struct_type.b.a.1b0) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %struct_type.b.a.1b0) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/import_thunk.carbon b/toolchain/check/testdata/impl/import_thunk.carbon
index 568645234d77..b9e4b0996150 100644
--- a/toolchain/check/testdata/impl/import_thunk.carbon
+++ b/toolchain/check/testdata/impl/import_thunk.carbon
@@ -550,7 +550,7 @@ fn G() {
 // CHECK:STDOUT:   fn;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C.387) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C.387) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @C(constants.%X) {
 // CHECK:STDOUT:   %X => constants.%X
diff --git a/toolchain/check/testdata/impl/lookup/canonical_query_self.carbon b/toolchain/check/testdata/impl/lookup/canonical_query_self.carbon
index 020a0cbcbc6f..b11154a65035 100644
--- a/toolchain/check/testdata/impl/lookup/canonical_query_self.carbon
+++ b/toolchain/check/testdata/impl/lookup/canonical_query_self.carbon
@@ -408,7 +408,7 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @I.II(constants.%Self.ab9) {
 // CHECK:STDOUT:   %Self => constants.%Self.ab9
diff --git a/toolchain/check/testdata/impl/lookup/impl_forall.carbon b/toolchain/check/testdata/impl/lookup/impl_forall.carbon
index d9046362a7b9..34ae4a3ff05d 100644
--- a/toolchain/check/testdata/impl/lookup/impl_forall.carbon
+++ b/toolchain/check/testdata/impl/lookup/impl_forall.carbon
@@ -204,7 +204,7 @@ fn TestSpecific(a: A({})*) -> {}* {
 // CHECK:STDOUT:   %impl.elem0.loc14_12.2: @A.as.I.impl.F.%.loc14_12.2 (%.b46) = impl_witness_access %Copy.lookup_impl_witness, element0 [symbolic = %impl.elem0.loc14_12.2 (constants.%impl.elem0.201)]
 // CHECK:STDOUT:   %specific_impl_fn.loc14_12.2: <specific function> = specific_impl_function %impl.elem0.loc14_12.2, @Copy.Op(%Copy.facet) [symbolic = %specific_impl_fn.loc14_12.2 (constants.%specific_impl_fn.b84)]
 // CHECK:STDOUT:
-// CHECK:STDOUT:   fn(%self.param: @A.as.I.impl.F.%A (%A.95c0c7.2)) -> out %return.param: @A.as.I.impl.F.%ptr.loc13_30.1 (%ptr.e8f8f9.2) {
+// CHECK:STDOUT:   fn(%self.param: ref @A.as.I.impl.F.%A (%A.95c0c7.2)) -> out %return.param: @A.as.I.impl.F.%ptr.loc13_30.1 (%ptr.e8f8f9.2) {
 // CHECK:STDOUT:   !entry:
 // CHECK:STDOUT:     %self.ref: ref @A.as.I.impl.F.%A (%A.95c0c7.2) = name_ref self, %self
 // CHECK:STDOUT:     %n.ref: @A.as.I.impl.F.%A.elem (%A.elem.8a20fa.2) = name_ref n, @A.%.loc4 [concrete = @A.%.loc4]
diff --git a/toolchain/check/testdata/impl/lookup/import.carbon b/toolchain/check/testdata/impl/lookup/import.carbon
index 82b5c24e2ccb..4e58e7b89002 100644
--- a/toolchain/check/testdata/impl/lookup/import.carbon
+++ b/toolchain/check/testdata/impl/lookup/import.carbon
@@ -1661,7 +1661,7 @@ fn Test(c: HasExtraInterfaces.C(type)) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %AnyParam.33d) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %AnyParam.33d) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @GenericInterface(constants.%U) {
 // CHECK:STDOUT:   %U.loc6_28.1 => constants.%U
@@ -1875,7 +1875,7 @@ fn Test(c: HasExtraInterfaces.C(type)) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @AnyParam.as.Y.impl.K [from "has_generic_interface.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %AnyParam.861) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %AnyParam.861) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @AnyParam(constants.%T, constants.%X) {
 // CHECK:STDOUT:   %T => constants.%T
@@ -2098,7 +2098,7 @@ fn Test(c: HasExtraInterfaces.C(type)) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %AnyParam.8e0) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %AnyParam.8e0) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @GenericClass(constants.%U) {
 // CHECK:STDOUT:   %U.loc6_20.1 => constants.%U
@@ -2308,7 +2308,7 @@ fn Test(c: HasExtraInterfaces.C(type)) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @AnyParam.as.Y.impl.K [from "has_generic_class.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %AnyParam.d71) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %AnyParam.d71) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @AnyParam(constants.%T, constants.%X) {
 // CHECK:STDOUT:   %T => constants.%T
diff --git a/toolchain/check/testdata/impl/lookup/specialization_with_symbolic_rewrite.carbon b/toolchain/check/testdata/impl/lookup/specialization_with_symbolic_rewrite.carbon
index 68f6c0637656..e0b38264fa42 100644
--- a/toolchain/check/testdata/impl/lookup/specialization_with_symbolic_rewrite.carbon
+++ b/toolchain/check/testdata/impl/lookup/specialization_with_symbolic_rewrite.carbon
@@ -937,7 +937,7 @@ fn F[T:! Ptr](var t: T) -> T.(Ptr.Type) {
 // CHECK:STDOUT:   %impl.elem0.loc10_10.2: @F.%.loc10_10.2 (%.b46) = impl_witness_access %Copy.lookup_impl_witness, element0 [symbolic = %impl.elem0.loc10_10.2 (constants.%impl.elem0.201)]
 // CHECK:STDOUT:   %specific_impl_fn.loc10_10.2: <specific function> = specific_impl_function %impl.elem0.loc10_10.2, @Copy.Op(%Copy.facet) [symbolic = %specific_impl_fn.loc10_10.2 (constants.%specific_impl_fn.b84)]
 // CHECK:STDOUT:
-// CHECK:STDOUT:   fn(%t.param: @F.%T.loc9_6.1 (%T.67d)) -> out %return.param: @F.%ptr (%ptr.e8f8f9.2) {
+// CHECK:STDOUT:   fn(%t.param: ref @F.%T.loc9_6.1 (%T.67d)) -> out %return.param: @F.%ptr (%ptr.e8f8f9.2) {
 // CHECK:STDOUT:   !entry:
 // CHECK:STDOUT:     %t.ref: ref @F.%T.loc9_6.1 (%T.67d) = name_ref t, %t
 // CHECK:STDOUT:     %addr: @F.%ptr (%ptr.e8f8f9.2) = addr_of %t.ref
@@ -1153,7 +1153,7 @@ fn F[T:! Ptr](var t: T) -> T.(Ptr.Type) {
 // CHECK:STDOUT:   %impl.elem0.loc10_10.2: @F.%.loc10_10.2 (%.4b6) = impl_witness_access %Copy.lookup_impl_witness, element0 [symbolic = %impl.elem0.loc10_10.2 (constants.%impl.elem0.8b5)]
 // CHECK:STDOUT:   %specific_impl_fn.loc10_10.2: <specific function> = specific_impl_function %impl.elem0.loc10_10.2, @Copy.Op(%Copy.facet) [symbolic = %specific_impl_fn.loc10_10.2 (constants.%specific_impl_fn.4b3)]
 // CHECK:STDOUT:
-// CHECK:STDOUT:   fn(%t.param: @F.%T.binding.as_type (%T.binding.as_type.3dc)) -> out %return.param: @F.%ptr (%ptr.a86) {
+// CHECK:STDOUT:   fn(%t.param: ref @F.%T.binding.as_type (%T.binding.as_type.3dc)) -> out %return.param: @F.%ptr (%ptr.a86) {
 // CHECK:STDOUT:   !entry:
 // CHECK:STDOUT:     %t.ref: ref @F.%T.binding.as_type (%T.binding.as_type.3dc) = name_ref t, %t
 // CHECK:STDOUT:     %addr: @F.%ptr (%ptr.a86) = addr_of %t.ref
@@ -1368,7 +1368,7 @@ fn F[T:! Ptr](var t: T) -> T.(Ptr.Type) {
 // CHECK:STDOUT:   %impl.elem0.loc10_10.2: @F.%.loc10_10.2 (%.4b6) = impl_witness_access %Copy.lookup_impl_witness, element0 [symbolic = %impl.elem0.loc10_10.2 (constants.%impl.elem0.8b5)]
 // CHECK:STDOUT:   %specific_impl_fn.loc10_10.2: <specific function> = specific_impl_function %impl.elem0.loc10_10.2, @Copy.Op(%Copy.facet) [symbolic = %specific_impl_fn.loc10_10.2 (constants.%specific_impl_fn.4b3)]
 // CHECK:STDOUT:
-// CHECK:STDOUT:   fn(%t.param: @F.%T.binding.as_type (%T.binding.as_type.3dc)) -> out %return.param: @F.%ptr (%ptr.a86) {
+// CHECK:STDOUT:   fn(%t.param: ref @F.%T.binding.as_type (%T.binding.as_type.3dc)) -> out %return.param: @F.%ptr (%ptr.a86) {
 // CHECK:STDOUT:   !entry:
 // CHECK:STDOUT:     %t.ref: ref @F.%T.binding.as_type (%T.binding.as_type.3dc) = name_ref t, %t
 // CHECK:STDOUT:     %addr: @F.%ptr (%ptr.a86) = addr_of %t.ref
diff --git a/toolchain/check/testdata/impl/lookup/transitive.carbon b/toolchain/check/testdata/impl/lookup/transitive.carbon
index a8adcff1c63c..b55c43aebbc2 100644
--- a/toolchain/check/testdata/impl/lookup/transitive.carbon
+++ b/toolchain/check/testdata/impl/lookup/transitive.carbon
@@ -383,7 +383,7 @@ fn Call() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @C.as.I.impl.F [from "c.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @I.F(constants.%Self.651) {
 // CHECK:STDOUT:   %Self => constants.%Self.651
diff --git a/toolchain/check/testdata/impl/use_assoc_entity.carbon b/toolchain/check/testdata/impl/use_assoc_entity.carbon
index 100c81b0676b..2cbb9e31465b 100644
--- a/toolchain/check/testdata/impl/use_assoc_entity.carbon
+++ b/toolchain/check/testdata/impl/use_assoc_entity.carbon
@@ -3505,7 +3505,7 @@ fn F() {
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %struct_type.x) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %struct_type.x) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @V(constants.%Self.44d) {}
 // CHECK:STDOUT:
@@ -4417,7 +4417,7 @@ fn F() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C.302) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C.302) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @X(constants.%Self.c59) {}
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/index/expr_category.carbon b/toolchain/check/testdata/index/expr_category.carbon
index adc77fd8844f..65c74110e1c1 100644
--- a/toolchain/check/testdata/index/expr_category.carbon
+++ b/toolchain/check/testdata/index/expr_category.carbon
@@ -279,9 +279,9 @@ fn ValueBinding(b: array(i32, 3)) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc21(%self.param: %ptr.235) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc21(%self.param: ref %ptr.235) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc18(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc18(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @ValueBinding(%b.param: %array_type) {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/index/fail_expr_category.carbon b/toolchain/check/testdata/index/fail_expr_category.carbon
index 2d7867ce2082..8960f0870efc 100644
--- a/toolchain/check/testdata/index/fail_expr_category.carbon
+++ b/toolchain/check/testdata/index/fail_expr_category.carbon
@@ -278,7 +278,7 @@ fn G(b: array(i32, 3)) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc41(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc41(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc36(%self.param: %ptr.235) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc36(%self.param: ref %ptr.235) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/index/fail_name_not_found.carbon b/toolchain/check/testdata/index/fail_name_not_found.carbon
index 92c1f3ed2fe3..9a57a099c318 100644
--- a/toolchain/check/testdata/index/fail_name_not_found.carbon
+++ b/toolchain/check/testdata/index/fail_name_not_found.carbon
@@ -78,5 +78,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interface/compound_member_access.carbon b/toolchain/check/testdata/interface/compound_member_access.carbon
index 010363ed247f..78a4d0ded687 100644
--- a/toolchain/check/testdata/interface/compound_member_access.carbon
+++ b/toolchain/check/testdata/interface/compound_member_access.carbon
@@ -824,7 +824,7 @@ fn Works() {
 // CHECK:STDOUT:   %Self.binding.as_type: type = symbolic_binding_type Self, 0, %Self [symbolic = %Self.binding.as_type (constants.%Self.binding.as_type)]
 // CHECK:STDOUT:   %pattern_type: type = pattern_type %Self.binding.as_type [symbolic = %pattern_type (constants.%pattern_type.9c1)]
 // CHECK:STDOUT:
-// CHECK:STDOUT:   fn(%self.param: @L1.S1.%Self.binding.as_type (%Self.binding.as_type));
+// CHECK:STDOUT:   fn(%self.param: ref @L1.S1.%Self.binding.as_type (%Self.binding.as_type));
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: generic fn @Simple4(%T.loc9_12.2: %L1.type) {
@@ -1081,7 +1081,7 @@ fn Works() {
 // CHECK:STDOUT:   %Self.binding.as_type: type = symbolic_binding_type Self, 0, %Self [symbolic = %Self.binding.as_type (constants.%Self.binding.as_type)]
 // CHECK:STDOUT:   %pattern_type: type = pattern_type %Self.binding.as_type [symbolic = %pattern_type (constants.%pattern_type.73b)]
 // CHECK:STDOUT:
-// CHECK:STDOUT:   fn(%self.param: @L2.S2.%Self.binding.as_type (%Self.binding.as_type));
+// CHECK:STDOUT:   fn(%self.param: ref @L2.S2.%Self.binding.as_type (%Self.binding.as_type));
