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 <float.h> 17 #include <stdint.h> 18 19 #include "math.h" 20 #include "math_private.h" 21 22 static const float 23 TWO23[2]={ 24 8.3886080000e+06, /* 0x4b000000 */ 25 -8.3886080000e+06, /* 0xcb000000 */ 26 }; 27 28 float 29 rintf(float x) 30 { 31 int32_t i0,j0,sx; 32 float w,t; 33 GET_FLOAT_WORD(i0,x); 34 sx = (i0>>31)&1; 35 j0 = ((i0>>23)&0xff)-0x7f; 36 if(j0<23) { 37 if(j0<0) { 38 if((i0&0x7fffffff)==0) return x; 39 STRICT_ASSIGN(float,w,TWO23[sx]+x); 40 t = w-TWO23[sx]; 41 GET_FLOAT_WORD(i0,t); 42 SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31)); 43 return t; 44 } 45 STRICT_ASSIGN(float,w,TWO23[sx]+x); 46 return w-TWO23[sx]; 47 } 48 if(j0==0x80) return x+x; /* inf or NaN */ 49 else return x; /* x is integral */ 50 } 51