[all-commits] [llvm/llvm-project] 35a304: [InstCombine] add support for multi-use Y of (X op...

[ZCBing via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 35a3048c2501f7e1de4f662ed402a37f4822feec
      https://github.com/llvm/llvm-project/commit/35a3048c2501f7e1de4f662ed402a37f4822feec
  Author: Chenbing Zheng <Chenbing.Zheng at streamcomputing.com>
  Date:   2022-08-31 (Wed, 31 Aug 2022)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
    M llvm/test/Transforms/InstCombine/and-or-not.ll

  Log Message:
  -----------
  [InstCombine] add support for multi-use Y of (X op Y) op Z --> (Y op Z) op X

For (X op Y) op Z --> (Y op Z) op X
we can still do transform when Y is multi-use. In D131356 limit it to one-use,
this patch remove this limit.

This is still not a complete solution, I add a todo test to show it.
In this case, X and Y are both multi use, we can't differentiate how to convert based on this.
But at least we don't make the code worse，and it can solve half the scenarios.