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: generic fn @Simple5(%T.loc10_12.2: %L2.type) {
@@ -1346,7 +1346,7 @@ fn Works() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @A.G(constants.%Self.c51) {}
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interface/default_fn.carbon b/toolchain/check/testdata/interface/default_fn.carbon
index cd43f90e911b..4d6feea8e99e 100644
--- a/toolchain/check/testdata/interface/default_fn.carbon
+++ b/toolchain/check/testdata/interface/default_fn.carbon
@@ -171,7 +171,7 @@ class C {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @I.F(constants.%Self.849) {
 // CHECK:STDOUT:   %Self => constants.%Self.849
diff --git a/toolchain/check/testdata/interface/generic_method.carbon b/toolchain/check/testdata/interface/generic_method.carbon
index 56dc2d2b03e6..2e48f4bf6ae1 100644
--- a/toolchain/check/testdata/interface/generic_method.carbon
+++ b/toolchain/check/testdata/interface/generic_method.carbon
@@ -468,9 +468,9 @@ fn CallIndirect() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc23(%self.param: %tuple.type.847) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc23(%self.param: ref %tuple.type.847) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: %Z) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: ref %Z) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: generic fn @CallGeneric(%T.loc26_16.2: %A.type.ab6) {
 // CHECK:STDOUT:   %T.loc26_16.1: %A.type.ab6 = symbolic_binding T, 0 [symbolic = %T.loc26_16.1 (constants.%T.2bc)]
@@ -1062,9 +1062,9 @@ fn CallIndirect() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc24_39(%self.param: %tuple.type.65a) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc24_39(%self.param: ref %tuple.type.65a) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc24_38(%self.param: %Z) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc24_38(%self.param: ref %Z) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: generic fn @CallGeneric(%T.loc27_16.2: %A.type.ab6) {
 // CHECK:STDOUT:   %T.loc27_16.1: %A.type.ab6 = symbolic_binding T, 0 [symbolic = %T.loc27_16.1 (constants.%T.2bc)]
diff --git a/toolchain/check/testdata/interop/cpp/builtins.carbon b/toolchain/check/testdata/interop/cpp/builtins.carbon
index fc7e840b6960..d188aa0591f8 100644
--- a/toolchain/check/testdata/interop/cpp/builtins.carbon
+++ b/toolchain/check/testdata/interop/cpp/builtins.carbon
@@ -607,5 +607,5 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %unsigned_int) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %unsigned_int) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/builtins.llp64.carbon b/toolchain/check/testdata/interop/cpp/builtins.llp64.carbon
index 699cd20d8ea7..330784303f05 100644
--- a/toolchain/check/testdata/interop/cpp/builtins.llp64.carbon
+++ b/toolchain/check/testdata/interop/cpp/builtins.llp64.carbon
@@ -822,7 +822,7 @@ fn CopyUnsignedLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- unsigned_long_long.carbon
 // CHECK:STDOUT:
@@ -988,7 +988,7 @@ fn CopyUnsignedLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- long.carbon
 // CHECK:STDOUT:
@@ -1294,11 +1294,11 @@ fn CopyUnsignedLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc26(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc26(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: %IntResult) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: ref %IntResult) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: %LongResult) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: ref %LongResult) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- copy_long.carbon
 // CHECK:STDOUT:
@@ -1379,7 +1379,7 @@ fn CopyUnsignedLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.long) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- comparisons_homogeneous_long.carbon
 // CHECK:STDOUT:
@@ -3087,7 +3087,7 @@ fn CopyUnsignedLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.long) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- compound_assignment_hereogeneous_long_and_i32.carbon
 // CHECK:STDOUT:
@@ -3592,7 +3592,7 @@ fn CopyUnsignedLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.long) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- compound_assignment_heterogeneous_long_and_int_literal.carbon
 // CHECK:STDOUT:
@@ -3691,7 +3691,7 @@ fn CopyUnsignedLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.long) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- compound_assignment_heterogeneous_long_and_runtime_i32.carbon
 // CHECK:STDOUT:
@@ -3832,7 +3832,7 @@ fn CopyUnsignedLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.long) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- increment_decrement_long.carbon
 // CHECK:STDOUT:
@@ -3912,7 +3912,7 @@ fn CopyUnsignedLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.long) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- unsigned_long.carbon
 // CHECK:STDOUT:
@@ -4202,11 +4202,11 @@ fn CopyUnsignedLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc24(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc24(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: %UIntResult) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: ref %UIntResult) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: %ULongResult) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: ref %ULongResult) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- copy_unsigned_long.carbon
 // CHECK:STDOUT:
@@ -4287,5 +4287,5 @@ fn CopyUnsignedLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.unsigned_long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.unsigned_long) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/builtins.lp64.carbon b/toolchain/check/testdata/interop/cpp/builtins.lp64.carbon
index 83ff42c2f52e..bbf994fe8757 100644
--- a/toolchain/check/testdata/interop/cpp/builtins.lp64.carbon
+++ b/toolchain/check/testdata/interop/cpp/builtins.lp64.carbon
@@ -770,7 +770,7 @@ fn CopyUnsignedLongLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- unsigned_long.carbon
 // CHECK:STDOUT:
@@ -936,7 +936,7 @@ fn CopyUnsignedLongLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- long_long.carbon
 // CHECK:STDOUT:
@@ -1217,11 +1217,11 @@ fn CopyUnsignedLongLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc24(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc24(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: %LongResult) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: ref %LongResult) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: %LongLongResult) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: ref %LongLongResult) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- copy_long_long.carbon
 // CHECK:STDOUT:
@@ -1302,7 +1302,7 @@ fn CopyUnsignedLongLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.long_long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.long_long) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- comparisons_homogeneous_long_long.carbon
 // CHECK:STDOUT:
@@ -2802,7 +2802,7 @@ fn CopyUnsignedLongLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.long_long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.long_long) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- compound_assignment_hereogeneous_long_long_and_i64.carbon
 // CHECK:STDOUT:
@@ -3307,7 +3307,7 @@ fn CopyUnsignedLongLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.long_long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.long_long) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- compound_assignment_heterogeneous_long_long_and_int_literal.carbon
 // CHECK:STDOUT:
@@ -3406,7 +3406,7 @@ fn CopyUnsignedLongLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.long_long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.long_long) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- compound_assignment_heterogeneous_long_long_and_runtime_i64.carbon
 // CHECK:STDOUT:
@@ -3547,7 +3547,7 @@ fn CopyUnsignedLongLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.long_long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.long_long) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- increment_decrement_long_long.carbon
 // CHECK:STDOUT:
@@ -3627,7 +3627,7 @@ fn CopyUnsignedLongLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.long_long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.long_long) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- unsigned_long_long.carbon
 // CHECK:STDOUT:
@@ -3918,11 +3918,11 @@ fn CopyUnsignedLongLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc24(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc24(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: %ULongResult) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: ref %ULongResult) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: %ULongLongResult) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: ref %ULongLongResult) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- copy_unsigned_long_long.carbon
 // CHECK:STDOUT:
@@ -4003,5 +4003,5 @@ fn CopyUnsignedLongLong() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Cpp.unsigned_long_long) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Cpp.unsigned_long_long) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/class/access.carbon b/toolchain/check/testdata/interop/cpp/class/access.carbon
index 9bcd893feaaa..f726f459f5b5 100644
--- a/toolchain/check/testdata/interop/cpp/class/access.carbon
+++ b/toolchain/check/testdata/interop/cpp/class/access.carbon
@@ -2032,9 +2032,9 @@ fn Call(var instance: Cpp.PublicPrivate) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: %PublicCall) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: ref %PublicCall) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_overload_set_protected_base.carbon
 // CHECK:STDOUT:
@@ -2229,9 +2229,9 @@ fn Call(var instance: Cpp.PublicPrivate) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: %PublicCall) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: ref %PublicCall) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc17(%self.param: %ProtectedCall) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc17(%self.param: ref %ProtectedCall) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_overload_set_public_base_class_call_public.carbon
 // CHECK:STDOUT:
@@ -2296,7 +2296,7 @@ fn Call(var instance: Cpp.PublicPrivate) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %PublicCall) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %PublicCall) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_overload_set_public_base_class_derived_call_non_private.carbon
 // CHECK:STDOUT:
@@ -2410,9 +2410,9 @@ fn Call(var instance: Cpp.PublicPrivate) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: %ProtectedCall) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: ref %ProtectedCall) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: %PublicCall) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: ref %PublicCall) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_overload_set_protected_base_class_derived_call_non_private.carbon
 // CHECK:STDOUT:
@@ -2526,9 +2526,9 @@ fn Call(var instance: Cpp.PublicPrivate) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: %ProtectedCall) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: ref %ProtectedCall) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: %PublicCall) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: ref %PublicCall) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- base_class_public_access_allowed.carbon
 // CHECK:STDOUT:
@@ -2617,7 +2617,7 @@ fn Call(var instance: Cpp.PublicPrivate) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Derived.CallInstance(%instance.param: %Public) {
