1 /* @(#)s_modf.c 5.1 93/09/24 */
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
10 * ====================================================
13 #if defined(LIBM_SCCS) && !defined(lint)
14 static char rcsid[] = "$NetBSD: s_modf.c,v 1.8 1995/05/10 20:47:55 jtc Exp $";
18 * modf(double x, double *iptr)
19 * return fraction part of x, and return x's integral part in *iptr.
28 #include "math_private.h"
31 static const double one = 1.0;
33 static double one = 1.0;
37 double modf(double x, double *iptr)
45 EXTRACT_WORDS(i0,i1,x);
46 j0 = ((i0>>20)&0x7ff)-0x3ff; /* exponent of x */
47 if(j0<20) { /* integer part in high x */
48 if(j0<0) { /* |x|<1 */
49 INSERT_WORDS(*iptr,i0&0x80000000,0); /* *iptr = +-0 */
53 if(((i0&i)|i1)==0) { /* x is integral */
56 GET_HIGH_WORD(high,x);
57 INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */
60 INSERT_WORDS(*iptr,i0&(~i),0);
64 } else if (j0>51) { /* no fraction part */
67 GET_HIGH_WORD(high,x);
68 INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */
70 } else { /* fraction part in low x */
71 i = ((u_int32_t)(0xffffffff))>>(j0-20);
72 if((i1&i)==0) { /* x is integral */
75 GET_HIGH_WORD(high,x);
76 INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */
79 INSERT_WORDS(*iptr,i0,i1&(~i));