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| author | Evan Cheng <evan.cheng@apple.com> | 2012-06-21 22:52:49 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2012-06-21 22:52:49 +0000 |
| commit | 2a5422b1a6955977d05af48222c86c77c7549484 (patch) | |
| tree | 8615d9db28212cc9b74bb852b0b2baeca27a471d /lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | |
| parent | 5791df830dd8bc91f44aff98446d5f74a96ae185 (diff) | |
Look pass zext to strength reduce an udiv. Patch by David Majnemer. rdar://11721329
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158946 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineMulDivRem.cpp')
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index 5168e2a113..35a0bbb761 100644 --- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -464,9 +464,12 @@ Instruction *InstCombiner::visitUDiv(BinaryOperator &I) { // X udiv (C1 << N), where C1 is "1<<C2" --> X >> (N+C2) { const APInt *CI; Value *N; - if (match(Op1, m_Shl(m_Power2(CI), m_Value(N)))) { + if (match(Op1, m_Shl(m_Power2(CI), m_Value(N))) || + match(Op1, m_ZExt(m_Shl(m_Power2(CI), m_Value(N))))) { if (*CI != 1) N = Builder->CreateAdd(N, ConstantInt::get(I.getType(),CI->logBase2())); + if (ZExtInst *Z = dyn_cast<ZExtInst>(Op1)) + N = Builder->CreateZExt(N, Z->getDestTy()); if (I.isExact()) return BinaryOperator::CreateExactLShr(Op0, N); return BinaryOperator::CreateLShr(Op0, N); |