[PATCH] D140417: [SelectionDAG] Fix EmitCopyFromReg for cloned nodes

Tue Dec 20 09:59:12 PST 2022

foad added reviewers: craig.topper, RKSimon.
foad added a comment.
Herald added a subscriber: StephenFan.

This fixes https://github.com/llvm/llvm-project/issues/59618

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Comment at: llvm/test/CodeGen/AMDGPU/bug-sdag-emitcopyfromreg.ll:1
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc -march=amdgcn -mcpu=gfx1010 < %s | FileCheck %s
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I am struggling to come up with a good test case. This one doesn't really demonstrate the problem. Immediately after isel there is a problem, because an S_AND_B32 instruction clobbers $scc when it should not. But then after isel the S_AND_B32 gets converted to V_AND_B32, so the problem goes away.

I could change the test to dump MIR with -stop-before=si-fix-sgpr-copies if that's acceptable.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D140417/new/

https://reviews.llvm.org/D140417