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Last change
on this file since 603 was 2, checked in by bird, 23 years ago |
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Initial revision
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Property cvs2svn:cvs-rev
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1.1
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Property svn:eol-style
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native
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Property svn:executable
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*
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File size:
1.6 KB
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| 1 | /* sf_rint.c -- float version of s_rint.c.
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| 2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, [email protected].
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| 3 | */
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| 4 |
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| 5 | /*
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| 6 | * ====================================================
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| 7 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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| 8 | *
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| 9 | * Developed at SunPro, a Sun Microsystems, Inc. business.
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| 10 | * Permission to use, copy, modify, and distribute this
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| 11 | * software is freely granted, provided that this notice
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| 12 | * is preserved.
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| 13 | * ====================================================
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| 14 | */
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| 15 |
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| 16 | #include "fdlibm.h"
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| 17 |
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| 18 | #ifdef __STDC__
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| 19 | static const float
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| 20 | #else
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| 21 | static float
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| 22 | #endif
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| 23 | TWO23[2]={
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| 24 | 8.3886080000e+06, /* 0x4b000000 */
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| 25 | -8.3886080000e+06, /* 0xcb000000 */
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| 26 | };
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| 27 |
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| 28 | #ifdef __STDC__
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| 29 | float rintf(float x)
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| 30 | #else
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| 31 | float rintf(x)
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| 32 | float x;
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| 33 | #endif
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| 34 | {
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| 35 | int32_t i0,j0,sx;
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| 36 | uint32_t i,i1;
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| 37 | float w,t;
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| 38 | GET_FLOAT_WORD(i0,x);
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| 39 | sx = (i0>>31)&1;
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| 40 | j0 = ((i0>>23)&0xff)-0x7f;
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| 41 | if(j0<23) {
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| 42 | if(j0<0) {
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| 43 | if((i0&0x7fffffff)==0) return x;
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| 44 | i1 = (i0&0x07fffff);
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| 45 | i0 &= 0xfff00000;
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| 46 | i0 |= ((i1|-i1)>>9)&0x400000;
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| 47 | SET_FLOAT_WORD(x,i0);
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| 48 | w = TWO23[sx]+x;
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| 49 | t = w-TWO23[sx];
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| 50 | GET_FLOAT_WORD(i0,t);
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| 51 | SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31));
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| 52 | return t;
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| 53 | } else {
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| 54 | i = (0x007fffff)>>j0;
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| 55 | if((i0&i)==0) return x; /* x is integral */
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| 56 | i>>=1;
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| 57 | if((i0&i)!=0) i0 = (i0&(~i))|((0x100000)>>j0);
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| 58 | }
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| 59 | } else {
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| 60 | if(j0==0x80) return x+x; /* inf or NaN */
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| 61 | else return x; /* x is integral */
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| 62 | }
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| 63 | SET_FLOAT_WORD(x,i0);
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| 64 | w = TWO23[sx]+x;
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| 65 | return w-TWO23[sx];
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| 66 | }
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| 67 |
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| 68 | #ifdef _DOUBLE_IS_32BITS
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| 69 |
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| 70 | #ifdef __STDC__
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| 71 | double rint(double x)
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| 72 | #else
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| 73 | double rint(x)
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| 74 | double x;
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| 75 | #endif
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| 76 | {
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| 77 | return (double) rintf((float) x);
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| 78 | }
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| 79 |
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| 80 | #endif /* defined(_DOUBLE_IS_32BITS) */
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