mirror of
https://git.planet-casio.com/Lephenixnoir/OpenLibm.git
synced 2024-12-28 20:43:41 +01:00
69 lines
1.8 KiB
C
69 lines
1.8 KiB
C
/* @(#)s_modf.c 5.1 93/09/24 */
|
|
/*
|
|
* ====================================================
|
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
|
*
|
|
* Developed at SunPro, a Sun Microsystems, Inc. business.
|
|
* Permission to use, copy, modify, and distribute this
|
|
* software is freely granted, provided that this notice
|
|
* is preserved.
|
|
* ====================================================
|
|
*/
|
|
|
|
/*
|
|
* modfl(long double x, long double *iptr)
|
|
* return fraction part of x, and return x's integral part in *iptr.
|
|
* Method:
|
|
* Bit twiddling.
|
|
*
|
|
* Exception:
|
|
* No exception.
|
|
*/
|
|
|
|
#include <openlibm.h>
|
|
|
|
#include "math_private.h"
|
|
|
|
static const long double one = 1.0;
|
|
|
|
long double
|
|
modfl(long double x, long double *iptr)
|
|
{
|
|
int32_t i0,i1,jj0;
|
|
u_int32_t i,se;
|
|
GET_LDOUBLE_WORDS(se,i0,i1,x);
|
|
jj0 = (se&0x7fff)-0x3fff; /* exponent of x */
|
|
if(jj0<32) { /* integer part in high x */
|
|
if(jj0<0) { /* |x|<1 */
|
|
SET_LDOUBLE_WORDS(*iptr,se&0x8000,0,0); /* *iptr = +-0 */
|
|
return x;
|
|
} else {
|
|
i = (0x7fffffff)>>jj0;
|
|
if(((i0&i)|i1)==0) { /* x is integral */
|
|
*iptr = x;
|
|
SET_LDOUBLE_WORDS(x,se&0x8000,0,0); /* return +-0 */
|
|
return x;
|
|
} else {
|
|
SET_LDOUBLE_WORDS(*iptr,se,i0&(~i),0);
|
|
return x - *iptr;
|
|
}
|
|
}
|
|
} else if (jj0>63) { /* no fraction part */
|
|
*iptr = x*one;
|
|
/* We must handle NaNs separately. */
|
|
if (jj0 == 0x4000 && ((i0 & 0x7fffffff) | i1))
|
|
return x*one;
|
|
SET_LDOUBLE_WORDS(x,se&0x8000,0,0); /* return +-0 */
|
|
return x;
|
|
} else { /* fraction part in low x */
|
|
i = ((u_int32_t)(0x7fffffff))>>(jj0-32);
|
|
if((i1&i)==0) { /* x is integral */
|
|
*iptr = x;
|
|
SET_LDOUBLE_WORDS(x,se&0x8000,0,0); /* return +-0 */
|
|
return x;
|
|
} else {
|
|
SET_LDOUBLE_WORDS(*iptr,se,i0,i1&(~i));
|
|
return x - *iptr;
|
|
}
|
|
}
|
|
}
|