Last change
on this file since 403 was 337, checked in by coas-nagasima, 6 years ago |
ASP3版ECNLを追加
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Property svn:eol-style
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Property svn:mime-type
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File size:
597 bytes
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1 | #include "libm.h"
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2 |
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3 | #if FLT_EVAL_METHOD==0 || FLT_EVAL_METHOD==1
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4 | #define EPS DBL_EPSILON
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5 | #elif FLT_EVAL_METHOD==2
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6 | #define EPS LDBL_EPSILON
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7 | #endif
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8 | static const double_t toint = 1/EPS;
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9 |
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10 | double round(double x)
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11 | {
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12 | union {double f; uint64_t i;} u = {x};
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13 | int e = u.i >> 52 & 0x7ff;
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14 | double_t y;
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15 |
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16 | if (e >= 0x3ff+52)
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17 | return x;
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18 | if (u.i >> 63)
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19 | x = -x;
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20 | if (e < 0x3ff-1) {
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21 | /* raise inexact if x!=0 */
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22 | FORCE_EVAL(x + toint);
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23 | return 0*u.f;
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24 | }
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25 | y = x + toint - toint - x;
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26 | if (y > 0.5)
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27 | y = y + x - 1;
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28 | else if (y <= -0.5)
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29 | y = y + x + 1;
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30 | else
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31 | y = y + x;
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32 | if (u.i >> 63)
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33 | y = -y;
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34 | return y;
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35 | }
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