1 /* s_modff.c -- float version of s_modf.c. 2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 3 */ 4 5 /* 6 * ==================================================== 7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 8 * 9 * Developed at SunPro, a Sun Microsystems, Inc. business. 10 * Permission to use, copy, modify, and distribute this 11 * software is freely granted, provided that this notice 12 * is preserved. 13 * ==================================================== 14 */ 15 16 #include <sys/cdefs.h> 17 #if defined(LIBM_SCCS) && !defined(lint) 18 __RCSID("$NetBSD: s_modff.c,v 1.9 2010/01/27 14:07:41 drochner Exp $"); 19 #endif 20 21 #include "math.h" 22 #include "math_private.h" 23 24 static const float one = 1.0; 25 26 float 27 modff(float x, float *iptr) 28 { 29 int32_t i0,jj0; 30 u_int32_t i; 31 GET_FLOAT_WORD(i0,x); 32 jj0 = ((i0>>23)&0xff)-0x7f; /* exponent of x */ 33 if(jj0<23) { /* integer part in x */ 34 if(jj0<0) { /* |x|<1 */ 35 SET_FLOAT_WORD(*iptr,i0&0x80000000); /* *iptr = +-0 */ 36 return x; 37 } else { 38 i = (0x007fffff)>>jj0; 39 if((i0&i)==0) { /* x is integral */ 40 u_int32_t ix; 41 *iptr = x; 42 GET_FLOAT_WORD(ix,x); 43 SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */ 44 return x; 45 } else { 46 SET_FLOAT_WORD(*iptr,i0&(~i)); 47 return x - *iptr; 48 } 49 } 50 } else { /* no fraction part */ 51 u_int32_t ix; 52 *iptr = x*one; 53 if (jj0 == 0x80) /* +-inf or NaN */ 54 return 0.0 / x; /* +-0 or NaN */ 55 GET_FLOAT_WORD(ix,x); 56 SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */ 57 return x; 58 } 59 } 60