Skip to content

[InstCombine] Add missing fold for fsqrt(select(b, c1, c2)) => select(b, fsqrt(c1), fsqrt(c2)) #113084

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

[InstCombine] Add missing fold for fsqrt(select(b, c1, c2)) => select(b, fsqrt(c1), fsqrt(c2)) #113084

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
11 changes: 11 additions & 0 deletions llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1699,6 +1699,17 @@ Instruction *InstCombinerImpl::FoldOpIntoSelect(Instruction &Op, SelectInst *SI,
if (SI->getType()->isIntOrIntVectorTy(1))
return nullptr;

if (auto *II = dyn_cast<IntrinsicInst>(&Op)) {
if (II->getIntrinsicID() == Intrinsic::sqrt) {
Value *NewTV = Builder.CreateUnaryIntrinsic(Intrinsic::sqrt, TV, nullptr,
"sqrt_fold");
Value *NewFV = Builder.CreateUnaryIntrinsic(Intrinsic::sqrt, FV, nullptr,
"sqrt_fold");
Comment on lines +1704 to +1707
Copy link
Contributor

@arsenm arsenm Oct 20, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Don't bother naming these values.

You should also be able to preserve at least some of the flags

return SelectInst::Create(SI->getCondition(), NewTV, NewFV, "", nullptr,
SI);
}
}
Copy link
Contributor

@goldsteinn goldsteinn Oct 20, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

As this currently exists, it will also fold if one of the arms is not constant.


// Test if a FCmpInst instruction is used exclusively by a select as
// part of a minimum or maximum operation. If so, refrain from doing
// any other folding. This helps out other analyses which understand
Expand Down
Loading