[all-commits] [llvm/llvm-project] 829d37: [InstSimplify] Don't simplify musttail calls

[Nikita Popov via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 829d377a98fd3ee087935ea215677e49c8b51b27
      https://github.com/llvm/llvm-project/commit/829d377a98fd3ee087935ea215677e49c8b51b27
  Author: Nikita Popov <nikita.ppv at gmail.com>
  Date:   2020-03-09 (Mon, 09 Mar 2020)

  Changed paths:
    M llvm/lib/Analysis/InstructionSimplify.cpp
    M llvm/test/Transforms/InstSimplify/call.ll

  Log Message:
  -----------
  [InstSimplify] Don't simplify musttail calls

As pointed out by jdoerfert on D75815, we must be careful when
simplifying musttail calls: We can only replace the return value
if we can eliminate the call entirely. As we can't make this
guarantee for all consumers of InstSimplify, this patch disables
simplification of musttail calls. Without this patch, musttail
simplification currently results in module verification errors.

Differential Revision: https://reviews.llvm.org/D75824