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-rw-r--r--src/math/e_sinhf.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/src/math/e_sinhf.c b/src/math/e_sinhf.c
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+/* e_sinhf.c -- float version of e_sinh.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 = 1.0, shuge = 1.0e37;
+
+float
+sinhf(float x)
+{
+        float t,w,h;
+        int32_t ix,jx;
+
+        GET_FLOAT_WORD(jx,x);
+        ix = jx&0x7fffffff;
+
+    /* x is INF or NaN */
+        if(ix>=0x7f800000) return x+x;
+
+        h = 0.5;
+        if (jx<0) h = -h;
+    /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */
+        if (ix < 0x41b00000) {          /* |x|<22 */
+            if (ix<0x31800000)          /* |x|<2**-28 */
+                if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */
+            t = expm1f(fabsf(x));
+            if(ix<0x3f800000) return h*((float)2.0*t-t*t/(t+one));
+            return h*(t+t/(t+one));
+        }
+
+    /* |x| in [22, log(maxdouble)] return 0.5*exp(|x|) */
+        if (ix < 0x42b17180)  return h*expf(fabsf(x));
+
+    /* |x| in [log(maxdouble), overflowthresold] */
+        if (ix<=0x42b2d4fc) {
+            w = expf((float)0.5*fabsf(x));
+            t = h*w;
+            return t*w;
+        }
+
+    /* |x| > overflowthresold, sinh(x) overflow */
+        return x*shuge;
+}