[all-commits] [llvm/llvm-project] e4b439: [ScalarEvolution] Fix overflow when computing max ...

[Philip Reames via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: e4b43973fbd41aee3b8197cf250e9fb9ac40f986
      https://github.com/llvm/llvm-project/commit/e4b43973fbd41aee3b8197cf250e9fb9ac40f986
  Author: Philip Reames <listmail at philipreames.com>
  Date:   2021-07-13 (Tue, 13 Jul 2021)

  Changed paths:
    M llvm/include/llvm/Analysis/ScalarEvolution.h
    M llvm/lib/Analysis/ScalarEvolution.cpp

  Log Message:
  -----------
  [ScalarEvolution] Fix overflow when computing max trip counts

This is split from D105216 to reduce patch complexity.  Original code by Eli with very minor modification by me.

The primary point of this patch is to add the getUDivCeilSCEV routine.  I included the two callers with constant arguments as we know those must constant fold even without any of the fancy inference logic.