diff options
Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineCompares.cpp')
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCompares.cpp | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index 1b96c3cca4..b0fc82f6f6 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -2034,6 +2034,15 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { CI->countTrailingZeros())); } + // Turn x&~y == 0 into x&y != 0 if x is a power of 2. + Value *X = 0, *Y = 0; + if (match(Op0, m_And(m_Value(X), m_Not(m_Value(Y)))) && + match(Op1, m_Zero()) && isPowerOfTwo(X, TD)) { + return new ICmpInst(ICmpInst::ICMP_NE, + Builder->CreateAnd(X, Y), + Op1); + } + break; } case ICmpInst::ICMP_NE: { @@ -2071,6 +2080,15 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { CI->countTrailingZeros())); } + // Turn x&~y != 0 into x&y == 0 if x is a power of 2. + Value *X = 0, *Y = 0; + if (match(Op0, m_And(m_Value(X), m_Not(m_Value(Y)))) && + match(Op1, m_Zero()) && isPowerOfTwo(X, TD)) { + return new ICmpInst(ICmpInst::ICMP_EQ, + Builder->CreateAnd(X, Y), + Op1); + } + break; } case ICmpInst::ICMP_ULT: |