[PATCH] D58428: [PowerPC] fix killed/dead flag after reg+reg to reg+imm transformation

[ChenZheng via Phabricator via llvm-commits]

shchenz created this revision.
shchenz added reviewers: nemanjai, steven.zhang, jsji, hfinkel, stefanp.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.

  ---
  name: testKilled
  tracksRegLiveness: true
  body: |
    bb.0.entry:
      liveins: $x3, $f1, $x5
      $x3 = ADDI8 $x5, 100
      STD killed $x5, $x5, 100
      STFSX killed $f1, $zero8, killed $x3
      BLR8 implicit $lr8, implicit $rm

`llc -mtriple=powerpc64le--linux-gnu -stop-after ppc-pre-emit-peephole t.mir -o - -verify-machineinstrs`

  # After PowerPC Pre-Emit Peephole
  # Machine code for function testKill: NoPHIs, TracksLiveness, NoVRegs
  
  bb.0.entry:
    liveins: $f1, $x3, $x5
    STD killed $x5, $x5, 100
    STFS killed $f1, 100, $x5
    BLR8 implicit $lr8, implicit $rm
  
  # End machine code for function testKill.
  
  *** Bad machine code: Using an undefined physical register ***
  - function:    testKill
  - basic block: %bb.0 entry (0x100313d8218)
  - instruction: STFS killed $f1, 100, $x5
  - operand 2:   $x5
  LLVM ERROR: Found 1 machine code errors.

PowerPC Peephole will convert `ADDI8` + `STFSX` to `STFS`. But currently it does not consider about killed/dead flag, so after transformation in the above case $x5 is used after killed.


https://reviews.llvm.org/D58428

Files:
  llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
  llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
  llvm/lib/Target/PowerPC/PPCInstrInfo.h
  llvm/test/CodeGen/PowerPC/convert-rr-to-ri-instr-add.mir
  llvm/test/CodeGen/PowerPC/convert-rr-to-ri-instrs-kill-flag.mir

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