[PATCH] D66132: [CodeGen] Add `isSpeculativeExecutionForbidden()` to `TargetTransformInfo`

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

I feel like this is lacking words.
What problem is this addressing?
Is it correctness-one or performance?
The current hook feels a little bit weird.
Does it mean to completely ban speculative execution?
If then there is a lot more places where it should be used, and not using it there may be surprising. 
Or does it only mean to ban PRE? But then, what was the original problem?
Or should it be per-MI hook?
etc


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D66132/new/

https://reviews.llvm.org/D66132