PVS-Studio warning V629 for smhasher

__inline__ unsigned long long int rdtsc()
{
#ifdef __x86_64__
  unsigned int a, d;
  __asm__ volatile ("rdtsc" : "=a" (a), "=d" (d));
  return (unsigned long)a | ((unsigned long)d << 32);
#elif defined(__i386__)
  unsigned long long int x;
  __asm__ volatile ("rdtsc" : "=A" (x));
  return x;
#else
#define NO_CYCLE_COUNTER
  return 0;
#endif
}

It may fail if the long type appears 32-bit - an overflow will occur in the "(unsigned long)d << 32" expression.

This suspicious code was found in smhasher project by PVS-Studio static code analyzer.
Warning message is:
V629 Consider inspecting the '(unsigned long) d << 32' expression. Bit shifting of the 32-bit value with a subsequent expansion to the 64-bit type. Platform.h 78

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