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| author | Sanjay Patel <spatel@rotateright.com> | 2017-10-13 17:47:25 +0000 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2017-10-13 17:47:25 +0000 |
| commit | a7bbf63f800a8976d3636d5d9f55fbee24f0baf7 (patch) | |
| tree | 47e8ffade934c3e058a9483d8f487b9722b0d785 /lib/Transforms | |
| parent | 5860eabc2fd220ad9d3ade38cfd05091cf18a31a (diff) | |
| download | llvm-a7bbf63f800a8976d3636d5d9f55fbee24f0baf7.tar.gz | |
[InstCombine] add hasOneUse check to add-zext-add fold to prevent increasing instructions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315718 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineAddSub.cpp | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/lib/Transforms/InstCombine/InstCombineAddSub.cpp index 92452d7df73..3921ab4374e 100644 --- a/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -988,10 +988,8 @@ Instruction *InstCombiner::foldAddWithConstant(BinaryOperator &Add) { return CastInst::Create(Instruction::SExt, X, Ty); // (add (zext (add nuw X, C2)), C) --> (zext (add nuw X, C2 + C)) - // FIXME: This should check hasOneUse to not increase the instruction count? - if (C->isNegative() && - match(Op0, m_ZExt(m_NUWAdd(m_Value(X), m_APInt(C2)))) && - C->sge(-C2->sext(C->getBitWidth()))) { + if (match(Op0, m_OneUse(m_ZExt(m_NUWAdd(m_Value(X), m_APInt(C2))))) && + C->isNegative() && C->sge(-C2->sext(C->getBitWidth()))) { Constant *NewC = ConstantInt::get(X->getType(), *C2 + C->trunc(C2->getBitWidth())); return new ZExtInst(Builder.CreateNUWAdd(X, NewC), Ty); |