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  • Committer: Package Import Robot
  • Author(s): Matthias Klose
  • Date: 2011-10-04 17:48:26 UTC
  • mfrom: (216.1.23 oneiric)
  • Revision ID: package-import@ubuntu.com-20111004174826-2cyb9ewn3ucymlsx
Tags: 2.13-20ubuntu5
https://launchpad.net/bugs/853688
libc6-dev: Don't break the current {gnat,gcj}-4.4-base versons. LP: #853688.

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sysdeps/ieee754/dbl-64/e_sinh.c
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 *
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 * Developed at SunPro, a Sun Microsystems, Inc. business.
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 * Permission to use, copy, modify, and distribute this
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 * software is freely granted, provided that this notice
 
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 * software is freely granted, provided that this notice 
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 * is preserved.
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 * ====================================================
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 */
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#endif
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/* __ieee754_sinh(x)
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 * Method :
 
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 * Method : 
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 * mathematically sinh(x) if defined to be (exp(x)-exp(-x))/2
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 *      1. Replace x by |x| (sinh(-x) = -sinh(x)).
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 *      2.
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 *                                                  E + E/(E+1)
 
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 *      1. Replace x by |x| (sinh(-x) = -sinh(x)). 
 
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 *      2. 
 
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 *                                                  E + E/(E+1)
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 *          0        <= x <= 22     :  sinh(x) := --------------, E=expm1(x)
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 *                                                      2
 
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 *                                                      2
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 *
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 *          22       <= x <= lnovft :  sinh(x) := exp(x)/2
 
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 *          22       <= x <= lnovft :  sinh(x) := exp(x)/2 
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 *          lnovft   <= x <= ln2ovft:  sinh(x) := exp(x/2)/2 * exp(x/2)
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 *          ln2ovft  <  x           :  sinh(x) := x*shuge (overflow)
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 *
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#include "math.h"
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#include "math_private.h"
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#ifdef __STDC__
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static const double one = 1.0, shuge = 1.0e307;
 
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#else
 
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static double one = 1.0, shuge = 1.0e307;
 
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#endif
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double
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__ieee754_sinh(double x)
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{
 
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#ifdef __STDC__
 
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        double __ieee754_sinh(double x)
 
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#else
 
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        double __ieee754_sinh(x)
 
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        double x;
 
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#endif
 
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{       
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        double t,w,h;
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        int32_t ix,jx;
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        u_int32_t lx;
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        ix = jx&0x7fffffff;
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    /* x is INF or NaN */
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        if(__builtin_expect(ix>=0x7ff00000, 0)) return x+x;
 
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        if(ix>=0x7ff00000) return x+x;  
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        h = 0.5;
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        if (jx<0) h = -h;
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    /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */
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        if (ix < 0x40360000) {          /* |x|<22 */
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            if (__builtin_expect(ix<0x3e300000, 0))     /* |x|<2**-28 */
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                if(shuge+x>one)
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                    return x;/* sinh(tiny) = tiny with inexact */
 
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            if (ix<0x3e300000)          /* |x|<2**-28 */
 
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                if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */
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            t = __expm1(fabs(x));
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            if(ix<0x3ff00000) return h*(2.0*t-t*t/(t+one));
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            return h*(t+t/(t+one));
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    /* |x| > overflowthresold, sinh(x) overflow */
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        return x*shuge;
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}
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strong_alias (__ieee754_sinh, __sinh_finite)