[PATCH 14/16] Implement hmin and hmax
Matthias Kretz
m.kretz@gsi.de
Wed Jan 27 20:42:50 GMT 2021
From: Matthias Kretz <kretz@kde.org>
From 9.7.4 in Parallelism TS 2. For some reason I overlooked these two
functions. Implement them via call to _S_reduce.
libstdc++-v3/ChangeLog:
* include/experimental/bits/simd.h: Add __detail::_Minimum and
__detail::_Maximum to use them as _BinaryOperation to _S_reduce.
Add hmin and hmax overloads for simd and const_where_expression.
* include/experimental/bits/simd_scalar.h
(_SimdImplScalar::_S_reduce): Make unused _BinaryOperation
parameter const-ref to allow calling _S_reduce with an rvalue.
* testsuite/experimental/simd/tests/reductions.cc: Add tests for
hmin and hmax. Since the compiler statically determined that all
tests pass, repeat the test after a call to make_value_unknown.
---
libstdc++-v3/include/experimental/bits/simd.h | 78 ++++++++++++++++++-
.../include/experimental/bits/simd_scalar.h | 2 +-
.../experimental/simd/tests/reductions.cc | 21 +++++
3 files changed, 99 insertions(+), 2 deletions(-)
diff --git a/libstdc++-v3/include/experimental/bits/simd.h b/libstdc++-v3/
include/experimental/bits/simd.h
index 14179491f9d..f08ef4c027d 100644
--- a/libstdc++-v3/include/experimental/bits/simd.h
+++ b/libstdc++-v3/include/experimental/bits/simd.h
@@ -204,6 +204,27 @@ template <size_t _Np>
template <size_t _X>
using _SizeConstant = integral_constant<size_t, _X>;
+namespace __detail {
+ struct _Minimum {
+ template <typename _Tp>
+ _GLIBCXX_SIMD_INTRINSIC constexpr
+ _Tp
+ operator()(_Tp __a, _Tp __b) const {
+ using std::min;
+ return min(__a, __b);
+ }
+ };
+ struct _Maximum {
+ template <typename _Tp>
+ _GLIBCXX_SIMD_INTRINSIC constexpr
+ _Tp
+ operator()(_Tp __a, _Tp __b) const {
+ using std::max;
+ return max(__a, __b);
+ }
+ };
+} // namespace __detail
+
// unrolled/pack execution helpers
// __execute_n_times{{{
template <typename _Fp, size_t... _I>
@@ -3408,7 +3429,7 @@ template <typename _Tp, typename _Ap>
// }}}1
// reductions [simd.reductions] {{{1
- template <typename _Tp, typename _Abi, typename _BinaryOperation = plus<>>
+template <typename _Tp, typename _Abi, typename _BinaryOperation = plus<>>
_GLIBCXX_SIMD_INTRINSIC _GLIBCXX_SIMD_CONSTEXPR _Tp
reduce(const simd<_Tp, _Abi>& __v,
_BinaryOperation __binary_op = _BinaryOperation())
@@ -3454,6 +3475,61 @@ template <typename _M, typename _V>
reduce(const const_where_expression<_M, _V>& __x, bit_xor<> __binary_op)
{ return reduce(__x, 0, __binary_op); }
+template <typename _Tp, typename _Abi>
+ _GLIBCXX_SIMD_INTRINSIC _GLIBCXX_SIMD_CONSTEXPR _Tp
+ hmin(const simd<_Tp, _Abi>& __v) noexcept
+ {
+ return _Abi::_SimdImpl::_S_reduce(__v, __detail::_Minimum());
+ }
+
+template <typename _Tp, typename _Abi>
+ _GLIBCXX_SIMD_INTRINSIC _GLIBCXX_SIMD_CONSTEXPR _Tp
+ hmax(const simd<_Tp, _Abi>& __v) noexcept
+ {
+ return _Abi::_SimdImpl::_S_reduce(__v, __detail::_Maximum());
+ }
+
+template <typename _M, typename _V>
+ _GLIBCXX_SIMD_INTRINSIC _GLIBCXX_SIMD_CONSTEXPR
+ typename _V::value_type
+ hmin(const const_where_expression<_M, _V>& __x) noexcept
+ {
+ using _Tp = typename _V::value_type;
