-/* @(#)e_acosh.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_acosh.c,v 1.9 1995/05/12 04:57:18 jtc Exp $";
-#endif
-
/* __ieee754_acosh(x)
* Method :
- * Based on
+ * Based on
* acosh(x) = log [ x + sqrt(x*x-1) ]
* we have
* acosh(x) := log(x)+ln2, if x is large; else
#include "math.h"
#include "math_private.h"
-#ifdef __STDC__
-static const double
-#else
-static double
-#endif
+static const double
one = 1.0,
ln2 = 6.93147180559945286227e-01; /* 0x3FE62E42, 0xFEFA39EF */
-#ifdef __STDC__
- double __ieee754_acosh(double x)
-#else
- double __ieee754_acosh(x)
- double x;
-#endif
-{
+double attribute_hidden __ieee754_acosh(double x)
+{
double t;
int32_t hx;
u_int32_t lx;
} else if(hx >=0x41b00000) { /* x > 2**28 */
if(hx >=0x7ff00000) { /* x is inf of NaN */
return x+x;
- } else
+ } else
return __ieee754_log(x)+ln2; /* acosh(huge)=log(2x) */
} else if(((hx-0x3ff00000)|lx)==0) {
return 0.0; /* acosh(1) = 0 */
return log1p(t+sqrt(2.0*t+t*t));
}
}
+
+/*
+ * wrapper acosh(x)
+ */
+#ifndef _IEEE_LIBM
+double acosh(double x)
+{
+ double z = __ieee754_acosh(x);
+ if (_LIB_VERSION == _IEEE_ || isnan(x))
+ return z;
+ if (x < 1.0)
+ return __kernel_standard(x, x, 29); /* acosh(x<1) */
+ return z;
+}
+#else
+strong_alias(__ieee754_acosh, acosh)
+#endif
+libm_hidden_def(acosh)