Back to index

lightning-sunbird  0.9+nobinonly
Functions | Variables
e_log10.c File Reference
#include "fdlibm.h"

Go to the source code of this file.

Functions

double __ieee754_log10 (double x)

Variables

static double two54 = 1.80143985094819840000e+16
static double ivln10 = 4.34294481903251816668e-01
static double log10_2hi = 3.01029995663611771306e-01
static double log10_2lo = 3.69423907715893078616e-13
static double zero = 0.0

Function Documentation

double __ieee754_log10 ( double  x)

Definition at line 102 of file e_log10.c.

{
        fd_twoints u;
       double y,z;
       int i,k,hx;
       unsigned lx;

        u.d = x;
       hx = __HI(u); /* high word of x */
       lx = __LO(u); /* low word of x */

        k=0;
        if (hx < 0x00100000) {                  /* x < 2**-1022  */
            if (((hx&0x7fffffff)|lx)==0)
                return -two54/zero;             /* log(+-0)=-inf */
            if (hx<0) return (x-x)/zero;        /* log(-#) = NaN */
            k -= 54; x *= two54; /* subnormal number, scale up x */
            u.d = x;
            hx = __HI(u);                /* high word of x */
        }
       if (hx >= 0x7ff00000) return x+x;
       k += (hx>>20)-1023;
       i  = ((unsigned)k&0x80000000)>>31;
        hx = (hx&0x000fffff)|((0x3ff-i)<<20);
        y  = (double)(k+i);
        u.d = x;
        __HI(u) = hx;
        x = u.d;
       z  = y*log10_2lo + ivln10*__ieee754_log(x);
       return  z+y*log10_2hi;
}

Here is the call graph for this function:

Here is the caller graph for this function:


Variable Documentation

double ivln10 = 4.34294481903251816668e-01 [static]

Definition at line 93 of file e_log10.c.

double log10_2hi = 3.01029995663611771306e-01 [static]

Definition at line 94 of file e_log10.c.

double log10_2lo = 3.69423907715893078616e-13 [static]

Definition at line 95 of file e_log10.c.

double two54 = 1.80143985094819840000e+16 [static]

Definition at line 92 of file e_log10.c.

double zero = 0.0 [static]

Definition at line 97 of file e_log10.c.