[PATCH] D87939: [PeepholeOptimizer] Enhance the redundant COPY elimination.

Tue Sep 22 07:02:19 PDT 2020

hliao added inline comments.

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Comment at: llvm/test/CodeGen/AMDGPU/GlobalISel/extractelement.i128.ll:301
 ; GFX9-NEXT:    s_load_dwordx16 s[0:15], s[2:3], 0x0
-; GFX9-NEXT:    v_lshlrev_b32_e32 v2, 1, v0
-; GFX9-NEXT:    v_cmp_eq_u32_e32 vcc, 1, v2
+; GFX9-NEXT:    v_lshlrev_b32_e32 v0, 1, v0
+; GFX9-NEXT:    v_cmp_eq_u32_e32 vcc, 1, v0
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arsenm wrote:
> I'm surprised there are so many changes here, but I guess it's probably papering over a number of combines that are missing
for this 3 global isel tests, I compared the new assembly against the old one, all the redundant copies are removed and overall code lengths are reduced.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D87939/new/

https://reviews.llvm.org/D87939