+// CHECK:STDOUT: fn @Derived.CallInstance(%instance.param: ref %Public) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %instance.ref.loc24: ref %Public = name_ref instance, %instance
 // CHECK:STDOUT:   %PublicInstance.ref: %Public.PublicInstance.cpp_overload_set.type = name_ref PublicInstance, imports.%Public.PublicInstance.cpp_overload_set.value [concrete = constants.%Public.PublicInstance.cpp_overload_set.value]
@@ -2634,7 +2634,7 @@ fn Call(var instance: Cpp.PublicPrivate) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Call(%instance.param: %Public) {
+// CHECK:STDOUT: fn @Call(%instance.param: ref %Public) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc33: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %Public.ref.loc33: type = name_ref Public, imports.%Public.decl [concrete = constants.%Public]
@@ -2682,7 +2682,7 @@ fn Call(var instance: Cpp.PublicPrivate) {
 // CHECK:STDOUT:   extend %Public.ref
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Derived.CallInstance(%instance.param: %Public) {
+// CHECK:STDOUT: fn @Derived.CallInstance(%instance.param: ref %Public) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %instance.ref: ref %Public = name_ref instance, %instance
 // CHECK:STDOUT:   %PrivateInstance.ref: <error> = name_ref PrivateInstance, <error> [concrete = <error>]
@@ -2776,7 +2776,7 @@ fn Call(var instance: Cpp.PublicPrivate) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Derived.CallInstance(%instance.param: %Protected) {
+// CHECK:STDOUT: fn @Derived.CallInstance(%instance.param: ref %Protected) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %instance.ref.loc24: ref %Protected = name_ref instance, %instance
 // CHECK:STDOUT:   %PublicInstance.ref: %Protected.PublicInstance.cpp_overload_set.type = name_ref PublicInstance, imports.%Protected.PublicInstance.cpp_overload_set.value [concrete = constants.%Protected.PublicInstance.cpp_overload_set.value]
@@ -2881,7 +2881,7 @@ fn Call(var instance: Cpp.PublicPrivate) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Derived.CallInstance(%instance.param: %PublicProtected) {
+// CHECK:STDOUT: fn @Derived.CallInstance(%instance.param: ref %PublicProtected) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %instance.ref.loc24: ref %PublicProtected = name_ref instance, %instance
 // CHECK:STDOUT:   %PublicInstance.ref: %PublicProtected.PublicInstance.cpp_overload_set.type = name_ref PublicInstance, imports.%PublicProtected.PublicInstance.cpp_overload_set.value [concrete = constants.%PublicProtected.PublicInstance.cpp_overload_set.value]
diff --git a/toolchain/check/testdata/interop/cpp/class/constructor.carbon b/toolchain/check/testdata/interop/cpp/class/constructor.carbon
index 06432b379bb4..b2bdab33991c 100644
--- a/toolchain/check/testdata/interop/cpp/class/constructor.carbon
+++ b/toolchain/check/testdata/interop/cpp/class/constructor.carbon
@@ -308,7 +308,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_non_default.carbon
 // CHECK:STDOUT:
@@ -402,7 +402,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_multiple.carbon
 // CHECK:STDOUT:
@@ -522,7 +522,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_default_arguments.carbon
 // CHECK:STDOUT:
@@ -650,7 +650,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_template.carbon
 // CHECK:STDOUT:
@@ -812,9 +812,9 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: bool) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: ref bool) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_implicit_single_argument.carbon
 // CHECK:STDOUT:
@@ -937,7 +937,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_implicit_multi_arguments.carbon
 // CHECK:STDOUT:
@@ -1106,5 +1106,5 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/class/method.carbon b/toolchain/check/testdata/interop/cpp/class/method.carbon
index 7d1c0da155e9..2400d4f7f9bd 100644
--- a/toolchain/check/testdata/interop/cpp/class/method.carbon
+++ b/toolchain/check/testdata/interop/cpp/class/method.carbon
@@ -430,9 +430,9 @@ fn Call(e: Cpp.ExplicitObjectParam, n: i32, a: Cpp.Another) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: %ptr.235) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: ref %ptr.235) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- use_object_param_qualifiers_qualified.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/enum/anonymous.carbon b/toolchain/check/testdata/interop/cpp/enum/anonymous.carbon
index 0d068bb60b21..facafce6816c 100644
--- a/toolchain/check/testdata/interop/cpp/enum/anonymous.carbon
+++ b/toolchain/check/testdata/interop/cpp/enum/anonymous.carbon
@@ -130,5 +130,5 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/enum/copy.carbon b/toolchain/check/testdata/interop/cpp/enum/copy.carbon
index 0b07320eb979..bbc6b4ab08e9 100644
--- a/toolchain/check/testdata/interop/cpp/enum/copy.carbon
+++ b/toolchain/check/testdata/interop/cpp/enum/copy.carbon
@@ -82,5 +82,5 @@ fn F() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Enum) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Enum) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/arithmetic_types_bridged.carbon b/toolchain/check/testdata/interop/cpp/function/arithmetic_types_bridged.carbon
index 63a2e481af97..9013ead5236e 100644
--- a/toolchain/check/testdata/interop/cpp/function/arithmetic_types_bridged.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/arithmetic_types_bridged.carbon
@@ -609,7 +609,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: bool) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref bool) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_bool_param_false.carbon
 // CHECK:STDOUT:
@@ -665,7 +665,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: bool) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref bool) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_signed_char_param.carbon
 // CHECK:STDOUT:
@@ -770,7 +770,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i8) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i8) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_unsigned_char_param.carbon
 // CHECK:STDOUT:
@@ -858,7 +858,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %u8) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %u8) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_char_param.carbon
 // CHECK:STDOUT:
@@ -931,7 +931,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %char) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %char) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_todo_import_wchar_t_param.carbon
 // CHECK:STDOUT:
@@ -1152,7 +1152,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_short_param_max.carbon
 // CHECK:STDOUT:
@@ -1240,7 +1240,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_short_param_min.carbon
 // CHECK:STDOUT:
@@ -1345,7 +1345,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_short_int_param.carbon
 // CHECK:STDOUT:
@@ -1435,7 +1435,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_signed_short_param.carbon
 // CHECK:STDOUT:
@@ -1525,7 +1525,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_signed_short_int_param.carbon
 // CHECK:STDOUT:
@@ -1615,7 +1615,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_int16_t_param.carbon
 // CHECK:STDOUT:
@@ -1705,7 +1705,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_float16_param.carbon
 // CHECK:STDOUT:
@@ -1794,7 +1794,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %f16.a6a) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %f16.a6a) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_float_param.carbon
 // CHECK:STDOUT:
@@ -1883,7 +1883,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %f32.97e) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %f32.97e) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_double_param.carbon
 // CHECK:STDOUT:
@@ -1972,7 +1972,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %f64.d77) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %f64.d77) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_float128_param.carbon
 // CHECK:STDOUT:
@@ -2061,7 +2061,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %f128.b8c) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %f128.b8c) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_bool_return.carbon
 // CHECK:STDOUT:
@@ -2116,7 +2116,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: bool) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref bool) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_short_return.carbon
 // CHECK:STDOUT:
@@ -2170,7 +2170,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_todo_import_bit_int_24_param.carbon
 // CHECK:STDOUT:
@@ -2248,5 +2248,5 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %f64.d77) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %f64.d77) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/class.carbon b/toolchain/check/testdata/interop/cpp/function/class.carbon
index 8ee5d6516461..6417e4b9d378 100644
--- a/toolchain/check/testdata/interop/cpp/function/class.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/class.carbon
@@ -699,7 +699,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_definition_in_relative_namespace_value_param_type.carbon
 // CHECK:STDOUT:
@@ -802,7 +802,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %O) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %O) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_definition_and_static_method_call_before.carbon
 // CHECK:STDOUT:
@@ -1013,7 +1013,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_decl_pointer_return_type.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/decayed_param.carbon b/toolchain/check/testdata/interop/cpp/function/decayed_param.carbon
index 058b57d867c7..d81ac377ebcf 100644
--- a/toolchain/check/testdata/interop/cpp/function/decayed_param.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/decayed_param.carbon
@@ -252,9 +252,9 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: %Optional.75d) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: ref %Optional.75d) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_todo_call_params_2.carbon
 // CHECK:STDOUT:
@@ -352,5 +352,5 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/default_arg.carbon b/toolchain/check/testdata/interop/cpp/function/default_arg.carbon
index 17d8146bf6d7..7ac9c2074c94 100644
--- a/toolchain/check/testdata/interop/cpp/function/default_arg.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/default_arg.carbon
@@ -409,7 +409,7 @@ fn Call() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %X) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %X) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- call_with_default.carbon
 // CHECK:STDOUT:
@@ -793,9 +793,9 @@ fn Call() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @GlobalNoReturn__carbon_thunk.2(%a.param: %i32, %b.param: %i32, %c.param: %i32);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @X.B(%self.param: %X, %a.param: %i32);
+// CHECK:STDOUT: fn @X.B(%self.param: ref %X, %a.param: %i32);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @B__carbon_thunk(%this.param: %X, %a.param: %i32);
+// CHECK:STDOUT: fn @B__carbon_thunk(%this.param: ref %X, %a.param: %i32);
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @X.C(%a.param: %i32);
 // CHECK:STDOUT:
@@ -805,9 +805,9 @@ fn Call() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @D__carbon_thunk(%_.param: %ptr.1f9, %a.param: %i32);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %X) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %X) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @X.cpp_destructor(%self.param: %X) = "no_op";
+// CHECK:STDOUT: fn @X.cpp_destructor(%self.param: ref %X) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_call_too_few_args.carbon
 // CHECK:STDOUT:
