diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Analysis/InstructionSimplify.cpp | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index ba76c5b0479..ce0b8a0fe64 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -1845,6 +1845,16 @@ static Value *SimplifyAndInst(Value *Op0, Value *Op1, const SimplifyQuery &Q, return Op1; } + // This is a similar pattern used for checking if a value is a power-of-2: + // (A - 1) & A --> 0 (if A is a power-of-2 or 0) + // A & (A - 1) --> 0 (if A is a power-of-2 or 0) + if (match(Op0, m_Add(m_Specific(Op1), m_AllOnes())) && + isKnownToBeAPowerOfTwo(Op1, Q.DL, /*OrZero*/ true, 0, Q.AC, Q.CxtI, Q.DT)) + return Constant::getNullValue(Op1->getType()); + if (match(Op1, m_Add(m_Specific(Op0), m_AllOnes())) && + isKnownToBeAPowerOfTwo(Op0, Q.DL, /*OrZero*/ true, 0, Q.AC, Q.CxtI, Q.DT)) + return Constant::getNullValue(Op0->getType()); + if (Value *V = simplifyAndOrOfCmps(Q, Op0, Op1, true)) return V; |
