[all-commits] [llvm/llvm-project] cb47b8: [LV] PreferPredicateOverEpilog respecting predicat...

[sjoerdmeijer via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: cb47b8783017a76c5f2e4b974cfd6b22c9f1d5ff
      https://github.com/llvm/llvm-project/commit/cb47b8783017a76c5f2e4b974cfd6b22c9f1d5ff
  Author: Sjoerd Meijer <sjoerd.meijer at arm.com>
  Date:   2019-11-14 (Thu, 14 Nov 2019)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/test/Transforms/LoopVectorize/ARM/prefer-tail-loop-folding.ll

  Log Message:
  -----------
  [LV] PreferPredicateOverEpilog respecting predicate loop hint

The vectoriser queries TTI->preferPredicateOverEpilogue to determine if
tail-folding is preferred for a loop, but it was not respecting loop hint
'predicate' that can disable this, which has now been added. This showed that
we were incorrectly initialising loop hint 'vectorize.predicate.enable' with 0
(i.e. FK_Disabled) but this should have been FK_Undefined, which has been
fixed.

Differential Revision: https://reviews.llvm.org/D70125