[PATCH] D88962: [SVE] Add support for scalable vectors with vectorize.scalable.enable loop attribute

[David Sherwood via Phabricator via llvm-commits]

david-arm added a comment.

Hi @paulwalker-arm, so the reason for this change is related to the child patch where we changed the vectorize_width #pragma to accept an additional optional argument "scalable" or "fixed". @SjoerdMeijer felt this was the wrong approach and that the scalable property should be specified only as an additional pragma, i.e.

#pragma clang loop vectorize_width(4) vectorize_style(scalable)

The reason for this is that we would have to add vectorize_style(scalable) anyway to support vectorisation where the width isn't specified, i.e.

#pragma clang loop some_other_pragma vectorize_style(scalable)

Also, if we support both a vectorize_style(scalable|fixed) pragma in addition to specifying the scalable property in vectorize_width it also means extra work managing potential conflicts. As a result of this change in approach it made sense to update the LLVM loop hint attribute too to reflect this.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D88962/new/

https://reviews.llvm.org/D88962