ping. OK to push? On Tuesday, 8 June 2021 14:12:23 CET Matthias Kretz wrote: > From: Matthias Kretz <kr...@kde.org> > > Explicitly support use of the stdx::simd implementation in situations > where the user links TUs that were compiled with different -m flags. In > general, this is always a (quasi) ODR violation for inline functions > because at least codegen may differ in important ways. However, in the > resulting executable only one (unspecified which one) of them might be > used. For simd we want to support users to compile code multiple times, > with different -m flags and have a runtime dispatch to the TU matching > the target CPU. But if internal functions are not inlined this may lead > to unexpected performance loss or execution of illegal instructions. > Therefore, inline functions that are not marked as always_inline must > use an additional template parameter somewhere in their name, to > disambiguate between the different -m translations. > > Signed-off-by: Matthias Kretz <m.kr...@gsi.de> > > libstdc++-v3/ChangeLog: > > * include/experimental/bits/simd.h: Move feature detection bools > and add __have_avx512bitalg, __have_avx512vbmi2, > __have_avx512vbmi, __have_avx512ifma, __have_avx512cd, > __have_avx512vnni, __have_avx512vpopcntdq. > (__detail::__machine_flags): New function which returns a unique > uint64 depending on relevant -m and -f flags. > (__detail::__odr_helper): New type alias for either an anonymous > type or a type specialized with the __machine_flags number. > (_SimdIntOperators): Change template parameters from _Impl to > _Tp, _Abi because _Impl now has an __odr_helper parameter which > may be _OdrEnforcer from the anonymous namespace, which makes > for a bad base class. > (many): Either add __odr_helper template parameter or mark as > always_inline. > * include/experimental/bits/simd_detail.h: Add defines for > AVX512BITALG, AVX512VBMI2, AVX512VBMI, AVX512IFMA, AVX512CD, > AVX512VNNI, AVX512VPOPCNTDQ, and AVX512VP2INTERSECT. > * include/experimental/bits/simd_builtin.h: Add __odr_helper > template parameter or mark as always_inline. > * include/experimental/bits/simd_fixed_size.h: Ditto. > * include/experimental/bits/simd_math.h: Ditto. > * include/experimental/bits/simd_scalar.h: Ditto. > * include/experimental/bits/simd_neon.h: Add __odr_helper > template parameter. > * include/experimental/bits/simd_ppc.h: Ditto. > * include/experimental/bits/simd_x86.h: Ditto. > --- > libstdc++-v3/include/experimental/bits/simd.h | 380 ++++++++++++------ > .../include/experimental/bits/simd_builtin.h | 41 +- > .../include/experimental/bits/simd_detail.h | 40 ++ > .../experimental/bits/simd_fixed_size.h | 39 +- > .../include/experimental/bits/simd_math.h | 45 ++- > .../include/experimental/bits/simd_neon.h | 4 +- > .../include/experimental/bits/simd_ppc.h | 4 +- > .../include/experimental/bits/simd_scalar.h | 71 +++- > .../include/experimental/bits/simd_x86.h | 4 +- > 9 files changed, 440 insertions(+), 188 deletions(-)
-- ────────────────────────────────────────────────────────────────────────── Dr. Matthias Kretz https://mattkretz.github.io GSI Helmholtz Centre for Heavy Ion Research https://gsi.de stdₓ::simd ──────────────────────────────────────────────────────────────────────────