+ constexpr _Tp __id_elem =
+#ifdef __FINITE_MATH_ONLY__
+ __finite_max_v<_Tp>;
+#else
+ __value_or<__infinity, _Tp>(__finite_max_v<_Tp>);
+#endif
+ _V __tmp = __id_elem;
+ _V::_Impl::_S_masked_assign(__data(__get_mask(__x)), __data(__tmp),
+ __data(__get_lvalue(__x)));
+ return _V::abi_type::_SimdImpl::_S_reduce(__tmp, __detail::_Minimum());
+ }
+
+template <typename _M, typename _V>
+ _GLIBCXX_SIMD_INTRINSIC _GLIBCXX_SIMD_CONSTEXPR
+ typename _V::value_type
+ hmax(const const_where_expression<_M, _V>& __x) noexcept
+ {
+ using _Tp = typename _V::value_type;
+ constexpr _Tp __id_elem =
+#ifdef __FINITE_MATH_ONLY__
+ __finite_min_v<_Tp>;
+#else
+ [] {
+ if constexpr (__value_exists_v<__infinity, _Tp>)
+ return -__infinity_v<_Tp>;
+ else
+ return __finite_min_v<_Tp>;
+ }();
+#endif
+ _V __tmp = __id_elem;
+ _V::_Impl::_S_masked_assign(__data(__get_mask(__x)), __data(__tmp),
+ __data(__get_lvalue(__x)));
+ return _V::abi_type::_SimdImpl::_S_reduce(__tmp, __detail::_Maximum());
+ }
+
// }}}1
// algorithms [simd.alg] {{{
template <typename _Tp, typename _Ap>
diff --git a/libstdc++-v3/include/experimental/bits/simd_scalar.h b/libstdc++-
v3/include/experimental/bits/simd_scalar.h
index 7680bc39c30..7e480ecdb37 100644
--- a/libstdc++-v3/include/experimental/bits/simd_scalar.h
+++ b/libstdc++-v3/include/experimental/bits/simd_scalar.h
@@ -182,7 +182,7 @@ struct _SimdImplScalar
// _S_reduce {{{2
template <typename _Tp, typename _BinaryOperation>
static constexpr inline _Tp
- _S_reduce(const simd<_Tp, simd_abi::scalar>& __x, _BinaryOperation&)
+ _S_reduce(const simd<_Tp, simd_abi::scalar>& __x, const
_BinaryOperation&)
{ return __x._M_data; }
// _S_min, _S_max {{{2
diff --git a/libstdc++-v3/testsuite/experimental/simd/tests/reductions.cc b/
libstdc++-v3/testsuite/experimental/simd/tests/reductions.cc
index 9d897d5ccd6..02df68fafbc 100644
--- a/libstdc++-v3/testsuite/experimental/simd/tests/reductions.cc
+++ b/libstdc++-v3/testsuite/experimental/simd/tests/reductions.cc
@@ -57,6 +57,8 @@ template <typename V>
}
{
+ COMPARE(hmin(V(1)), T(1));
+ COMPARE(hmax(V(1)), T(1));
const V z([](T i) { return i + 1; });
COMPARE(std::experimental::reduce(z,
[](auto a, auto b) {
@@ -79,6 +81,25 @@ template <typename V>
}),
T(V::size() == 1 ? 117 : 2))
<< "z: " << z;
+ COMPARE(hmin(z), T(1));
+ COMPARE(hmax(z), T(V::size()));
+ if (V::size() > 1)
+ {
+ COMPARE(hmin(where(z > 1, z)), T(2));
+ COMPARE(hmax(where(z > 1, z)), T(V::size()));
+ }
+ COMPARE(hmin(where(z < 4, z)), T(1));
+ COMPARE(hmax(where(z < 4, z)), std::min(T(V::size()), T(3)));
+ const V zz = make_value_unknown(z);
+ COMPARE(hmin(zz), T(1));
+ COMPARE(hmax(zz), T(V::size()));
+ if (V::size() > 1)
+ {
+ COMPARE(hmin(where(zz > 1, zz)), T(2));
+ COMPARE(hmax(where(zz > 1, zz)), T(V::size()));
+ }
+ COMPARE(hmin(where(zz < 4, zz)), T(1));
+ COMPARE(hmax(where(zz < 4, zz)), std::min(T(V::size()), T(3)));
}
test_values<V>({}, {1000}, [](V x) {
--
──────────────────────────────────────────────────────────────────────────
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
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