[all-commits] [llvm/llvm-project] 1c4522: [ValueTracking] Check uses of Argument if it is gi...

[Juneyoung Lee via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 1c45220028a8aa39ad2f26c8c3c6234d1a816086
      https://github.com/llvm/llvm-project/commit/1c45220028a8aa39ad2f26c8c3c6234d1a816086
  Author: Juneyoung Lee <aqjune at gmail.com>
  Date:   2020-09-25 (Fri, 25 Sep 2020)

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

  Log Message:
  -----------
  [ValueTracking] Check uses of Argument if it is given to isGuaranteedNotToBeUndefOrPoison

This is a patch that allows isGuaranteedNotToBeUndefOrPoison to return more precise result
when an argument is given, by looking through its uses at the entry block (and following blocks as well, if it is checking poison only).

This is useful when there is a function call with noundef arguments at the entry block.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D88207