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glibc  2.9
Functions | Variables
s_ceil.c File Reference
#include "math.h"
#include "math_private.h"
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Functions

double __ceil (double x)

Variables

static double huge = 1.0e300

Function Documentation

double __ceil ( double  x)

Definition at line 38 of file s_ceil.c.

{
       int32_t i0,i1,j0;
       u_int32_t i,j;
       EXTRACT_WORDS(i0,i1,x);
       j0 = ((i0>>20)&0x7ff)-0x3ff;
       if(j0<20) {
           if(j0<0) {       /* raise inexact if x != 0 */
              if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */
                  if(i0<0) {i0=0x80000000;i1=0;}
                  else if((i0|i1)!=0) { i0=0x3ff00000;i1=0;}
              }
           } else {
              i = (0x000fffff)>>j0;
              if(((i0&i)|i1)==0) return x; /* x is integral */
              if(huge+x>0.0) {     /* raise inexact flag */
                  if(i0>0) i0 += (0x00100000)>>j0;
                  i0 &= (~i); i1=0;
              }
           }
       } else if (j0>51) {
           if(j0==0x400) return x+x;      /* inf or NaN */
           else return x;          /* x is integral */
       } else {
           i = ((u_int32_t)(0xffffffff))>>(j0-20);
           if((i1&i)==0) return x; /* x is integral */
           if(huge+x>0.0) {               /* raise inexact flag */
              if(i0>0) {
                  if(j0==20) i0+=1;
                  else {
                     j = i1 + (1<<(52-j0));
                     if(j<i1) i0+=1;      /* got a carry */
                     i1 = j;
                  }
              }
              i1 &= (~i);
           }
       }
       INSERT_WORDS(x,i0,i1);
       return x;
}

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Variable Documentation

double huge = 1.0e300 [static]

Definition at line 32 of file s_ceil.c.