[all-commits] [llvm/llvm-project] cdcefd: [IRCE] Implement runtime overflow check for comput...

[Aleksandr Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: cdcefd2f9a2d08e774fc7dcf631361a03bf6b810
      https://github.com/llvm/llvm-project/commit/cdcefd2f9a2d08e774fc7dcf631361a03bf6b810
  Author: Aleksandr Popov <a.popov.tmb at gmail.com>
  Date:   2023-07-12 (Wed, 12 Jul 2023)

  Changed paths:
    M llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
    M llvm/test/Transforms/IRCE/iv-plus-offset-range-check.ll

  Log Message:
  -----------
  [IRCE] Implement runtime overflow check for computed range's end

Here is activated check elimination which was parsed previously in
https://reviews.llvm.org/D154069

* Added runtime check that computed range's boundary doesn't overflow in
terms of range type.

* From the statement INT_MIN <= END <= INT_MAX is inferred check:
isNonNegative(INT_MAX - END) * isNonNegative(END - INT_MIN).

* If overflow happens, check will return 0 and the safe interval will be
empty.

Reviewed By: skatkov

Differential Revision: https://reviews.llvm.org/D154188