Back to index

glibc  2.9
Functions
s_ilogbl.c File Reference
#include "soft-fp.h"
#include "quad.h"
#include <math.h>

Go to the source code of this file.

Functions

int __ilogbl (long double x)

Function Documentation

int __ilogbl ( long double  x)

Definition at line 32 of file s_ilogbl.c.

{
  FP_DECL_EX;
  FP_DECL_Q(X);

/*
  FP_UNPACK_Q(X, x);
  switch (X_c)
    {
    case FP_CLS_ZERO:
      return FP_ILOGB0;
    case FP_CLS_NAN:
    case FP_CLS_INF:
      return FP_ILOGBNAN;
    default:
      return X_e;
    }
 */
  FP_UNPACK_RAW_Q(X, x);
  switch (X_e)
    {
    default:
      return X_e - _FP_EXPBIAS_Q;
    case 0:
#if (2 * _FP_W_TYPE_SIZE) < _FP_FRACBITS_Q
      if (_FP_FRAC_ZEROP_4(X))
       return FP_ILOGB0;
      else
       {
         _FP_I_TYPE shift;
         _FP_FRAC_CLZ_4(shift, X);
         shift -= _FP_FRACXBITS_Q;
         return X_e - _FP_EXPBIAS_Q - 1 + shift;
       }
#else
      if (_FP_FRAC_ZEROP_2(X))
       return FP_ILOGB0;
      else
       {
         _FP_I_TYPE shift;
         _FP_FRAC_CLZ_2(shift, X);
         shift -= _FP_FRACXBITS_Q;
         return X_e - _FP_EXPBIAS_Q - 1 + shift;
       }
#endif
    case _FP_EXPBIAS_Q:
      return FP_ILOGBNAN;
    }
}

Here is the caller graph for this function: