diff options
Diffstat (limited to 'llvm/lib/Analysis/InstructionSimplify.cpp')
| -rw-r--r-- | llvm/lib/Analysis/InstructionSimplify.cpp | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index 73c3c47e909..1e62b9d407e 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -680,14 +680,14 @@ static Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, if (match(Op0, m_Zero())) { // 0 - X -> 0 if the sub is NUW. if (isNUW) - return Op0; + return Constant::getNullValue(Op0->getType()); KnownBits Known = computeKnownBits(Op1, Q.DL, 0, Q.AC, Q.CxtI, Q.DT); if (Known.Zero.isMaxSignedValue()) { // Op1 is either 0 or the minimum signed value. If the sub is NSW, then // Op1 must be 0 because negating the minimum signed value is undefined. if (isNSW) - return Op0; + return Constant::getNullValue(Op0->getType()); // 0 - X -> X if X is 0 or the minimum signed value. return Op1; @@ -799,12 +799,9 @@ static Value *SimplifyMulInst(Value *Op0, Value *Op1, const SimplifyQuery &Q, return C; // X * undef -> 0 - if (match(Op1, m_Undef())) - return Constant::getNullValue(Op0->getType()); - // X * 0 -> 0 - if (match(Op1, m_Zero())) - return Op1; + if (match(Op1, m_CombineOr(m_Undef(), m_Zero()))) + return Constant::getNullValue(Op0->getType()); // X * 1 -> X if (match(Op1, m_One())) @@ -888,7 +885,7 @@ static Value *simplifyDivRem(Value *Op0, Value *Op1, bool IsDiv) { // 0 / X -> 0 // 0 % X -> 0 if (match(Op0, m_Zero())) - return Op0; + return Constant::getNullValue(Op0->getType()); // X / X -> 1 // X % X -> 0 @@ -1147,7 +1144,7 @@ static Value *SimplifyShift(Instruction::BinaryOps Opcode, Value *Op0, // 0 shift by X -> 0 if (match(Op0, m_Zero())) - return Op0; + return Constant::getNullValue(Op0->getType()); // X shift by 0 -> X if (match(Op1, m_Zero())) @@ -1689,7 +1686,7 @@ static Value *SimplifyAndInst(Value *Op0, Value *Op1, const SimplifyQuery &Q, // X & 0 = 0 if (match(Op1, m_Zero())) - return Op1; + return Constant::getNullValue(Op0->getType()); // X & -1 = X if (match(Op1, m_AllOnes())) @@ -3068,8 +3065,7 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, Type *ITy = GetCompareTy(LHS); // The return type. // icmp X, X -> true/false - // X icmp undef -> true/false. For example, icmp ugt %X, undef -> false - // because X could be 0. + // icmp X, undef -> true/false because undef could be X. if (LHS == RHS || isa<UndefValue>(RHS)) return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred)); |
