[all-commits] [llvm/llvm-project] 3f8513: [PowerPC] implement target hook isProfitableToHoist

[Chen Zheng via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 3f85134d710c1cdfd6bd3175756aee6ac267a240
      https://github.com/llvm/llvm-project/commit/3f85134d710c1cdfd6bd3175756aee6ac267a240
  Author: Chen Zheng <czhengsz at cn.ibm.com>
  Date:   2020-03-19 (Thu, 19 Mar 2020)

  Changed paths:
    M llvm/lib/Target/PowerPC/PPCISelLowering.cpp
    M llvm/lib/Target/PowerPC/PPCISelLowering.h
    M llvm/test/Transforms/SimplifyCFG/PowerPC/prefer-fma.ll

  Log Message:
  -----------
  [PowerPC] implement target hook isProfitableToHoist

On Powerpc fma is faster than fadd + fmul for some types,
(PPCTargetLowering::isFMAFasterThanFMulAndFAdd). we should implement target
hook isProfitableToHoist to prevent simplifyCFGpass from breaking fma
pattern by hoisting fmul to predecessor block.

Reviewed By: nemanjai

Differential Revision: https://reviews.llvm.org/D76207