diff options
Diffstat (limited to 'lib/VMCore/ConstantFold.cpp')
| -rw-r--r-- | lib/VMCore/ConstantFold.cpp | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/lib/VMCore/ConstantFold.cpp b/lib/VMCore/ConstantFold.cpp index 06dc9dc89f..451190fc94 100644 --- a/lib/VMCore/ConstantFold.cpp +++ b/lib/VMCore/ConstantFold.cpp @@ -660,25 +660,28 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode, case Instruction::Xor: return ConstantInt::get(C1V ^ C2V); case Instruction::Shl: - if (uint32_t shiftAmt = C2V.getZExtValue()) + if (uint32_t shiftAmt = C2V.getZExtValue()) { if (shiftAmt < C1V.getBitWidth()) return ConstantInt::get(C1V.shl(shiftAmt)); else return UndefValue::get(C1->getType()); // too big shift is undef + } return const_cast<ConstantInt*>(CI1); // Zero shift is identity case Instruction::LShr: - if (uint32_t shiftAmt = C2V.getZExtValue()) + if (uint32_t shiftAmt = C2V.getZExtValue()) { if (shiftAmt < C1V.getBitWidth()) return ConstantInt::get(C1V.lshr(shiftAmt)); else return UndefValue::get(C1->getType()); // too big shift is undef + } return const_cast<ConstantInt*>(CI1); // Zero shift is identity case Instruction::AShr: - if (uint32_t shiftAmt = C2V.getZExtValue()) + if (uint32_t shiftAmt = C2V.getZExtValue()) { if (shiftAmt < C1V.getBitWidth()) return ConstantInt::get(C1V.ashr(shiftAmt)); else return UndefValue::get(C1->getType()); // too big shift is undef + } return const_cast<ConstantInt*>(CI1); // Zero shift is identity } } @@ -1083,18 +1086,20 @@ static ICmpInst::Predicate evaluateICmpRelation(const Constant *V1, // Ok, we ran out of things they have in common. If any leftovers // are non-zero then we have a difference, otherwise we are equal. for (; i < CE1->getNumOperands(); ++i) - if (!CE1->getOperand(i)->isNullValue()) + if (!CE1->getOperand(i)->isNullValue()) { if (isa<ConstantInt>(CE1->getOperand(i))) return isSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT; else return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal. + } for (; i < CE2->getNumOperands(); ++i) - if (!CE2->getOperand(i)->isNullValue()) + if (!CE2->getOperand(i)->isNullValue()) { if (isa<ConstantInt>(CE2->getOperand(i))) return isSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT; else return ICmpInst::BAD_ICMP_PREDICATE; // Might be equal. + } return ICmpInst::ICMP_EQ; } } @@ -1123,20 +1128,22 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred, if (C1->isNullValue()) { if (const GlobalValue *GV = dyn_cast<GlobalValue>(C2)) // Don't try to evaluate aliases. External weak GV can be null. - if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage()) + if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage()) { if (pred == ICmpInst::ICMP_EQ) return ConstantInt::getFalse(); else if (pred == ICmpInst::ICMP_NE) return ConstantInt::getTrue(); + } // icmp eq/ne(GV,null) -> false/true } else if (C2->isNullValue()) { if (const GlobalValue *GV = dyn_cast<GlobalValue>(C1)) // Don't try to evaluate aliases. External weak GV can be null. - if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage()) + if (!isa<GlobalAlias>(GV) && !GV->hasExternalWeakLinkage()) { if (pred == ICmpInst::ICMP_EQ) return ConstantInt::getFalse(); else if (pred == ICmpInst::ICMP_NE) return ConstantInt::getTrue(); + } } if (isa<ConstantInt>(C1) && isa<ConstantInt>(C2)) { |