@@ -887,5 +887,5 @@ fn Call() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %X) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %X) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/full_semir.carbon b/toolchain/check/testdata/interop/cpp/function/full_semir.carbon
index 837900d8e548..d5dec2041a72 100644
--- a/toolchain/check/testdata/interop/cpp/function/full_semir.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/full_semir.carbon
@@ -196,7 +196,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @foo__carbon_thunk(%a.param: %ptr.251);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_int_param.carbon
 // CHECK:STDOUT:
@@ -381,5 +381,5 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @foo_short__carbon_thunk(%return.param: %ptr);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/inline.carbon b/toolchain/check/testdata/interop/cpp/function/inline.carbon
index 8d8f01188836..2ce2fe2640e2 100644
--- a/toolchain/check/testdata/interop/cpp/function/inline.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/inline.carbon
@@ -370,5 +370,5 @@ fn MyF() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/operators.carbon b/toolchain/check/testdata/interop/cpp/function/operators.carbon
index b9195bf0465b..3a9a69e4975d 100644
--- a/toolchain/check/testdata/interop/cpp/function/operators.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/operators.carbon
@@ -1174,7 +1174,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_binary_operators.carbon
 // CHECK:STDOUT:
@@ -1965,9 +1965,9 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc45(%self.param: bool) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc45(%self.param: ref bool) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc23(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc23(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- multiple_calls.carbon
 // CHECK:STDOUT:
@@ -2114,7 +2114,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_todo_rewrite_spaceship.carbon
 // CHECK:STDOUT:
@@ -2282,9 +2282,9 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc36(%self.param: bool) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc36(%self.param: ref bool) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_todo_rewrite_equal.carbon
 // CHECK:STDOUT:
@@ -2409,9 +2409,9 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: bool) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: ref bool) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_single_namespace.carbon
 // CHECK:STDOUT:
@@ -2523,7 +2523,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_multiple_namespaces.carbon
 // CHECK:STDOUT:
@@ -2686,9 +2686,9 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: %C2) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: ref %C2) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %C1) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %C1) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_todo_import_operands_in_namespace_operator_in_global.carbon
 // CHECK:STDOUT:
@@ -2781,7 +2781,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_inner_class.carbon
 // CHECK:STDOUT:
@@ -2891,7 +2891,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_inner_class_in_namespace.carbon
 // CHECK:STDOUT:
@@ -3010,7 +3010,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_member_add_with.carbon
 // CHECK:STDOUT:
@@ -3144,7 +3144,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- indirect_template_instantiation.carbon
 // CHECK:STDOUT:
@@ -3231,5 +3231,5 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/overloads.carbon b/toolchain/check/testdata/interop/cpp/function/overloads.carbon
index c0e369a08ef4..b77f66a054f7 100644
--- a/toolchain/check/testdata/interop/cpp/function/overloads.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/overloads.carbon
@@ -921,7 +921,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @bar__carbon_thunk(%a.param: %ptr.251);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_overloaded_functions.carbon
 // CHECK:STDOUT:
@@ -1192,7 +1192,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @foo__carbon_thunk(%a.param: %ptr.251);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_multiple_overloaded_sets.carbon
 // CHECK:STDOUT:
@@ -1782,7 +1782,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @foo__carbon_thunk(%a.param: %ptr.974, %return.param: %ptr.974);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i128) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i128) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_import_large_int_literal.carbon
 // CHECK:STDOUT:
@@ -2221,7 +2221,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @foo__carbon_thunk(%a.param: %ptr.bcc, %return.param: %ptr.bcc);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %f64.d77) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %f64.d77) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_import_large_floating_point_literal.carbon
 // CHECK:STDOUT:
@@ -2363,7 +2363,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @foo__carbon_thunk(%a.param: %ptr.bcc, %return.param: %ptr.bcc);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %f64.d77) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %f64.d77) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- struct_init.carbon
 // CHECK:STDOUT:
@@ -2467,7 +2467,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @MakeEmpty() -> out %return.param: %empty_struct_type;
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Empty(%value.param: %empty_struct_type, %reference.param: %empty_struct_type) {
+// CHECK:STDOUT: fn @Empty(%value.param: %empty_struct_type, %reference.param: ref %empty_struct_type) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc9: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %PassNoFields.ref.loc9: %PassNoFields.cpp_overload_set.type = name_ref PassNoFields, imports.%PassNoFields.cpp_overload_set.value [concrete = constants.%PassNoFields.cpp_overload_set.value]
@@ -2533,11 +2533,11 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @PassNoFields__carbon_thunk(%s.param: %ptr.dd0);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc15_30.1(%self.param: %NoFields) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc15_30.1(%self.param: ref %NoFields) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @NoFields.cpp_destructor(%self.param: %NoFields) = "no_op";
+// CHECK:STDOUT: fn @NoFields.cpp_destructor(%self.param: ref %NoFields) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc15_30.2(%self.param: %empty_struct_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc15_30.2(%self.param: ref %empty_struct_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_todo_struct_init_nonempty.carbon
 // CHECK:STDOUT:
@@ -2675,7 +2675,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @MakeThreeFields() -> out %return.param: %struct_type.a.b.c.0b6;
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @ThreeFields.loc8(%value.param: %struct_type.a.b.c.0b6, %reference.param: %struct_type.a.b.c.0b6) {
+// CHECK:STDOUT: fn @ThreeFields.loc8(%value.param: %struct_type.a.b.c.0b6, %reference.param: ref %struct_type.a.b.c.0b6) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc20: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %PassThreeFields.ref.loc20: %PassThreeFields.cpp_overload_set.type = name_ref PassThreeFields, imports.%PassThreeFields.cpp_overload_set.value [concrete = constants.%PassThreeFields.cpp_overload_set.value]
@@ -3032,7 +3032,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @MakeEmpty() -> out %return.param: %empty_tuple.type;
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @Empty(%value.param: %empty_tuple.type, %reference.param: %empty_tuple.type) {
+// CHECK:STDOUT: fn @Empty(%value.param: %empty_tuple.type, %reference.param: ref %empty_tuple.type) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc23: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %PassNoFields.ref.loc23: %PassNoFields.cpp_overload_set.type = name_ref PassNoFields, imports.%PassNoFields.cpp_overload_set.value [concrete = constants.%PassNoFields.cpp_overload_set.value]
@@ -3068,7 +3068,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @MakeThreeFields() -> out %return.param: %tuple.type.189;
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @ThreeFields.loc67(%value.param: %tuple.type.189, %reference.param: %tuple.type.189) {
+// CHECK:STDOUT: fn @ThreeFields.loc67(%value.param: %tuple.type.189, %reference.param: ref %tuple.type.189) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   %Cpp.ref.loc79: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
 // CHECK:STDOUT:   %PassThreeFields.ref.loc79: %PassThreeFields.cpp_overload_set.type = name_ref PassThreeFields, imports.%PassThreeFields.cpp_overload_set.value [concrete = constants.%PassThreeFields.cpp_overload_set.value]
diff --git a/toolchain/check/testdata/interop/cpp/function/pointer.carbon b/toolchain/check/testdata/interop/cpp/function/pointer.carbon
index 2af2863382c2..58201f1816d4 100644
--- a/toolchain/check/testdata/interop/cpp/function/pointer.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/pointer.carbon
@@ -486,7 +486,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_non_nullable_pointer_param_using_const_pointer.carbon
 // CHECK:STDOUT:
@@ -550,7 +550,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %const) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %const) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_double_non_nullable_pointer_param.carbon
 // CHECK:STDOUT:
@@ -649,9 +649,9 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: %ptr.5c7) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: ref %ptr.5c7) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_non_nullable_pointer_to_const_param_using_const.carbon
 // CHECK:STDOUT:
@@ -713,7 +713,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %const) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %const) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_non_nullable_pointer_to_const_param_using_non_const.carbon
 // CHECK:STDOUT:
@@ -777,7 +777,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_const_non_nullable_pointer_param_using_const.carbon
 // CHECK:STDOUT:
@@ -841,7 +841,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %const) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %const) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_const_non_nullable_pointer_param_using_non_const.carbon
 // CHECK:STDOUT:
@@ -901,7 +901,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %ptr) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %ptr) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_const_nullable_pointer_param_using_const.carbon
 // CHECK:STDOUT:
@@ -1030,9 +1030,9 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: %Optional.065) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: ref %Optional.065) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: %const.b9a) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: ref %const.b9a) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_const_nullable_pointer_param_using_non_const.carbon
 // CHECK:STDOUT:
@@ -1151,7 +1151,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: %Optional.065) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: ref %Optional.065) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_non_nullable_pointer_return.carbon
 // CHECK:STDOUT:
@@ -1405,9 +1405,9 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: %Optional.065) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: ref %Optional.065) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- null_pointer_arg_to_pointer_param.carbon
 // CHECK:STDOUT:
