Add detection for SME features supported by LLVM and the Linux Kernel.
Include commented-out hwcap fields for features supported by Linux but not by LLVM.
This commit adds feature detection for the following features:
- FEAT_SME
- FEAT_SME_F16F16
- FEAT_SME_F64F64
- FEAT_SME_F8F16
- FEAT_SME_F8F32
- FEAT_SME_FA64
- FEAT_SME_I16I64
- FEAT_SME_LUTv2
- FEAT_SME2
- FEAT_SME2p1
- FEAT_SSVE_FP8DOT2
- FEAT_SSVE_FP8DOT4
- FEAT_SSVE_FP8FMA
Linux features: https://github.com/torvalds/linux/blob/master/arch/arm64/include/uapi/asm/hwcap.h
LLVM features: llvm-project/llvm/lib/Target/AArch64/AArch64.td
Add detection for various aarch64 CPU features already supported by LLVM and Linux.
This commit adds feature detection for the following features:
- FEAT_CSSC
- FEAT_ECV
- FEAT_FAMINMAX
- FEAT_FLAGM2
- FEAT_FP8
- FEAT_FP8DOT2
- FEAT_FP8DOT4
- FEAT_FP8FMA
- FEAT_HBC
- FEAT_LSE128
- FEAT_LUT
- FEAT_MOPS
- FEAT_LRCPC3
- FEAT_SVE_B16B16
- FEAT_SVE2p1
- FEAT_WFxT
It also adds feature detection for FEAT_FPMR. It is somewhat of a
special case because FPMR only exists as a feature in LLVM 18, it has
been removed from the LLVM upstream. On that account the intention is
for it to be detectable at runtime through stdarch but not have a
corresponding compile-time Rust target feature.
Linux features: https://github.com/torvalds/linux/blob/master/arch/arm64/include/uapi/asm/hwcap.h
LLVM features: llvm-project/llvm/lib/Target/AArch64/AArch64.td
It looks like LLVM requires that `simd128` is active to use these
intrinsics and `relaxed-simd` isn't implicitly enabling them. This is
probably something to fix at the LLVM layer as well but for now enable
both the `simd128` feature as well as the `relaxed-simd` feature to fix
things on our side.
`_mm512_kunpackb` was implemented wrong, and `simd_reduce_max` uses `maxnum` for comparison, which adheres to IEEE754, but Intel specifically says that they do NOT adhere to IEEE754 for NaNs, which can give wrong results
fixed reduce-add and reduce-mul. and load/store of mask32 and mask64. added preserves-flags to mov asm. fixed the missing list. fixed `_mm_loadu_si64`. Added `assert_instr`
