math: sinh.c cleanup similar to the cosh one

[musl] / src / math / sinhf.c

diff --git a/src/math/sinhf.c b/src/math/sinhf.c
index b8d8822..6ad19ea 100644 (file)
--- 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;
 }