src/string/memory_utils/x86_64/inline_memset.h

//===-- Memset 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 LIBC_SRC_STRING_MEMORY_UTILS_X86_64_INLINE_MEMSET_H
#define LIBC_SRC_STRING_MEMORY_UTILS_X86_64_INLINE_MEMSET_H

#include "src/__support/macros/attributes.h" // LIBC_INLINE
#include "src/string/memory_utils/op_generic.h"
#include "src/string/memory_utils/op_x86.h"
#include "src/string/memory_utils/utils.h" // Ptr, CPtr

#include <stddef.h> // size_t

namespace __llvm_libc {

[[maybe_unused]] LIBC_INLINE static void
inline_memset_x86(Ptr dst, uint8_t value, size_t count) {
#if defined(__AVX512F__)
  using uint128_t = generic_v128;
  using uint256_t = generic_v256;
  using uint512_t = generic_v512;
#elif defined(__AVX__)
  using uint128_t = generic_v128;
  using uint256_t = generic_v256;
  using uint512_t = cpp::array<generic_v256, 2>;
#elif defined(__SSE2__)
  using uint128_t = generic_v128;
  using uint256_t = cpp::array<generic_v128, 2>;
  using uint512_t = cpp::array<generic_v128, 4>;
#else
  using uint128_t = cpp::array<uint64_t, 2>;
  using uint256_t = cpp::array<uint64_t, 4>;
  using uint512_t = cpp::array<uint64_t, 8>;
#endif

  if (count == 0)
    return;
  if (count == 1)
    return generic::Memset<uint8_t>::block(dst, value);
  if (count == 2)
    return generic::Memset<uint16_t>::block(dst, value);
  if (count == 3)
    return generic::MemsetSequence<uint16_t, uint8_t>::block(dst, value);
  if (count <= 8)
    return generic::Memset<uint32_t>::head_tail(dst, value, count);
  if (count <= 16)
    return generic::Memset<uint64_t>::head_tail(dst, value, count);
  if (count <= 32)
    return generic::Memset<uint128_t>::head_tail(dst, value, count);
  if (count <= 64)
    return generic::Memset<uint256_t>::head_tail(dst, value, count);
  if (count <= 128)
    return generic::Memset<uint512_t>::head_tail(dst, value, count);
  // Aligned loop
  generic::Memset<uint256_t>::block(dst, value);
  align_to_next_boundary<32>(dst, count);
  return generic::Memset<uint256_t>::loop_and_tail(dst, value, count);
}
} // namespace __llvm_libc

#endif // LIBC_SRC_STRING_MEMORY_UTILS_X86_64_INLINE_MEMSET_H