highway.h
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// Copyright 2020 Google LLC
// SPDX-License-Identifier: Apache-2.0
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// This include guard is checked by foreach_target, so avoid the usual _H_
// suffix to prevent copybara from renaming it. NOTE: ops/*-inl.h are included
// after/outside this include guard.
#ifndef HWY_HIGHWAY_INCLUDED
#define HWY_HIGHWAY_INCLUDED
// Main header required before using vector types.
#include "hwy/base.h"
#include "hwy/targets.h"
namespace hwy {
// API version (https://semver.org/); keep in sync with CMakeLists.txt.
#define HWY_MAJOR 1
#define HWY_MINOR 0
#define HWY_PATCH 2
//------------------------------------------------------------------------------
// Shorthand for tags (defined in shared-inl.h) used to select overloads.
// Note that ScalableTag<T> is preferred over HWY_FULL, and CappedTag<T, N> over
// HWY_CAPPED(T, N).
// HWY_FULL(T[,LMUL=1]) is a native vector/group. LMUL is the number of
// registers in the group, and is ignored on targets that do not support groups.
#define HWY_FULL1(T) hwy::HWY_NAMESPACE::ScalableTag<T>
#define HWY_FULL2(T, LMUL) \
hwy::HWY_NAMESPACE::ScalableTag<T, hwy::CeilLog2(HWY_MAX(0, LMUL))>
#define HWY_3TH_ARG(arg1, arg2, arg3, ...) arg3
// Workaround for MSVC grouping __VA_ARGS__ into a single argument
#define HWY_FULL_RECOMPOSER(args_with_paren) HWY_3TH_ARG args_with_paren
// Trailing comma avoids -pedantic false alarm
#define HWY_CHOOSE_FULL(...) \
HWY_FULL_RECOMPOSER((__VA_ARGS__, HWY_FULL2, HWY_FULL1, ))
#define HWY_FULL(...) HWY_CHOOSE_FULL(__VA_ARGS__())(__VA_ARGS__)
// Vector of up to MAX_N lanes. It's better to use full vectors where possible.
#define HWY_CAPPED(T, MAX_N) hwy::HWY_NAMESPACE::CappedTag<T, MAX_N>
//------------------------------------------------------------------------------
// Export user functions for static/dynamic dispatch
// Evaluates to 0 inside a translation unit if it is generating anything but the
// static target (the last one if multiple targets are enabled). Used to prevent
// redefinitions of HWY_EXPORT. Unless foreach_target.h is included, we only
// compile once anyway, so this is 1 unless it is or has been included.
#ifndef HWY_ONCE
#define HWY_ONCE 1
#endif
// HWY_STATIC_DISPATCH(FUNC_NAME) is the namespace-qualified FUNC_NAME for
// HWY_STATIC_TARGET (the only defined namespace unless HWY_TARGET_INCLUDE is
// defined), and can be used to deduce the return type of Choose*.
#if HWY_STATIC_TARGET == HWY_SCALAR
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_SCALAR::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_EMU128
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_EMU128::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_RVV
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_RVV::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_WASM_EMU256
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_WASM_EMU256::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_WASM
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_WASM::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_NEON
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_NEON::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_SVE
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_SVE::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_SVE2
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_SVE2::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_SVE_256
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_SVE_256::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_SVE2_128
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_SVE2_128::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_PPC8
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_PPC8::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_SSSE3
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_SSSE3::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_SSE4
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_SSE4::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_AVX2
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_AVX2::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_AVX3
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_AVX3::FUNC_NAME
#elif HWY_STATIC_TARGET == HWY_AVX3_DL
#define HWY_STATIC_DISPATCH(FUNC_NAME) N_AVX3_DL::FUNC_NAME
#endif
// HWY_CHOOSE_*(FUNC_NAME) expands to the function pointer for that target or
// nullptr is that target was not compiled.
#if HWY_TARGETS & HWY_EMU128
#define HWY_CHOOSE_FALLBACK(FUNC_NAME) &N_EMU128::FUNC_NAME
#elif HWY_TARGETS & HWY_SCALAR
#define HWY_CHOOSE_FALLBACK(FUNC_NAME) &N_SCALAR::FUNC_NAME
#else
// When HWY_SCALAR/HWY_EMU128 are not present and other targets were disabled at
// runtime, fall back to the baseline with HWY_STATIC_DISPATCH().
