return Overflow;
}
-/// True if C2 is a multiple of C1. Quotient contains C2/C1.
+/// True if C1 is a multiple of C2. Quotient contains C1/C2.
static bool isMultiple(const APInt &C1, const APInt &C2, APInt &Quotient,
bool IsSigned) {
assert(C1.getBitWidth() == C2.getBitWidth() && "Constant widths not equal");
APInt C1Shifted = APInt::getOneBitSet(
C1->getBitWidth(), static_cast<unsigned>(C1->getLimitedValue()));
- // (X << C1) / C2 -> X / (C2 >> C1) if C2 is a multiple of C1.
+ // (X << C1) / C2 -> X / (C2 >> C1) if C2 is a multiple of 1 << C1.
if (isMultiple(*C2, C1Shifted, Quotient, IsSigned)) {
auto *BO = BinaryOperator::Create(I.getOpcode(), X,
ConstantInt::get(Ty, Quotient));
return BO;
}
- // (X << C1) / C2 -> X * (C2 >> C1) if C1 is a multiple of C2.
+ // (X << C1) / C2 -> X * ((1 << C1) / C2) if 1 << C1 is a multiple of C2.
if (isMultiple(C1Shifted, *C2, Quotient, IsSigned)) {
auto *Mul = BinaryOperator::Create(Instruction::Mul, X,
ConstantInt::get(Ty, Quotient));