@@ -1504,7 +1504,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %Optional.7f5) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %Optional.7f5) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- nonnull_pointer_arg_to_pointer_param.carbon
 // CHECK:STDOUT:
@@ -1629,9 +1629,9 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: %Optional.065) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: ref %Optional.065) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- forward_nullable_pointer.carbon
 // CHECK:STDOUT:
@@ -1712,7 +1712,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %Optional.ece) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %Optional.ece) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_deduced_any_param_as_pointer.carbon
 // CHECK:STDOUT:
@@ -1785,7 +1785,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_deduced_pointer_param_as_pointer.carbon
 // CHECK:STDOUT:
@@ -1971,7 +1971,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13_58(%self.param: %Optional.065) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13_58(%self.param: ref %Optional.065) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13_48(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13_48(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/qualified_param.carbon b/toolchain/check/testdata/interop/cpp/function/qualified_param.carbon
index c11fb7306e8e..23c49100cc06 100644
--- a/toolchain/check/testdata/interop/cpp/function/qualified_param.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/qualified_param.carbon
@@ -139,5 +139,5 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/reference.carbon b/toolchain/check/testdata/interop/cpp/function/reference.carbon
index aababf9a0df0..bb8677a17074 100644
--- a/toolchain/check/testdata/interop/cpp/function/reference.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/reference.carbon
@@ -372,7 +372,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_param_lvalue_ref.carbon
 // CHECK:STDOUT:
@@ -476,9 +476,9 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc41(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc41(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc30(%self.param: %T) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc30(%self.param: ref %T) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- call_param_rvalue_ref.carbon
 // CHECK:STDOUT:
@@ -532,7 +532,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- todo_fail_param_value_arg_for_rvalue_ref.carbon
 // CHECK:STDOUT:
@@ -594,7 +594,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_param_rvalue_ref.carbon
 // CHECK:STDOUT:
@@ -679,9 +679,9 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc38(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc38(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: %T) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: ref %T) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- call_param_const_lvalue_ref_with_ref.carbon
 // CHECK:STDOUT:
@@ -764,7 +764,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- call_param_const_lvalue_ref_with_value.carbon
 // CHECK:STDOUT:
@@ -845,7 +845,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- call_return_lvalue_ref.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/return.carbon b/toolchain/check/testdata/interop/cpp/function/return.carbon
index a6e8c621fa48..73280a34e5d5 100644
--- a/toolchain/check/testdata/interop/cpp/function/return.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/return.carbon
@@ -173,7 +173,7 @@ fn Var() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i16) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i16) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- var_from_thunk_param.carbon
 // CHECK:STDOUT:
@@ -228,7 +228,7 @@ fn Var() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: %Cpp.nullptr_t) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: ref %Cpp.nullptr_t) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- return_from_thunk_param.carbon
 // CHECK:STDOUT:
@@ -393,5 +393,5 @@ fn Var() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @ReturnU32() -> out %return.param: %u32;
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %u32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %u32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/struct.carbon b/toolchain/check/testdata/interop/cpp/function/struct.carbon
index f26d6d18c553..a4fdcc3e73f9 100644
--- a/toolchain/check/testdata/interop/cpp/function/struct.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/struct.carbon
@@ -698,7 +698,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_definition_in_relative_namespace_value_param_type.carbon
 // CHECK:STDOUT:
@@ -801,7 +801,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %O) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %O) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_definition_and_static_method_call_before.carbon
 // CHECK:STDOUT:
@@ -1012,7 +1012,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %S) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %S) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_decl_pointer_return_type.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/union.carbon b/toolchain/check/testdata/interop/cpp/function/union.carbon
index 5954702666a5..3417ef5cddad 100644
--- a/toolchain/check/testdata/interop/cpp/function/union.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/union.carbon
@@ -623,7 +623,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %U) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %U) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_definition_in_relative_namespace_value_param_type.carbon
 // CHECK:STDOUT:
@@ -726,7 +726,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %O) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %O) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_definition_and_static_method_call_before.carbon
 // CHECK:STDOUT:
@@ -937,7 +937,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %U) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %U) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_decl_pointer_return_type.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/function/void_pointer.carbon b/toolchain/check/testdata/interop/cpp/function/void_pointer.carbon
index 4f9cfdd620de..2e4d3bf25404 100644
--- a/toolchain/check/testdata/interop/cpp/function/void_pointer.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/void_pointer.carbon
@@ -286,7 +286,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: %Optional.804) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: ref %Optional.804) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- null_param.carbon
 // CHECK:STDOUT:
@@ -390,7 +390,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: %Optional.ad7) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: ref %Optional.ad7) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- nullable_return_value.carbon
 // CHECK:STDOUT:
@@ -485,7 +485,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: %Optional.bb8) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: ref %Optional.bb8) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- non_nullable_pointer.carbon
 // CHECK:STDOUT:
@@ -556,7 +556,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %ptr.e0b) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %ptr.e0b) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- non_nullable_const.carbon
 // CHECK:STDOUT:
@@ -627,5 +627,5 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %ptr) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %ptr) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/impls/as.carbon b/toolchain/check/testdata/interop/cpp/impls/as.carbon
index 4f3b48f45eab..2fb0bc010615 100644
--- a/toolchain/check/testdata/interop/cpp/impls/as.carbon
+++ b/toolchain/check/testdata/interop/cpp/impls/as.carbon
@@ -239,7 +239,7 @@ fn ConversionExplicit(s: Cpp.ConditionallyExplicitFalse) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %Dest) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %Dest) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @ConstructorConversion(%s.param: %Source2) {
 // CHECK:STDOUT: !entry:
@@ -259,7 +259,7 @@ fn ConversionExplicit(s: Cpp.ConditionallyExplicitFalse) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc14(%self.param: %Dest2) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc14(%self.param: ref %Dest2) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @ExplicitConstructorTest(%s.param: %Source) {
 // CHECK:STDOUT: !entry:
@@ -279,7 +279,7 @@ fn ConversionExplicit(s: Cpp.ConditionallyExplicitFalse) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc20(%self.param: %ExplicitConstructor) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc20(%self.param: ref %ExplicitConstructor) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @ExplicitConversionTest(%s.param: %ExplicitConversion) {
 // CHECK:STDOUT: !entry:
@@ -404,7 +404,7 @@ fn ConversionExplicit(s: Cpp.ConditionallyExplicitFalse) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: %ConditionallyExplicit.c52b91.1) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: ref %ConditionallyExplicit.c52b91.1) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @ConstructorExplicit(%s.param: %Source) {
 // CHECK:STDOUT: !entry:
@@ -424,7 +424,7 @@ fn ConversionExplicit(s: Cpp.ConditionallyExplicitFalse) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc15(%self.param: %ConditionallyExplicit.c52b91.2) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc15(%self.param: ref %ConditionallyExplicit.c52b91.2) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @ConversionNotExplicit(%s.param: %ConditionallyExplicit.c52b91.1) {
 // CHECK:STDOUT: !entry:
@@ -462,7 +462,7 @@ fn ConversionExplicit(s: Cpp.ConditionallyExplicitFalse) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: %Dest) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: ref %Dest) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @ConversionExplicit(%s.param: %ConditionallyExplicit.c52b91.1) {
 // CHECK:STDOUT: !entry:
@@ -568,5 +568,5 @@ fn ConversionExplicit(s: Cpp.ConditionallyExplicitFalse) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Dest.5e7) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Dest.5e7) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/impls/destroy.carbon b/toolchain/check/testdata/interop/cpp/impls/destroy.carbon
index 665d13c9fbaf..ce3e51cf95e4 100644
--- a/toolchain/check/testdata/interop/cpp/impls/destroy.carbon
+++ b/toolchain/check/testdata/interop/cpp/impls/destroy.carbon
@@ -278,9 +278,9 @@ fn EqualWitnesses(p: Wrap(Cpp.PublicDestructor)*) -> Wrap(Cpp.PublicDestructor)*
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: %PublicDestructor) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: ref %PublicDestructor) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @PublicDestructor.cpp_destructor(%self.param: %PublicDestructor);
+// CHECK:STDOUT: fn @PublicDestructor.cpp_destructor(%self.param: ref %PublicDestructor);
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @TrivialDestroy() {
 // CHECK:STDOUT: !entry:
@@ -303,9 +303,9 @@ fn EqualWitnesses(p: Wrap(Cpp.PublicDestructor)*) -> Wrap(Cpp.PublicDestructor)*
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc15(%self.param: %TrivialDestructor) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc15(%self.param: ref %TrivialDestructor) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @TrivialDestructor.cpp_destructor(%self.param: %TrivialDestructor) = "no_op";
+// CHECK:STDOUT: fn @TrivialDestructor.cpp_destructor(%self.param: ref %TrivialDestructor) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- destroy_protected_base_destructor.carbon
 // CHECK:STDOUT:
@@ -349,7 +349,7 @@ fn EqualWitnesses(p: Wrap(Cpp.PublicDestructor)*) -> Wrap(Cpp.PublicDestructor)*
