s_modf.c File Reference

Go to the source code of this file.

Classes
union	ieee_double_shape_type

Macros
#define	__int32_t   long
#define	__uint32_t   unsigned long
#define	__IEEE_LITTLE_ENDIAN
#define	EXTRACT_WORDS(ix0, ix1, d)
#define	GET_HIGH_WORD(i, d)
#define	GET_LOW_WORD(i, d)
#define	INSERT_WORDS(d, ix0, ix1)

Functions
double	modf (double x, double *iptr)

Variables
static const double	one = 1.0

Macro Definition Documentation

__IEEE_LITTLE_ENDIAN

#define __IEEE_LITTLE_ENDIAN

Definition at line 78 of file s_modf.c.

__int32_t

#define __int32_t   long

Definition at line 76 of file s_modf.c.

__uint32_t

#define __uint32_t   unsigned long

Definition at line 77 of file s_modf.c.

EXTRACT_WORDS

#define EXTRACT_WORDS	(		ix0,
			ix1,
			d
	)

Value:

do {                                \
  ieee_double_shape_type ew_u;                  \
  ew_u.value = (d);                     \
  (ix0) = ew_u.parts.msw;                   \
  (ix1) = ew_u.parts.lsw;                   \
} while (0)

Definition at line 111 of file s_modf.c.

GET_HIGH_WORD

#define GET_HIGH_WORD	(		i,
			d
	)

Value:

do {                                \
  ieee_double_shape_type gh_u;                  \
  gh_u.value = (d);                     \
  (i) = gh_u.parts.msw;                     \
} while (0)

Definition at line 121 of file s_modf.c.

GET_LOW_WORD

#define GET_LOW_WORD	(		i,
			d
	)

Value:

do {                                \
  ieee_double_shape_type gl_u;                  \
  gl_u.value = (d);                     \
  (i) = gl_u.parts.lsw;                     \
} while (0)

Definition at line 130 of file s_modf.c.

INSERT_WORDS

#define INSERT_WORDS	(		d,
			ix0,
			ix1
	)

Value:

do {                                \
  ieee_double_shape_type iw_u;                  \
  iw_u.parts.msw = (ix0);                   \
  iw_u.parts.lsw = (ix1);                   \
  (d) = iw_u.value;                     \
} while (0)

Definition at line 139 of file s_modf.c.

Function Documentation

modf()

double modf	(	double	x,
		double *	iptr
	)

Definition at line 150 of file s_modf.c.

{
    __int32_t i0,i1,j_0;
    __uint32_t i;
    EXTRACT_WORDS(i0,i1,x);
    j_0 = ((i0>>20)&0x7ff)-0x3ff;   /* exponent of x */
    if(j_0<20) {            /* integer part in high x */
        if(j_0<0) {         /* |x|<1 */
            INSERT_WORDS(*iptr,i0&0x80000000U,0);   /* *iptr = +-0 */
        return x;
        } else {
        i = (0x000fffff)>>j_0;
        if(((i0&i)|i1)==0) {        /* x is integral */
            __uint32_t high;
            *iptr = x;
            GET_HIGH_WORD(high,x);
            INSERT_WORDS(x,high&0x80000000U,0); /* return +-0 */
            return x;
        } else {
            INSERT_WORDS(*iptr,i0&(~i),0);
            return x - *iptr;
        }
        }
    } else if (j_0>51) {        /* no fraction part */
        __uint32_t high;
        *iptr = x*one;
        GET_HIGH_WORD(high,x);
        INSERT_WORDS(x,high&0x80000000U,0); /* return +-0 */
        return x;
    } else {            /* fraction part in low x */
        i = ((__uint32_t)(0xffffffffU))>>(j_0-20);
        if((i1&i)==0) {         /* x is integral */
            __uint32_t high;
        *iptr = x;
        GET_HIGH_WORD(high,x);
        INSERT_WORDS(x,high&0x80000000U,0); /* return +-0 */
        return x;
        } else {
            INSERT_WORDS(*iptr,i0,i1&(~i));
        return x - *iptr;
        }
    }
}

Variable Documentation

one

const double one = 1.0

static

Definition at line 74 of file s_modf.c.

Referenced by modf().