-/* @(#)e_cosh.c 5.1 93/09/24 */
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
- * software is freely granted, provided that this notice
+ * software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
-#if defined(LIBM_SCCS) && !defined(lint)
-static char rcsid[] = "$NetBSD: e_cosh.c,v 1.7 1995/05/10 20:44:58 jtc Exp $";
-#endif
-
/* __ieee754_cosh(x)
- * Method :
+ * Method :
* mathematically cosh(x) if defined to be (exp(x)+exp(-x))/2
- * 1. Replace x by |x| (cosh(x) = cosh(-x)).
- * 2.
- * [ exp(x) - 1 ]^2
+ * 1. Replace x by |x| (cosh(x) = cosh(-x)).
+ * 2.
+ * [ exp(x) - 1 ]^2
* 0 <= x <= ln2/2 : cosh(x) := 1 + -------------------
* 2*exp(x)
*
* exp(x) + 1/exp(x)
* ln2/2 <= x <= 22 : cosh(x) := -------------------
* 2
- * 22 <= x <= lnovft : cosh(x) := exp(x)/2
+ * 22 <= x <= lnovft : cosh(x) := exp(x)/2
* lnovft <= x <= ln2ovft: cosh(x) := exp(x/2)/2 * exp(x/2)
* ln2ovft < x : cosh(x) := huge*huge (overflow)
*
#include "math.h"
#include "math_private.h"
-#ifdef __STDC__
static const double one = 1.0, half=0.5, huge = 1.0e300;
-#else
-static double one = 1.0, half=0.5, huge = 1.0e300;
-#endif
-#ifdef __STDC__
- double __ieee754_cosh(double x)
-#else
- double __ieee754_cosh(x)
- double x;
-#endif
-{
+double attribute_hidden __ieee754_cosh(double x)
+{
double t,w;
int32_t ix;
u_int32_t lx;
ix &= 0x7fffffff;
/* x is INF or NaN */
- if(ix>=0x7ff00000) return x*x;
+ if(ix>=0x7ff00000) return x*x;
/* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */
if(ix<0x3fd62e43) {
/* |x| in [log(maxdouble), overflowthresold] */
GET_LOW_WORD(lx,x);
- if (ix<0x408633CE ||
- (ix==0x408633ce)&&(lx<=(u_int32_t)0x8fb9f87d)) {
+ if (ix<0x408633CE ||
+ ((ix==0x408633ce)&&(lx<=(u_int32_t)0x8fb9f87d))) {
w = __ieee754_exp(half*fabs(x));
t = half*w;
return t*w;
/* |x| > overflowthresold, cosh(x) overflow */
return huge*huge;
}
+
+/*
+ * wrapper cosh(x)
+ */
+#ifndef _IEEE_LIBM
+double cosh(double x)
+{
+ double z = __ieee754_cosh(x);
+ if (_LIB_VERSION == _IEEE_ || isnan(x))
+ return z;
+ if (fabs(x) > 7.10475860073943863426e+02)
+ return __kernel_standard(x, x, 5); /* cosh overflow */
+ return z;
+}
+#else
+strong_alias(__ieee754_cosh, cosh)
+#endif
+libm_hidden_def(cosh)