Re: [PATCH] libstdc++: Fix conversion of simd to vector builtin

[Jonathan Wakely <jwakely@redhat.com>]

On Mon, 22 Apr 2024 at 16:30, Matthias Kretz <m.kretz@gsi.de> wrote:
>
> Tested on x86_64-linux-gnu, powerpc64le-linux-gnu, aarch64-linux-gnu, arm-
> linux-gnueabihf
>
> OK for trunk and backports?

OK


>
> ----------------------------- 8< ---------------------------------
>
> Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
>
> libstdc++-v3/ChangeLog:
>
>         PR libstdc++/114803
>         * include/experimental/bits/simd_builtin.h
>         (_SimdBase2::operator __vector_type_t): There is no __builtin()
>         function in _SimdWrapper, instead use its conversion operator.
>         * testsuite/experimental/simd/pr114803_vecbuiltin_cvt.cc: New
>         test.
> ---
>  .../include/experimental/bits/simd_builtin.h  |   2 +-
>  .../simd/pr114803_vecbuiltin_cvt.cc           | 105 ++++++++++++++++++
>  2 files changed, 106 insertions(+), 1 deletion(-)
>  create mode 100644 libstdc++-v3/testsuite/experimental/simd/
> pr114803_vecbuiltin_cvt.cc
>
> diff --git a/libstdc++-v3/include/experimental/bits/simd_builtin.h b/libstdc+
> +-v3/include/experimental/bits/simd_builtin.h
> index 49c7c7e1c70..4ceeb423894 100644
> --- a/libstdc++-v3/include/experimental/bits/simd_builtin.h
> +++ b/libstdc++-v3/include/experimental/bits/simd_builtin.h
> @@ -841,7 +841,7 @@ struct _SimdBase2
>
>        _GLIBCXX_SIMD_ALWAYS_INLINE explicit
>        operator __vector_type_t<_Tp, _Np>() const
> -      { return static_cast<const simd<_Tp, _Abi>*>(this)-
> >_M_data.__builtin(); }
> +      { return __data(*static_cast<const simd<_Tp, _Abi>*>(this)); }
>      };
>
>      struct _SimdBase1
> diff --git a/libstdc++-v3/testsuite/experimental/simd/
> pr114803_vecbuiltin_cvt.cc b/libstdc++-v3/testsuite/experimental/simd/
> pr114803_vecbuiltin_cvt.cc
> new file mode 100644
> index 00000000000..103dd19394c
> --- /dev/null
> +++ b/libstdc++-v3/testsuite/experimental/simd/pr114803_vecbuiltin_cvt.cc
> @@ -0,0 +1,105 @@
> +// { dg-options "-std=gnu++17" }
> +// { dg-do compile { target c++17 } }
> +
> +#include <experimental/simd>
> +
> +template <typename T>
> +  void
> +  maybe_test()
> +  {
> +    using V = std::experimental::simd<T,
> std::experimental::simd_abi::_VecBuiltin<16>>;
> +    if constexpr (std::is_destructible_v<V>)
> +      {
> +       using V2 [[gnu::vector_size(16)]] = T;
> +       V x = {};
> +       V2 x2 = static_cast<V2>(x);
> +       x = static_cast<V>(x2);
> +       for (unsigned i = 0; i < V::size(); ++i)
> +         {
> +           if (x2[i] != 0)
> +             __builtin_abort();
> +         }
> +#ifdef __SSE__
> +       if constexpr (std::is_same_v<T, float>)
> +         x = static_cast<V>(static_cast<__m128>(x));
> +       else if constexpr (std::is_same_v<T, double>)
> +         x = static_cast<V>(static_cast<__m128d>(x));
> +       else if constexpr (std::is_integral_v<T>)
> +         x = static_cast<V>(static_cast<__m128i>(x));
> +#elif __ALTIVEC__
> +       if constexpr (std::is_same_v<T, float>)
> +         x = static_cast<V>(static_cast<__vector float>(x));
> +#ifdef __VSX__
> +       else if constexpr (std::is_same_v<T, double>)
> +         x = static_cast<V>(static_cast<__vector double>(x));
> +#endif
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) ==
> sizeof(signed char)
> +                            && std::is_signed_v<T>)
> +         x = static_cast<V>(static_cast<__vector signed char>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) ==
> sizeof(signed char))
> +         x = static_cast<V>(static_cast<__vector unsigned char>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) ==
> sizeof(short)
> +                            && std::is_signed_v<T>)
> +         x = static_cast<V>(static_cast<__vector signed short>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) ==
> sizeof(short))
> +         x = static_cast<V>(static_cast<__vector unsigned short>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) == sizeof(int)
> +                            && std::is_signed_v<T>)
> +         x = static_cast<V>(static_cast<__vector signed int>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) == sizeof(int))
> +         x = static_cast<V>(static_cast<__vector unsigned int>(x));
> +#ifdef __VSX__
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) == sizeof(long
> long)
> +                            && std::is_signed_v<T>)
> +         x = static_cast<V>(static_cast<__vector signed long long>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) == sizeof(long
> long))
> +         x = static_cast<V>(static_cast<__vector unsigned long long>(x));
> +#endif
> +#elif __ARM_NEON
> +       if constexpr (std::is_same_v<T, float>)
> +         x = static_cast<V>(static_cast<float32x4_t>(x));
> +#ifdef __aarch64__
> +       else if constexpr (std::is_same_v<T, double>)
> +         x = static_cast<V>(static_cast<float64x2_t>(x));
> +#endif
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) == 1 &&
> std::is_signed_v<T>)
> +         x = static_cast<V>(static_cast<int8x16_t>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) == 1)
> +         x = static_cast<V>(static_cast<uint8x16_t>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) == 2 &&
> std::is_signed_v<T>)
> +         x = static_cast<V>(static_cast<int16x8_t>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) == 2)
> +         x = static_cast<V>(static_cast<uint16x8_t>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) == 4 &&
> std::is_signed_v<T>)
> +         x = static_cast<V>(static_cast<int32x4_t>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) == 4)
> +         x = static_cast<V>(static_cast<uint32x4_t>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) == 8 &&
> std::is_signed_v<T>)
> +         x = static_cast<V>(static_cast<int64x2_t>(x));
> +       else if constexpr (std::is_integral_v<T> && sizeof(T) == 8)
> +         x = static_cast<V>(static_cast<uint64x2_t>(x));
> +#endif
> +      }
> +  }
> +
> +int main()
> +{
> +  maybe_test<char>();
> +  maybe_test<wchar_t>();
> +  maybe_test<char16_t>();
> +  maybe_test<char32_t>();
> +
> +  maybe_test<signed char>();
> +  maybe_test<unsigned char>();
> +  maybe_test<short>();
> +  maybe_test<unsigned short>();
> +  maybe_test<int>();
> +  maybe_test<unsigned int>();
> +  maybe_test<long>();
> +  maybe_test<unsigned long>();
> +  maybe_test<long long>();
> +  maybe_test<unsigned long long>();
> +  maybe_test<float>();
> +  maybe_test<double>();
> +  maybe_test<long double>();
> +}
> --
> ──────────────────────────────────────────────────────────────────────────
>  Dr. Matthias Kretz                           https://mattkretz.github.io
>  GSI Helmholtz Centre for Heavy Ion Research               https://gsi.de
>  stdₓ::simd
> ──────────────────────────────────────────────────────────────────────────
>