X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fmath%2Ftanl.c;h=6af067127ade990b98d26696594e5737fbf50ade;hb=9b132e556774c744f9052581d2d8d0fab417e97c;hp=462ead912881860a8fc724b094bdb2049108e2ee;hpb=b69f695acedd4ce2798ef9ea28d834ceccc789bd;p=musl

diff --git a/src/math/tanl.c b/src/math/tanl.c
index 462ead91..6af06712 100644
--- a/src/math/tanl.c
+++ b/src/math/tanl.c
@@ -1,35 +1,3 @@
-/* origin: FreeBSD /usr/src/lib/msun/src/s_tanl.c */
-/*-
- * Copyright (c) 2007 Steven G. Kargl
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice unmodified, this list of conditions, and the following
- *    disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-/*
- * Limited testing on pseudorandom numbers drawn within [0:4e8] shows
- * an accuracy of <= 1.5 ULP where 247024 values of x out of 40 million
- * possibles resulted in tan(x) that exceeded 0.5 ULP (ie., 0.6%).
- */
-
 #include "libm.h"
 
 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
@@ -38,47 +6,24 @@ long double tanl(long double x)
 	return tan(x);
 }
 #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
-#include "__rem_pio2l.h"
-
 long double tanl(long double x)
 {
-	union IEEEl2bits z;
-	int e0, s;
+	union ldshape u = {x};
 	long double y[2];
-	long double hi, lo;
-
-	z.e = x;
-	s = z.bits.sign;
-	z.bits.sign = 0;
-
-	/* If x = +-0 or x is subnormal, then tan(x) = x. */
-	if (z.bits.exp == 0)
-		return x;
-
-	/* If x = NaN or Inf, then tan(x) = NaN. */
-	if (z.bits.exp == 32767)
-		return (x - x) / (x - x);
-
-	/* Optimize the case where x is already within range. */
-	if (z.e < M_PI_4) {
-		hi = __tanl(z.e, 0, 0);
-		return s ? -hi : hi;
-	}
-
-	e0 = __rem_pio2l(x, y);
-	hi = y[0];
-	lo = y[1];
-
-	switch (e0 & 3) {
-	case 0:
-	case 2:
-		hi = __tanl(hi, lo, 0);
-		break;
-	case 1:
-	case 3:
-		hi = __tanl(hi, lo, 1);
-		break;
+	unsigned n;
+
+	u.i.se &= 0x7fff;
+	if (u.i.se == 0x7fff)
+		return x - x;
+	if (u.f < M_PI_4) {
+		if (u.i.se < 0x3fff - LDBL_MANT_DIG/2) {
+			/* raise inexact if x!=0 and underflow if subnormal */
+			FORCE_EVAL(u.i.se == 0 ? x*0x1p-120f : x+0x1p120f);
+			return x;
+		}
+		return __tanl(x, 0, 0);
 	}
-	return hi;
+	n = __rem_pio2l(x, y);
+	return __tanl(y[0], y[1], n&1);
 }
 #endif