[all-commits] [llvm/llvm-project] 26f356: [LazyCallGraph] Fix ambiguous index value

[Brian Gesiak via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 26f356350bd56f5418e5fae230b1a6931774c8f1
      https://github.com/llvm/llvm-project/commit/26f356350bd56f5418e5fae230b1a6931774c8f1
  Author: Brian Gesiak <modocache at gmail.com>
  Date:   2020-02-18 (Tue, 18 Feb 2020)

  Changed paths:
    M llvm/lib/Analysis/LazyCallGraph.cpp
    M llvm/unittests/Analysis/CGSCCPassManagerTest.cpp

  Log Message:
  -----------
  [LazyCallGraph] Fix ambiguous index value

After having committed https://reviews.llvm.org/D72226, 2 buildbots
running GCC 5.4.0 began failing. The cause was the order in which those
compilers evaluated the left- and right-hand sides of the expression
`RC.SCCIndices[C] = RC.SCCIndices.size();`. This commit splits the
expression into multiple statements to avoid ambiguity, and adds a test
case that exercises the code that caused the test failures on those
older compilers (which was originally included in the reviewed patch,
https://reviews.llvm.org/D72226).