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[Test] Opportunity for sinking to unreachable in InstCombine

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Max Kazantsev
2020-05-18 16:27:16 +07:00
parent 525a591f0f
commit a2a4e5aae8
1 changed files with 72 additions and 0 deletions
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llvm/test/Transforms/InstCombine/sink_to_unreachable.ll
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -instcombine -S < %s | FileCheck %s
; RUN: opt -passes=instcombine -S < %s | FileCheck %s
declare void @use(i32 %x)
define void @test_01(i32 %x, i32 %y) {
; CHECK-LABEL: @test_01(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C2:%.*]] = icmp slt i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: br i1 [[C2]], label [[EXIT:%.*]], label [[UNREACHED:%.*]]
; CHECK: unreached:
; CHECK-NEXT: [[C1:%.*]] = icmp ne i32 [[X]], [[Y]]
; CHECK-NEXT: [[COMPARATOR:%.*]] = zext i1 [[C1]] to i32
; CHECK-NEXT: call void @use(i32 [[COMPARATOR]])
; CHECK-NEXT: unreachable
; CHECK: exit:
; CHECK-NEXT: ret void
;
entry:
%c1 = icmp eq i32 %x, %y
%c2 = icmp slt i32 %x, %y
%signed = select i1 %c2, i32 -1, i32 1
%comparator = select i1 %c1, i32 0, i32 %signed
br i1 %c2, label %exit, label %unreached
unreached:
call void @use(i32 %comparator)
unreachable
exit:
ret void
}
; TODO: %comparator and %signed can be sunk down to unreachable just as in
; test above.
define void @test_02(i32 %x, i32 %y) {
; CHECK-LABEL: @test_02(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C1:%.*]] = icmp eq i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: [[C2:%.*]] = icmp slt i32 [[X]], [[Y]]
; CHECK-NEXT: [[SIGNED:%.*]] = select i1 [[C2]], i32 -1, i32 1
; CHECK-NEXT: [[COMPARATOR:%.*]] = select i1 [[C1]], i32 0, i32 [[SIGNED]]
; CHECK-NEXT: br i1 [[C2]], label [[EXIT:%.*]], label [[MEDIUM:%.*]]
; CHECK: medium:
; CHECK-NEXT: [[C3:%.*]] = icmp sgt i32 [[X]], [[Y]]
; CHECK-NEXT: br i1 [[C3]], label [[EXIT]], label [[UNREACHED:%.*]]
; CHECK: unreached:
; CHECK-NEXT: call void @use(i32 [[COMPARATOR]])
; CHECK-NEXT: unreachable
; CHECK: exit:
; CHECK-NEXT: ret void
;
entry:
%c1 = icmp eq i32 %x, %y
%c2 = icmp slt i32 %x, %y
%signed = select i1 %c2, i32 -1, i32 1
%comparator = select i1 %c1, i32 0, i32 %signed
br i1 %c2, label %exit, label %medium
medium:
%c3 = icmp sgt i32 %x, %y
br i1 %c3, label %exit, label %unreached
unreached:
call void @use(i32 %comparator)
unreachable
exit:
ret void
}