summaryrefslogtreecommitdiff
path: root/src/math/e_acosh.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/math/e_acosh.c')
-rw-r--r--src/math/e_acosh.c59
1 files changed, 0 insertions, 59 deletions
diff --git a/src/math/e_acosh.c b/src/math/e_acosh.c
deleted file mode 100644
index 8b454e75..00000000
--- a/src/math/e_acosh.c
+++ /dev/null
@@ -1,59 +0,0 @@
-
-/* @(#)e_acosh.c 1.3 95/01/18 */
-/*
- * ====================================================
- * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
- *
- * Developed at SunSoft, a Sun Microsystems, Inc. business.
- * Permission to use, copy, modify, and distribute this
- * software is freely granted, provided that this notice
- * is preserved.
- * ====================================================
- *
- */
-
-/* acosh(x)
- * Method :
- * Based on
- * acosh(x) = log [ x + sqrt(x*x-1) ]
- * we have
- * acosh(x) := log(x)+ln2, if x is large; else
- * acosh(x) := log(2x-1/(sqrt(x*x-1)+x)) if x>2; else
- * acosh(x) := log1p(t+sqrt(2.0*t+t*t)); where t=x-1.
- *
- * Special cases:
- * acosh(x) is NaN with signal if x<1.
- * acosh(NaN) is NaN without signal.
- */
-
-#include <math.h>
-#include "math_private.h"
-
-static const double
-one = 1.0,
-ln2 = 6.93147180559945286227e-01; /* 0x3FE62E42, 0xFEFA39EF */
-
-double
-acosh(double x)
-{
- double t;
- int32_t hx;
- uint32_t lx;
- EXTRACT_WORDS(hx,lx,x);
- if(hx<0x3ff00000) { /* x < 1 */
- return (x-x)/(x-x);
- } else if(hx >=0x41b00000) { /* x > 2**28 */
- if(hx >=0x7ff00000) { /* x is inf of NaN */
- return x+x;
- } else
- return log(x)+ln2; /* acosh(huge)=log(2x) */
- } else if(((hx-0x3ff00000)|lx)==0) {
- return 0.0; /* acosh(1) = 0 */
- } else if (hx > 0x40000000) { /* 2**28 > x > 2 */
- t=x*x;
- return log(2.0*x-one/(x+sqrt(t-one)));
- } else { /* 1<x<2 */
- t = x-one;
- return log1p(t+sqrt(2.0*t+t*t));
- }
-}