Commit Graph

2 Commits

Author SHA1 Message Date
Cullen Rhodes 511d5aaca3 [Transforms][SROA] Skip uses of allocas where the type is scalable
When visiting load and store instructions in SROA skip scalable vectors.
This is relevant in the implementation of the 'arm_sve_vector_bits'
attribute that is used to define VLS types, where an alloca of a
fixed-length vector could be bitcasted to scalable. See D85128 for more
information.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D85725
2020-08-12 09:35:48 +00:00
Cullen Rhodes 84aa6cf1a9 [Transforms][SROA] Promote allocas with mem2reg for scalable types
Summary:
Aggregate types containing scalable vectors aren't supported and as far
as I can tell this pass is mostly concerned with optimisations on
aggregate types, so the majority of this pass isn't very useful for
scalable vectors.

This patch modifies SROA such that mem2reg is run on allocas with
scalable types that are promotable, but nothing else such as slicing is
done.

The use of TypeSize in this pass has also been updated to be explicitly
fixed size. When invoking the following methods in DataLayout:

    * getTypeSizeInBits
    * getTypeStoreSize
    * getTypeStoreSizeInBits
    * getTypeAllocSize

we now called getFixedSize on the resultant TypeSize. This is quite an
extensive change with around 50 calls to these functions, and also the
first change of this kind (being explicit about fixed vs scalable
size) as far as I'm aware, so feedback welcome.

A test is included containing IR with scalable vectors that this pass is
able to optimise.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D76720
2020-04-01 10:34:11 +00:00