diff options
Diffstat (limited to 'lib/VMCore/ConstantFold.cpp')
-rw-r--r-- | lib/VMCore/ConstantFold.cpp | 31 |
1 files changed, 6 insertions, 25 deletions
diff --git a/lib/VMCore/ConstantFold.cpp b/lib/VMCore/ConstantFold.cpp index 194a6d4..549977c 100644 --- a/lib/VMCore/ConstantFold.cpp +++ b/lib/VMCore/ConstantFold.cpp @@ -1818,7 +1818,7 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred, // Handle some degenerate cases first if (isa<UndefValue>(C1) || isa<UndefValue>(C2)) - return UndefValue::get(ResultTy); + return ConstantInt::get(ResultTy, CmpInst::isTrueWhenEqual(pred)); // No compile-time operations on this type yet. if (C1->getType()->isPPC_FP128Ty()) @@ -2070,7 +2070,7 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred, if (ConstantExpr *CE2 = dyn_cast<ConstantExpr>(C2)) { Constant *CE2Op0 = CE2->getOperand(0); if (CE2->getOpcode() == Instruction::BitCast && - CE2->getType()->isVectorTy()==CE2Op0->getType()->isVectorTy()) { + CE2->getType()->isVectorTy() == CE2Op0->getType()->isVectorTy()) { Constant *Inverse = ConstantExpr::getBitCast(C1, CE2Op0->getType()); return ConstantExpr::getICmp(pred, Inverse, CE2Op0); } @@ -2078,8 +2078,8 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred, // If the left hand side is an extension, try eliminating it. if (ConstantExpr *CE1 = dyn_cast<ConstantExpr>(C1)) { - if (CE1->getOpcode() == Instruction::SExt || - CE1->getOpcode() == Instruction::ZExt) { + if ((CE1->getOpcode() == Instruction::SExt && ICmpInst::isSigned(pred)) || + (CE1->getOpcode() == Instruction::ZExt && !ICmpInst::isSigned(pred))){ Constant *CE1Op0 = CE1->getOperand(0); Constant *CE1Inverse = ConstantExpr::getTrunc(CE1, CE1Op0->getType()); if (CE1Inverse == CE1Op0) { @@ -2097,27 +2097,8 @@ Constant *llvm::ConstantFoldCompareInstruction(unsigned short pred, // If C2 is a constant expr and C1 isn't, flip them around and fold the // other way if possible. // Also, if C1 is null and C2 isn't, flip them around. - switch (pred) { - case ICmpInst::ICMP_EQ: - case ICmpInst::ICMP_NE: - // No change of predicate required. - return ConstantExpr::getICmp(pred, C2, C1); - - case ICmpInst::ICMP_ULT: - case ICmpInst::ICMP_SLT: - case ICmpInst::ICMP_UGT: - case ICmpInst::ICMP_SGT: - case ICmpInst::ICMP_ULE: - case ICmpInst::ICMP_SLE: - case ICmpInst::ICMP_UGE: - case ICmpInst::ICMP_SGE: - // Change the predicate as necessary to swap the operands. - pred = ICmpInst::getSwappedPredicate((ICmpInst::Predicate)pred); - return ConstantExpr::getICmp(pred, C2, C1); - - default: // These predicates cannot be flopped around. - break; - } + pred = ICmpInst::getSwappedPredicate((ICmpInst::Predicate)pred); + return ConstantExpr::getICmp(pred, C2, C1); } } return 0; |