s_modff.c (1459B)
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 #ifndef lint 17 static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_modff.c,v 1.7 2002/05/28 18:15:04 alfred Exp $"; 18 #endif 19 20 #include "math.h" 21 #include "math_private.h" 22 23 static const float one = 1.0; 24 25 float 26 modff(float x, float *iptr) 27 { 28 int32_t i0,j0; 29 u_int32_t i; 30 GET_FLOAT_WORD(i0,x); 31 j0 = ((i0>>23)&0xff)-0x7f; /* exponent of x */ 32 if(j0<23) { /* integer part in x */ 33 if(j0<0) { /* |x|<1 */ 34 SET_FLOAT_WORD(*iptr,i0&0x80000000); /* *iptr = +-0 */ 35 return x; 36 } else { 37 i = (0x007fffff)>>j0; 38 if((i0&i)==0) { /* x is integral */ 39 u_int32_t ix; 40 *iptr = x; 41 GET_FLOAT_WORD(ix,x); 42 SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */ 43 return x; 44 } else { 45 SET_FLOAT_WORD(*iptr,i0&(~i)); 46 return x - *iptr; 47 } 48 } 49 } else { /* no fraction part */ 50 u_int32_t ix; 51 *iptr = x*one; 52 GET_FLOAT_WORD(ix,x); 53 SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */ 54 return x; 55 } 56 }