1 files changed, 83 insertions, 0 deletions
diff --git a/usr/src/lib/libc/port/gen/fls.c b/usr/src/lib/libc/port/gen/fls.c
new file mode 100644
index 0000000000..e685451c3e
--- /dev/null
+++ b/usr/src/lib/libc/port/gen/fls.c
@@ -0,0 +1,83 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+ */
+
+#include "lint.h"
+#include <string.h>
+#include <strings.h>
+#include <sys/types.h>
+
+static int
+fls_impl(uint64_t bits)
+{
+	int i = 1;
+	uint32_t bits32;
+
+	if (bits == 0)
+		return (0);
+
+	if ((bits32 = (uint32_t)(bits >> 32)) != 0)
+		i += 32;
+	else
+		bits32 = (uint32_t)bits;
+
+	if ((bits32 & 0xffff0000) != 0) {
+		bits32 >>= 16;
+		i += 16;
+	}
+	if ((bits32 & 0xff00) != 0) {
+		bits32 >>= 8;
+		i += 8;
+	}
+	if ((bits32 & 0xf0) != 0) {
+		bits32 >>= 4;
+		i += 4;
+	}
+	if ((bits32 & 0xc) != 0) {
+		bits32 >>= 2;
+		i += 2;
+	}
+	if ((bits32 & 0x2) != 0)
+		i += 1;
+
+	return (i);
+}
+
+int
+fls(int bits)
+{
+	return (fls_impl((uint64_t)(uint_t)bits));
+}
+
+int
+flsl(long bits)
+{
+	return (fls_impl((uint64_t)(ulong_t)bits));
+}
+
+int
+flsll(long long bits)
+{
+	return (fls_impl((uint64_t)(u_longlong_t)bits));
+}