1 | #include <stdio.h>
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2 | #include <float.h>
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3 | #include <signal.h>
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4 |
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5 | #define JSDOUBLE_HI32_SIGNBIT 0x80000000
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6 | #define JSDOUBLE_HI32_EXPMASK 0x7ff00000
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7 | #define JSDOUBLE_HI32_MANTMASK 0x000fffff
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8 | #define JSVAL_INT_POW2(n) ((unsigned long)1 << (n))
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9 | #define JSVAL_INT_MAX (JSVAL_INT_POW2(30) - 1)
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10 | #define JSVAL_INT_MIN ((unsigned long)1 - JSVAL_INT_POW2(30))
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11 |
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12 | typedef unsigned uint32;
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13 | typedef uint32 jsuint;
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14 | typedef int jsint;
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15 |
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16 |
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17 | #define JSDOUBLE_HI32(x) (((uint32 *)&(x))[1])
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18 | #define JSDOUBLE_LO32(x) (((uint32 *)&(x))[0])
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19 |
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20 | #define JSDOUBLE_IS_NEGZERO(d) (JSDOUBLE_HI32(d) == JSDOUBLE_HI32_SIGNBIT && \
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21 | JSDOUBLE_LO32(d) == 0)
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22 | #define JSDOUBLE_IS_FINITE(x) \
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23 | ((JSDOUBLE_HI32(x) & JSDOUBLE_HI32_EXPMASK) != JSDOUBLE_HI32_EXPMASK)
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24 |
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25 | #define JSDOUBLE_IS_INT(d, i) (JSDOUBLE_IS_FINITE(d) \
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26 | && !JSDOUBLE_IS_NEGZERO(d) \
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27 | && ((d) == (i = (jsint)(d))))
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28 |
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29 | #define INT_FITS_IN_JSVAL(i) ((jsuint)((i)+JSVAL_INT_MAX) <= 2*JSVAL_INT_MAX)
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30 |
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31 |
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32 | int js_NewNumberValue(void *cx, double d, int *rval)
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33 | {
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34 | int i = -1;
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35 | _control87(0x262, 0xFFF);
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36 | #if 1
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37 | if ( JSDOUBLE_IS_INT(d, i)
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38 | && INT_FITS_IN_JSVAL(i))
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39 | {
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40 | *rval = i;
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41 | return 1;
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42 | }
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43 |
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44 | #else
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45 | if (((((unsigned *)&d)[1]) & JSDOUBLE_HI32_EXPMASK) != JSDOUBLE_HI32_EXPMASK )
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46 | if ( !((((unsigned *)&d)[1]) == JSDOUBLE_HI32_SIGNBIT && (((unsigned *)&d)[0]) == 0))
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47 | if (d == (i = (int)d))
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48 | if ((unsigned long)((i)+JSVAL_INT_MAX) <= 2*JSVAL_INT_MAX)
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49 | return i;
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50 | #endif
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51 | *rval = i;
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52 | return 0;
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53 | }
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54 |
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55 | void sigfun(int sig)
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56 | {
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57 | printf("SIGFPE!\n");
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58 | }
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59 |
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60 | int main()
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61 | {
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62 | double rd1 = 0.0;
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63 | double rd2 = 1.000000000e8;
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64 | double rd3 = 2.147746133e9;
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65 | int l = -1;
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66 |
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67 | _control87(0x262, 0xFFF);
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68 | signal(SIGFPE, sigfun);
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69 |
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70 | l = -1;
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71 | js_NewNumberValue(NULL, rd1, &l);
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72 | printf("%11d %f\n", l, rd1);
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73 |
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74 | l = -1;
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75 | js_NewNumberValue(NULL, rd2, &l);
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76 | printf("%11d %f\n", l, rd2);
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77 |
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78 | l = -1;
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79 | js_NewNumberValue(NULL, rd3, &l);
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80 | printf("%11d %f\n", l, rd3);
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81 | return 0;
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82 | }
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83 |
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