[all-commits] [llvm/llvm-project] 11455a: [CodeGen] Allow partial tail duplication in Machin...

[Hongtao Yu via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 11455a7905947f61533a689e5f8ef45d5d1f26ff
      https://github.com/llvm/llvm-project/commit/11455a7905947f61533a689e5f8ef45d5d1f26ff
  Author: Hongtao Yu <hoy at fb.com>
  Date:   2020-04-11 (Sat, 11 Apr 2020)

  Changed paths:
    M llvm/lib/CodeGen/MachineBlockPlacement.cpp
    A llvm/test/CodeGen/X86/tail-dup-partial.ll

  Log Message:
  -----------
  [CodeGen] Allow partial tail duplication in Machine Block Placement.

Summary: A count profile may affect tail duplication's heuristic causing a block to be duplicated in only a part of its predecessors. This is not allowed in the Machine Block Placement pass where an assert will go off. I'm removing the assert and making the optimization bail out when such case happens.

Reviewers: wenlei, davidxl, Carrot

Reviewed By: Carrot

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77748