[all-commits] [llvm/llvm-project] d1dded: [PowerPC] Spill CR LT bits on P9 using setb

[Amy Kwan via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: d1dded28da2808200dacdc1eda46058cc0a0759b
      https://github.com/llvm/llvm-project/commit/d1dded28da2808200dacdc1eda46058cc0a0759b
  Author: Amy Kwan <amy.kwan1 at ibm.com>
  Date:   2019-11-24 (Sun, 24 Nov 2019)

  Changed paths:
    M llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp
    A llvm/test/CodeGen/PowerPC/spill_p9_setb.ll

  Log Message:
  -----------
  [PowerPC] Spill CR LT bits on P9 using setb

This patch aims to spill CR[0-7]LT bits on POWER9 using the setb instruction.
The sequence on P9 to spill these bits will be:

setb %reg, %CRREG
stw %reg, $FI

Instead of the typical sequence:

mfocrf %reg, %CRREG
rlwinm %reg1, %reg, $SH, 0, 0
stw %reg1, $FI

Differential Revision: https://reviews.llvm.org/D68443