Split the witness table into a separate ImplWitnessTable instruction (#5272)

This allows us to import the table for a given impl only once, while we
can import many ImplWitness instructions with different specifics for a
generic impl.

For example in convert_facet_value_to_narrowed_facet_type.carbon we see
that a single witness table is imported for the BitAnd interface, with
multiple witnesses (for different specifics) imported and sharing the
same table.

The ImplWitnessTable now contains a back-link to the Impl the witness is
for, allowing inst namer to name that interface in the textual semir,
and allowing the interface to be found when debugging from a witness.

---------

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
This commit is contained in:
Dana Jansens
2025-04-11 20:30:04 +00:00
committed by GitHub
co-authored by Richard Smith
parent c34a8d0a3a
commit 0e8d354567
273 changed files with 4091 additions and 3391 deletions
+5 -4
View File
@@ -25,11 +25,12 @@ fn F() -> i32 {
// CHECK:STDOUT: %int_0.5c6: Core.IntLiteral = int_value 0 [concrete]
// CHECK:STDOUT: %ImplicitAs.type.205: type = facet_type <@ImplicitAs, @ImplicitAs(%i32)> [concrete]
// CHECK:STDOUT: %Convert.type.1b6: type = fn_type @Convert.1, @ImplicitAs(%i32) [concrete]
// CHECK:STDOUT: %impl_witness.d39: <witness> = impl_witness (imports.%Core.import_ref.a5b), @impl.4f9(%int_32) [concrete]
// CHECK:STDOUT: %ImplicitAs.impl_witness_table.a2f = impl_witness_table (imports.%Core.import_ref.a5b), @impl.4f9 [concrete]
// CHECK:STDOUT: %ImplicitAs.impl_witness.c75: <witness> = impl_witness %ImplicitAs.impl_witness_table.a2f, @impl.4f9(%int_32) [concrete]
// CHECK:STDOUT: %Convert.type.035: type = fn_type @Convert.2, @impl.4f9(%int_32) [concrete]
// CHECK:STDOUT: %Convert.956: %Convert.type.035 = struct_value () [concrete]
// CHECK:STDOUT: %ImplicitAs.facet: %ImplicitAs.type.205 = facet_value Core.IntLiteral, (%impl_witness.d39) [concrete]
// CHECK:STDOUT: %.be7: type = fn_type_with_self_type %Convert.type.1b6, %ImplicitAs.facet [concrete]
// CHECK:STDOUT: %ImplicitAs.facet: %ImplicitAs.type.205 = facet_value Core.IntLiteral, (%ImplicitAs.impl_witness.c75) [concrete]
// CHECK:STDOUT: %.9c3: type = fn_type_with_self_type %Convert.type.1b6, %ImplicitAs.facet [concrete]
// CHECK:STDOUT: %Convert.bound: <bound method> = bound_method %int_0.5c6, %Convert.956 [concrete]
// CHECK:STDOUT: %Convert.specific_fn: <specific function> = specific_function %Convert.956, @Convert.2(%int_32) [concrete]
// CHECK:STDOUT: %bound_method: <bound method> = bound_method %int_0.5c6, %Convert.specific_fn [concrete]
@@ -71,7 +72,7 @@ fn F() -> i32 {
// CHECK:STDOUT: }
// CHECK:STDOUT: %n.var: ref %i32 = var n
// CHECK:STDOUT: %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0.5c6]
// CHECK:STDOUT: %impl.elem0: %.be7 = impl_witness_access constants.%impl_witness.d39, element0 [concrete = constants.%Convert.956]
// CHECK:STDOUT: %impl.elem0: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
// CHECK:STDOUT: %bound_method.loc12_3.1: <bound method> = bound_method %int_0, %impl.elem0 [concrete = constants.%Convert.bound]
// CHECK:STDOUT: %specific_fn: <specific function> = specific_function %impl.elem0, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
// CHECK:STDOUT: %bound_method.loc12_3.2: <bound method> = bound_method %int_0, %specific_fn [concrete = constants.%bound_method]