Mercurial > hg > CbC > CbC_gcc

annotate libquadmath/math/cbrtq.c @ 72:20c18990c3e4

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merge gcc/c-typeck.c
author Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
date Sun, 21 Aug 2011 22:22:32 +0900
parents 561a7518be6b
children 04ced10e8804
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rev   line source
68
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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1 #include "quadmath-imp.h"
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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2 #include <math.h>
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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3 #include <float.h>
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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4
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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5 __float128
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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6 cbrtq (const __float128 x)
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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7 {
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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8 __float128 y;
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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9 int exp, i;
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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10
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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11 if (x == 0)
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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12 return x;
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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13
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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14 if (isnanq (x))
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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15 return x;
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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16
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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17 if (x <= DBL_MAX && x >= DBL_MIN)
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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18 {
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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19 /* Use double result as starting point. */
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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20 y = cbrt ((double) x);
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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21
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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22 /* Two Newton iterations. */
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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23 y -= 0.333333333333333333333333333333333333333333333333333Q
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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24 * (y - x / (y * y));
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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25 y -= 0.333333333333333333333333333333333333333333333333333Q
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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26 * (y - x / (y * y));
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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27 return y;
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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28 }
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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29
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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30 #ifdef HAVE_CBRTL
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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31 if (x <= LDBL_MAX && x >= LDBL_MIN)
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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32 {
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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33 /* Use long double result as starting point. */
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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34 y = cbrtl ((long double) x);
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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35
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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36 /* One Newton iteration. */
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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37 y -= 0.333333333333333333333333333333333333333333333333333Q
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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38 * (y - x / (y * y));
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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39 return y;
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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40 }
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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41 #endif
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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42
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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43 /* If we're outside of the range of C types, we have to compute
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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44 the initial guess the hard way. */
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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45 y = frexpq (x, &exp);
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46
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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47 i = exp % 3;
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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48 y = (i >= 0 ? i : -i);
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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49 if (i == 1)
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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50 y *= 2, exp--;
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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51 else if (i == 2)
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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52 y *= 4, exp -= 2;
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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53
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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54 y = cbrt (y);
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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55 y = scalbnq (y, exp / 3);
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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56
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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57 /* Two Newton iterations. */
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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58 y -= 0.333333333333333333333333333333333333333333333333333Q
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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59 * (y - x / (y * y));
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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60 y -= 0.333333333333333333333333333333333333333333333333333Q
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
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61 * (y - x / (y * y));
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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62 return y;
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Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp>
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63 }
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64