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Derived) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Derived) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- todo_fail_destroy_private_base_destructor.carbon
 // CHECK:STDOUT:
@@ -393,5 +393,5 @@ fn EqualWitnesses(p: Wrap(Cpp.PublicDestructor)*) -> Wrap(Cpp.PublicDestructor)*
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Derived) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Derived) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/impls/implicit_as.carbon b/toolchain/check/testdata/interop/cpp/impls/implicit_as.carbon
index b4aedbb29705..7d844147835a 100644
--- a/toolchain/check/testdata/interop/cpp/impls/implicit_as.carbon
+++ b/toolchain/check/testdata/interop/cpp/impls/implicit_as.carbon
@@ -522,9 +522,9 @@ fn InitFromStruct() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %Dest) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %Dest) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @NonConstConversion.loc12(%s.param: %NonConstConversion.480) {
+// CHECK:STDOUT: fn @NonConstConversion.loc12(%s.param: ref %NonConstConversion.480) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   name_binding_decl {
 // CHECK:STDOUT:     %_.patt: %pattern_type.69a = value_binding_pattern _ [concrete]
@@ -573,7 +573,7 @@ fn InitFromStruct() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc20(%self.param: %Dest2) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc20(%self.param: ref %Dest2) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_expr_category.carbon
 // CHECK:STDOUT:
@@ -640,7 +640,7 @@ fn InitFromStruct() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %Dest) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %Dest) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_access.carbon
 // CHECK:STDOUT:
@@ -726,7 +726,7 @@ fn InitFromStruct() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: %InaccessibleConstructor) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: ref %InaccessibleConstructor) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @InaccessibleConversionTest(%s.param: %InaccessibleConversion) {
 // CHECK:STDOUT: !entry:
@@ -752,7 +752,7 @@ fn InitFromStruct() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc30(%self.param: %Dest) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc30(%self.param: ref %Dest) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_deleted.carbon
 // CHECK:STDOUT:
@@ -915,7 +915,7 @@ fn InitFromStruct() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %IntConstructor.f49) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %IntConstructor.f49) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_no_u32_to_int_conversion_in_carbon.carbon
 // CHECK:STDOUT:
@@ -970,7 +970,7 @@ fn InitFromStruct() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %IntConstructor) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %IntConstructor) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- default_constructor.carbon
 // CHECK:STDOUT:
@@ -1041,7 +1041,7 @@ fn InitFromStruct() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %DefaultConstructor) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %DefaultConstructor) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- construct_multi_argument.carbon
 // CHECK:STDOUT:
@@ -1236,9 +1236,9 @@ fn InitFromStruct() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: %ThreeWithDefault) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: ref %ThreeWithDefault) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %Two) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %Two) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_todo_aggregate_from_tuple.carbon
 // CHECK:STDOUT:
@@ -1513,7 +1513,7 @@ fn InitFromStruct() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %NonAggregate) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %NonAggregate) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- todo_fail_non_aggregate_from_empty_struct.carbon
 // CHECK:STDOUT:
@@ -1557,7 +1557,7 @@ fn InitFromStruct() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %NonAggregate) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %NonAggregate) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_non_aggregate_from_struct.carbon
 // CHECK:STDOUT:
@@ -1640,5 +1640,5 @@ fn InitFromStruct() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %NonAggregate) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %NonAggregate) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/macros.carbon b/toolchain/check/testdata/interop/cpp/macros.carbon
index 20699ae8b14e..2e30b4ca2ddf 100644
--- a/toolchain/check/testdata/interop/cpp/macros.carbon
+++ b/toolchain/check/testdata/interop/cpp/macros.carbon
@@ -1083,7 +1083,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_unary_operator.carbon
 // CHECK:STDOUT:
@@ -1816,7 +1816,7 @@ fn F() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: %Optional.1d0) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: ref %Optional.1d0) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- enums.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/namespace.carbon b/toolchain/check/testdata/interop/cpp/namespace.carbon
index d93aad822743..443ff1efffe8 100644
--- a/toolchain/check/testdata/interop/cpp/namespace.carbon
+++ b/toolchain/check/testdata/interop/cpp/namespace.carbon
@@ -403,7 +403,7 @@ fn Use(y: Cpp.Y) -> i32 {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %X) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %X) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- import_special_name_call_escpaed.carbon
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/stdlib/initializer_list.carbon b/toolchain/check/testdata/interop/cpp/stdlib/initializer_list.carbon
index d865167eaee3..486195f64185 100644
--- a/toolchain/check/testdata/interop/cpp/stdlib/initializer_list.carbon
+++ b/toolchain/check/testdata/interop/cpp/stdlib/initializer_list.carbon
@@ -367,9 +367,9 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @initializer_list.initializer_list.loc12(%_.param: %array_type) -> out %return.param: %initializer_list = "cpp.std.initializer_list.make";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc12_44.1(%self.param: %InitListConstructor) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc12_44.1(%self.param: ref %InitListConstructor) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc12_44.2(%self.param: %initializer_list) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc12_44.2(%self.param: ref %initializer_list) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc12_44.3(%self.param: %array_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc12_44.3(%self.param: ref %array_type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/interop/cpp/typedef.carbon b/toolchain/check/testdata/interop/cpp/typedef.carbon
index 16a78650ac09..dbb79ec8234d 100644
--- a/toolchain/check/testdata/interop/cpp/typedef.carbon
+++ b/toolchain/check/testdata/interop/cpp/typedef.carbon
@@ -150,9 +150,9 @@ fn H(var c: Cpp.C, var d: Cpp.D) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: %ptr.235) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: ref %ptr.235) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- use_class_typedef.carbon
 // CHECK:STDOUT:
@@ -187,7 +187,7 @@ fn H(var c: Cpp.C, var d: Cpp.D) {
 // CHECK:STDOUT:   %Copy.impl_witness_table.c3a = impl_witness_table (%Core.import_ref.203), @ptr.as.Copy.impl [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @H(%c.param: %C, %d.param: %C) {
+// CHECK:STDOUT: fn @H(%c.param: ref %C, %d.param: ref %C) {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   name_binding_decl {
 // CHECK:STDOUT:     %pd.patt: %pattern_type.a31 = ref_binding_pattern pd [concrete]
@@ -234,5 +234,5 @@ fn H(var c: Cpp.C, var d: Cpp.D) {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %ptr.d9e) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %ptr.d9e) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/namespace/merging_with_indirections.carbon b/toolchain/check/testdata/namespace/merging_with_indirections.carbon
index 4a502031ca5a..51435e268251 100644
--- a/toolchain/check/testdata/namespace/merging_with_indirections.carbon
+++ b/toolchain/check/testdata/namespace/merging_with_indirections.carbon
@@ -251,5 +251,5 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @F [from "b.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %A) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %A) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/namespace/shadow.carbon b/toolchain/check/testdata/namespace/shadow.carbon
index e3930b3e4cb8..251d660aabd0 100644
--- a/toolchain/check/testdata/namespace/shadow.carbon
+++ b/toolchain/check/testdata/namespace/shadow.carbon
@@ -183,5 +183,5 @@ fn N.M.B() -> i32 {
 // CHECK:STDOUT:   return %.loc31
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/builtin/and.carbon b/toolchain/check/testdata/operators/builtin/and.carbon
index 6367a83aeb6f..7700c5f0ce65 100644
--- a/toolchain/check/testdata/operators/builtin/and.carbon
+++ b/toolchain/check/testdata/operators/builtin/and.carbon
@@ -360,9 +360,9 @@ fn PartialConstant(x: bool) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc26(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc26(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc23(%self.param: bool) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc23(%self.param: ref bool) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @PartialConstant(%x.param: bool) {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/operators/builtin/assignment.carbon b/toolchain/check/testdata/operators/builtin/assignment.carbon
index 6f8acb2a8176..e9601df75e2c 100644
--- a/toolchain/check/testdata/operators/builtin/assignment.carbon
+++ b/toolchain/check/testdata/operators/builtin/assignment.carbon
@@ -359,11 +359,11 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc27(%self.param: %ptr.235) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc27(%self.param: ref %ptr.235) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc23(%self.param: %struct_type.a.b.501) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc23(%self.param: ref %struct_type.a.b.501) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: %tuple.type.d07) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc19(%self.param: ref %tuple.type.d07) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/builtin/fail_assignment_to_non_assignable.carbon b/toolchain/check/testdata/operators/builtin/fail_assignment_to_non_assignable.carbon
index 4af9255b120d..4c6439b6f517 100644
--- a/toolchain/check/testdata/operators/builtin/fail_assignment_to_non_assignable.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_assignment_to_non_assignable.carbon
@@ -376,5 +376,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/builtin/fail_redundant_compound_access.carbon b/toolchain/check/testdata/operators/builtin/fail_redundant_compound_access.carbon
index ea327e5c6a65..f096fb9c0ddd 100644
--- a/toolchain/check/testdata/operators/builtin/fail_redundant_compound_access.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_redundant_compound_access.carbon
@@ -170,5 +170,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/builtin/fail_type_mismatch.carbon b/toolchain/check/testdata/operators/builtin/fail_type_mismatch.carbon
index a520ba0b0752..24933ddfc9e7 100644
--- a/toolchain/check/testdata/operators/builtin/fail_type_mismatch.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_type_mismatch.carbon
