endian.h

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// Protocol Buffers - Google's data interchange format
// Copyright 2023 Google LLC.  All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
 
#ifndef UPB_BASE_INTERNAL_ENDIAN_H_
#define UPB_BASE_INTERNAL_ENDIAN_H_
 
#include <stdint.h>
 
// Must be last.
#include "upb/port/def.inc"
 
#ifdef __cplusplus
extern "C" {
#endif
 
UPB_INLINE bool upb_IsLittleEndian(void) {
  const int x = 1;
  return *(char*)&x == 1;
}
 
UPB_INLINE uint32_t upb_BigEndian32(uint32_t val) {
  if (upb_IsLittleEndian()) return val;
 
  return ((val & 0xff) << 24) | ((val & 0xff00) << 8) |
         ((val & 0xff0000) >> 8) | ((val & 0xff000000) >> 24);
}
 
UPB_INLINE uint64_t upb_BigEndian64(uint64_t val) {
  if (upb_IsLittleEndian()) return val;
 
  const uint64_t hi = ((uint64_t)upb_BigEndian32((uint32_t)val)) << 32;
  const uint64_t lo = upb_BigEndian32((uint32_t)(val >> 32));
  return hi | lo;
}
 
#ifdef __cplusplus
} /* extern "C" */
#endif
 
#include "upb/port/undef.inc"
 
#endif /* UPB_BASE_INTERNAL_ENDIAN_H_ */