s_floor.c File Reference

#include "math_libm.h"
#include "math_private.h"

Include dependency graph for s_floor.c:

Go to the source code of this file.

Functions
double	floor (double x)

Variables
static const double	huge = 1.0e300

Function Documentation

floor()

double floor

(

double

x

)

Definition at line 33 of file s_floor.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=i1=0;}
                    else if(((i0&0x7fffffff)|i1)!=0)
                        { i0=0xbff00000;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<(u_int32_t)i1) i0 +=1 ;    /* got a carry */
                        i1=j;
                    }
                }
                i1 &= (~i);
            }
        }
        INSERT_WORDS(x,i0,i1);
        return x;
}

References EXTRACT_WORDS, huge, i, i1, INSERT_WORDS, and j.

Referenced by __kernel_rem_pio2(), and SDL_floor().

Variable Documentation

huge

const double huge = 1.0e300

static

Definition at line 31 of file s_floor.c.

Referenced by floor().