From: Matthias Kretz <kr...@kde.org> POWER7 does not support __vector long long reductions, making the generic _S_popcount implementation ill-formed. Specializing _S_popcount for PPC allows optimization and avoids the issue.
libstdc++-v3/ChangeLog: * include/experimental/bits/simd.h: Add __have_power10vec conditional on _ARCH_PWR10. * include/experimental/bits/simd_builtin.h: Forward declare _MaskImplPpc and use it as _MaskImpl when __ALTIVEC__ is defined. (_MaskImplBuiltin::_S_some_of): Call _S_popcount from the _SuperImpl for optimizations and correctness. * include/experimental/bits/simd_ppc.h: Add _MaskImplPpc. (_MaskImplPpc::_S_popcount): Implement via vec_cntm for POWER10. Otherwise, for >=int use -vec_sums divided by a sizeof factor. For <int use -vec_sums(vec_sum4s(...)) to sum all mask entries. --- libstdc++-v3/include/experimental/bits/simd.h | 5 +++ .../include/experimental/bits/simd_builtin.h | 6 ++-- .../include/experimental/bits/simd_ppc.h | 35 ++++++++++++++++++- 3 files changed, 43 insertions(+), 3 deletions(-) diff --git a/libstdc++-v3/include/experimental/bits/simd.h b/libstdc++-v3/ include/experimental/bits/simd.h index 9685df0be9e..14179491f9d 100644 --- a/libstdc++-v3/include/experimental/bits/simd.h +++ b/libstdc++-v3/include/experimental/bits/simd.h @@ -477,6 +477,11 @@ constexpr inline bool __support_neon_float = false; #endif +#ifdef _ARCH_PWR10 +constexpr inline bool __have_power10vec = true; +#else +constexpr inline bool __have_power10vec = false; +#endif #ifdef __POWER9_VECTOR__ constexpr inline bool __have_power9vec = true; #else diff --git a/libstdc++-v3/include/experimental/bits/simd_builtin.h b/libstdc+ +-v3/include/experimental/bits/simd_builtin.h index f2c99faa4ee..044edc93317 100644 --- a/libstdc++-v3/include/experimental/bits/simd_builtin.h +++ b/libstdc++-v3/include/experimental/bits/simd_builtin.h @@ -920,6 +920,7 @@ template <typename _Abi> struct _MaskImplX86; template <typename _Abi> struct _SimdImplNeon; template <typename _Abi> struct _MaskImplNeon; template <typename _Abi> struct _SimdImplPpc; +template <typename _Abi> struct _MaskImplPpc; // simd_abi::_VecBuiltin {{{ template <int _UsedBytes> @@ -959,10 +960,11 @@ template <int _UsedBytes> using _CommonImpl = _CommonImplBuiltin; #ifdef __ALTIVEC__ using _SimdImpl = _SimdImplPpc<_VecBuiltin<_UsedBytes>>; + using _MaskImpl = _MaskImplPpc<_VecBuiltin<_UsedBytes>>; #else using _SimdImpl = _SimdImplBuiltin<_VecBuiltin<_UsedBytes>>; -#endif using _MaskImpl = _MaskImplBuiltin<_VecBuiltin<_UsedBytes>>; +#endif #endif // }}} @@ -2899,7 +2901,7 @@ template <typename _Abi> _GLIBCXX_SIMD_INTRINSIC static bool _S_some_of(simd_mask<_Tp, _Abi> __k) { - const int __n_true = _S_popcount(__k); + const int __n_true = _SuperImpl::_S_popcount(__k); return __n_true > 0 && __n_true < int(_S_size<_Tp>); } diff --git a/libstdc++-v3/include/experimental/bits/simd_ppc.h b/libstdc++-v3/ include/experimental/bits/simd_ppc.h index c00d2323ac6..1d649931eb9 100644 --- a/libstdc++-v3/include/experimental/bits/simd_ppc.h +++ b/libstdc++-v3/include/experimental/bits/simd_ppc.h @@ -30,6 +30,7 @@ #ifndef __ALTIVEC__ #error "simd_ppc.h may only be included when AltiVec/VMX is available" #endif +#include <altivec.h> _GLIBCXX_SIMD_BEGIN_NAMESPACE @@ -114,10 +115,42 @@ template <typename _Abi> // }}} }; +// }}} +// _MaskImplPpc {{{ +template <typename _Abi> + struct _MaskImplPpc : _MaskImplBuiltin<_Abi> + { + using _Base = _MaskImplBuiltin<_Abi>; + + // _S_popcount {{{ + template <typename _Tp> + _GLIBCXX_SIMD_INTRINSIC static int _S_popcount(simd_mask<_Tp, _Abi> __k) + { + const auto __kv = __as_vector(__k); + if constexpr (__have_power10vec) + { + return vec_cntm(__to_intrin(__kv), 1); + } + else if constexpr (sizeof(_Tp) >= sizeof(int)) + { + using _Intrin = __intrinsic_type16_t<int>; + const int __sum = -vec_sums(__intrin_bitcast<_Intrin>(__kv), _Intrin())[3]; + return __sum / (sizeof(_Tp) / sizeof(int)); + } + else + { + const auto __summed_to_int = vec_sum4s(__to_intrin(__kv), __intrinsic_type16_t<int>()); + return -vec_sums(__summed_to_int, __intrinsic_type16_t<int>())[3]; + } + } + + // }}} + }; + // }}} _GLIBCXX_SIMD_END_NAMESPACE #endif // __cplusplus >= 201703L #endif // _GLIBCXX_EXPERIMENTAL_SIMD_PPC_H_ -// vim: foldmethod=marker sw=2 noet ts=8 sts=2 tw=80 +// vim: foldmethod=marker foldmarker={{{,}}} sw=2 noet ts=8 sts=2 tw=100 -- ────────────────────────────────────────────────────────────────────────── Dr. Matthias Kretz https://mattkretz.github.io GSI Helmholtz Centre for Heavy Ion Research https://gsi.de std::experimental::simd https://github.com/VcDevel/std-simd ──────────────────────────────────────────────────────────────────────────