[all-commits] [llvm/llvm-project] 5c8659: [CSSPGO][llvm-profgen] Handle return to external t...

[Hongtao Yu via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5c8659801a4976ef2b327f4071d98086efd42a36
      https://github.com/llvm/llvm-project/commit/5c8659801a4976ef2b327f4071d98086efd42a36
  Author: Hongtao Yu <hoy at fb.com>
  Date:   2021-06-22 (Tue, 22 Jun 2021)

  Changed paths:
    M llvm/tools/llvm-profgen/PerfReader.cpp

  Log Message:
  -----------
  [CSSPGO][llvm-profgen] Handle return to external transition.

In a callback case, a return from internal code, say A, to external runtime can happen. The external runtime can then call back to another internal routine, say B. Making an artificial branch that looks like a return from A to B can confuse the unwinder to treat the instruction before B as the call instruction.

Reviewed By: wenlei, wmi

Differential Revision: https://reviews.llvm.org/D104546