Dedicated ranges::minmax vectorization that does not unnecessarily track element pointer

benchmarks/src/minmax_element.cpp

@@ -13,6 +13,9 @@ enum class Op {
     Min,
     Max,
     Both,
+    Min_val,
+    Max_val,
+    Both_val,
 };
 
 using namespace std;
@@ -38,49 +41,85 @@ void bm(benchmark::State& state) {
             benchmark::DoNotOptimize(ranges::max_element(a));
         } else if constexpr (Operation == Op::Both) {
             benchmark::DoNotOptimize(ranges::minmax_element(a));
+        } else if constexpr (Operation == Op::Min_val) {
+            benchmark::DoNotOptimize(ranges::min(a));
+        } else if constexpr (Operation == Op::Max_val) {
+            benchmark::DoNotOptimize(ranges::max(a));
+        } else if constexpr (Operation == Op::Both_val) {
+            benchmark::DoNotOptimize(ranges::minmax(a));
         }
     }
 }
 
 BENCHMARK(bm<uint8_t, 8021, Op::Min>);
 BENCHMARK(bm<uint8_t, 8021, Op::Max>);
 BENCHMARK(bm<uint8_t, 8021, Op::Both>);
+BENCHMARK(bm<uint8_t, 8021, Op::Min_val>);
+BENCHMARK(bm<uint8_t, 8021, Op::Max_val>);
+BENCHMARK(bm<uint8_t, 8021, Op::Both_val>);
 
 BENCHMARK(bm<uint16_t, 8021, Op::Min>);
 BENCHMARK(bm<uint16_t, 8021, Op::Max>);
 BENCHMARK(bm<uint16_t, 8021, Op::Both>);
+BENCHMARK(bm<uint16_t, 8021, Op::Min_val>);
+BENCHMARK(bm<uint16_t, 8021, Op::Max_val>);
+BENCHMARK(bm<uint16_t, 8021, Op::Both_val>);
 
 BENCHMARK(bm<uint32_t, 8021, Op::Min>);
 BENCHMARK(bm<uint32_t, 8021, Op::Max>);
 BENCHMARK(bm<uint32_t, 8021, Op::Both>);
+BENCHMARK(bm<uint32_t, 8021, Op::Min_val>);
+BENCHMARK(bm<uint32_t, 8021, Op::Max_val>);
+BENCHMARK(bm<uint32_t, 8021, Op::Both_val>);
 
 BENCHMARK(bm<uint64_t, 8021, Op::Min>);
 BENCHMARK(bm<uint64_t, 8021, Op::Max>);
 BENCHMARK(bm<uint64_t, 8021, Op::Both>);
+BENCHMARK(bm<uint64_t, 8021, Op::Min_val>);
+BENCHMARK(bm<uint64_t, 8021, Op::Max_val>);
+BENCHMARK(bm<uint64_t, 8021, Op::Both_val>);
 
 BENCHMARK(bm<int8_t, 8021, Op::Min>);
 BENCHMARK(bm<int8_t, 8021, Op::Max>);
 BENCHMARK(bm<int8_t, 8021, Op::Both>);
+BENCHMARK(bm<int8_t, 8021, Op::Min_val>);
+BENCHMARK(bm<int8_t, 8021, Op::Max_val>);
+BENCHMARK(bm<int8_t, 8021, Op::Both_val>);
 
 BENCHMARK(bm<int16_t, 8021, Op::Min>);
 BENCHMARK(bm<int16_t, 8021, Op::Max>);
 BENCHMARK(bm<int16_t, 8021, Op::Both>);
+BENCHMARK(bm<int16_t, 8021, Op::Min_val>);
+BENCHMARK(bm<int16_t, 8021, Op::Max_val>);
+BENCHMARK(bm<int16_t, 8021, Op::Both_val>);
 
 BENCHMARK(bm<int32_t, 8021, Op::Min>);
 BENCHMARK(bm<int32_t, 8021, Op::Max>);
 BENCHMARK(bm<int32_t, 8021, Op::Both>);
+BENCHMARK(bm<int32_t, 8021, Op::Min_val>);
+BENCHMARK(bm<int32_t, 8021, Op::Max_val>);
+BENCHMARK(bm<int32_t, 8021, Op::Both_val>);
 
