[all-commits] [llvm/llvm-project] 00a604: [ARM] Combine sub 0, csinc X, Y, CC -> csinv -X, Y...

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 00a60454734ceb554baa6da931e18ee07e035939
      https://github.com/llvm/llvm-project/commit/00a60454734ceb554baa6da931e18ee07e035939
  Author: David Green <david.green at arm.com>
  Date:   2021-04-16 (Fri, 16 Apr 2021)

  Changed paths:
    M llvm/lib/Target/ARM/ARMISelLowering.cpp
    M llvm/test/CodeGen/Thumb2/mve-masked-store.ll
    M llvm/test/CodeGen/Thumb2/mve-pred-build-var.ll
    M llvm/test/CodeGen/Thumb2/mve-vmovimm.ll

  Log Message:
  -----------
  [ARM] Combine sub 0, csinc X, Y, CC -> csinv -X, Y, CC

Combine sub 0, csinc X, Y, CC to csinv -X, Y, CC providing that the
negation of X is cheap, currently just handling constants. This comes up
during the splat of an i1 to a predicate, where we now generate csetm,
as opposed to cset; rsb.

Differential Revision: https://reviews.llvm.org/D99940