[all-commits] [llvm/llvm-project] 646e97: [llvm-stress] Fix dead code preventing us generati...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 646e970d44d7eaf4f56e2956fb58b48eb9360cb3
      https://github.com/llvm/llvm-project/commit/646e970d44d7eaf4f56e2956fb58b48eb9360cb3
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2021-06-11 (Fri, 11 Jun 2021)

  Changed paths:
    M llvm/tools/llvm-stress/llvm-stress.cpp

  Log Message:
  -----------
  [llvm-stress] Fix dead code preventing us generating per-element vector selects

This has been reported several times by the PVS Studio team as well as coming up in some static analysis.

getRandom() % 1 always returns 0 so we never actually test this codepath, (git blame suggests this has always been like this) - given that we have plenty of other "getRandom() & 1" the typo is pretty obvious, and matches the intention in the comment above - with this change we generate a nice mixture of scalar/vector condition selects of vectors.

I don't know llvm-stress that well - but I don't think we guarantee that the same seed value will always generate the same IR for later versions of the program - just that the same binary would.

Differential Revision: https://reviews.llvm.org/D104022