 BENCHMARK(bm<int64_t, 8021, Op::Min>);
 BENCHMARK(bm<int64_t, 8021, Op::Max>);
 BENCHMARK(bm<int64_t, 8021, Op::Both>);
+BENCHMARK(bm<int64_t, 8021, Op::Min_val>);
+BENCHMARK(bm<int64_t, 8021, Op::Max_val>);
+BENCHMARK(bm<int64_t, 8021, Op::Both_val>);
 
 BENCHMARK(bm<float, 8021, Op::Min>);
 BENCHMARK(bm<float, 8021, Op::Max>);
 BENCHMARK(bm<float, 8021, Op::Both>);
+BENCHMARK(bm<float, 8021, Op::Min_val>);
+BENCHMARK(bm<float, 8021, Op::Max_val>);
+BENCHMARK(bm<float, 8021, Op::Both_val>);
 
 BENCHMARK(bm<double, 8021, Op::Min>);
 BENCHMARK(bm<double, 8021, Op::Max>);
 BENCHMARK(bm<double, 8021, Op::Both>);
+BENCHMARK(bm<double, 8021, Op::Min_val>);
+BENCHMARK(bm<double, 8021, Op::Max_val>);
+BENCHMARK(bm<double, 8021, Op::Both_val>);
 
 
 BENCHMARK_MAIN();

stl/CMakeLists.txt

@@ -15,6 +15,7 @@ set(HEADERS
     ${CMAKE_CURRENT_LIST_DIR}/inc/__msvc_formatter.hpp
     ${CMAKE_CURRENT_LIST_DIR}/inc/__msvc_int128.hpp
     ${CMAKE_CURRENT_LIST_DIR}/inc/__msvc_iter_core.hpp
+    ${CMAKE_CURRENT_LIST_DIR}/inc/__msvc_minmax.hpp
     ${CMAKE_CURRENT_LIST_DIR}/inc/__msvc_print.hpp
     ${CMAKE_CURRENT_LIST_DIR}/inc/__msvc_sanitizer_annotate_container.hpp
     ${CMAKE_CURRENT_LIST_DIR}/inc/__msvc_system_error_abi.hpp

stl/inc/__msvc_minmax.hpp

@@ -0,0 +1,86 @@
+// __msvc_minmax.hpp internal header (core)
+
+// Copyright (c) Microsoft Corporation.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#ifndef __MSVC_MINMAX_HPP
+#define __MSVC_MINMAX_HPP
+#include <yvals_core.h>
+#if _STL_COMPILER_PREPROCESSOR
+#include <cstdint>
+
+#pragma pack(push, _CRT_PACKING)
+#pragma warning(push, _STL_WARNING_LEVEL)
+#pragma warning(disable : _STL_DISABLED_WARNINGS)
+_STL_DISABLE_CLANG_WARNINGS
+#pragma push_macro("new")
+#undef new
+
+extern "C" {
+struct _Min_max_element_t {
+    const void* _Min;
+    const void* _Max;
+};
+
+struct _Min_max_1i {
+    int8_t _Min;
+    int8_t _Max;
+};
+
+struct _Min_max_1u {
+    uint8_t _Min;
+    uint8_t _Max;
+};
+
+struct _Min_max_2i {
+    int16_t _Min;
+    int16_t _Max;
+};
+
+struct _Min_max_2u {
+    uint16_t _Min;
+    uint16_t _Max;
+};
+
+struct _Min_max_4i {
+    int32_t _Min;
+    int32_t _Max;
+};
+
+struct _Min_max_4u {
+    uint32_t _Min;
+    uint32_t _Max;
+};
+
+struct _Min_max_8i {
+    int64_t _Min;
+    int64_t _Max;
+};
+
+struct _Min_max_8u {
+    uint64_t _Min;
+    uint64_t _Max;
+};
+
+struct _Min_max_f {
+    float _Min;
+    float _Max;
+};
+
+struct _Min_max_d {
+    double _Min;
+    double _Max;
+};
+
+struct _Min_max_p {
+    void* _Min;
+    void* _Max;
+};
+} // extern "C"
+
+#pragma pop_macro("new")
+_STL_RESTORE_CLANG_WARNINGS
+#pragma warning(pop)
+#pragma pack(pop)
+#endif // _STL_COMPILER_PREPROCESSOR
+#endif // __MSVC_MINMAX_HPP

stl/inc/algorithm

@@ -7,6 +7,7 @@
 #define _ALGORITHM_
 #include <yvals_core.h>
 #if _STL_COMPILER_PREPROCESSOR
+#include <__msvc_minmax.hpp>
 #include <xmemory>
 
