[PATCH] D84308: [PowerPC] Retrieve the offset from load/store if it stores to stack slots

[Qing Shan Zhang via Phabricator via llvm-commits]

steven.zhang created this revision.
steven.zhang added reviewers: jsji, qiucf, jasonliu, PowerPC.
Herald added subscribers: shchenz, wuzish, dexonsmith, kbarton, hiraditya, nemanjai.
Herald added a project: LLVM.

Scheduler will try to retrieve the offset and base addr to determine if two loads/stores are disjoint memory access. PowerPC failed to handle this for frame index which will bring extra memory dependency for loads/stores. See.

  SU(15):   STW %7:gprc, 28, %fixed-stack.0 :: (store 4 into %fixed-stack.0 + 28)
    # preds left       : 1
    # succs left       : 2
    # rdefs left       : 0
    Latency            : 1
    Depth              : 1
    Height             : 7
    Predecessors:
      SU(0): Data Latency=1 Reg=%7
    Successors:
      SU(17): Ord  Latency=1 Memory
      SU(16): Ord  Latency=1 Memory
    Pressure Diff      : GPRC 1    SPILLTOVSRRC 1    SPILLTOVSRRC_with_VFRC 1    F4RC_with_SPILLTOVSRRC 1    VSSRC_with_SPILLTOVSRRC 1
    Single Issue       : false;
  SU(16):   %8:gprc = LWZ 84, %fixed-stack.0 :: (dereferenceable load 4 from %ir.arrayidx_b + 4, align 8)
    # preds left       : 8
    # succs left       : 1
    # rdefs left       : 0
    Latency            : 1
    Depth              : 2
    Height             : 6
    Predecessors:
      SU(15): Ord  Latency=1 Memory   #<--- Extra dependency which is not needed.
      SU(14): Ord  Latency=1 Memory
      SU(13): Ord  Latency=1 Memory
      SU(12): Ord  Latency=1 Memory
      SU(11): Ord  Latency=1 Memory
      SU(10): Ord  Latency=1 Memory
      SU(9): Ord  Latency=1 Memory
      SU(8): Ord  Latency=1 Memory


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D84308

Files:
  llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
  llvm/test/CodeGen/PowerPC/aix-cc-byval-split.ll
  llvm/test/CodeGen/PowerPC/aix-cc-byval.ll
  llvm/test/CodeGen/PowerPC/aix32-cc-abi-vaarg.ll
  llvm/test/CodeGen/PowerPC/aix64-cc-abi-vaarg.ll

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