We would like to make the ACLE NEON and SVE intrinsics more useable by
gating them on the target, not by ifdef preprocessor macros. In order to
do this the types they use need to be available. This patches makes
__bf16 always available under AArch64 not just when the bf16
architecture feature is present. This bringing it in-line with GCC. In
subsequent patches the NEON bfloat16x8_t and SVE svbfloat16_t types
(along with bfloat16_t used in arm_sve.h) will be made unconditional
too.
The operations valid on the types are still very limited. They can be
used as a storage type, but the intrinsics used for convertions are
still behind an ifdef guard in arm_neon.h/arm_bf16.h.
Differential Revision: https://reviews.llvm.org/D130973
Summary:
This patch upstreams support for a new storage only bfloat16 C type.
This type is used to implement primitive support for bfloat16 data, in
line with the Bfloat16 extension of the Armv8.6-a architecture, as
detailed here:
https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a
The bfloat type, and its properties are specified in the Arm Architecture
Reference Manual:
https://developer.arm.com/docs/ddi0487/latest/arm-architecture-reference-manual-armv8-for-armv8-a-architecture-profile
In detail this patch:
- introduces an opaque, storage-only C-type __bf16, which introduces a new bfloat IR type.
This is part of a patch series, starting with command-line and Bfloat16
assembly support. The subsequent patches will upstream intrinsics
support for BFloat16, followed by Matrix Multiplication and the
remaining Virtualization features of the armv8.6-a architecture.
The following people contributed to this patch:
- Luke Cheeseman
- Momchil Velikov
- Alexandros Lamprineas
- Luke Geeson
- Simon Tatham
- Ties Stuij
Reviewers: SjoerdMeijer, rjmccall, rsmith, liutianle, RKSimon, craig.topper, jfb, LukeGeeson, fpetrogalli
Reviewed By: SjoerdMeijer
Subscribers: labrinea, majnemer, asmith, dexonsmith, kristof.beyls, arphaman, danielkiss, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76077
David Green