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
| 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 97413 2002-05-28 18:15:04Z alfred $";
| 17static char rcsid[] = "$FreeBSD: head/lib/msun/src/s_rintf.c 130285 2004-06-09 21:24:52Z das $";
|
18#endif 19
| 18#endif 19
|
| 20#include <sys/types.h>
|
20#include "math.h" 21#include "math_private.h" 22
| 21#include "math.h" 22#include "math_private.h" 23
|
23/* 24 * TWO23 is double instead of float to avoid a bug in gcc. Without 25 * this, gcc thinks that TWO23[sx]+x and w-TWO23[sx] already have float 26 * precision and doesn't clip them to float precision when they are 27 * assigned and returned. 28 */ 29static const double
| 24static const float
|
30TWO23[2]={ 31 8.3886080000e+06, /* 0x4b000000 */ 32 -8.3886080000e+06, /* 0xcb000000 */ 33}; 34 35float 36rintf(float x) 37{ 38 int32_t i0,j0,sx;
| 25TWO23[2]={ 26 8.3886080000e+06, /* 0x4b000000 */ 27 -8.3886080000e+06, /* 0xcb000000 */ 28}; 29 30float 31rintf(float x) 32{ 33 int32_t i0,j0,sx;
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39 u_int32_t i,i1; 40 float w,t;
| 34 volatile float w,t; /* volatile works around gcc bug */
|
41 GET_FLOAT_WORD(i0,x); 42 sx = (i0>>31)&1; 43 j0 = ((i0>>23)&0xff)-0x7f; 44 if(j0<23) { 45 if(j0<0) { 46 if((i0&0x7fffffff)==0) return x;
| 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;
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47 i1 = (i0&0x07fffff); 48 i0 &= 0xfff00000; 49 i0 |= ((i1|-i1)>>9)&0x400000; 50 SET_FLOAT_WORD(x,i0);
| |
51 w = TWO23[sx]+x; 52 t = w-TWO23[sx];
| 41 w = TWO23[sx]+x; 42 t = w-TWO23[sx];
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53 GET_FLOAT_WORD(i0,t); 54 SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31));
| |
55 return t;
| 43 return t;
|
56 } else { 57 i = (0x007fffff)>>j0; 58 if((i0&i)==0) return x; /* x is integral */ 59 i>>=1; 60 if((i0&i)!=0) i0 = (i0&(~i))|((0x100000)>>j0);
| |
61 }
| 44 }
|
62 } else { 63 if(j0==0x80) return x+x; /* inf or NaN */ 64 else return x; /* x is integral */
| 45 w = TWO23[sx]+x; 46 return w-TWO23[sx];
|
65 }
| 47 }
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66 SET_FLOAT_WORD(x,i0); 67 w = TWO23[sx]+x; 68 return w-TWO23[sx];
| 48 if(j0==0x80) return x+x; /* inf or NaN */ 49 else return x; /* x is integral */
|
69}
| 50}
|