[all-commits] [llvm/llvm-project] c1943b: [ValueLattice] Update markConstantRange to return ...

[Florian Hahn via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: c1943b42c5b7feff5d0e0c1358d02889e2be165f
      https://github.com/llvm/llvm-project/commit/c1943b42c5b7feff5d0e0c1358d02889e2be165f
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2020-02-15 (Sat, 15 Feb 2020)

  Changed paths:
    M llvm/include/llvm/Analysis/ValueLattice.h
    M llvm/unittests/Analysis/ValueLatticeTest.cpp

  Log Message:
  -----------
  [ValueLattice] Update markConstantRange to return false equal ranges.

Currently we always return true, when markConstantRange is used on an
object already containing a constant range. If NewR is equal to the
existing constant range however, nothing changes and we should return
false.

I also went ahead and added a clarifying comment and improved the
assertion.

Reviewers: efriedma, davide, nikic

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D73240