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-rw-r--r--src/math/s_asinhf.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/src/math/s_asinhf.c b/src/math/s_asinhf.c
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+/* s_asinhf.c -- float version of s_asinh.c.
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+
+/*
+ * ====================================================
+ * 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
+ * is preserved.
+ * ====================================================
+ */
+
+#include <math.h>
+#include "math_private.h"
+
+static const float
+one =  1.0000000000e+00, /* 0x3F800000 */
+ln2 =  6.9314718246e-01, /* 0x3f317218 */
+huge=  1.0000000000e+30;
+
+float
+asinhf(float x)
+{
+        float t,w;
+        int32_t hx,ix;
+        GET_FLOAT_WORD(hx,x);
+        ix = hx&0x7fffffff;
+        if(ix>=0x7f800000) return x+x;  /* x is inf or NaN */
+        if(ix< 0x31800000) {    /* |x|<2**-28 */
+            if(huge+x>one) return x;    /* return x inexact except 0 */
+        }
+        if(ix>0x4d800000) {     /* |x| > 2**28 */
+            w = logf(fabsf(x))+ln2;
+        } else if (ix>0x40000000) {     /* 2**28 > |x| > 2.0 */
+            t = fabsf(x);
+            w = logf((float)2.0*t+one/(sqrtf(x*x+one)+t));
+        } else {                /* 2.0 > |x| > 2**-28 */
+            t = x*x;
+            w =log1pf(fabsf(x)+t/(one+sqrtf(one+t)));
+        }
+        if(hx>0) return w; else return -w;
+}