#define HWY_CHOOSE_FALLBACK(FUNC_NAME) &HWY_STATIC_DISPATCH(FUNC_NAME)
#endif
#if HWY_TARGETS & HWY_WASM_EMU256
#define HWY_CHOOSE_WASM_EMU256(FUNC_NAME) &N_WASM_EMU256::FUNC_NAME
#else
#define HWY_CHOOSE_WASM_EMU256(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_WASM
#define HWY_CHOOSE_WASM(FUNC_NAME) &N_WASM::FUNC_NAME
#else
#define HWY_CHOOSE_WASM(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_RVV
#define HWY_CHOOSE_RVV(FUNC_NAME) &N_RVV::FUNC_NAME
#else
#define HWY_CHOOSE_RVV(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_NEON
#define HWY_CHOOSE_NEON(FUNC_NAME) &N_NEON::FUNC_NAME
#else
#define HWY_CHOOSE_NEON(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_SVE
#define HWY_CHOOSE_SVE(FUNC_NAME) &N_SVE::FUNC_NAME
#else
#define HWY_CHOOSE_SVE(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_SVE2
#define HWY_CHOOSE_SVE2(FUNC_NAME) &N_SVE2::FUNC_NAME
#else
#define HWY_CHOOSE_SVE2(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_SVE_256
#define HWY_CHOOSE_SVE_256(FUNC_NAME) &N_SVE_256::FUNC_NAME
#else
#define HWY_CHOOSE_SVE_256(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_SVE2_128
#define HWY_CHOOSE_SVE2_128(FUNC_NAME) &N_SVE2_128::FUNC_NAME
#else
#define HWY_CHOOSE_SVE2_128(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_PPC8
#define HWY_CHOOSE_PCC8(FUNC_NAME) &N_PPC8::FUNC_NAME
#else
#define HWY_CHOOSE_PPC8(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_SSSE3
#define HWY_CHOOSE_SSSE3(FUNC_NAME) &N_SSSE3::FUNC_NAME
#else
#define HWY_CHOOSE_SSSE3(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_SSE4
#define HWY_CHOOSE_SSE4(FUNC_NAME) &N_SSE4::FUNC_NAME
#else
#define HWY_CHOOSE_SSE4(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_AVX2
#define HWY_CHOOSE_AVX2(FUNC_NAME) &N_AVX2::FUNC_NAME
#else
#define HWY_CHOOSE_AVX2(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_AVX3
#define HWY_CHOOSE_AVX3(FUNC_NAME) &N_AVX3::FUNC_NAME
#else
#define HWY_CHOOSE_AVX3(FUNC_NAME) nullptr
#endif
#if HWY_TARGETS & HWY_AVX3_DL
#define HWY_CHOOSE_AVX3_DL(FUNC_NAME) &N_AVX3_DL::FUNC_NAME
#else
#define HWY_CHOOSE_AVX3_DL(FUNC_NAME) nullptr
#endif
// MSVC 2017 workaround: the non-type template parameter to ChooseAndCall
// apparently cannot be an array. Use a function pointer instead, which has the
// disadvantage that we call the static (not best) target on the first call to
// any HWY_DYNAMIC_DISPATCH.
#if HWY_COMPILER_MSVC && HWY_COMPILER_MSVC < 1915
#define HWY_DISPATCH_WORKAROUND 1
#else
#define HWY_DISPATCH_WORKAROUND 0
#endif
// Provides a static member function which is what is called during the first
// HWY_DYNAMIC_DISPATCH, where GetIndex is still zero, and instantiations of
// this function are the first entry in the tables created by HWY_EXPORT.
template <typename RetType, typename... Args>
struct FunctionCache {
public:
typedef RetType(FunctionType)(Args...);
#if HWY_DISPATCH_WORKAROUND
template <FunctionType* const func>
static RetType ChooseAndCall(Args... args) {
ChosenTarget& chosen_target = GetChosenTarget();
chosen_target.Update(SupportedTargets());
return (*func)(args...);
}
#else
// A template function that when instantiated has the same signature as the
// function being called. This function initializes the bit array of targets
// supported by the current CPU and then calls the appropriate entry within
// the HWY_EXPORT table. Subsequent calls via HWY_DYNAMIC_DISPATCH to any
// exported functions, even those defined by different translation units,
// will dispatch directly to the best available target.
