RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-10-22 04:22:57 +02:00
Code Issues Projects Releases Wiki Activity

[InstCombine] Corrections in comments for division transformation (NFC)

Browse Source 
The actual code seems to be correct, but the comments were misleading.

Patch by Aaron Puchert!

Differential Revision: https://reviews.llvm.org/D49276

llvm-svn: 337131
This commit is contained in:
Sanjay Patel 2018-07-15 17:06:59 +00:00
parent b6a12c439f
commit ea7295ae5a
1 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
View File

@ -628,7 +628,7 @@ static bool multiplyOverflows(const APInt &C1, const APInt &C2, APInt &Product,
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");
@ -714,7 +714,7 @@ Instruction *InstCombiner::commonIDivTransforms(BinaryOperator &I) {
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));
@ -722,7 +722,7 @@ Instruction *InstCombiner::commonIDivTransforms(BinaryOperator &I) {
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));