[PATCH] D133345: [AArch64] Increase AddedComplexity of BIC

[Alexander Shaposhnikov via Phabricator via llvm-commits]

alexander-shaposhnikov created this revision.
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This diff adjusts AddedComplexity of BIC to bump its position in the list of patterns to make LLVM pick it instead  of MVN + AND.
MVN + AND requires 2 cycles, so does e.g. MOV + BIC, but the latter outperforms the former if the instructions producing the operands of BIC can be issued in parallel. One may consider the following example:

ldur  x15, [x0, #2]  # 4 cycles
mvn x10, x15         # 1 cycle (depends on ldur)
and x9, x10, #0x8080808080808080

vs.

ldur   x15, [x0, #2]                               # 4 cycles
mov    x9, #0x8080808080808080  # 1 cycle (can be executed in parallel with ldur)
bic    x9, x9, x15.                                  # 1 cycle

Test plan: ninja check-all


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D133345

Files:
  llvm/lib/Target/AArch64/AArch64InstrFormats.td
  llvm/lib/Target/AArch64/AArch64InstrInfo.td
  llvm/test/CodeGen/AArch64/addsub.ll
  llvm/test/CodeGen/AArch64/dag-combine-setcc.ll
  llvm/test/CodeGen/AArch64/select_const.ll

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