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authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /sysdeps/generic/sincos.c
initial import
Diffstat (limited to 'sysdeps/generic/sincos.c')
-rw-r--r--sysdeps/generic/sincos.c98
1 files changed, 98 insertions, 0 deletions
diff --git a/sysdeps/generic/sincos.c b/sysdeps/generic/sincos.c
new file mode 100644
index 0000000000..ab885607cf
--- /dev/null
+++ b/sysdeps/generic/sincos.c
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+/*
+ * Copyright (c) 1987, 1993
+ * The Regents of the University of California. 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, 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.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)sincos.c 8.1 (Berkeley) 6/4/93";
+#endif /* not lint */
+
+#include "trig.h"
+double
+sin(x)
+double x;
+{
+ double a,c,z;
+
+ if(!finite(x)) /* sin(NaN) and sin(INF) must be NaN */
+ return x-x;
+ x=drem(x,PI2); /* reduce x into [-PI,PI] */
+ a=copysign(x,one);
+ if (a >= PIo4) {
+ if(a >= PI3o4) /* ... in [3PI/4,PI] */
+ x = copysign((a = PI-a),x);
+ else { /* ... in [PI/4,3PI/4] */
+ a = PIo2-a; /* rtn. sign(x)*C(PI/2-|x|) */
+ z = a*a;
+ c = cos__C(z);
+ z *= half;
+ a = (z >= thresh ? half-((z-half)-c) : one-(z-c));
+ return copysign(a,x);
+ }
+ }
+
+ if (a < small) { /* rtn. S(x) */
+ big+a;
+ return x;
+ }
+ return x+x*sin__S(x*x);
+}
+
+double
+cos(x)
+double x;
+{
+ double a,c,z,s = 1.0;
+
+ if(!finite(x)) /* cos(NaN) and cos(INF) must be NaN */
+ return x-x;
+ x=drem(x,PI2); /* reduce x into [-PI,PI] */
+ a=copysign(x,one);
+ if (a >= PIo4) {
+ if (a >= PI3o4) { /* ... in [3PI/4,PI] */
+ a = PI-a;
+ s = negone;
+ }
+ else { /* ... in [PI/4,3PI/4] */
+ a = PIo2-a;
+ return a+a*sin__S(a*a); /* rtn. S(PI/2-|x|) */
+ }
+ }
+ if (a < small) {
+ big+a;
+ return s; /* rtn. s*C(a) */
+ }
+ z = a*a;
+ c = cos__C(z);
+ z *= half;
+ a = (z >= thresh ? half-((z-half)-c) : one-(z-c));
+ return copysign(a,s);
+}