Rev 4872 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4349 | Serge | 1 | /* sf_rint.c -- float version of s_rint.c. |
| 2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
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| 3 | */ |
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| 4 | |||
| 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 | |||
| 16 | #include "fdlibm.h" |
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| 17 | |||
| 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 | |||
| 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,ix; |
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| 37 | float t; |
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| 38 | volatile float w; |
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| 39 | GET_FLOAT_WORD(i0,x); |
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| 40 | sx = (i0>>31)&1; |
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| 41 | ix = (i0&0x7fffffff); |
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| 42 | j0 = (ix>>23)-0x7f; |
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| 43 | if(j0<23) { |
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| 44 | if(FLT_UWORD_IS_ZERO(ix)) |
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| 45 | return x; |
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| 46 | if(j0<0) { |
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| 47 | i1 = (i0&0x07fffff); |
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| 48 | i0 &= 0xfff00000; |
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| 49 | i0 |= ((i1|-i1)>>9)&0x400000; |
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| 50 | SET_FLOAT_WORD(x,i0); |
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| 51 | w = TWO23[sx]+x; |
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| 52 | t = w-TWO23[sx]; |
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| 53 | GET_FLOAT_WORD(i0,t); |
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| 54 | SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31)); |
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| 55 | return t; |
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| 56 | } else { |
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| 57 | i = (0x007fffff)>>j0; |
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| 58 | if((i0&i)==0) return x; /* x is integral */ |
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| 59 | i>>=1; |
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| 60 | if((i0&i)!=0) i0 = (i0&(~i))|((0x200000)>>j0); |
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| 61 | } |
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| 62 | } else { |
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| 63 | if(!FLT_UWORD_IS_FINITE(ix)) return x+x; /* inf or NaN */ |
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| 64 | else |
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| 65 | return x; /* x is integral */ |
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| 66 | } |
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| 67 | SET_FLOAT_WORD(x,i0); |
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| 68 | w = TWO23[sx]+x; |
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| 69 | return w-TWO23[sx]; |
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| 70 | } |
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| 71 | |||
| 72 | #ifdef _DOUBLE_IS_32BITS |
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| 73 | |||
| 74 | #ifdef __STDC__ |
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| 75 | double rint(double x) |
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| 76 | #else |
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| 77 | double rint(x) |
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| 78 | double x; |
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| 79 | #endif |
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| 80 | { |
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| 81 | return (double) rintf((float) x); |
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| 82 | } |
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| 83 | |||
| 84 | #endif /* defined(_DOUBLE_IS_32BITS) */ |