[all-commits] [llvm/llvm-project] df0b97: [ValueTracking] Add with.overflow intrinsics to po...

[Juneyoung Lee via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: df0b97dab08abb8605533974f6b977c183f6be37
      https://github.com/llvm/llvm-project/commit/df0b97dab08abb8605533974f6b977c183f6be37
  Author: Juneyoung Lee <aqjune at gmail.com>
  Date:   2021-04-01 (Thu, 01 Apr 2021)

  Changed paths:
    M llvm/lib/Analysis/ValueTracking.cpp
    M llvm/unittests/Analysis/ValueTrackingTest.cpp

  Log Message:
  -----------
  [ValueTracking] Add with.overflow intrinsics to poison analysis functions

This is a patch teaching ValueTracking that `s/u*.with.overflow` intrinsics do not
create undef/poison and they propagate poison.
I couldn't write a nice example like the one with ctpop; ValueTrackingTest.cpp were simply updated
to check these instead.
This patch helps reducing regression while fixing https://llvm.org/pr49688 .

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D99671