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-rw-r--r--src/math/asinhf.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/src/math/asinhf.c b/src/math/asinhf.c
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+/* origin: FreeBSD /usr/src/lib/msun/src/s_asinhf.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 "libm.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)   /* x is inf or NaN */
+		return x+x;
+	if (ix < 0x31800000) {  /* |x| < 2**-28 */
+		/* return x inexact except 0 */
+		if (huge+x > one)
+			return x;
+	}
+	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;
+	return -w;
+}