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3362 | Serge | 1 | /* wf_exp.c -- float version of w_exp.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 | /* |
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17 | * wrapper expf(x) |
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18 | */ |
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19 | |||
20 | #include "fdlibm.h" |
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21 | #include |
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22 | |||
23 | #ifdef __STDC__ |
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24 | static const float |
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25 | #else |
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26 | static float |
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27 | #endif |
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28 | o_threshold= 8.8721679688e+01, /* 0x42b17180 */ |
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29 | u_threshold= -1.0397208405e+02; /* 0xc2cff1b5 */ |
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30 | |||
31 | #ifdef __STDC__ |
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32 | float expf(float x) /* wrapper expf */ |
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33 | #else |
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34 | float expf(x) /* wrapper expf */ |
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35 | float x; |
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36 | #endif |
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37 | { |
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38 | #ifdef _IEEE_LIBM |
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39 | return __ieee754_expf(x); |
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40 | #else |
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41 | float z; |
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42 | struct exception exc; |
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43 | z = __ieee754_expf(x); |
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44 | if(_LIB_VERSION == _IEEE_) return z; |
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45 | if(finitef(x)) { |
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46 | if(x>o_threshold) { |
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47 | /* expf(finite) overflow */ |
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48 | #ifndef HUGE_VAL |
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49 | #define HUGE_VAL inf |
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50 | double inf = 0.0; |
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51 | |||
52 | SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */ |
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53 | #endif |
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54 | exc.type = OVERFLOW; |
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55 | exc.name = "expf"; |
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56 | exc.err = 0; |
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57 | exc.arg1 = exc.arg2 = (double)x; |
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58 | if (_LIB_VERSION == _SVID_) |
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59 | exc.retval = HUGE; |
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60 | else |
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61 | exc.retval = HUGE_VAL; |
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62 | if (_LIB_VERSION == _POSIX_) |
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63 | errno = ERANGE; |
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64 | else if (!matherr(&exc)) { |
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65 | errno = ERANGE; |
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66 | } |
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67 | if (exc.err != 0) |
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68 | errno = exc.err; |
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69 | return exc.retval; |
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70 | } else if(x |
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71 | /* expf(finite) underflow */ |
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72 | exc.type = UNDERFLOW; |
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73 | exc.name = "expf"; |
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74 | exc.err = 0; |
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75 | exc.arg1 = exc.arg2 = (double)x; |
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76 | exc.retval = 0.0; |
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77 | if (_LIB_VERSION == _POSIX_) |
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78 | errno = ERANGE; |
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79 | else if (!matherr(&exc)) { |
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80 | errno = ERANGE; |
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81 | } |
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82 | if (exc.err != 0) |
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83 | errno = exc.err; |
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84 | return exc.retval; |
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85 | } |
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86 | } |
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87 | return z; |
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88 | #endif |
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89 | } |
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90 | |||
91 | #ifdef _DOUBLE_IS_32BITS |
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92 | |||
93 | #ifdef __STDC__ |
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94 | double exp(double x) |
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95 | #else |
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96 | double exp(x) |
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97 | double x; |
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98 | #endif |
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99 | { |
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100 | return (double) expf((float) x); |
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101 | } |
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102 | |||
103 | #endif /* defined(_DOUBLE_IS_32BITS) */ |