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#include "bid_internal.h"

#define BID32_NAN 0x7c000000ul

#if (defined(_MSC_VER) && !defined(__INTEL_COMPILER))
double log(double);
#else
double log2(double);
#endif

BID_TYPE0_FUNCTION_ARGTYPE1(BID_UINT32, bid32_log2, BID_UINT32, x)


// Declare local variables

  BID_UINT32 res;
  double xd, rd;
  int z;

// Check for NaN and just return the same NaN, quieted and canonized

  if ((x & NAN_MASK32) == NAN_MASK32)
   {
     #ifdef BID_SET_STATUS_FLAGS
     if ((x & SNAN_MASK32) == SNAN_MASK32)
        __set_status_flags (pfpsf, BID_INVALID_EXCEPTION);
     #endif
     res = x & 0xfc0ffffful;
     if ((res & 0x000ffffful) > 999999ul) res &= ~0x000ffffful;
     BID_RETURN(res);
   }

  BIDECIMAL_CALL1_NORND_NOSTAT (bid32_isZero, z, x);
  if (z)
   { // -Infinite and Divide by Zero according C99
     res = 0xf8000000;
     #ifdef BID_SET_STATUS_FLAGS
     __set_status_flags (pfpsf, BID_ZERO_DIVIDE_EXCEPTION);
     #endif
     BID_RETURN (res);
   }

  if (x & MASK_SIGN32)
   { // QNaN Indefinite
     res = 0x7c000000;
     #ifdef BID_SET_STATUS_FLAGS
     __set_status_flags (pfpsf, BID_INVALID_EXCEPTION);
     #endif
     BID_RETURN (res);
   }

  BIDECIMAL_CALL1 (bid32_to_binary64, xd, x);

 #if (defined(_MSC_VER) && !defined(__INTEL_COMPILER))
  rd = log(xd)*(1.0/log(2.0));
#else
 rd = log2(xd);
#endif

  BIDECIMAL_CALL1 (binary64_to_bid32, res, rd);
  BID_RETURN (res);
}