@@ -84,5 +84,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: bool) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref bool) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/builtin/fail_type_mismatch_assignment.carbon b/toolchain/check/testdata/operators/builtin/fail_type_mismatch_assignment.carbon
index f1fe2290b1e9..23e6736a8a4d 100644
--- a/toolchain/check/testdata/operators/builtin/fail_type_mismatch_assignment.carbon
+++ b/toolchain/check/testdata/operators/builtin/fail_type_mismatch_assignment.carbon
@@ -111,5 +111,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/builtin/or.carbon b/toolchain/check/testdata/operators/builtin/or.carbon
index d42f1f94d6e7..45f8b7e05288 100644
--- a/toolchain/check/testdata/operators/builtin/or.carbon
+++ b/toolchain/check/testdata/operators/builtin/or.carbon
@@ -367,9 +367,9 @@ fn PartialConstant(x: bool) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc26(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc26(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc25(%self.param: bool) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc25(%self.param: ref bool) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @PartialConstant(%x.param: bool) {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/operators/builtin/unary_op.carbon b/toolchain/check/testdata/operators/builtin/unary_op.carbon
index a6f3421d3b5d..001506885629 100644
--- a/toolchain/check/testdata/operators/builtin/unary_op.carbon
+++ b/toolchain/check/testdata/operators/builtin/unary_op.carbon
@@ -206,9 +206,9 @@ fn Constant() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc24(%self.param: bool) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc24(%self.param: ref bool) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc23(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc23(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/operators/overloaded/fail_assign_non_ref.carbon b/toolchain/check/testdata/operators/overloaded/fail_assign_non_ref.carbon
index 28993835dbc7..02074fbe70a8 100644
--- a/toolchain/check/testdata/operators/overloaded/fail_assign_non_ref.carbon
+++ b/toolchain/check/testdata/operators/overloaded/fail_assign_non_ref.carbon
@@ -179,9 +179,9 @@ fn TestAddAssignNonRef(a: C, b: C) {
 // CHECK:STDOUT:   .Self = constants.%C
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @C.as.Inc.impl.Op(%self.param: %C);
+// CHECK:STDOUT: fn @C.as.Inc.impl.Op(%self.param: ref %C);
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @C.as.AddAssignWith.impl.Op(%self.param: %C, %other.param: %C);
+// CHECK:STDOUT: fn @C.as.AddAssignWith.impl.Op(%self.param: ref %C, %other.param: %C);
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @TestIncNonRef(%a.param: %C) {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/operators/overloaded/fail_no_impl.carbon b/toolchain/check/testdata/operators/overloaded/fail_no_impl.carbon
index 58c7f6cd1bea..16e5f2db6647 100644
--- a/toolchain/check/testdata/operators/overloaded/fail_no_impl.carbon
+++ b/toolchain/check/testdata/operators/overloaded/fail_no_impl.carbon
@@ -187,5 +187,5 @@ fn TestRef(b: C) {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/overloaded/implicit_as.carbon b/toolchain/check/testdata/operators/overloaded/implicit_as.carbon
index 1cfd2ab973c0..49fca1b223e0 100644
--- a/toolchain/check/testdata/operators/overloaded/implicit_as.carbon
+++ b/toolchain/check/testdata/operators/overloaded/implicit_as.carbon
@@ -340,7 +340,7 @@ fn Test() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %X) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %X) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @Source(constants.%T.67d) {
 // CHECK:STDOUT:   %T.loc31_11.1 => constants.%T.67d
diff --git a/toolchain/check/testdata/operators/overloaded/index.carbon b/toolchain/check/testdata/operators/overloaded/index.carbon
index d94ff41f2f7d..e444df26bd43 100644
--- a/toolchain/check/testdata/operators/overloaded/index.carbon
+++ b/toolchain/check/testdata/operators/overloaded/index.carbon
@@ -489,7 +489,7 @@ fn F() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %C) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %C) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: specific @IndexWith(constants.%SubscriptType, constants.%ElementType) {
 // CHECK:STDOUT:   %SubscriptType => constants.%SubscriptType
diff --git a/toolchain/check/testdata/package_expr/fail_not_found.carbon b/toolchain/check/testdata/package_expr/fail_not_found.carbon
index b557804b1e56..6558f6cc980b 100644
--- a/toolchain/check/testdata/package_expr/fail_not_found.carbon
+++ b/toolchain/check/testdata/package_expr/fail_not_found.carbon
@@ -77,5 +77,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/package_expr/syntax.carbon b/toolchain/check/testdata/package_expr/syntax.carbon
index 4566a3af29d1..778943bd7ad6 100644
--- a/toolchain/check/testdata/package_expr/syntax.carbon
+++ b/toolchain/check/testdata/package_expr/syntax.carbon
@@ -284,7 +284,7 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/patterns/underscore.carbon b/toolchain/check/testdata/patterns/underscore.carbon
index a5e576d4cec2..f0d8911e1b84 100644
--- a/toolchain/check/testdata/patterns/underscore.carbon
+++ b/toolchain/check/testdata/patterns/underscore.carbon
@@ -193,7 +193,7 @@ fn F() -> {} {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_struct_type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_struct_type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/pointer/address_of_deref.carbon b/toolchain/check/testdata/pointer/address_of_deref.carbon
index c69b2bca328d..52e43fb2abda 100644
--- a/toolchain/check/testdata/pointer/address_of_deref.carbon
+++ b/toolchain/check/testdata/pointer/address_of_deref.carbon
@@ -136,5 +136,5 @@ fn F() -> i32 {
 // CHECK:STDOUT:   return %Int.as.Copy.impl.Op.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/pointer/address_of_lvalue.carbon b/toolchain/check/testdata/pointer/address_of_lvalue.carbon
index 825464e5dd22..1cbc38b9faca 100644
--- a/toolchain/check/testdata/pointer/address_of_lvalue.carbon
+++ b/toolchain/check/testdata/pointer/address_of_lvalue.carbon
@@ -322,11 +322,11 @@ fn F() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc24(%self.param: %ptr.235) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc24(%self.param: ref %ptr.235) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: %tuple.type.d07) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc22(%self.param: ref %tuple.type.d07) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc18(%self.param: %ptr.3ee) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc18(%self.param: ref %ptr.3ee) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: %struct_type.a.b.501) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: ref %struct_type.a.b.501) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/pointer/basic.carbon b/toolchain/check/testdata/pointer/basic.carbon
index e7c181508751..c1d82349ea6d 100644
--- a/toolchain/check/testdata/pointer/basic.carbon
+++ b/toolchain/check/testdata/pointer/basic.carbon
@@ -171,7 +171,7 @@ fn F() -> i32 {
 // CHECK:STDOUT:   return %Int.as.Copy.impl.Op.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc17(%self.param: %ptr.235) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc17(%self.param: ref %ptr.235) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc16(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/return/fail_return_with_returned_var.carbon b/toolchain/check/testdata/return/fail_return_with_returned_var.carbon
index fd04fa11dba7..b38bd309db2e 100644
--- a/toolchain/check/testdata/return/fail_return_with_returned_var.carbon
+++ b/toolchain/check/testdata/return/fail_return_with_returned_var.carbon
@@ -177,7 +177,7 @@ fn G() -> C {
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @G() -> out %return.param: %C {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/return/fail_returned_var_no_return_type.carbon b/toolchain/check/testdata/return/fail_returned_var_no_return_type.carbon
index 702c450642ee..46985bb5b0a0 100644
--- a/toolchain/check/testdata/return/fail_returned_var_no_return_type.carbon
+++ b/toolchain/check/testdata/return/fail_returned_var_no_return_type.carbon
@@ -100,7 +100,7 @@ fn ForgotReturnType() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_forgot_return_type.carbon
 // CHECK:STDOUT:
@@ -154,5 +154,5 @@ fn ForgotReturnType() {
 // CHECK:STDOUT:   return <error>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/return/fail_returned_var_shadow.carbon b/toolchain/check/testdata/return/fail_returned_var_shadow.carbon
index 5780160202ad..c9b2bcd725ea 100644
--- a/toolchain/check/testdata/return/fail_returned_var_shadow.carbon
+++ b/toolchain/check/testdata/return/fail_returned_var_shadow.carbon
@@ -188,7 +188,7 @@ fn DifferentScopes() -> i32 {
 // CHECK:STDOUT:   return %.loc27
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @DifferentScopes() -> out %return.param: %i32 {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/return/fail_returned_var_type.carbon b/toolchain/check/testdata/return/fail_returned_var_type.carbon
index d03d737f5bcd..01794e7eff1d 100644
--- a/toolchain/check/testdata/return/fail_returned_var_type.carbon
+++ b/toolchain/check/testdata/return/fail_returned_var_type.carbon
@@ -124,5 +124,5 @@ fn Mismatch() -> i32 {
 // CHECK:STDOUT:   return %.loc23_16
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %f64.d77) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %f64.d77) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/return/import_convert_function.carbon b/toolchain/check/testdata/return/import_convert_function.carbon
index fde81e9fb72c..216d72f2975f 100644
--- a/toolchain/check/testdata/return/import_convert_function.carbon
+++ b/toolchain/check/testdata/return/import_convert_function.carbon
@@ -1345,35 +1345,35 @@ fn F0(n: i32) -> P.D {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @C.as.ImplicitAs.impl.Convert.1 [from "library.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc7(%self.param: %C.b00) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc7(%self.param: ref %C.b00) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @C.as.ImplicitAs.impl.Convert.2 [from "library.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: %C.674) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc8(%self.param: ref %C.674) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @C.as.ImplicitAs.impl.Convert.3 [from "library.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: %C.681) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9(%self.param: ref %C.681) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @C.as.ImplicitAs.impl.Convert.4 [from "library.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: %C.7ac) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc10(%self.param: ref %C.7ac) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @C.as.ImplicitAs.impl.Convert.5 [from "library.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: %C.89d) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc11(%self.param: ref %C.89d) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @C.as.ImplicitAs.impl.Convert.6 [from "library.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: %C.f0a) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc12(%self.param: ref %C.f0a) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @C.as.ImplicitAs.impl.Convert.7 [from "library.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: %C.c60) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: ref %C.c60) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @C.as.ImplicitAs.impl.Convert.8 [from "library.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc14(%self.param: %C.304) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc14(%self.param: ref %C.304) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @Make [from "library.carbon"];
