[all-commits] [llvm/llvm-project] ef4feb: [Attributor] AAUndefinedBehavior: Check for branch...

[Hideto Ueno via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: ef4febd85b543afd264dda34c750b8515c4754e2
      https://github.com/llvm/llvm-project/commit/ef4febd85b543afd264dda34c750b8515c4754e2
  Author: Hideto Ueno <uenoku.tokotoko at gmail.com>
  Date:   2019-12-29 (Sun, 29 Dec 2019)

  Changed paths:
    M llvm/include/llvm/Transforms/IPO/Attributor.h
    M llvm/lib/Transforms/IPO/Attributor.cpp
    M llvm/test/Transforms/Attributor/IPConstantProp/PR26044.ll
    M llvm/test/Transforms/Attributor/IPConstantProp/fp-bc-icmp-const-fold.ll
    M llvm/test/Transforms/Attributor/IPConstantProp/solve-after-each-resolving-undefs-for-function.ll
    M llvm/test/Transforms/Attributor/undefined_behavior.ll

  Log Message:
  -----------
  [Attributor] AAUndefinedBehavior: Check for branches on undef value.

A branch is considered UB if it depends on an undefined / uninitialized value.
At this point this handles simple UB branches in the form: `br i1 undef, ...`
We query `AAValueSimplify` to get a value for the branch condition, so the branch
can be more complicated than just: `br i1 undef, ...`.

Patch By: Stefanos Baziotis (@baziotis)

Reviewers: jdoerfert, sstefan1, uenoku

Reviewed By: uenoku

Differential Revision: https://reviews.llvm.org/D71799