libstc++: Implement hmin and hmax

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.

diff --git a/libstdc++-v3/include/experimental/bits/simd.h b/libstdc++-v3/include/experimental/bits/simd.h
index becd1d6a4bb7104938d62f3274c29ea9e768a154..c452778832fa936aa9e7fe239f4306482dbfa02d 100644 (file)
--- a/libstdc++-v3/include/experimental/bits/simd.h
+++ b/libstdc++-v3/include/experimental/bits/simd.h
@@ -204,6 +204,33 @@ 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 +3435,7 @@ 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 +3481,61 @@ 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 d5a90ef22929c889b90803d96cc3bef5d75d69d5..48e13f6c7195b33834dfb58299ea608b90d86a3b 100644 (file)
--- 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 51aad92c8621de829e789e2bc229fdcbb7becd03..1f20961825b76d3b3b4faf5793070ba07b5bf4ee 100644 (file)
--- 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) {