1 /* @(#)s_floor.c 5.1 93/09/24 */ 2 /* 3 * ==================================================== 4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 5 * 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 9 * is preserved. 10 * ==================================================== 11 */ 12 13 #include "cdefs-compat.h" 14 //__FBSDID("$FreeBSD: src/lib/msun/src/s_truncf.c,v 1.1 2004/06/20 09:25:43 das Exp $"); 15 16 /* 17 * truncf(x) 18 * Return x rounded toward 0 to integral value 19 * Method: 20 * Bit twiddling. 21 * Exception: 22 * Inexact flag raised if x not equal to truncf(x). 23 */ 24 25 #include <openlibm_math.h> 26 27 #include "math_private.h" 28 29 static const float huge = 1.0e30F; 30 31 OLM_DLLEXPORT float 32 truncf(float x) 33 { 34 int32_t i0,j0; 35 u_int32_t i; 36 GET_FLOAT_WORD(i0,x); 37 j0 = ((i0>>23)&0xff)-0x7f; 38 if(j0<23) { 39 if(j0<0) { /* raise inexact if x != 0 */ 40 if(huge+x>0.0F) /* |x|<1, so return 0*sign(x) */ 41 i0 &= 0x80000000; 42 } else { 43 i = (0x007fffff)>>j0; 44 if((i0&i)==0) return x; /* x is integral */ 45 if(huge+x>0.0F) /* raise inexact flag */ 46 i0 &= (~i); 47 } 48 } else { 49 if(j0==0x80) return x+x; /* inf or NaN */ 50 else return x; /* x is integral */ 51 } 52 SET_FLOAT_WORD(x,i0); 53 return x; 54 } 55