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| author | David Majnemer <david.majnemer@gmail.com> | 2013-07-09 08:09:32 +0000 |
|---|---|---|
| committer | David Majnemer <david.majnemer@gmail.com> | 2013-07-09 08:09:32 +0000 |
| commit | 36b6f7409d9f607317de9815ffc10656b608eab7 (patch) | |
| tree | 081e67d12a3ba9360c1ae1494a7e57cb912acb8e /lib/Transforms | |
| parent | ff16df71f50231c79c379a146dc55b4d6867cbd9 (diff) | |
| download | external_llvm-36b6f7409d9f607317de9815ffc10656b608eab7.zip external_llvm-36b6f7409d9f607317de9815ffc10656b608eab7.tar.gz external_llvm-36b6f7409d9f607317de9815ffc10656b608eab7.tar.bz2 | |
InstCombine: X & -C != -C -> X <= u ~C
Tests were added in r185910 somehow.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185912 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCompares.cpp | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index fd2b68a..e9f3458 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -1277,6 +1277,15 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, return Res; } } + + // X & -C == -C -> X > u ~C + // X & -C != -C -> X <= u ~C + // iff C is a power of 2 + if (ICI.isEquality() && RHS == LHSI->getOperand(1) && (-RHSV).isPowerOf2()) + return new ICmpInst( + ICI.getPredicate() == ICmpInst::ICMP_EQ ? ICmpInst::ICMP_UGT + : ICmpInst::ICMP_ULE, + LHSI->getOperand(0), SubOne(RHS)); break; case Instruction::Or: { |