Module Name: src
Committed By: martin
Date: Thu Mar 6 10:57:01 UTC 2014
Added Files:
src/lib/libm/noieee_src: n_log2.c
Log Message:
log2() for vax
To generate a diff of this commit:
cvs rdiff -u -r0 -r1.1 src/lib/libm/noieee_src/n_log2.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Added files:
Index: src/lib/libm/noieee_src/n_log2.c
diff -u /dev/null src/lib/libm/noieee_src/n_log2.c:1.1
--- /dev/null Thu Mar 6 10:57:01 2014
+++ src/lib/libm/noieee_src/n_log2.c Thu Mar 6 10:57:01 2014
@@ -0,0 +1,59 @@
+/* $NetBSD: n_log2.c,v 1.1 2014/03/06 10:57:01 martin Exp $ */
+/*-
+ * Copyright (c) 2014 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Martin Husemann <[email protected]>.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+/* LOG2(X)
+ * RETURN THE BASE 10 LOGARITHM OF x
+ *
+ * Required kernel function:
+ * log(x)
+ *
+ * Method :
+ * log(x)
+ * log2(x) = ---------
+ * log(2)
+ */
+
+#define _LIBM_STATIC
+#include "mathimpl.h"
+
+
+static const double ln2 = .6931471805599453094172321214581765680755;
+
+double
+log2(double x)
+{
+ return log(x)/ln2;
+}
+
+float
+log2f(float x)
+{
+ return logf(x)/ln2;
+}
