diff options
Diffstat (limited to 'llvm/lib/Transforms/Scalar/InstructionCombining.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/InstructionCombining.cpp | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp index f663ae6137f..763ffe1d019 100644 --- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp @@ -2116,6 +2116,8 @@ Instruction *InstCombiner::visitSetCondInst(BinaryOperator &I) { ConstantInt *Prod; bool ProdOV = MulWithOverflow(Prod, CI, DivRHS); + Instruction::BinaryOps Opcode = I.getOpcode(); + if (DivRHS->isNullValue()) { // Don't hack on divide by zeros. } else if (LHSI->getType()->isUnsigned()) { // udiv LoBound = Prod; @@ -2152,15 +2154,13 @@ Instruction *InstCombiner::visitSetCondInst(BinaryOperator &I) { HiBound = cast<ConstantInt>(ConstantExpr::getSub(Prod, DivRHS)); } - /// FIXME: This code is disabled, because we do not compile the - /// divisor case < 0 correctly. For example, this code is incorrect - /// in the case of "X/-10 < 1". - LoBound = 0; + // Dividing by a negate swaps the condition. + Opcode = SetCondInst::getSwappedCondition(Opcode); } if (LoBound) { Value *X = LHSI->getOperand(0); - switch (I.getOpcode()) { + switch (Opcode) { default: assert(0 && "Unhandled setcc opcode!"); case Instruction::SetEQ: if (LoOverflow && HiOverflow) |
