1 /* s_rintf.c -- float version of s_rint.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 __FBSDID("$FreeBSD: src/lib/msun/src/s_rintf.c,v 1.12 2008/02/22 02:30:35 das Exp $"); 18 19 #include <float.h> 20 #include <stdint.h> 21 22 #include "math.h" 23 #include "math_private.h" 24 25 static const float 26 TWO23[2]={ 27 8.3886080000e+06, /* 0x4b000000 */ 28 -8.3886080000e+06, /* 0xcb000000 */ 29 }; 30 31 float 32 rintf(float x) 33 { 34 int32_t i0,j0,sx; 35 float w,t; 36 GET_FLOAT_WORD(i0,x); 37 sx = (i0>>31)&1; 38 j0 = ((i0>>23)&0xff)-0x7f; 39 if(j0<23) { 40 if(j0<0) { 41 if((i0&0x7fffffff)==0) return x; 42 STRICT_ASSIGN(float,w,TWO23[sx]+x); 43 t = w-TWO23[sx]; 44 GET_FLOAT_WORD(i0,t); 45 SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31)); 46 return t; 47 } 48 STRICT_ASSIGN(float,w,TWO23[sx]+x); 49 return w-TWO23[sx]; 50 } 51 if(j0==0x80) return x+x; /* inf or NaN */ 52 else return x; /* x is integral */ 53 } 54