Page MenuHomePhabricator
Differential D90952

[GlobalISel] Add combine for (x | mask) -> x when (x | mask) == x
ClosedPublic
Actions

Authored by mbrkusanin on Nov 6 2020, 8:50 AM.

Details

Reviewers
arsenm
foad
paquette
Commits
rGa75d6178b809: [GlobalISel] Add combine for (x | mask) -> x when (x | mask) == x
Summary

If we have a mask, and a value x, where (x | mask) == x, we can drop the OR
and just use x.

Diff Detail

Event Timeline

mbrkusanin created this revision.Nov 6 2020, 8:50 AM
Herald added subscribers: kerbowa, hiraditya, rovka and 2 others. · View Herald TranscriptNov 6 2020, 8:50 AM
mbrkusanin requested review of this revision.Nov 6 2020, 8:50 AM
Herald added a subscriber: wdng. · View Herald TranscriptNov 6 2020, 8:50 AM
Harbormaster completed remote builds in B77898: Diff 303470.Nov 6 2020, 8:51 AM
mbrkusanin added a parent revision: D90674: [GlobalISel] Expand combine for (x & mask) -> x when (x & mask) == x.Nov 6 2020, 8:51 AM
foad accepted this revision.Nov 9 2020, 2:05 AM
foad added a reviewer: paquette.

LGTM modulo minor comments inline.

llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
441

matchRedundantOr?

llvm/include/llvm/Target/GlobalISel/Combine.td
393

Update comment to say that (x | y) could be simplified to either x or y.

This revision is now accepted and ready to land.Nov 9 2020, 2:05 AM
mbrkusanin updated this revision to Diff 304114.Nov 10 2020, 2:36 AM
  • Rename
  • Updated comments
Closed by commit rGa75d6178b809: [GlobalISel] Add combine for (x | mask) -> x when (x | mask) == x (authored by mbrkusanin). · Explain WhyNov 10 2020, 2:38 AM
This revision was automatically updated to reflect the committed changes.
mbrkusanin added a commit: rGa75d6178b809: [GlobalISel] Add combine for (x | mask) -> x when (x | mask) == x.

Revision Contents
Changeset List

PathSize
llvm/
include/
llvm/
CodeGen/
GlobalISel/
9 lines
Target/
GlobalISel/
11 lines
lib/
CodeGen/
GlobalISel/
46 lines
Target/
AArch64/
2 lines
test/
CodeGen/
AMDGPU/
GlobalISel/
156 lines
3 lines
69 lines
41 lines

Diff 304118

View Options

llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h

Loading...
View Options

llvm/include/llvm/Target/GlobalISel/Combine.td

Loading...
View Options

llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp

Loading...
View Options

llvm/lib/Target/AArch64/AArch64Combine.td

Loading...
View Options

llvm/test/CodeGen/AMDGPU/GlobalISel/combine-or-redundant.mir

Loading...
View Options

llvm/test/CodeGen/AMDGPU/GlobalISel/combine-shift-of-shifted-logic.ll

Loading...
View Options

llvm/test/CodeGen/AMDGPU/GlobalISel/sdiv.i64.ll

Loading...
View Options

llvm/test/CodeGen/AMDGPU/GlobalISel/srem.i64.ll

Loading...