[all-commits] [llvm/llvm-project] 293e8f: [llvm-exegesis] Disable the LBR check on AMD

[Vy Nguyen via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 293e8fa13d3f05e993771577a4c022deee5cbf6e
      https://github.com/llvm/llvm-project/commit/293e8fa13d3f05e993771577a4c022deee5cbf6e
  Author: Vy Nguyen <vyng at google.com>
  Date:   2021-03-04 (Thu, 04 Mar 2021)

  Changed paths:
    M llvm/include/llvm/Support/Host.h
    M llvm/lib/Support/Host.cpp
    M llvm/tools/llvm-exegesis/lib/X86/Target.cpp

  Log Message:
  -----------
  [llvm-exegesis] Disable the LBR check on AMD

https://bugs.llvm.org/show_bug.cgi?id=48918

The bug reported a hang (or very very slow runtime) on a Zen2. Unfortunately, we don't have the hardware right now to debug it and I was not able to reproduce the bug on a HSW.
Theory we've got is that the lbr-checking code could be confused on AMD.

Differential Revision: https://reviews.llvm.org/D97504