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| Rev | Author | Line No. | Line |
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| 4349 | Serge | 1 | |
| 2 | |||
| 3 | * ==================================================== |
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| 4 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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| 5 | * |
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| 6 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
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| 7 | * Permission to use, copy, modify, and distribute this |
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| 8 | * software is freely granted, provided that this notice |
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| 9 | * is preserved. |
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| 10 | * ==================================================== |
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| 11 | */ |
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| 12 | |||
| 13 | /* |
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| 14 | |||
| 15 | < |
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| 16 | INDEX |
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| 17 | pow |
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| 18 | INDEX |
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| 19 | powf |
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| 20 | |||
| 21 | |||
| 22 | |||
| 23 | |||
| 24 | double pow(double <[x]>, double <[y]>); |
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| 25 | float powf(float <[x]>, float <[y]>); |
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| 26 | |||
| 27 | TRAD_SYNOPSIS |
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| 28 | |||
| 29 | double pow(<[x]>, <[y]>); |
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| 30 | double <[x]>, <[y]>; |
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| 31 | |||
| 32 | float powf(<[x]>, <[y]>); |
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| 33 | |||
| 34 | |||
| 35 | DESCRIPTION |
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| 36 | |||
| 37 | @tex |
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| 38 | (That is, $x^y$.) |
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| 39 | @end tex |
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| 40 | |||
| 41 | RETURNS |
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| 42 | |||
| 43 | |||
| 44 | When the argument values would produce overflow, < |
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| 45 | |||
| 46 | argument <[x]> passed to < |
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| 47 | noninteger, and <[y]> is also not an integer, then < |
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| 48 | is set to < |
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| 49 | < |
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| 50 | |||
| 51 | You can modify error handling for these functions using < |
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| 52 | |||
| 53 | PORTABILITY |
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| 54 | |||
| 55 | |||
| 56 | /* |
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| 57 | |||
| 58 | */ |
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| 59 | |||
| 60 | #include "fdlibm.h" |
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| 61 | |||
| 62 | |||
| 63 | #ifndef _DOUBLE_IS_32BITS |
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| 64 | |||
| 65 | #ifdef __STDC__ |
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| 66 | |||
| 67 | #else |
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| 68 | double pow(x,y) /* wrapper pow */ |
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| 69 | double x,y; |
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| 70 | #endif |
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| 71 | { |
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| 72 | #ifdef _IEEE_LIBM |
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| 73 | return __ieee754_pow(x,y); |
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| 74 | #else |
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| 75 | double z; |
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| 76 | #ifndef HUGE_VAL |
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| 77 | #define HUGE_VAL inf |
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| 78 | double inf = 0.0; |
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| 79 | |||
| 80 | SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */ |
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| 81 | |||
| 82 | struct exception exc; |
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| 83 | z=__ieee754_pow(x,y); |
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| 84 | if(_LIB_VERSION == _IEEE_|| isnan(y)) return z; |
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| 85 | if(isnan(x)) { |
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| 86 | if(y==0.0) { |
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| 87 | /* pow(NaN,0.0) */ |
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| 88 | /* error only if _LIB_VERSION == _SVID_ & _XOPEN_ */ |
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| 89 | exc.type = DOMAIN; |
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| 90 | exc.name = "pow"; |
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| 91 | exc.err = 0; |
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| 92 | exc.arg1 = x; |
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| 93 | exc.arg2 = y; |
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| 94 | exc.retval = 1.0; |
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| 95 | if (_LIB_VERSION == _IEEE_ || |
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| 96 | _LIB_VERSION == _POSIX_) exc.retval = 1.0; |
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| 97 | else if (!matherr(&exc)) { |
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| 98 | errno = EDOM; |
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| 99 | } |
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| 100 | if (exc.err != 0) |
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| 101 | errno = exc.err; |
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| 102 | return exc.retval; |
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| 103 | } else |
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| 104 | return z; |
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| 105 | } |
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| 106 | if(x==0.0){ |
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| 107 | if(y==0.0) { |
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| 108 | /* pow(0.0,0.0) */ |
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| 109 | /* error only if _LIB_VERSION == _SVID_ */ |
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| 110 | exc.type = DOMAIN; |
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| 111 | exc.name = "pow"; |
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| 112 | exc.err = 0; |
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| 113 | exc.arg1 = x; |
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| 114 | exc.arg2 = y; |
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| 115 | exc.retval = 0.0; |
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| 116 | if (_LIB_VERSION != _SVID_) exc.retval = 1.0; |
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| 117 | else if (!matherr(&exc)) { |
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| 118 | errno = EDOM; |
