5918f62301
Use KnownBits to infer the nneg flag on zext instructions. Currently we only set nneg when converting sext -> zext, but don't set it when we have a zext in the first place. If we want to use it in optimizations, we should make sure the flag inference is consistent.
16 lines
389 B
LLVM
16 lines
389 B
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt < %s -passes=instcombine -S | FileCheck %s
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define i32 @test1(i8 %X) {
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; CHECK-LABEL: @test1(
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; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X:%.*]], 8
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; CHECK-NEXT: [[Z:%.*]] = zext nneg i8 [[TMP1]] to i32
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; CHECK-NEXT: ret i32 [[Z]]
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;
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%Y = zext i8 %X to i32
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%Z = and i32 %Y, 65544
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ret i32 %Z
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}
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