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glibc  2.9
Functions
s_ilogbl.c File Reference
#include <limits.h>
#include "math.h"
#include "math_private.h"
#include <math_ldbl_opt.h>

Go to the source code of this file.

Functions

int __ilogbl (long double x)
 long_double_symbol (libm, __ilogbl, ilogbl)

Function Documentation

int __ilogbl ( long double  x)

Definition at line 35 of file s_ilogbl.c.

{
       int64_t hx,lx;
       int ix;

       GET_LDOUBLE_WORDS64(hx,lx,x);
       hx &= 0x7fffffffffffffffLL;
       if(hx <= 0x0010000000000000LL) {
           if((hx|(lx&0x7fffffffffffffffLL))==0)
              return FP_ILOGB0;    /* ilogbl(0) = FP_ILOGB0 */
           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<0x7ff0000000000000LL) return (hx>>52)-0x3ff;
       else if (FP_ILOGBNAN != INT_MAX) {
           /* ISO C99 requires ilogbl(+-Inf) == INT_MAX.  */
           if (((hx^0x7ff0000000000000LL)|lx) == 0)
              return INT_MAX;
       }
       return FP_ILOGBNAN;
}
long_double_symbol ( libm  ,
__ilogbl  ,
ilogbl   
)