 #if _HAS_CXX23
@@ -29,11 +30,6 @@ _STL_DISABLE_CLANG_WARNINGS
 #if _USE_STD_VECTOR_ALGORITHMS
 
 extern "C" {
-struct _Min_max_element_t {
-    const void* _Min;
-    const void* _Max;
-};
-
 // The "noalias" attribute tells the compiler optimizer that pointers going into these hand-vectorized algorithms
 // won't be stored beyond the lifetime of the function, and that the function will only reference arrays denoted by
 // those pointers. The optimizer also assumes in that case that a pointer parameter is not returned to the caller via
@@ -61,6 +57,17 @@ const void* __stdcall __std_find_last_trivial_1(const void* _First, const void*
 const void* __stdcall __std_find_last_trivial_2(const void* _First, const void* _Last, uint16_t _Val) noexcept;
 const void* __stdcall __std_find_last_trivial_4(const void* _First, const void* _Last, uint32_t _Val) noexcept;
 const void* __stdcall __std_find_last_trivial_8(const void* _First, const void* _Last, uint64_t _Val) noexcept;
+
+__declspec(noalias) _Min_max_1i __stdcall __std_minmax_1i(const void* _First, const void* _Last) noexcept;
+__declspec(noalias) _Min_max_1u __stdcall __std_minmax_1u(const void* _First, const void* _Last) noexcept;
+__declspec(noalias) _Min_max_2i __stdcall __std_minmax_2i(const void* _First, const void* _Last) noexcept;
+__declspec(noalias) _Min_max_2u __stdcall __std_minmax_2u(const void* _First, const void* _Last) noexcept;
+__declspec(noalias) _Min_max_4i __stdcall __std_minmax_4i(const void* _First, const void* _Last) noexcept;
+__declspec(noalias) _Min_max_4u __stdcall __std_minmax_4u(const void* _First, const void* _Last) noexcept;
+__declspec(noalias) _Min_max_8i __stdcall __std_minmax_8i(const void* _First, const void* _Last) noexcept;
+__declspec(noalias) _Min_max_8u __stdcall __std_minmax_8u(const void* _First, const void* _Last) noexcept;
+__declspec(noalias) _Min_max_f __stdcall __std_minmax_f(const void* _First, const void* _Last) noexcept;
+__declspec(noalias) _Min_max_d __stdcall __std_minmax_d(const void* _First, const void* _Last) noexcept;
 } // extern "C"
 
 _STD_BEGIN
@@ -89,6 +96,50 @@ _STD pair<_Ty*, _Ty*> __std_minmax_element(_Ty* _First, _Ty* _Last) noexcept {
     return {const_cast<_Ty*>(static_cast<const _Ty*>(_Res._Min)), const_cast<_Ty*>(static_cast<const _Ty*>(_Res._Max))};
 }
 
