[all-commits] [llvm/llvm-project] 679c3a: [TargetLowering] use stable_sort to avoid nondeter...

[Sam McCall via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 679c3a1791b51f2ad0771b8ce924130b071a956f
      https://github.com/llvm/llvm-project/commit/679c3a1791b51f2ad0771b8ce924130b071a956f
  Author: Sam McCall <sam.mccall at gmail.com>
  Date:   2023-09-26 (Tue, 26 Sep 2023)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp

  Log Message:
  -----------
  [TargetLowering] use stable_sort to avoid nondeterminism

After 330fa7d2a4e0cfbb4b078 we were seeing nondeterministic failures of
llvm/test/CodeGen/ARM/thumb-big-stack.ll, with different code being
generated in different runs.

Switching sort -> stable_sort fixes this.
It looks like the old algorithm picked the first best option, and using
stable_sort restores that behavior.