abseil-cpp/absl/base/internal/unaligned_access.h

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//
// Copyright 2017 The Abseil Authors.
//
// 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
//
//      https://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.
//
 
#ifndef ABSL_BASE_INTERNAL_UNALIGNED_ACCESS_H_
#define ABSL_BASE_INTERNAL_UNALIGNED_ACCESS_H_
 
#include <string.h>
 
#include <cstdint>
 
#include "absl/base/attributes.h"
#include "absl/base/config.h"
 
// unaligned APIs
 
// Portable handling of unaligned loads, stores, and copies.
 
// The unaligned API is C++ only.  The declarations use C++ features
// (namespaces, inline) which are absent or incompatible in C.
#if defined(__cplusplus)
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace base_internal {
 
inline uint16_t UnalignedLoad16(const void *p) {
  uint16_t t;
  memcpy(&t, p, sizeof t);
  return t;
}
 
inline uint32_t UnalignedLoad32(const void *p) {
  uint32_t t;
  memcpy(&t, p, sizeof t);
  return t;
}
 
inline uint64_t UnalignedLoad64(const void *p) {
  uint64_t t;
  memcpy(&t, p, sizeof t);
  return t;
}
 
inline void UnalignedStore16(void *p, uint16_t v) { memcpy(p, &v, sizeof v); }
 
inline void UnalignedStore32(void *p, uint32_t v) { memcpy(p, &v, sizeof v); }
 
inline void UnalignedStore64(void *p, uint64_t v) { memcpy(p, &v, sizeof v); }
 
}  // namespace base_internal
ABSL_NAMESPACE_END
}  // namespace absl
 
#define ABSL_INTERNAL_UNALIGNED_LOAD16(_p) \
  (absl::base_internal::UnalignedLoad16(_p))
#define ABSL_INTERNAL_UNALIGNED_LOAD32(_p) \
  (absl::base_internal::UnalignedLoad32(_p))
#define ABSL_INTERNAL_UNALIGNED_LOAD64(_p) \
  (absl::base_internal::UnalignedLoad64(_p))
 
#define ABSL_INTERNAL_UNALIGNED_STORE16(_p, _val) \
  (absl::base_internal::UnalignedStore16(_p, _val))
#define ABSL_INTERNAL_UNALIGNED_STORE32(_p, _val) \
  (absl::base_internal::UnalignedStore32(_p, _val))
#define ABSL_INTERNAL_UNALIGNED_STORE64(_p, _val) \
  (absl::base_internal::UnalignedStore64(_p, _val))
 
#endif  // defined(__cplusplus), end of unaligned API
 
#endif  // ABSL_BASE_INTERNAL_UNALIGNED_ACCESS_H_