[all-commits] [llvm/llvm-project] 71bd59: [SVE] Add support for scalable vectors with vector...

[david-arm via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 71bd59f0cb6db0211418b07127e8b311d944e2c2
      https://github.com/llvm/llvm-project/commit/71bd59f0cb6db0211418b07127e8b311d944e2c2
  Author: David Sherwood <david.sherwood at arm.com>
  Date:   2020-12-02 (Wed, 02 Dec 2020)

  Changed paths:
    M llvm/docs/LangRef.rst
    M llvm/include/llvm/Transforms/Utils/LoopUtils.h
    M llvm/include/llvm/Transforms/Vectorize/LoopVectorizationLegality.h
    M llvm/lib/Transforms/Scalar/WarnMissedTransforms.cpp
    M llvm/lib/Transforms/Utils/LoopUtils.cpp
    M llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/test/Transforms/LoopVectorize/metadata-width.ll
    A llvm/test/Transforms/LoopVectorize/no_array_bounds_scalable.ll

  Log Message:
  -----------
  [SVE] Add support for scalable vectors with vectorize.scalable.enable loop attribute

In this patch I have added support for a new loop hint called
vectorize.scalable.enable that says whether we should enable scalable
vectorization or not. If a user wants to instruct the compiler to
vectorize a loop with scalable vectors they can now do this as
follows:

  br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !2
  ...
  !2 = !{!2, !3, !4}
  !3 = !{!"llvm.loop.vectorize.width", i32 8}
  !4 = !{!"llvm.loop.vectorize.scalable.enable", i1 true}

Setting the hint to false simply reverts the behaviour back to the
default, using fixed width vectors.

Differential Revision: https://reviews.llvm.org/D88962