Currently, bf16 has been scatteredly added to the PTX codegen. This patch aims to complete the set of instructions and code path required to support bf16 data type.
Reviewed By: tra
Differential Revision: https://reviews.llvm.org/D144911
Co-authored-by: Artem Belevich <tra@google.com>
i16/f16/bf16 will use the same .b16 registers and
i32/v2f16 and v2bf16 will share .b32 registers.
The changes are mostly mechanical, intended to remove unnecessary register
classes which tend to produce redundant register moves.
Differential Revision: https://reviews.llvm.org/D151601
v2f16 regtype conversion to i32
Pursuant to discussions at
https://discourse.llvm.org/t/rfc-c-23-p1467r9-extended-floating-point-types-and-standard-names/70033/22,
this commit enhances the handling of the __bf16 type in Clang.
- Firstly, it upgrades __bf16 from a storage-only type to an arithmetic
type.
- Secondly, it changes the mangling of __bf16 to DF16b on all
architectures except ARM. This change has been made in
accordance with the finalization of the mangling for the
std::bfloat16_t type, as discussed at
https://github.com/itanium-cxx-abi/cxx-abi/pull/147.
- Finally, this commit extends the existing excess precision support to
the __bf16 type. This applies to hardware architectures that do not
natively support bfloat16 arithmetic.
Appropriate tests have been added to verify the effects of these
changes and ensure no regressions in other areas of the compiler.
Reviewed By: rjmccall, pengfei, zahiraam
Differential Revision: https://reviews.llvm.org/D150913
Recent Clang changes expose _bf16 types for SSE2-enabled host compilations and
that makes those types visible furing GPU-side compilation, where it currently
fails with Sema complaining that __bf16 is not supported.
Considering that __bf16 is a storage-only type, enabling it for NVPTX if it's
enabled on the host should pose no issues, correctness-wise.
Recent NVIDIA GPUs have introduced bf16 support, so we'll likely grow better
support for __bf16 on NVPTX going forward.
Differential Revision: https://reviews.llvm.org/D136311
