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| author | Shuxin Yang <shuxin.llvm@gmail.com> | 2012-12-04 03:28:32 +0000 |
|---|---|---|
| committer | Shuxin Yang <shuxin.llvm@gmail.com> | 2012-12-04 03:28:32 +0000 |
| commit | 86c0e232b7ce1fe640d474c7dcb57f1e19253c7c (patch) | |
| tree | 90cf3a47027a0c374ab6df7f818784db809a6684 | |
| parent | beb15ca8f09ab596f3d16b622226ed563064645a (diff) | |
| download | llvm-86c0e232b7ce1fe640d474c7dcb57f1e19253c7c.zip llvm-86c0e232b7ce1fe640d474c7dcb57f1e19253c7c.tar.gz llvm-86c0e232b7ce1fe640d474c7dcb57f1e19253c7c.tar.bz2 | |
rdar://12329730 (2nd part, revised)
The type of shirt-right (logical or arithemetic) should remain unchanged
when transforming "X << C1 >> C2" into "X << (C1-C2)"
llvm-svn: 169209
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp | 3 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/shift.ll | 2 |
2 files changed, 3 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp index c65076e..c832ca5 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp @@ -876,7 +876,8 @@ Value *InstCombiner::SimplifyShrShlDemandedBits(Instruction *Shr, New->setHasNoUnsignedWrap(Orig->hasNoUnsignedWrap()); } else { Constant *Amt = ConstantInt::get(VarX->getType(), ShrAmt - ShlAmt); - New = BinaryOperator::CreateLShr(VarX, Amt); + New = isLshr ? BinaryOperator::CreateLShr(VarX, Amt) : + BinaryOperator::CreateAShr(VarX, Amt); } return InsertNewInstWith(New, *Shl); diff --git a/llvm/test/Transforms/InstCombine/shift.ll b/llvm/test/Transforms/InstCombine/shift.ll index b152816..fad0bd7 100644 --- a/llvm/test/Transforms/InstCombine/shift.ll +++ b/llvm/test/Transforms/InstCombine/shift.ll @@ -723,7 +723,7 @@ define i32 @test60(i32 %x) { %or = or i32 %shl, 1 ret i32 %or ; CHECK: @test60 -; CHECK: lshr i32 %x, 3 +; CHECK: ashr i32 %x, 3 } |