[all-commits] [llvm/llvm-project] 68717a: [LoopIdiomRecognizePass] Options to disable part o...

[Anh Tuyen Tran via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 68717acb24e505169509b590e8c83557da54451e
      https://github.com/llvm/llvm-project/commit/68717acb24e505169509b590e8c83557da54451e
  Author: Anh Tuyen Tran <anhtuyen at ca.ibm.com>
  Date:   2020-09-01 (Tue, 01 Sep 2020)

  Changed paths:
    M llvm/include/llvm/Transforms/Scalar/LoopIdiomRecognize.h
    M llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
    A llvm/test/Transforms/LoopIdiom/disable-options.ll

  Log Message:
  -----------
  [LoopIdiomRecognizePass] Options to disable part or the entire Loop Idiom Recognize Pass

Loop Idiom Recognize Pass (LIRP) attempts to transform loops with subscripted arrays
into memcpy/memset function calls. In some particular situation, this transformation
introduces negative impacts. For example: https://bugs.llvm.org/show_bug.cgi?id=47300

This patch will enable users to disable a particular part of the transformation, while
he/she can still enjoy the benefit brought about by the rest of LIRP. The default
behavior stays unchanged: no part of LIRP is disabled by default.

Reviewed By: etiotto (Ettore Tiotto)

Differential Revision: https://reviews.llvm.org/D86262