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| 2 | /* @(#)e_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 | * __ieee754_scalb(x, 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 <libm/fdlibm.h> |
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| 21 | |
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| 22 | #ifdef _SCALB_INT |
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| 23 | #ifdef __STDC__ |
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| 24 | double __ieee754_scalb(double x, int fn) |
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| 25 | #else |
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| 26 | double __ieee754_scalb(x,fn) |
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| 27 | double x; int fn; |
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| 28 | #endif |
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| 29 | #else |
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| 30 | #ifdef __STDC__ |
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| 31 | double __ieee754_scalb(double x, double fn) |
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| 32 | #else |
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| 33 | double __ieee754_scalb(x,fn) |
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| 34 | double x, fn; |
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| 35 | #endif |
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| 36 | #endif |
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| 37 | { |
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| 38 | #ifdef _SCALB_INT |
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| 39 | return scalbn(x,fn); |
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| 40 | #else |
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| 41 | if (isnan(x)||isnan(fn)) return x*fn; |
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| 42 | if (!finite(fn)) { |
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| 43 | if(fn>0.0) return x*fn; |
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| 44 | else return x/(-fn); |
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| 45 | } |
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| 46 | if (rint(fn)!=fn) return (fn-fn)/(fn-fn); |
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| 47 | if ( fn > 65000.0) return scalbn(x, 65000); |
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| 48 | if (-fn > 65000.0) return scalbn(x,-65000); |
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| 49 | return scalbn(x,(int)fn); |
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| 50 | #endif |
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| 51 | } |
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