[all-commits] [llvm/llvm-project] a91033: [FuncSpec] Conditional jump or move depends on uni...

[Alexandros Lamprineas via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a910337b5d01b2ad889abbd41db04314fcad664e
      https://github.com/llvm/llvm-project/commit/a910337b5d01b2ad889abbd41db04314fcad664e
  Author: Alexandros Lamprineas <alexandros.lamprineas at arm.com>
  Date:   2022-04-27 (Wed, 27 Apr 2022)

  Changed paths:
    M llvm/lib/Transforms/Utils/SCCPSolver.cpp
    A llvm/test/Transforms/FunctionSpecialization/bug55000-read-uninitialized-value.ll

  Log Message:
  -----------
  [FuncSpec] Conditional jump or move depends on uninitialised value(s).

I found this bug when performing a two-stage build of clang with
Function Specialization enabled and tuned aggressively. The crash
appears only on release builds.

Fixes https://github.com/llvm/llvm-project/issues/55000.

Before accessing the contents of the ArgInfo iterator inside
SCCPInstVisitor::markArgInFuncSpecialization, we should be
checking that the iterator is valid.

Differential Revision: https://reviews.llvm.org/D124114