[all-commits] [llvm/llvm-project] a42053: [llvm-tblgen] CodeGenSchedModels::hasReadOfWrite g...

[Zi Xuan Wu (Zeson) via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a42053a1fa81c3041ba4140c476a766ef71010b2
      https://github.com/llvm/llvm-project/commit/a42053a1fa81c3041ba4140c476a766ef71010b2
  Author: Zi Xuan Wu (Zeson) <zixuan.wu at linux.alibaba.com>
  Date:   2022-09-19 (Mon, 19 Sep 2022)

  Changed paths:
    A llvm/test/TableGen/CompressWriteLatencyEntry.td
    M llvm/utils/TableGen/CodeGenSchedule.cpp

  Log Message:
  -----------
  [llvm-tblgen] CodeGenSchedModels::hasReadOfWrite gets wrong predication result

CodeGenSchedModels::hasReadOfWrite tries to predicate whether the WriteDef is contained in the list of ValidWrites of someone ProcReadAdvance,
so that WriteID of WriteDef can be compressed and reusable.

It tries to iterate all ProcReadAdvance entry, but not all ProcReadAdvance defs also inherit from SchedRead.
Some ProcReadAdvances are defined by ReadAdvance.So it's not complete to enumerate all ProcReadAdvances if just iterate all SchedReads.

Differential Revision: https://reviews.llvm.org/D132205