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glibc  2.9
Functions | Variables
e_coshl.c File Reference
#include "math.h"
#include "math_private.h"

Go to the source code of this file.

Functions

long double __ieee754_coshl (long double x)

Variables

static long double one = 1.0L
static long double half = 0.5L
static long double huge = 1.0e300L

Function Documentation

long double __ieee754_coshl ( long double  x)

Definition at line 50 of file e_coshl.c.

{
       long double t,w;
       int64_t ix;

    /* High word of |x|. */
       GET_LDOUBLE_MSW64(ix,x);
       ix &= 0x7fffffffffffffffLL;

    /* x is INF or NaN */
       if(ix>=0x7ff0000000000000LL) return x*x;

    /* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */
       if(ix<0x3fd62e42fefa39efLL) {
           t = __expm1l(fabsl(x));
           w = one+t;
           if (ix<0x3c80000000000000LL) return w;       /* cosh(tiny) = 1 */
           return one+(t*t)/(w+w);
       }

    /* |x| in [0.5*ln2,22], return (exp(|x|)+1/exp(|x|)/2; */
       if (ix < 0x4036000000000000LL) {
              t = __ieee754_expl(fabsl(x));
              return half*t+half/t;
       }

    /* |x| in [22, log(maxdouble)] return half*exp(|x|) */
       if (ix < 0x40862e42fefa39efLL)  return half*__ieee754_expl(fabsl(x));

    /* |x| in [log(maxdouble), overflowthresold] */
        if (ix < 0x408633ce8fb9f87dLL) {
           w = __ieee754_expl(half*fabsl(x));
           t = half*w;
           return t*w;
       }

    /* |x| > overflowthresold, cosh(x) overflow */
       return huge*huge;
}

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Variable Documentation

long double half = 0.5L [static]

Definition at line 44 of file e_coshl.c.

long double huge = 1.0e300L [static]

Definition at line 44 of file e_coshl.c.

long double one = 1.0L [static]

Definition at line 44 of file e_coshl.c.