[all-commits] [llvm/llvm-project] a41ea7: [SelectionDAG] Enable CTPOP optimization fine tuning

[David Zarzycki via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: a41ea782c8e1273af4a39a647e41d6f0f42c3411
      https://github.com/llvm/llvm-project/commit/a41ea782c8e1273af4a39a647e41d6f0f42c3411
  Author: David Zarzycki <dave at znu.io>
  Date:   2020-11-09 (Mon, 09 Nov 2020)

  Changed paths:
    M llvm/include/llvm/CodeGen/TargetLowering.h
    M llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp

  Log Message:
  -----------
  [SelectionDAG] Enable CTPOP optimization fine tuning

Add a TLI hook to allow SelectionDAG to fine tune the conversion of CTPOP to a chain of "x & (x - 1)" when CTPOP isn't legal.

A subsequent patch will attempt to fine tune the X86 code gen.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D89952