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| 119 | } |
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| 120 | if (exc.err != 0) |
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| 121 | errno = exc.err; |
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| 122 | return exc.retval; |
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| 123 | } |
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| 124 | if(finite(y)&&y<0.0) { |
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| 125 | /* 0**neg */ |
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| 126 | exc.type = DOMAIN; |
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| 127 | exc.name = "pow"; |
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| 128 | exc.err = 0; |
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| 129 | exc.arg1 = x; |
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| 130 | exc.arg2 = y; |
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| 131 | if (_LIB_VERSION == _SVID_) |
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| 132 | exc.retval = 0.0; |
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| 133 | else |
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| 134 | exc.retval = -HUGE_VAL; |
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| 135 | if (_LIB_VERSION == _POSIX_) |
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| 136 | errno = EDOM; |
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| 137 | else if (!matherr(&exc)) { |
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| 138 | errno = EDOM; |
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| 139 | } |
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| 140 | if (exc.err != 0) |
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| 141 | errno = exc.err; |
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| 142 | return exc.retval; |
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| 143 | } |
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| 144 | return z; |
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| 145 | } |
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| 146 | if(!finite(z)) { |
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| 147 | if(finite(x)&&finite(y)) { |
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| 148 | if(isnan(z)) { |
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| 149 | /* neg**non-integral */ |
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| 150 | exc.type = DOMAIN; |
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| 151 | exc.name = "pow"; |
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| 152 | exc.err = 0; |
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| 153 | exc.arg1 = x; |
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| 154 | exc.arg2 = y; |
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| 155 | if (_LIB_VERSION == _SVID_) |
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| 156 | exc.retval = 0.0; |
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| 157 | else |
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| 158 | exc.retval = 0.0/0.0; /* X/Open allow NaN */ |
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| 159 | if (_LIB_VERSION == _POSIX_) |
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| 160 | errno = EDOM; |
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| 161 | else if (!matherr(&exc)) { |
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| 162 | errno = EDOM; |
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| 163 | } |
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| 164 | if (exc.err != 0) |
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| 165 | errno = exc.err; |
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| 166 | return exc.retval; |
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| 167 | } else { |
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| 168 | /* pow(x,y) overflow */ |
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| 169 | exc.type = OVERFLOW; |
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| 170 | exc.name = "pow"; |
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| 171 | exc.err = 0; |
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| 172 | exc.arg1 = x; |
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| 173 | exc.arg2 = y; |
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| 174 | if (_LIB_VERSION == _SVID_) { |
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| 175 | exc.retval = HUGE; |
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| 176 | y *= 0.5; |
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| 177 | if(x<0.0&&rint(y)!=y) exc.retval = -HUGE; |
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| 178 | } else { |
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| 179 | exc.retval = HUGE_VAL; |
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| 180 | y *= 0.5; |
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| 181 | if(x<0.0&&rint(y)!=y) exc.retval = -HUGE_VAL; |
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| 182 | } |
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| 183 | if (_LIB_VERSION == _POSIX_) |
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| 184 | errno = ERANGE; |
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| 185 | else if (!matherr(&exc)) { |
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| 186 | errno = ERANGE; |
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| 187 | } |
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| 188 | if (exc.err != 0) |
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| 189 | errno = exc.err; |
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| 190 | return exc.retval; |
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| 191 | } |
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| 192 | } |
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| 193 | } |
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| 194 | if(z==0.0&&finite(x)&&finite(y)) { |
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| 195 | /* pow(x,y) underflow */ |
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| 196 | exc.type = UNDERFLOW; |
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| 197 | exc.name = "pow"; |
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| 198 | exc.err = 0; |
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| 199 | exc.arg1 = x; |
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| 200 | exc.arg2 = y; |
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| 201 | exc.retval = 0.0; |
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| 202 | if (_LIB_VERSION == _POSIX_) |
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| 203 | errno = ERANGE; |
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| 204 | else if (!matherr(&exc)) { |
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| 205 | errno = ERANGE; |
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| 206 | } |
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| 207 | if (exc.err != 0) |
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| 208 | errno = exc.err; |
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| 209 | return exc.retval; |
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| 210 | } |
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| 211 | return z; |
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| 212 | #endif |
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| 213 | } |
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| 214 | |||
| 215 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
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| 216 |