[all-commits] [llvm/llvm-project] a8ac11: [X86] add dwarf information for loop stack probe

[erikdesjardins via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a8ac117d98f6548635b18b58159c9cfb31ba4762
      https://github.com/llvm/llvm-project/commit/a8ac117d98f6548635b18b58159c9cfb31ba4762
  Author: Erik Desjardins <erikdesjardinspublic at gmail.com>
  Date:   2022-01-07 (Fri, 07 Jan 2022)

  Changed paths:
    M llvm/lib/Target/X86/X86FrameLowering.cpp
    M llvm/test/CodeGen/X86/stack-clash-large.ll

  Log Message:
  -----------
  [X86] add dwarf information for loop stack probe

This patch is based on https://reviews.llvm.org/D99585.

While inside the stack probing loop, temporarily change the CFA
to be based on r11/eax, which are already used to hold the loop bound.
The stack pointer cannot be used for CFI here as it changes during the loop,
so it does not have a constant offset to the CFA.

Co-authored-by: YangKeao <keao.yang at yahoo.com>

Reviewed By: nagisa

Differential Revision: https://reviews.llvm.org/D116628