[all-commits] [llvm/llvm-project] 8f786b: [InstCombine] fix comments to match code; NFC

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  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 8f786b4618cff89880a3fb752fe8fb849f7ecba4
      https://github.com/llvm/llvm-project/commit/8f786b4618cff89880a3fb752fe8fb849f7ecba4
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2021-10-29 (Fri, 29 Oct 2021)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp

  Log Message:
  -----------
  [InstCombine] fix comments to match code; NFC


  Commit: 837518d6a08b793906b3f45251cdc4d04ff02317
      https://github.com/llvm/llvm-project/commit/837518d6a08b793906b3f45251cdc4d04ff02317
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2021-10-29 (Fri, 29 Oct 2021)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/lib/Target/X86/X86ISelLowering.h

  Log Message:
  -----------
  [x86] make mayFold* helpers visible to more files; NFC

The first function is needed for D112464, but we might
as well keep these together in case the others can be
used someday.


  Commit: 285b8abce483eaa25e20d3f3bd704592c3bdec88
      https://github.com/llvm/llvm-project/commit/285b8abce483eaa25e20d3f3bd704592c3bdec88
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2021-10-29 (Fri, 29 Oct 2021)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
    M llvm/test/CodeGen/X86/combine-sub.ll

  Log Message:
  -----------
  [x86] limit vector increment fold to allow load folding

The tests are based on the example from:
https://llvm.org/PR52032

I suspect that it looks worse than it actually is. :)
That is, llvm-mca says there's no uop/timing difference with the
load folding and pcmpeq vs. broadcast on Haswell (and probably
other targets).
The load-folding definitely makes the code smaller, so it's good
for that at least. So this requires carving a narrow hole in the
transform to get just this case without changing others that look
good as-is (in other words, the transform still seems good for
most examples).

Differential Revision: https://reviews.llvm.org/D112464


Compare: https://github.com/llvm/llvm-project/compare/d7cc760f3b49...285b8abce483