1 /* sf_rint.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 "fdlibm.h" 17 18 #ifdef __STDC__ 19 static const float 20 #else 21 static float 22 #endif 23 TWO23[2]={ 24 8.3886080000e+06, /* 0x4b000000 */ 25 -8.3886080000e+06, /* 0xcb000000 */ 26 }; 27 28 #ifdef __STDC__ rintf(float x)29 float rintf(float x) 30 #else 31 float rintf(x) 32 float x; 33 #endif 34 { 35 int32_t i0,j0,sx; 36 uint32_t i,i1; 37 float w,t; 38 GET_FLOAT_WORD(i0,x); 39 sx = (i0>>31)&1; 40 j0 = ((i0>>23)&0xff)-0x7f; 41 if(j0<23) { 42 if(j0<0) { 43 if((i0&0x7fffffff)==0) return x; 44 i1 = (i0&0x07fffff); 45 i0 &= 0xfff00000; 46 i0 |= ((i1|-i1)>>9)&0x400000; 47 SET_FLOAT_WORD(x,i0); 48 w = TWO23[sx]+x; 49 t = w-TWO23[sx]; 50 GET_FLOAT_WORD(i0,t); 51 SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31)); 52 return t; 53 } else { 54 i = (0x007fffff)>>j0; 55 if((i0&i)==0) return x; /* x is integral */ 56 i>>=1; 57 if((i0&i)!=0) i0 = (i0&(~i))|((0x100000)>>j0); 58 } 59 } else { 60 if(j0==0x80) return x+x; /* inf or NaN */ 61 else return x; /* x is integral */ 62 } 63 SET_FLOAT_WORD(x,i0); 64 w = TWO23[sx]+x; 65 return w-TWO23[sx]; 66 } 67 68 #ifdef _DOUBLE_IS_32BITS 69 70 #ifdef __STDC__ rint(double x)71 double rint(double x) 72 #else 73 double rint(x) 74 double x; 75 #endif 76 { 77 return (double) rintf((float) x); 78 } 79 80 #endif /* defined(_DOUBLE_IS_32BITS) */ 81