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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 | bba3eb054a4e0e052cdeff22e678c52c4e59f07e (patch) | |
| tree | 5d2f2bdc5691d86fd14c6736477f1e32763fa0c2 | |
| parent | b715b205a41dc53942acbcfbfdbdce6bdaf9a4aa (diff) | |
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)"
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169209 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp | 3 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/shift.ll | 2 |
2 files changed, 3 insertions, 2 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp index c65076e883..c832ca5644 100644 --- a/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp +++ b/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/test/Transforms/InstCombine/shift.ll b/test/Transforms/InstCombine/shift.ll index b152816d2b..fad0bd7ede 100644 --- a/test/Transforms/InstCombine/shift.ll +++ b/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 } |