[all-commits] [llvm/llvm-project] 9d5af5: [X86][CodeGenPrepare] Try to reuse IV's incremente...

[max-azul via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 9d5af555891d8187bfb4a5f573e059081af99571
      https://github.com/llvm/llvm-project/commit/9d5af555891d8187bfb4a5f573e059081af99571
  Author: Max Kazantsev <mkazantsev at azul.com>
  Date:   2021-03-04 (Thu, 04 Mar 2021)

  Changed paths:
    M llvm/lib/CodeGen/CodeGenPrepare.cpp
    M llvm/test/CodeGen/X86/2020_12_02_decrementing_loop.ll
    M llvm/test/CodeGen/X86/overflowing-iv.ll
    M llvm/test/CodeGen/X86/usub_inc_iv.ll

  Log Message:
  -----------
  [X86][CodeGenPrepare] Try to reuse IV's incremented value instead of adding the offset, part 2

This patch enables the case where we do not completely eliminate offset.
Supposedly in this case we reduce live range overlap that never harms, but
since there are doubts this is true, this goes as a separate change.

Differential Revision: https://reviews.llvm.org/D96399
Reviewed By: reames