[all-commits] [llvm/llvm-project] a40af8: [RS4GC] Handle special cases in unreachable code f...

[Max Kazantsev via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a40af8589e88f7ebaf81d11a9aa5a4eaf1735eff
      https://github.com/llvm/llvm-project/commit/a40af8589e88f7ebaf81d11a9aa5a4eaf1735eff
  Author: Max Kazantsev <mkazantsev at azul.com>
  Date:   2022-07-22 (Fri, 22 Jul 2022)

  Changed paths:
    M llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
    A llvm/test/Transforms/RewriteStatepointsForGC/pr56493.ll

  Log Message:
  -----------
  [RS4GC] Handle special cases in unreachable code for memcpy/memmov

The existing code doesn't expect dummy values (undef, poison, null-derived
constants etc) as arguments of these intrinsics. However, they can be there
in unreached code. Currently we fail trying to find base for them.

Handle these cases separately. Return null as base for them to be consistent
with the handling in the main algorithm in findBaseDefiningValue.

Differential Revision: https://reviews.llvm.org/D129561
Reviewed By: apilipenko