[all-commits] [llvm/llvm-project] 6022a8: [SCEV] Drop cached ranges of AddRecs after flag up...

[max-azul via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 6022a8b7e8d1796284541bbf6bad40449c785fef
      https://github.com/llvm/llvm-project/commit/6022a8b7e8d1796284541bbf6bad40449c785fef
  Author: Max Kazantsev <mkazantsev at azul.com>
  Date:   2020-11-10 (Tue, 10 Nov 2020)

  Changed paths:
    M llvm/include/llvm/Analysis/ScalarEvolution.h
    M llvm/lib/Analysis/ScalarEvolution.cpp
    M llvm/test/Analysis/ScalarEvolution/srem.ll
    M llvm/test/Transforms/IndVarSimplify/floating-point-iv.ll

  Log Message:
  -----------
  [SCEV] Drop cached ranges of AddRecs after flag update

Our range computation methods benefit from no-wrap flags. But if the ranges
were first computed before the flags were set, the cached range will be too
pessimistic.

We need to drop cached ranges whenever we sharpen AddRec's no wrap flags.

Differential Revision: https://reviews.llvm.org/D89847
Reviewed By: fhahn