text: // Copyright (c) 2014 The Bitcoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #ifndef BITCOIN_CRYPTO_COMMON_H
  #define BITCOIN_CRYPTO_COMMON_H
  
  #if defined(HAVE_CONFIG_H)
  #include "xgalaxy-config.h"
  #endif
  
  #include <stdint.h>
  #include <string.h>
  
  #include "compat/endian.h"
  
  uint16_t static inline ReadLE16(const unsigned char* ptr)
  {
      uint16_t x;
      memcpy((char*)&x, ptr, 2);
      return le16toh(x);
  }
  
  uint32_t static inline ReadLE32(const unsigned char* ptr)
  {
      uint32_t x;
      memcpy((char*)&x, ptr, 4);
      return le32toh(x);
  }
  
  uint64_t static inline ReadLE64(const unsigned char* ptr)
  {
      uint64_t x;
      memcpy((char*)&x, ptr, 8);
      return le64toh(x);
  }
  
  void static inline WriteLE16(unsigned char* ptr, uint16_t x)
  {
      uint16_t v = htole16(x);
      memcpy(ptr, (char*)&v, 2);
  }
  
  void static inline WriteLE32(unsigned char* ptr, uint32_t x)
  {
      uint32_t v = htole32(x);
      memcpy(ptr, (char*)&v, 4);
  }
  
  void static inline WriteLE64(unsigned char* ptr, uint64_t x)
  {
      uint64_t v = htole64(x);
      memcpy(ptr, (char*)&v, 8);
  }
  
  uint32_t static inline ReadBE32(const unsigned char* ptr)
  {
      uint32_t x;
      memcpy((char*)&x, ptr, 4);
      return be32toh(x);
  }
  
  uint64_t static inline ReadBE64(const unsigned char* ptr)
  {
      uint64_t x;
      memcpy((char*)&x, ptr, 8);
      return be64toh(x);
  }
  
  void static inline WriteBE32(unsigned char* ptr, uint32_t x)
  {
      uint32_t v = htobe32(x);
      memcpy(ptr, (char*)&v, 4);
  }
  
  void static inline WriteBE64(unsigned char* ptr, uint64_t x)
  {
      uint64_t v = htobe64(x);
      memcpy(ptr, (char*)&v, 8);
  }
  
  /** Return the smallest number n such that (x >> n) == 0 (or 64 if the highest bit in x is set. */
  uint64_t static inline CountBits(uint64_t x)
  {
  #ifdef HAVE_DECL___BUILTIN_CLZL
      if (sizeof(unsigned long) >= sizeof(uint64_t)) {
          return x ? 8 * sizeof(unsigned long) - __builtin_clzl(x) : 0;
      }
  #endif
  #ifdef HAVE_DECL___BUILTIN_CLZLL
      if (sizeof(unsigned long long) >= sizeof(uint64_t)) {
          return x ? 8 * sizeof(unsigned long long) - __builtin_clzll(x) : 0;
      }
  #endif
      int ret = 0;
      while (x) {
          x >>= 1;
          ++ret;
      }
      return ret;
  }
  
  #endif // BITCOIN_CRYPTO_COMMON_H
  