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

Go to the source code of this file.

Functions

int fd_ilogb (double x)

Function Documentation

int fd_ilogb ( double  x)

Definition at line 63 of file s_ilogb.c.

{
       int hx,lx,ix;
        fd_twoints u;
        u.d = x;
       hx  = (__HI(u))&0x7fffffff; /* high word of x */
       if(hx<0x00100000) {
           lx = __LO(u);
           if((hx|lx)==0) 
              return 0x80000001;   /* ilogb(0) = 0x80000001 */
           else                    /* subnormal x */
              if(hx==0) {
                  for (ix = -1043; lx>0; lx<<=1) ix -=1;
              } else {
                  for (ix = -1022,hx<<=11; hx>0; hx<<=1) ix -=1;
              }
           return ix;
       }
       else if (hx<0x7ff00000) return (hx>>20)-1023;
       else return 0x7fffffff;
}

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