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| 2 | /* @(#)w_scalb.c 5.1 93/09/24 */ |
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| 3 | /* |
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| 4 | * ==================================================== |
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| 5 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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| 6 | * |
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| 7 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
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| 8 | * Permission to use, copy, modify, and distribute this |
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| 9 | * software is freely granted, provided that this notice |
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| 10 | * is preserved. |
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| 11 | * ==================================================== |
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| 12 | */ |
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| 13 | |
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| 14 | /* |
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| 15 | * wrapper scalb(double x, double fn) is provide for |
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| 16 | * passing various standard test suite. One |
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| 17 | * should use scalbn() instead. |
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| 18 | */ |
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| 19 | |
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| 20 | #include "fdlibm.h" |
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| 21 | #include <errno.h> |
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| 22 | |
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| 23 | #ifndef _DOUBLE_IS_32BITS |
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| 24 | |
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| 25 | #ifdef __STDC__ |
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| 26 | #ifdef _SCALB_INT |
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| 27 | double scalb(double x, int fn) /* wrapper scalb */ |
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| 28 | #else |
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| 29 | double scalb(double x, double fn) /* wrapper scalb */ |
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| 30 | #endif |
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| 31 | #else |
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| 32 | double scalb(x,fn) /* wrapper scalb */ |
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| 33 | #ifdef _SCALB_INT |
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| 34 | double x; int fn; |
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| 35 | #else |
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| 36 | double x,fn; |
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| 37 | #endif |
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| 38 | #endif |
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| 39 | { |
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| 40 | #ifdef _IEEE_LIBM |
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| 41 | return __ieee754_scalb(x,fn); |
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| 42 | #else |
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| 43 | double z; |
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| 44 | #ifndef HUGE_VAL |
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| 45 | #define HUGE_VAL inf |
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| 46 | double inf = 0.0; |
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| 47 | |
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| 48 | SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */ |
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| 49 | #endif |
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| 50 | struct exception exc; |
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| 51 | z = __ieee754_scalb(x,fn); |
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| 52 | if(_LIB_VERSION == _IEEE_) return z; |
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| 53 | if(!(finite(z)||isnan(z))&&finite(x)) { |
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| 54 | /* scalb overflow; SVID also returns +-HUGE_VAL */ |
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| 55 | exc.type = OVERFLOW; |
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| 56 | exc.name = "scalb"; |
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| 57 | exc.err = 0; |
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| 58 | exc.arg1 = x; |
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| 59 | exc.arg2 = fn; |
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| 60 | exc.retval = x > 0.0 ? HUGE_VAL : -HUGE_VAL; |
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| 61 | if (_LIB_VERSION == _POSIX_) |
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| 62 | errno = ERANGE; |
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| 63 | else if (!matherr(&exc)) { |
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| 64 | errno = ERANGE; |
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| 65 | } |
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| 66 | if (exc.err != 0) |
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| 67 | errno = exc.err; |
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| 68 | return exc.retval; |
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| 69 | } |
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| 70 | if(z==0.0&&z!=x) { |
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| 71 | /* scalb underflow */ |
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| 72 | exc.type = UNDERFLOW; |
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| 73 | exc.name = "scalb"; |
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| 74 | exc.err = 0; |
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| 75 | exc.arg1 = x; |
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| 76 | exc.arg2 = fn; |
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| 77 | exc.retval = copysign(0.0,x); |
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| 78 | if (_LIB_VERSION == _POSIX_) |
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| 79 | errno = ERANGE; |
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| 80 | else if (!matherr(&exc)) { |
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| 81 | errno = ERANGE; |
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| 82 | } |
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| 83 | if (exc.err != 0) |
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| 84 | errno = exc.err; |
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| 85 | return exc.retval; |
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| 86 | } |
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| 87 | #ifndef _SCALB_INT |
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| 88 | if(!finite(fn)) errno = ERANGE; |
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| 89 | #endif |
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| 90 | return z; |
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| 91 | #endif |
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| 92 | } |
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| 93 | |
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| 94 | #endif /* defined(_DOUBLE_IS_32BITS) */ |
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