1 /* s_rintf.c -- float version of s_rint.c. 2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian (at) 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_rintf.c,v 1.10 2005/12/03 09:00:29 bde Exp $"; 18 #endif 19 20 #include <sys/types.h> 21 #include "math.h" 22 #include "math_private.h" 23 24 static const float 25 TWO23[2]={ 26 8.3886080000e+06, /* 0x4b000000 */ 27 -8.3886080000e+06, /* 0xcb000000 */ 28 }; 29 30 float 31 rintf(float x) 32 { 33 int32_t i0,j0,sx; 34 volatile float w,t; /* volatile works around gcc bug */ 35 GET_FLOAT_WORD(i0,x); 36 sx = (i0>>31)&1; 37 j0 = ((i0>>23)&0xff)-0x7f; 38 if(j0<23) { 39 if(j0<0) { 40 if((i0&0x7fffffff)==0) return x; 41 w = TWO23[sx]+x; 42 t = w-TWO23[sx]; 43 GET_FLOAT_WORD(i0,t); 44 SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31)); 45 return t; 46 } 47 w = TWO23[sx]+x; 48 return w-TWO23[sx]; 49 } 50 if(j0==0x80) return x+x; /* inf or NaN */ 51 else return x; /* x is integral */ 52 } 53
