[PATCH] D22194: Power9 - Add exploitation of oris/ori fusion

[Chuang-Yu Cheng via llvm-commits]

cycheng added a comment.

In http://reviews.llvm.org/D22194#480485, @MatzeB wrote:

> Can you explain why you need a custom mutator here? At first glance it looks like overriding TargetInstrInfo::shouldScheduleAdjacent() and using the default MacroFusion mutator is enough.


No, because default MacroFusion can only detect one pattern:

  XXXInstr (on X86: Test, Cmp, Inc; On AArch64: CMN, CMP, TST, ALU)
  BranchInstr

Also I didn't see any simple way to make MacroFusion more generic, so that's why we added a customized MacroFusion.


http://reviews.llvm.org/D22194