+template <class _Ty>
+auto __std_minmax(_Ty* _First, _Ty* _Last) noexcept {
+    constexpr bool _Signed = _STD is_signed_v<_Ty>;
+
+    if constexpr (_STD is_pointer_v<_Ty>) {
+#ifdef _WIN64
+        const auto _Result = ::__std_minmax_8u(_First, _Last);
+#else
+        const auto _Result = ::__std_minmax_4u(_First, _Last);
+#endif
+        return _Min_max_p{reinterpret_cast<void*>(_Result._Min), reinterpret_cast<void*>(_Result._Max)};
+    } else if constexpr (_STD is_same_v<_STD remove_const_t<_Ty>, float>) {
+        return ::__std_minmax_f(_First, _Last);
+    } else if constexpr (_STD _Is_any_of_v<_STD remove_const_t<_Ty>, double, long double>) {
+        return ::__std_minmax_d(_First, _Last);
+    } else if constexpr (sizeof(_Ty) == 1) {
+        if constexpr (_Signed) {
+            return ::__std_minmax_1i(_First, _Last);
+        } else {
+            return ::__std_minmax_1u(_First, _Last);
+        }
+    } else if constexpr (sizeof(_Ty) == 2) {
+        if constexpr (_Signed) {
+            return ::__std_minmax_2i(_First, _Last);
+        } else {
+            return ::__std_minmax_2u(_First, _Last);
+        }
+    } else if constexpr (sizeof(_Ty) == 4) {
+        if constexpr (_Signed) {
+            return ::__std_minmax_4i(_First, _Last);
+        } else {
+            return ::__std_minmax_4u(_First, _Last);
+        }
+    } else if constexpr (sizeof(_Ty) == 8) {
+        if constexpr (_Signed) {
+            return ::__std_minmax_8i(_First, _Last);
+        } else {
+            return ::__std_minmax_8u(_First, _Last);
+        }
+    } else {
+        static_assert(_STD _Always_false<_Ty>, "Unexpected size");
+    }
+}
+
 template <class _Ty, class _TVal>
 _Ty* __std_find_last_trivial(_Ty* _First, _Ty* _Last, const _TVal _Val) noexcept {
     if constexpr (_STD is_pointer_v<_TVal> || _STD is_null_pointer_v<_TVal>) {
@@ -10070,6 +10121,16 @@ _NODISCARD constexpr pair<const _Ty&, const _Ty&> minmax(const _Ty& _Left _MSVC_
 _EXPORT_STD template <class _Ty, class _Pr>
 _NODISCARD constexpr pair<_Ty, _Ty> minmax(initializer_list<_Ty> _Ilist, _Pr _Pred) {
     // return {leftmost/smallest, rightmost/largest}
+    _STL_ASSERT(
+        _Ilist.size() != 0, "An initializer_list passed to std::minmax must not be empty. (N4971 [alg.min.max]/21)");
+#if _USE_STD_VECTOR_ALGORITHMS
+    if constexpr (_Is_min_max_optimization_safe<const _Ty*, _Pr>) {
+        if (!_STD _Is_constant_evaluated()) {
+            const auto _Result = _STD __std_minmax(_Ilist.begin(), _Ilist.end());
+            return {static_cast<_Ty>(_Result._Min), static_cast<_Ty>(_Result._Max)};
+        }
+    }
+#endif // _USE_STD_VECTOR_ALGORITHMS
     pair<const _Ty*, const _Ty*> _Res =
         _STD _Minmax_element_unchecked(_Ilist.begin(), _Ilist.end(), _STD _Pass_fn(_Pred));
     return pair<_Ty, _Ty>(*_Res.first, *_Res.second);
@@ -10119,7 +10180,7 @@ namespace ranges {
             const auto _First = _Range.begin();
             const auto _Last  = _Range.end();
             _STL_ASSERT(_First != _Last,
-                "An initializer_list passed to std::ranges::minmax must not be empty. (N4950 [alg.min.max]/21)");
+                "An initializer_list passed to std::ranges::minmax must not be empty. (N4971 [alg.min.max]/21)");
             return _Minmax_fwd_unchecked(_First, _Last, _STD _Pass_fn(_Pred), _STD _Pass_fn(_Proj));
         }
 
@@ -10131,7 +10192,7 @@ namespace ranges {
             auto _UFirst = _RANGES _Ubegin(_Range);
             auto _ULast  = _RANGES _Uend(_Range);
             _STL_ASSERT(
-                _UFirst != _ULast, "A range passed to std::ranges::minmax must not be empty. (N4950 [alg.min.max]/21)");
+                _UFirst != _ULast, "A range passed to std::ranges::minmax must not be empty. (N4971 [alg.min.max]/21)");
             if constexpr (forward_range<_Rng> && _Prefer_iterator_copies<iterator_t<_Rng>>) {
                 return _Minmax_fwd_unchecked(
                     _STD move(_UFirst), _STD move(_ULast), _STD _Pass_fn(_Pred), _STD _Pass_fn(_Proj));
@@ -10197,8 +10258,8 @@ namespace ranges {
                 if (!_STD is_constant_evaluated()) {
                     const auto _First_ptr = _STD to_address(_First);
                     const auto _Last_ptr  = _First_ptr + (_Last - _First);
-                    const auto _Result    = _STD __std_minmax_element(_First_ptr, _Last_ptr);
-                    return {static_cast<_Vty>(*_Result.first), static_cast<_Vty>(*_Result.second)};
+                    const auto _Result    = _STD __std_minmax(_First_ptr, _Last_ptr);
+                    return {static_cast<_Vty>(_Result._Min), static_cast<_Vty>(_Result._Max)};
                 }
             }
 #endif // _USE_STD_VECTOR_ALGORITHMS

stl/inc/header-units.json

@@ -13,6 +13,7 @@
         "__msvc_formatter.hpp",
         "__msvc_int128.hpp",
         "__msvc_iter_core.hpp",
+        "__msvc_minmax.hpp",
         "__msvc_print.hpp",
         "__msvc_sanitizer_annotate_container.hpp",
         "__msvc_system_error_abi.hpp",