Skip to content

TwoAddressInstruction: Fix assert on undef operand with -early-live-intervals #125518

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
merged 1 commit into from
Feb 3, 2025
Merged

TwoAddressInstruction: Fix assert on undef operand with -early-live-intervals #125518

Show file tree
Hide file tree
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
3 changes: 3 additions & 0 deletions llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -489,6 +489,9 @@ MachineInstr *TwoAddressInstructionImpl::findOnlyInterestingUse(
bool &IsDstPhys) const {
MachineOperand *UseOp = nullptr;
for (MachineOperand &MO : MRI->use_nodbg_operands(Reg)) {
if (MO.isUndef())
continue;

Copy link
Collaborator

@sdesmalen-arm sdesmalen-arm Feb 3, 2025

Choose a reason for hiding this comment

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

Unrelated to your patch, but should there be a break after line 499?

Copy link
Contributor Author

@arsenm arsenm Feb 3, 2025

Choose a reason for hiding this comment

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

It probably should, but I'd need to look exactly at all the implementations of isPlainlyKilled. At least the LiveIntervals one checks there's only one value in the interval

MachineInstr *MI = MO.getParent();
if (MI->getParent() != MBB)
return nullptr;
Expand Down
24 changes: 24 additions & 0 deletions llvm/test/CodeGen/ARM/twoaddress-asserts-liveints-undef-use.mir
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,24 @@
# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
# RUN: llc -mtriple=thumbv8.1m.main-none-none-eabi -mattr=+mve -verify-machineinstrs -run-pass=liveintervals,twoaddressinstruction -o - %s | FileCheck %s

---
name: undef_use_asserts_lr
tracksRegLiveness: true
noPhis: true
body: |
bb.0:
liveins: $q0

; CHECK-LABEL: name: undef_use_asserts_lr
; CHECK: liveins: $q0
; CHECK-NEXT: {{ $}}
; CHECK-NEXT: [[COPY:%[0-9]+]]:mqpr = COPY $q0
; CHECK-NEXT: [[DEF:%[0-9]+]]:spr = IMPLICIT_DEF
; CHECK-NEXT: [[COPY1:%[0-9]+]]:mqpr = COPY [[COPY]]
; CHECK-NEXT: dead [[COPY1:%[0-9]+]].ssub_2:mqpr = COPY [[DEF]]
; CHECK-NEXT: dead [[COPY2:%[0-9]+]]:spr = COPY undef [[COPY1]].ssub_3
%0:mqpr = COPY $q0
%1:spr = IMPLICIT_DEF
%2:mqpr = INSERT_SUBREG %0, %1, %subreg.ssub_2
dead %4:spr = COPY undef %2.ssub_3
...