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/return/returned_var.carbon b/toolchain/check/testdata/return/returned_var.carbon
index 598b80aecfb7..654b79128654 100644
--- a/toolchain/check/testdata/return/returned_var.carbon
+++ b/toolchain/check/testdata/return/returned_var.carbon
@@ -200,5 +200,5 @@ fn G() -> i32 {
 // CHECK:STDOUT:   return %.loc26_16
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/return/returned_var_scope.carbon b/toolchain/check/testdata/return/returned_var_scope.carbon
index 24095f835dbe..509bebc868b3 100644
--- a/toolchain/check/testdata/return/returned_var_scope.carbon
+++ b/toolchain/check/testdata/return/returned_var_scope.carbon
@@ -197,7 +197,7 @@ fn EnclosingButAfter(b: bool) -> i32 {
 // CHECK:STDOUT:   return %.loc22
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %i32) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %i32) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @EnclosingButAfter(%b.param: bool) -> out %return.param: %i32 {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/struct/literal_member_access.carbon b/toolchain/check/testdata/struct/literal_member_access.carbon
index f96bb8786108..09a7c0867b72 100644
--- a/toolchain/check/testdata/struct/literal_member_access.carbon
+++ b/toolchain/check/testdata/struct/literal_member_access.carbon
@@ -136,5 +136,5 @@ fn F() -> i32 {
 // CHECK:STDOUT:   return %Int.as.Copy.impl.Op.call
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %struct_type.x.y.z) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %struct_type.x.y.z) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/struct/nested_struct_in_place.carbon b/toolchain/check/testdata/struct/nested_struct_in_place.carbon
index 3a9e848ea2ce..59a5fed63c75 100644
--- a/toolchain/check/testdata/struct/nested_struct_in_place.carbon
+++ b/toolchain/check/testdata/struct/nested_struct_in_place.carbon
@@ -123,5 +123,5 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %struct_type.a.b.2f9) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %struct_type.a.b.2f9) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/tuple/in_place_tuple_init.carbon b/toolchain/check/testdata/tuple/in_place_tuple_init.carbon
index 898d4877f52d..9df9633e9797 100644
--- a/toolchain/check/testdata/tuple/in_place_tuple_init.carbon
+++ b/toolchain/check/testdata/tuple/in_place_tuple_init.carbon
@@ -114,7 +114,7 @@ fn H() {
 // CHECK:STDOUT:   return %F.call.loc9 to %return.param
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %tuple.type.d07) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %tuple.type.d07) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @H() -> out %return.param: %i32 {
 // CHECK:STDOUT: !entry:
@@ -228,7 +228,7 @@ fn H() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc7(%self.param: %tuple.type.99b) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc7(%self.param: ref %tuple.type.99b) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @H() {
 // CHECK:STDOUT: !entry:
@@ -284,5 +284,5 @@ fn H() {
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: %tuple.type.516) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc13(%self.param: ref %tuple.type.516) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/tuple/tuple_pattern.carbon b/toolchain/check/testdata/tuple/tuple_pattern.carbon
index 83ddd7e90d6b..f018445bcfa3 100644
--- a/toolchain/check/testdata/tuple/tuple_pattern.carbon
+++ b/toolchain/check/testdata/tuple/tuple_pattern.carbon
@@ -197,7 +197,7 @@ let (a: {}, b: {}) = ({}, {}, {});
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %tuple.type.b6b) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %tuple.type.b6b) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- variable.carbon
 // CHECK:STDOUT:
@@ -284,7 +284,7 @@ let (a: {}, b: {}) = ({}, {}, {});
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %tuple.type.b6b) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %tuple.type.b6b) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @G() {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/var/decl.carbon b/toolchain/check/testdata/var/decl.carbon
index 51478d48bb1f..26fc6847bfe6 100644
--- a/toolchain/check/testdata/var/decl.carbon
+++ b/toolchain/check/testdata/var/decl.carbon
@@ -66,5 +66,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/var/decl_with_init.carbon b/toolchain/check/testdata/var/decl_with_init.carbon
index 234710218bbf..29f6ba004e40 100644
--- a/toolchain/check/testdata/var/decl_with_init.carbon
+++ b/toolchain/check/testdata/var/decl_with_init.carbon
@@ -70,5 +70,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/var/fail_duplicate_decl.carbon b/toolchain/check/testdata/var/fail_duplicate_decl.carbon
index 11cd7106038c..0d0c18e92ac6 100644
--- a/toolchain/check/testdata/var/fail_duplicate_decl.carbon
+++ b/toolchain/check/testdata/var/fail_duplicate_decl.carbon
@@ -94,5 +94,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/var/fail_init_with_self.carbon b/toolchain/check/testdata/var/fail_init_with_self.carbon
index c19f3e0a0ff3..ff666bd99582 100644
--- a/toolchain/check/testdata/var/fail_init_with_self.carbon
+++ b/toolchain/check/testdata/var/fail_init_with_self.carbon
@@ -72,5 +72,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/var/fail_lookup_outside_scope.carbon b/toolchain/check/testdata/var/fail_lookup_outside_scope.carbon
index aa190e317032..a85b3df0ceeb 100644
--- a/toolchain/check/testdata/var/fail_lookup_outside_scope.carbon
+++ b/toolchain/check/testdata/var/fail_lookup_outside_scope.carbon
@@ -84,7 +84,7 @@ var y: () = x;
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/var/global_lookup_in_scope.carbon b/toolchain/check/testdata/var/global_lookup_in_scope.carbon
index 66b8b38a04cf..63c55066b3b2 100644
--- a/toolchain/check/testdata/var/global_lookup_in_scope.carbon
+++ b/toolchain/check/testdata/var/global_lookup_in_scope.carbon
@@ -92,7 +92,7 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %struct_type.v) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %struct_type.v) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @__global_init() {
 // CHECK:STDOUT: !entry:
diff --git a/toolchain/check/testdata/var/lookup.carbon b/toolchain/check/testdata/var/lookup.carbon
index 885b74252b39..296a409c2955 100644
--- a/toolchain/check/testdata/var/lookup.carbon
+++ b/toolchain/check/testdata/var/lookup.carbon
@@ -70,5 +70,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/var/shadowing.carbon b/toolchain/check/testdata/var/shadowing.carbon
index aa88bf33d1b8..3c062bceff8c 100644
--- a/toolchain/check/testdata/var/shadowing.carbon
+++ b/toolchain/check/testdata/var/shadowing.carbon
@@ -133,5 +133,5 @@ fn Main() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/var/var_pattern.carbon b/toolchain/check/testdata/var/var_pattern.carbon
index 4a3d642fd438..0e3c063e3f38 100644
--- a/toolchain/check/testdata/var/var_pattern.carbon
+++ b/toolchain/check/testdata/var/var_pattern.carbon
@@ -197,7 +197,7 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- var_in_tuple.carbon
 // CHECK:STDOUT:
@@ -265,7 +265,7 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- tuple_in_var.carbon
 // CHECK:STDOUT:
@@ -339,7 +339,7 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %tuple.type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- tuple_in_let_var.carbon
 // CHECK:STDOUT:
@@ -413,7 +413,7 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %tuple.type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- function.carbon
 // CHECK:STDOUT:
@@ -469,7 +469,7 @@ fn G() {
 // CHECK:STDOUT:   %G.decl: %G.type = fn_decl @G [concrete = constants.%G] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @F(%x.param: %empty_tuple.type, %y.param: %empty_tuple.type);
+// CHECK:STDOUT: fn @F(%x.param: %empty_tuple.type, %y.param: ref %empty_tuple.type);
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @G() {
 // CHECK:STDOUT: !entry:
@@ -504,7 +504,7 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- public_function.carbon
 // CHECK:STDOUT:
@@ -551,7 +551,7 @@ fn G() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @F(%x.param: %empty_tuple.type, %y.param: %empty_tuple.type);
+// CHECK:STDOUT: fn @F(%x.param: %empty_tuple.type, %y.param: ref %empty_tuple.type);
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- public_function.impl.carbon
 // CHECK:STDOUT:
@@ -600,7 +600,7 @@ fn G() {
 // CHECK:STDOUT:   }
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @F(%x.param: %empty_tuple.type, %y.param: %empty_tuple.type) [from "public_function.carbon"] {
+// CHECK:STDOUT: fn @F(%x.param: %empty_tuple.type, %y.param: ref %empty_tuple.type) [from "public_function.carbon"] {
 // CHECK:STDOUT: !entry:
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
@@ -675,7 +675,7 @@ fn G() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: fn @F [from "public_function.carbon"];
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_nested.carbon
 // CHECK:STDOUT:
@@ -772,9 +772,9 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9_15(%self.param: %tuple.type.bcd) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9_15(%self.param: ref %tuple.type.bcd) = "no_op";
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp.loc9_27(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp.loc9_27(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- fail_compile_time.carbon
 // CHECK:STDOUT:
@@ -835,7 +835,7 @@ fn G() {
 // CHECK:STDOUT:   .F = %C.F.decl
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @C.F(%self.param: %C);
+// CHECK:STDOUT: fn @C.F(%self.param: ref %C);
 // CHECK:STDOUT:
 // CHECK:STDOUT: --- nested_match.carbon
 // CHECK:STDOUT:
@@ -936,5 +936,5 @@ fn G() {
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @DestroyOp(%self.param: %empty_tuple.type) = "no_op";
+// CHECK:STDOUT: fn @DestroyOp(%self.param: ref %empty_tuple.type) = "no_op";
 // CHECK:STDOUT:
diff --git a/toolchain/sem_ir/formatter.cpp b/toolchain/sem_ir/formatter.cpp
index 7d553f34777c..4c4548aae616 100644
--- a/toolchain/sem_ir/formatter.cpp
+++ b/toolchain/sem_ir/formatter.cpp
@@ -754,9 +754,7 @@ auto Formatter::FormatParamList(InstBlockId params_id,
       continue;
     }
     CARBON_CHECK(!sem_ir_->insts().Is<OutParam>(param_id));
-    FormatName(param_id);
-    out_ << ": ";
-    FormatTypeOfInst(param_id);
+    FormatNameAndForm(param_id, sem_ir_->insts().Get(param_id));
   }
 
   out_ << ")";
@@ -1011,6 +1009,12 @@ auto Formatter::FormatInstLhs(InstId inst_id, Inst inst) -> void {
     return;
   }
 
+  FormatNameAndForm(inst_id, inst);
+
+  out_ << " = ";
+}
+
+auto Formatter::FormatNameAndForm(InstId inst_id, Inst inst) -> void {
   FormatName(inst_id);
 
   if (inst.kind().has_type()) {
@@ -1040,8 +1044,6 @@ auto Formatter::FormatInstLhs(InstId inst_id, Inst inst) -> void {
       }
     }
   }
-
-  out_ << " = ";
 }
 
 auto Formatter::FormatInstArgAndKind(Inst::ArgAndKind arg_and_kind) -> void {
diff --git a/toolchain/sem_ir/formatter.h b/toolchain/sem_ir/formatter.h
index cdf4a04ba3f8..51b1b34fe08f 100644
--- a/toolchain/sem_ir/formatter.h
+++ b/toolchain/sem_ir/formatter.h
@@ -249,10 +249,13 @@ class Formatter {
   // no such arguments.
   auto FormatPendingConstantValue(AddSpace space_where) -> void;
 
-  // Formats `<name>[: <type>] = `. Skips unnamed instructions (according to
+  // Formats `<name>[: <form>] = `. Skips unnamed instructions (according to
   // `inst_namer_`). Typed instructions must be named.
   auto FormatInstLhs(InstId inst_id, Inst inst) -> void;
 
+  // Formats `<name>[: <form>]`. The inst must have a name.
+  auto FormatNameAndForm(InstId inst_id, Inst inst) -> void;
+
   // Formats arguments to an instruction. This will typically look like "
   // <arg0>, <arg1>".
   auto FormatInstRhs(Inst inst) -> void;