template <FunctionType* const table[]>
static RetType ChooseAndCall(Args... args) {
ChosenTarget& chosen_target = GetChosenTarget();
chosen_target.Update(SupportedTargets());
return (table[chosen_target.GetIndex()])(args...);
}
#endif // HWY_DISPATCH_WORKAROUND
};
// Used to deduce the template parameters RetType and Args from a function.
template <typename RetType, typename... Args>
FunctionCache<RetType, Args...> DeduceFunctionCache(RetType (*)(Args...)) {
return FunctionCache<RetType, Args...>();
}
#define HWY_DISPATCH_TABLE(FUNC_NAME) \
HWY_CONCAT(FUNC_NAME, HighwayDispatchTable)
// HWY_EXPORT(FUNC_NAME); expands to a static array that is used by
// HWY_DYNAMIC_DISPATCH() to call the appropriate function at runtime. This
// static array must be defined at the same namespace level as the function
// it is exporting.
// After being exported, it can be called from other parts of the same source
// file using HWY_DYNAMIC_DISPATCH(), in particular from a function wrapper
// like in the following example:
//
// #include "hwy/highway.h"
// HWY_BEFORE_NAMESPACE();
// namespace skeleton {
// namespace HWY_NAMESPACE {
//
// void MyFunction(int a, char b, const char* c) { ... }
//
// // NOLINTNEXTLINE(google-readability-namespace-comments)
// } // namespace HWY_NAMESPACE
// } // namespace skeleton
// HWY_AFTER_NAMESPACE();
//
// namespace skeleton {
// HWY_EXPORT(MyFunction); // Defines the dispatch table in this scope.
//
// void MyFunction(int a, char b, const char* c) {
// return HWY_DYNAMIC_DISPATCH(MyFunction)(a, b, c);
// }
// } // namespace skeleton
//
#if HWY_IDE || ((HWY_TARGETS & (HWY_TARGETS - 1)) == 0)
// Simplified version for IDE or the dynamic dispatch case with only one target.
// This case still uses a table, although of a single element, to provide the
// same compile error conditions as with the dynamic dispatch case when multiple
// targets are being compiled.
#define HWY_EXPORT(FUNC_NAME) \
HWY_MAYBE_UNUSED static decltype(&HWY_STATIC_DISPATCH(FUNC_NAME)) const \
HWY_DISPATCH_TABLE(FUNC_NAME)[1] = {&HWY_STATIC_DISPATCH(FUNC_NAME)}
#define HWY_DYNAMIC_DISPATCH(FUNC_NAME) HWY_STATIC_DISPATCH(FUNC_NAME)
#else
// Simplified version for MSVC 2017: function pointer instead of table.
#if HWY_DISPATCH_WORKAROUND
#define HWY_EXPORT(FUNC_NAME) \
static decltype(&HWY_STATIC_DISPATCH(FUNC_NAME)) const HWY_DISPATCH_TABLE( \
FUNC_NAME)[HWY_MAX_DYNAMIC_TARGETS + 2] = { \
/* The first entry in the table initializes the global cache and \
* calls the function from HWY_STATIC_TARGET. */ \
&decltype(hwy::DeduceFunctionCache(&HWY_STATIC_DISPATCH( \
FUNC_NAME)))::ChooseAndCall<&HWY_STATIC_DISPATCH(FUNC_NAME)>, \
HWY_CHOOSE_TARGET_LIST(FUNC_NAME), \
HWY_CHOOSE_FALLBACK(FUNC_NAME), \
}
#else
// Dynamic dispatch case with one entry per dynamic target plus the fallback
// target and the initialization wrapper.
#define HWY_EXPORT(FUNC_NAME) \
static decltype(&HWY_STATIC_DISPATCH(FUNC_NAME)) const HWY_DISPATCH_TABLE( \
FUNC_NAME)[HWY_MAX_DYNAMIC_TARGETS + 2] = { \
/* The first entry in the table initializes the global cache and \
* calls the appropriate function. */ \
&decltype(hwy::DeduceFunctionCache(&HWY_STATIC_DISPATCH( \
FUNC_NAME)))::ChooseAndCall<HWY_DISPATCH_TABLE(FUNC_NAME)>, \
HWY_CHOOSE_TARGET_LIST(FUNC_NAME), \
HWY_CHOOSE_FALLBACK(FUNC_NAME), \
}
#endif // HWY_DISPATCH_WORKAROUND
#define HWY_DYNAMIC_DISPATCH(FUNC_NAME) \
(*(HWY_DISPATCH_TABLE(FUNC_NAME)[hwy::GetChosenTarget().GetIndex()]))
#endif // HWY_IDE || ((HWY_TARGETS & (HWY_TARGETS - 1)) == 0)
// DEPRECATED names; please use HWY_HAVE_* instead.
