[PATCH] D55402: [AMDGPU] Simplify negated condition

[Stanislav Mekhanoshin via Phabricator via llvm-commits]

rampitec created this revision.
rampitec added a reviewer: arsenm.
Herald added subscribers: t-tye, tpr, dstuttard, yaxunl, nhaehnle, wdng, jvesely, kzhuravl.

Optimize sequence:

  %sel = V_CNDMASK_B32_e64 0, 1, %cc
  %cmp = V_CMP_NE_U32 1, %1
  $vcc = S_AND_B64 $exec, %cmp
  S_CBRANCH_VCC[N]Z

>
=

  $vcc = S_ANDN2_B64 $exec, %cc
  S_CBRANCH_VCC[N]Z

It is the negation pattern inserted by DAGCombiner::visitBRCOND() in the rebuildSetCC().


https://reviews.llvm.org/D55402

Files:
  lib/Target/AMDGPU/SIOptimizeExecMaskingPreRA.cpp
  lib/Target/AMDGPU/SIRegisterInfo.cpp
  lib/Target/AMDGPU/SIRegisterInfo.h
  test/CodeGen/AMDGPU/optimize-negated-cond-exec-masking.mir
  test/CodeGen/AMDGPU/optimize-negated-cond.ll

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