[all-commits] [llvm/llvm-project] 45d928: [PowerPC] use inst-level fast-math-flags to drive ...

[Chen Zheng via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 45d92806eaf8bd1d0edb94e983ac540f1633a2a6
      https://github.com/llvm/llvm-project/commit/45d92806eaf8bd1d0edb94e983ac540f1633a2a6
  Author: Chen Zheng <czhengsz at cn.ibm.com>
  Date:   2020-04-28 (Tue, 28 Apr 2020)

  Changed paths:
    M llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
    M llvm/lib/Target/PowerPC/PPCInstrInfo.h
    M llvm/test/CodeGen/PowerPC/machine-combiner.ll

  Log Message:
  -----------
  [PowerPC] use inst-level fast-math-flags to drive MachineCombiner

Currently, on PowerPC target, it uses function scope UnsafeFPMath
option to drive Machine Combiner pass.

This is not accurate in two ways:
1: the scope is not accurate. Machine Combiner pass only requires
   instruction-level flags instead of the function scope.
2: the float point flag is not accurate. Machine Combiner pass
   only requires float point flags reassoc and nsz.

Reviewed By: steven.zhang

Differential Revision: https://reviews.llvm.org/D78183