Back to index

glibc  2.9
Functions
e_gammaf_r.c File Reference
#include <math.h>
#include <math_private.h>

Go to the source code of this file.

Functions

float __ieee754_gammaf_r (float x, int *signgamp)

Function Documentation

float __ieee754_gammaf_r ( float  x,
int signgamp 
)

Definition at line 26 of file e_gammaf_r.c.

{
  /* We don't have a real gamma implementation now.  We'll use lgamma
     and the exp function.  But due to the required boundary
     conditions we must check some values separately.  */
  int32_t hx;

  GET_FLOAT_WORD (hx, x);

  if ((hx & 0x7fffffff) == 0)
    {
      /* Return value for x == 0 is Inf with divide by zero exception.  */
      *signgamp = 0;
      return 1.0 / x;
    }
  if (hx < 0 && (u_int32_t) hx < 0xff800000 && __rintf (x) == x)
    {
      /* Return value for integer x < 0 is NaN with invalid exception.  */
      *signgamp = 0;
      return (x - x) / (x - x);
    }
  if (hx == 0xff800000)
    {
      /* x == -Inf.  According to ISO this is NaN.  */
      *signgamp = 0;
      return x - x;
    }

  /* XXX FIXME.  */
  return __ieee754_expf (__ieee754_lgammaf_r (x, signgamp));
}

Here is the call graph for this function:

Here is the caller graph for this function: