[444] | 1 | /* wf_pow.c -- float version of w_pow.c. |
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| 2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
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| 3 | */ |
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| 4 | |
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| 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 | |
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| 16 | /* |
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| 17 | * wrapper powf(x,y) return x**y |
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| 18 | */ |
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| 19 | |
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| 20 | #include "fdlibm.h" |
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| 21 | #if __OBSOLETE_MATH |
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| 22 | #include <errno.h> |
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| 23 | |
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| 24 | #ifdef __STDC__ |
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| 25 | float powf(float x, float y) /* wrapper powf */ |
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| 26 | #else |
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| 27 | float powf(x,y) /* wrapper powf */ |
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| 28 | float x,y; |
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| 29 | #endif |
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| 30 | { |
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| 31 | #ifdef _IEEE_LIBM |
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| 32 | return __ieee754_powf(x,y); |
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| 33 | #else |
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| 34 | float z; |
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| 35 | struct exception exc; |
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| 36 | z=__ieee754_powf(x,y); |
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| 37 | if(_LIB_VERSION == _IEEE_|| isnan(y)) return z; |
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| 38 | if(isnan(x)) { |
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| 39 | if(y==(float)0.0) { |
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| 40 | /* powf(NaN,0.0) */ |
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| 41 | /* error only if _LIB_VERSION == _SVID_ & _XOPEN_ */ |
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| 42 | exc.type = DOMAIN; |
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| 43 | exc.name = "powf"; |
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| 44 | exc.err = 0; |
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| 45 | exc.arg1 = (double)x; |
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| 46 | exc.arg2 = (double)y; |
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| 47 | exc.retval = 1.0; |
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| 48 | if (_LIB_VERSION == _IEEE_ || |
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| 49 | _LIB_VERSION == _POSIX_) exc.retval = 1.0; |
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| 50 | else if (!matherr(&exc)) { |
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| 51 | errno = EDOM; |
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| 52 | } |
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| 53 | if (exc.err != 0) |
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| 54 | errno = exc.err; |
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| 55 | return (float)exc.retval; |
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| 56 | } else |
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| 57 | return z; |
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| 58 | } |
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| 59 | if(x==(float)0.0){ |
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| 60 | if(y==(float)0.0) { |
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| 61 | /* powf(0.0,0.0) */ |
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| 62 | /* error only if _LIB_VERSION == _SVID_ */ |
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| 63 | exc.type = DOMAIN; |
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| 64 | exc.name = "powf"; |
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| 65 | exc.err = 0; |
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| 66 | exc.arg1 = (double)x; |
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| 67 | exc.arg2 = (double)y; |
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| 68 | exc.retval = 0.0; |
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| 69 | if (_LIB_VERSION != _SVID_) exc.retval = 1.0; |
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| 70 | else if (!matherr(&exc)) { |
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| 71 | errno = EDOM; |
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| 72 | } |
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| 73 | if (exc.err != 0) |
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| 74 | errno = exc.err; |
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| 75 | return (float)exc.retval; |
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| 76 | } |
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| 77 | if(finitef(y)&&y<(float)0.0) { |
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| 78 | /* 0**neg */ |
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| 79 | exc.type = DOMAIN; |
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| 80 | exc.name = "powf"; |
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| 81 | exc.err = 0; |
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| 82 | exc.arg1 = (double)x; |
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| 83 | exc.arg2 = (double)y; |
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| 84 | if (_LIB_VERSION == _SVID_) |
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| 85 | exc.retval = 0.0; |
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| 86 | else |
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| 87 | exc.retval = -HUGE_VAL; |
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| 88 | if (_LIB_VERSION == _POSIX_) |
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| 89 | errno = EDOM; |
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| 90 | else if (!matherr(&exc)) { |
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| 91 | errno = EDOM; |
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| 92 | } |
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| 93 | if (exc.err != 0) |
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| 94 | errno = exc.err; |
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| 95 | return (float)exc.retval; |
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| 96 | } |
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| 97 | return z; |
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| 98 | } |
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| 99 | if(!finitef(z)) { |
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| 100 | if(finitef(x)&&finitef(y)) { |
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| 101 | if(isnan(z)) { |
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| 102 | /* neg**non-integral */ |
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| 103 | exc.type = DOMAIN; |
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| 104 | exc.name = "powf"; |
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| 105 | exc.err = 0; |
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| 106 | exc.arg1 = (double)x; |
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| 107 | exc.arg2 = (double)y; |
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| 108 | if (_LIB_VERSION == _SVID_) |
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| 109 | exc.retval = 0.0; |
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| 110 | else |
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| 111 | /* Use a float divide, to avoid a soft-float double |
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| 112 | divide call on single-float only targets. */ |
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| 113 | exc.retval = (0.0f/0.0f); /* X/Open allow NaN */ |
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| 114 | if (_LIB_VERSION == _POSIX_) |
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| 115 | errno = EDOM; |
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| 116 | else if (!matherr(&exc)) { |
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| 117 | errno = EDOM; |
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| 118 | } |
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| 119 | if (exc.err != 0) |
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| 120 | errno = exc.err; |
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| 121 | return (float)exc.retval; |
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| 122 | } else { |
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| 123 | /* powf(x,y) overflow */ |
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| 124 | exc.type = OVERFLOW; |
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| 125 | exc.name = "powf"; |
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| 126 | exc.err = 0; |
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| 127 | exc.arg1 = (double)x; |
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| 128 | exc.arg2 = (double)y; |
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| 129 | if (_LIB_VERSION == _SVID_) { |
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| 130 | exc.retval = HUGE; |
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| 131 | y *= 0.5; |
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| 132 | if(x<0.0f&&rintf(y)!=y) exc.retval = -HUGE; |
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| 133 | } else { |
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| 134 | exc.retval = HUGE_VAL; |
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| 135 | y *= 0.5; |
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| 136 | if(x<0.0f&&rintf(y)!=y) exc.retval = -HUGE_VAL; |
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| 137 | } |
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| 138 | if (_LIB_VERSION == _POSIX_) |
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| 139 | errno = ERANGE; |
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| 140 | else if (!matherr(&exc)) { |
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| 141 | errno = ERANGE; |
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| 142 | } |
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| 143 | if (exc.err != 0) |
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| 144 | errno = exc.err; |
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| 145 | return (float)exc.retval; |
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| 146 | } |
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| 147 | } |
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| 148 | } |
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| 149 | if(z==(float)0.0&&finitef(x)&&finitef(y)) { |
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| 150 | /* powf(x,y) underflow */ |
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| 151 | exc.type = UNDERFLOW; |
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| 152 | exc.name = "powf"; |
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| 153 | exc.err = 0; |
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| 154 | exc.arg1 = (double)x; |
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| 155 | exc.arg2 = (double)y; |
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| 156 | exc.retval = 0.0; |
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| 157 | if (_LIB_VERSION == _POSIX_) |
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| 158 | errno = ERANGE; |
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| 159 | else if (!matherr(&exc)) { |
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| 160 | errno = ERANGE; |
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| 161 | } |
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| 162 | if (exc.err != 0) |
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| 163 | errno = exc.err; |
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| 164 | return (float)exc.retval; |
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| 165 | } |
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| 166 | return z; |
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| 167 | #endif |
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| 168 | } |
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| 169 | |
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| 170 | #ifdef _DOUBLE_IS_32BITS |
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| 171 | |
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| 172 | #ifdef __STDC__ |
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| 173 | double pow(double x, double y) |
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| 174 | #else |
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| 175 | double pow(x,y) |
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| 176 | double x,y; |
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| 177 | #endif |
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| 178 | { |
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| 179 | return (double) powf((float) x, (float) y); |
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| 180 | } |
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| 181 | |
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| 182 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
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| 183 | #endif /* __OBSOLETE_MATH */ |
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