[PATCH] D119696: [AMDGPU] Improve v_cmpx usage on GFX10.3.

[Thomas Symalla via Phabricator via llvm-commits]

tsymalla marked an inline comment as done.
tsymalla added inline comments.


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Comment at: llvm/lib/Target/AMDGPU/SIOptimizeExecMasking.cpp:571
+  // After all s_op_saveexec instructions are inserted,
+  // replace (on GFX10.3)
+  // v_cmp_* SGPR, IMM, VGPR
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arsenm wrote:
> nhaehnle wrote:
> > gfx10.3 and later.
> Why only do this on gfx10.3? Every target has v_cmpx?
We decided to do so because it is unclear if on < GFX10 this gives any performance advantage and on 10.1 / 10.2 an additional s_waitcnt_depctr needs to be inserted for correctness, so probably there won't be any performance gain from this on these targets.

@foad might elaborate more details for this.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D119696/new/

https://reviews.llvm.org/D119696