[all-commits] [llvm/llvm-project] 8018f7: [PowerPC] Do not emit HW loop with half precision ...

[Nemanja Ivanovic via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 8018f731f028d99d6698666a218ad6cf8408b0bb
      https://github.com/llvm/llvm-project/commit/8018f731f028d99d6698666a218ad6cf8408b0bb
  Author: Nemanja Ivanovic <nemanja.i.ibm at gmail.com>
  Date:   2021-01-25 (Mon, 25 Jan 2021)

  Changed paths:
    M llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
    M llvm/test/CodeGen/PowerPC/pr48519.ll

  Log Message:
  -----------
  [PowerPC] Do not emit HW loop with half precision operations

If a loop has any operations on half precision values, there will be calls to
library functions on Power8. Even on Power9, there is a small subset of
instructions that are actually supported for the type.

This patch disables HW loops whenever any operations on the type are found
(other than the handfull of supported ones when compiling for Power9). Fixes a
few PR's opened by Julia:

https://bugs.llvm.org/show_bug.cgi?id=48785
https://bugs.llvm.org/show_bug.cgi?id=48786
https://bugs.llvm.org/show_bug.cgi?id=48519

Differential revision: https://reviews.llvm.org/D94980