#define HWY_CAP_INTEGER64 HWY_HAVE_INTEGER64
#define HWY_CAP_FLOAT16 HWY_HAVE_FLOAT16
#define HWY_CAP_FLOAT64 HWY_HAVE_FLOAT64
} // namespace hwy
#endif // HWY_HIGHWAY_INCLUDED
//------------------------------------------------------------------------------
// NOTE: the following definitions and ops/*.h depend on HWY_TARGET, so we want
// to include them once per target, which is ensured by the toggle check.
// Because ops/*.h are included under it, they do not need their own guard.
#if defined(HWY_HIGHWAY_PER_TARGET) == defined(HWY_TARGET_TOGGLE)
#ifdef HWY_HIGHWAY_PER_TARGET
#undef HWY_HIGHWAY_PER_TARGET
#else
#define HWY_HIGHWAY_PER_TARGET
#endif
// These define ops inside namespace hwy::HWY_NAMESPACE.
#if HWY_TARGET == HWY_SSSE3 || HWY_TARGET == HWY_SSE4
#include "hwy/ops/x86_128-inl.h"
#elif HWY_TARGET == HWY_AVX2
#include "hwy/ops/x86_256-inl.h"
#elif HWY_TARGET == HWY_AVX3 || HWY_TARGET == HWY_AVX3_DL
#include "hwy/ops/x86_512-inl.h"
#elif HWY_TARGET == HWY_PPC8
#error "PPC is not yet supported"
#elif HWY_TARGET == HWY_NEON
#include "hwy/ops/arm_neon-inl.h"
#elif HWY_TARGET == HWY_SVE || HWY_TARGET == HWY_SVE2 || \
HWY_TARGET == HWY_SVE_256 || HWY_TARGET == HWY_SVE2_128
#include "hwy/ops/arm_sve-inl.h"
#elif HWY_TARGET == HWY_WASM_EMU256
#include "hwy/ops/wasm_256-inl.h"
#elif HWY_TARGET == HWY_WASM
#include "hwy/ops/wasm_128-inl.h"
#elif HWY_TARGET == HWY_RVV
#include "hwy/ops/rvv-inl.h"
#elif HWY_TARGET == HWY_EMU128
#include "hwy/ops/emu128-inl.h"
#elif HWY_TARGET == HWY_SCALAR
#include "hwy/ops/scalar-inl.h"
#else
#pragma message("HWY_TARGET does not match any known target")
#endif // HWY_TARGET
#include "hwy/ops/generic_ops-inl.h"
#endif // HWY_HIGHWAY_PER_TARGET
arm_neon-inl.h
arm_sve-inl.h
base.h
emu128-inl.h
generic_ops-inl.h
hwy
Definition aligned_allocator.h:27
hwy::DeduceFunctionCache
FunctionCache< RetType, Args... > DeduceFunctionCache(RetType(*)(Args...))
Definition highway.h:242
hwy::GetChosenTarget
HWY_DLLEXPORT ChosenTarget & GetChosenTarget()
hwy::SupportedTargets
HWY_DLLEXPORT int64_t SupportedTargets()
rvv-inl.h
scalar-inl.h
hwy::ChosenTarget
Definition targets.h:278
hwy::ChosenTarget::GetIndex
size_t HWY_INLINE GetIndex() const
Definition targets.h:301
hwy::ChosenTarget::Update
void Update(int64_t targets)
Definition targets.h:282
hwy::FunctionCache
Definition highway.h:213
hwy::FunctionCache::FunctionType
RetType() FunctionType(Args...)
Definition highway.h:215
hwy::FunctionCache::ChooseAndCall
static RetType ChooseAndCall(Args... args)
Definition highway.h:232
targets.h
wasm_128-inl.h
wasm_256-inl.h
x86_128-inl.h
x86_256-inl.h
x86_512-inl.h