llvm/libc/src/string/memory_utils/x86_64/inline_memcpy.h

//===-- Memcpy implementation for x86_64 ------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_X86_64_INLINE_MEMCPY_H
#define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_X86_64_INLINE_MEMCPY_H

#include "src/__support/macros/attributes.h"   // LIBC_INLINE_VAR
#include "src/__support/macros/config.h"       // LIBC_INLINE
#include "src/__support/macros/optimization.h" // LIBC_UNLIKELY
#include "src/string/memory_utils/op_builtin.h"
#include "src/string/memory_utils/op_x86.h"
#include "src/string/memory_utils/utils.h"

#include <stddef.h> // size_t
#include <stdint.h> // SIZE_MAX

#ifdef LLVM_LIBC_MEMCPY_X86_USE_ONLY_REPMOVSB
#error LLVM_LIBC_MEMCPY_X86_USE_ONLY_REPMOVSB is deprecated use LIBC_COPT_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE=0 instead.
#endif // LLVM_LIBC_MEMCPY_X86_USE_ONLY_REPMOVSB

#ifdef LLVM_LIBC_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE
#error LLVM_LIBC_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE is deprecated use LIBC_COPT_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE=0 instead.
#endif // LLVM_LIBC_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE

namespace LIBC_NAMESPACE_DECL {

namespace x86 {

LIBC_INLINE_VAR constexpr size_t K_ONE_CACHELINE = …;
LIBC_INLINE_VAR constexpr size_t K_TWO_CACHELINES = …;
LIBC_INLINE_VAR constexpr size_t K_THREE_CACHELINES = …;

LIBC_INLINE_VAR constexpr bool K_USE_SOFTWARE_PREFETCHING = …;

// Whether to use rep;movsb exclusively (0), not at all (SIZE_MAX), or only
// above a certain threshold. Defaults to "do not use rep;movsb".
#ifndef LIBC_COPT_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE
#define LIBC_COPT_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE …
#endif
LIBC_INLINE_VAR constexpr size_t K_REP_MOVSB_THRESHOLD = …;

} // namespace x86

[[maybe_unused]] LIBC_INLINE void
inline_memcpy_x86_sse2_ge64(Ptr __restrict dst, CPtr __restrict src,
                            size_t count) { … }

[[maybe_unused]] LIBC_INLINE void
inline_memcpy_x86_avx_ge64(Ptr __restrict dst, CPtr __restrict src,
                           size_t count) { … }

[[maybe_unused]] LIBC_INLINE void inline_memcpy_prefetch(Ptr __restrict dst,
                                                         CPtr __restrict src,
                                                         size_t distance) { … }

[[maybe_unused]] LIBC_INLINE void
inline_memcpy_x86_sse2_ge64_sw_prefetching(Ptr __restrict dst,
                                           CPtr __restrict src, size_t count) { … }

[[maybe_unused]] LIBC_INLINE void
inline_memcpy_x86_avx_ge64_sw_prefetching(Ptr __restrict dst,
                                          CPtr __restrict src, size_t count) { … }

[[maybe_unused]] LIBC_INLINE void
inline_memcpy_x86(Ptr __restrict dst, CPtr __restrict src, size_t count) { … }

[[maybe_unused]] LIBC_INLINE void
inline_memcpy_x86_maybe_interpose_repmovsb(Ptr __restrict dst,
                                           CPtr __restrict src, size_t count) { … }

} // namespace LIBC_NAMESPACE_DECL

#endif // LLVM_LIBC_SRC_STRING_MEMORY_UTILS_X86_64_INLINE_MEMCPY_H