[PATCH] D154193: [X86]Remove TEST in AND32+TEST16rr in peephole-opt

[Wang, Xin via Phabricator via llvm-commits]

XinWang10 created this revision.
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Previously we remove a pattern like:
 %reg = and32ri %in_reg, 5

  ...                         // EFLAGS not changed.
  %src_reg = subreg_to_reg 0, %reg, %subreg.sub_index
  test64rr %src_reg, %src_reg, implicit-def $eflags

We can remove test64rr since it has same functionality as and subreg_to_reg avoid the opt in previous code, so we handle this case specially.
And this case is also can be opted for the same reason, like:

  %reg = and32ri %in_reg, 5
  ...                         // EFLAGS not changed.
  %src_reg = copy %reg.sub_16bit:gr32
  test16rr %src_reg, %src_reg, implicit-def $eflags

The COPY from gr32 to gr16 prevent the opt in previous code too, just handle it specially as what we do for test64rr.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D154193

Files:
  llvm/lib/Target/X86/X86InstrInfo.cpp
  llvm/test/CodeGen/X86/peephole-test-after-add.mir

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