math: sinh.c cleanup similar to the cosh one

comments are kept in the double version of the function

1 files changed, 20 insertions, 46 deletions

diff --git a/src/math/sinhf.c b/src/math/sinhf.c
index b8d88224..6ad19ea2 100644
--- a/src/math/sinhf.c
+++ b/src/math/sinhf.c
@@ -1,57 +1,31 @@
-/* origin: FreeBSD /usr/src/lib/msun/src/e_sinhf.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 huge = 1.0e37;
-
 float sinhf(float x)
 {
-	float t, h;
-	int32_t ix, jx;
-
-	GET_FLOAT_WORD(jx, x);
-	ix = jx & 0x7fffffff;
-
-	/* x is INF or NaN */
-	if (ix >= 0x7f800000)
-		return x + x;
+	union {float f; uint32_t i;} u = {.f = x};
+	uint32_t w;
+	float t, h, absx;
 
 	h = 0.5;
-	if (jx < 0)
+	if (u.i >> 31)
 		h = -h;
-	/* |x| in [0,9], return sign(x)*0.5*(E+E/(E+1))) */
-	if (ix < 0x41100000) {   /* |x|<9 */
-		if (ix < 0x39800000)  /* |x|<2**-12 */
-			/* raise inexact, return x */
-			if (huge+x > 1.0f)
+	/* |x| */
+	u.i &= 0x7fffffff;
+	absx = u.f;
+	w = u.i;
+
+	/* |x| < log(FLT_MAX) */
+	if (w < 0x42b17217) {
+		t = expm1f(absx);
+		if (w < 0x3f800000) {
+			if (w < 0x3f800000 - (12<<23))
 				return x;
-		t = expm1f(fabsf(x));
-		if (ix < 0x3f800000)
-			return h*(2.0f*t - t*t/(t+1.0f));
-		return h*(t + t/(t+1.0f));
+			return h*(2*t - t*t/(t+1));
+		}
+		return h*(t + t/(t+1));
 	}
 
-	/* |x| in [9, logf(maxfloat)] return 0.5*exp(|x|) */
-	if (ix < 0x42b17217)
-		return h*expf(fabsf(x));
-
-	/* |x| in [logf(maxfloat), overflowthresold] */
-	if (ix <= 0x42b2d4fc)
-		return h * 2.0f * __expo2f(fabsf(x)); /* h is for sign only */
-
-	/* |x| > overflowthresold, sinh(x) overflow */
-	return x*huge;
+	/* |x| > logf(FLT_MAX) or nan */
+	t = 2*h*__expo2f(absx);
+	return t;
 }