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Fix builin_expect lowering bug 

PR33346

Skip cases when expected value is not constant int.

llvm-svn: 304933
This commit is contained in:
Xinliang David Li 2017-06-07 18:32:24 +00:00
parent c1e7a0dde5
commit 4f49bee764
2 changed files with 25 additions and 1 deletions
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4
llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
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@ -93,7 +93,9 @@ static bool handleSwitchExpect(SwitchInst &SI) {
/// the branch probability info for the originating branch can be inferred.
static void handlePhiDef(CallInst *Expect) {
Value &Arg = *Expect->getArgOperand(0);
ConstantInt *ExpectedValue = cast<ConstantInt>(Expect->getArgOperand(1));
ConstantInt *ExpectedValue = dyn_cast<ConstantInt>(Expect->getArgOperand(1));
if (!ExpectedValue)
return;
const APInt &ExpectedPhiValue = ExpectedValue->getValue();
// Walk up in backward a list of instructions that

22
llvm/test/Transforms/LowerExpectIntrinsic/PR33346.ll Normal file
View File

@ -0,0 +1,22 @@
; RUN: opt -lower-expect -S < %s
; RUN: opt -passes='function(lower-expect)' -S < %s
define i64 @foo(i64 %arg) #0 {
bb:
%tmp = alloca i64, align 8
store i64 %arg, i64* %tmp, align 8
%tmp1 = load i64, i64* %tmp, align 8
%tmp2 = load i64, i64* %tmp, align 8
%tmp3 = call i64 @llvm.expect.i64(i64 %tmp1, i64 %tmp2)
ret i64 %tmp3
}
; Function Attrs: nounwind readnone
declare i64 @llvm.expect.i64(i64, i64)
!llvm.module.flags = !{!0}
!llvm.ident = !{!1}
!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{!"clang version 5.0.0 (trunk 304723)"}