Skip to content

JIT: Fold "shift-by-zero" in lower #61222

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

Merged
EgorBo merged 4 commits into from
Nov 5, 2021
Merged

JIT: Fold "shift-by-zero" in lower #61222

Changes from 1 commit
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
f653bf2
fold "shift-by-zero" in lower
EgorBo Nov 4, 2021
2e8f67a
oh, the test actually throws NRE
EgorBo Nov 4, 2021
2240c3a
Update Runtime_61045.cs
EgorBo Nov 4, 2021
d6f463d
Update lower.cpp
EgorBo Nov 5, 2021
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
Prev Previous commit
Update lower.cpp
  • Loading branch information
@EgorBo
EgorBo authored Nov 5, 2021
commit d6f463d8474f1715b913d98e1963f7058359afee
10 changes: 0 additions & 10 deletions src/coreclr/jit/lower.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5754,16 +5754,6 @@ void Lowering::LowerShift(GenTreeOp* shift)
}
ContainCheckShiftRotate(shift);

// Fold any kind of shift by zero, e.g. LSH(X, 0) => X
LIR::Use use;
if (shift->gtGetOp2()->IsIntegralConst(0) && BlockRange().TryGetUse(shift, &use))
{
use.ReplaceWith(shift->gtGetOp1());
BlockRange().Remove(shift->gtGetOp2());
BlockRange().Remove(shift);
return;
}

#ifdef TARGET_ARM64
// Try to recognize ubfiz/sbfiz idiom in LSH(CAST(X), CNS) tree
if (comp->opts.OptimizationEnabled() && shift->OperIs(GT_LSH) && shift->gtGetOp1()->OperIs(GT_CAST) &&
Expand Down