s_rintf.c revision 175480
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#ifndef lint 17static char rcsid[] = "$FreeBSD: head/lib/msun/src/s_rintf.c 175480 2008-01-19 16:37:57Z bde $"; 18#endif 19 20#include <float.h> 21#include <stdint.h> 22 23#include "math.h" 24#include "math_private.h" 25 26static const float 27TWO23[2]={ 28 8.3886080000e+06, /* 0x4b000000 */ 29 -8.3886080000e+06, /* 0xcb000000 */ 30}; 31 32float 33rintf(float x) 34{ 35 int32_t i0,j0,sx; 36 float w,t; 37 GET_FLOAT_WORD(i0,x); 38 sx = (i0>>31)&1; 39 j0 = ((i0>>23)&0xff)-0x7f; 40 if(j0<23) { 41 if(j0<0) { 42 if((i0&0x7fffffff)==0) return x; 43 STRICT_ASSIGN(float,w,TWO23[sx]+x); 44 t = w-TWO23[sx]; 45 GET_FLOAT_WORD(i0,t); 46 SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31)); 47 return t; 48 } 49 STRICT_ASSIGN(float,w,TWO23[sx]+x); 50 return w-TWO23[sx]; 51 } 52 if(j0==0x80) return x+x; /* inf or NaN */ 53 else return x; /* x is integral */ 54} 55