case Instruction::SDiv:
case Instruction::SRem: {
// x / y is undefined if y == 0 or x == INT_MIN and y == -1
- const APInt *X, *Y;
- if (match(Inst->getOperand(1), m_APInt(Y))) {
- if (*Y != 0) {
- if (*Y == -1) {
- // The numerator can't be MinSignedValue if the denominator is -1.
- if (match(Inst->getOperand(0), m_APInt(X)))
- return !Y->isMinSignedValue();
- // The numerator *might* be MinSignedValue.
- return false;
- }
- // The denominator is not 0 or -1, it's safe to proceed.
- return true;
- }
- }
+ const APInt *Numerator, *Denominator;
+ if (!match(Inst->getOperand(1), m_APInt(Denominator)))
+ return false;
+ // We cannot hoist this division if the denominator is 0.
+ if (*Denominator == 0)
+ return false;
+ // It's safe to hoist if the denominator is not 0 or -1.
+ if (*Denominator != -1)
+ return true;
+ // At this point we know that the denominator is -1. It is safe to hoist as
+ // long we know that the numerator is not INT_MIN.
+ if (match(Inst->getOperand(0), m_APInt(Numerator)))
+ return !Numerator->isMinSignedValue();
+ // The numerator *might* be MinSignedValue.
return false;
}
case Instruction::Load: {