[all-commits] [llvm/llvm-project] 6bc64e: [GlobalISel] Clear unreachable blocks' contents af...

[Amara Emerson via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 6bc64e24c38a42f2797ee64c78cb2d42b245b59e
      https://github.com/llvm/llvm-project/commit/6bc64e24c38a42f2797ee64c78cb2d42b245b59e
  Author: Amara Emerson <amara at apple.com>
  Date:   2021-10-05 (Tue, 05 Oct 2021)

  Changed paths:
    M llvm/lib/CodeGen/GlobalISel/InstructionSelect.cpp
    M llvm/test/CodeGen/AArch64/GlobalISel/select-blockaddress.mir
    A llvm/test/CodeGen/AArch64/GlobalISel/select-unreachable-blocks.mir

  Log Message:
  -----------
  [GlobalISel] Clear unreachable blocks' contents after selection.

If these blocks are unreachable, then we can discard all of the instructions.
However, keep the block around because it may have an address taken or the
block may have a stale reference from a PHI somewhere. Instead of finding
those PHIs and fixing them up, just leave the block empty.

Differential Revision: https://reviews.llvm.org/D111201