//===-- Trivial byte per byte implementations ----------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// Straightforward implementations targeting the smallest code size possible.
// This needs to be compiled with '-Os' or '-Oz'.
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIBC_SRC_STRING_MEMORY_UTILS_GENERIC_BYTE_PER_BYTE_H
#define LLVM_LIBC_SRC_STRING_MEMORY_UTILS_GENERIC_BYTE_PER_BYTE_H
#include "src/__support/macros/attributes.h" // LIBC_INLINE
#include "src/__support/macros/optimization.h" // LIBC_LOOP_NOUNROLL
#include "src/string/memory_utils/utils.h" // Ptr, CPtr
#include <stddef.h> // size_t
namespace LIBC_NAMESPACE_DECL {
[[maybe_unused]] LIBC_INLINE void
inline_memcpy_byte_per_byte(Ptr dst, CPtr src, size_t count,
size_t offset = 0) {
LIBC_LOOP_NOUNROLL
for (; offset < count; ++offset)
dst[offset] = src[offset];
}
[[maybe_unused]] LIBC_INLINE void
inline_memmove_byte_per_byte(Ptr dst, CPtr src, size_t count) {
if (count == 0 || dst == src)
return;
if (dst < src) {
LIBC_LOOP_NOUNROLL
for (size_t offset = 0; offset < count; ++offset)
dst[offset] = src[offset];
} else {
LIBC_LOOP_NOUNROLL
for (ptrdiff_t offset = count - 1; offset >= 0; --offset)
dst[offset] = src[offset];
}
}
[[maybe_unused]] LIBC_INLINE static void
inline_memset_byte_per_byte(Ptr dst, uint8_t value, size_t count,
size_t offset = 0) {
LIBC_LOOP_NOUNROLL
for (; offset < count; ++offset)
dst[offset] = static_cast<cpp::byte>(value);
}
[[maybe_unused]] LIBC_INLINE BcmpReturnType
inline_bcmp_byte_per_byte(CPtr p1, CPtr p2, size_t count, size_t offset = 0) {
LIBC_LOOP_NOUNROLL
for (; offset < count; ++offset)
if (p1[offset] != p2[offset])
return BcmpReturnType::nonzero();
return BcmpReturnType::zero();
}
[[maybe_unused]] LIBC_INLINE MemcmpReturnType
inline_memcmp_byte_per_byte(CPtr p1, CPtr p2, size_t count, size_t offset = 0) {
LIBC_LOOP_NOUNROLL
for (; offset < count; ++offset) {
const int32_t a = static_cast<int32_t>(p1[offset]);
const int32_t b = static_cast<int32_t>(p2[offset]);
const int32_t diff = a - b;
if (diff)
return diff;
}
return MemcmpReturnType::zero();
}
} // namespace LIBC_NAMESPACE_DECL
#endif // LLVM_LIBC_SRC_STRING_MEMORY_UTILS_GENERIC_BYTE_PER_BYTE_H