diff options
| author | Chris Lattner <sabre@nondot.org> | 2011-02-17 02:23:02 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2011-02-17 02:23:02 +0000 |
| commit | 41429e3f1e4d72ee4f7d4df786b5b0c87405f5b0 (patch) | |
| tree | b84c775e728c3187f9450e611f2b6115eef0a6ef /lib/Transforms/InstCombine/InstCombineAddSub.cpp | |
| parent | 3e468e1efafe905b34f51517f7211ae62cbff480 (diff) | |
preserve NUW/NSW when transforming add x,x
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125711 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineAddSub.cpp')
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineAddSub.cpp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/lib/Transforms/InstCombine/InstCombineAddSub.cpp index 4ff005e26c..89cc540da7 100644 --- a/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -147,8 +147,13 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) { return BinaryOperator::CreateXor(LHS, RHS); // X + X --> X << 1 - if (LHS == RHS && I.getType()->isIntegerTy()) - return BinaryOperator::CreateShl(LHS, ConstantInt::get(I.getType(), 1)); + if (LHS == RHS && I.getType()->isIntegerTy()) { + BinaryOperator *New = + BinaryOperator::CreateShl(LHS, ConstantInt::get(I.getType(), 1)); + New->setHasNoSignedWrap(I.hasNoSignedWrap()); + New->setHasNoUnsignedWrap(I.hasNoUnsignedWrap()); + return New; + } // -A + B --> B - A // -A + -B --> -(A + B) |