Preliminary userland bits for OpenBSD/landisk, many things coming from

NetBSD.

1 files changed, 100 insertions, 0 deletions

diff --git a/lib/libc/arch/sh/string/ffs.S b/lib/libc/arch/sh/string/ffs.S
new file mode 100644
index 00000000000..df1a495f469
--- /dev/null
+++ b/lib/libc/arch/sh/string/ffs.S
@@ -0,0 +1,100 @@
+/*	$OpenBSD: ffs.S,v 1.1 2006/10/10 22:07:10 miod Exp $	*/
+/*	$NetBSD: ffs.S,v 1.1 2005/12/20 19:28:50 christos Exp $	*/
+
+/*-
+ * Copyright (c) 2002 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by ITOH Yasufumi.
+ *
+ * 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 NetBSD
+ *	Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation 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 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.
+ */
+
+#include <machine/asm.h>
+
+/*
+ * ffs - find first bit set
+ *
+ * This code makes use of ``test 8bit'' and ``shift 8bit'' instructions.
+ * The remaining 8bit is tested in every 2bit.
+ */
+
+ENTRY(ffs)
+	mov	r4,r0		! using r0 specific instructions
+	tst	#0xff,r0
+	bf/s	L8bit
+	mov	#0+1,r1		! ret = 1..8
+
+	tst	r0,r0		! ffs(0) is 0
+	bt	Lzero		! testing here to accelerate ret=1..8 cases
+
+	shlr8	r0
+	tst	#0xff,r0
+	bf/s	L8bit
+	mov	#8+1,r1		! ret = 9..16
+
+	shlr8	r0
+	tst	#0xff,r0
+	bf/s	L8bit
+	mov	#16+1,r1	! ret = 17..24
+
+	shlr8	r0
+	mov	#24+1,r1	! ret = 25..32
+
+L8bit:
+	tst	#0x0f,r0
+	bt	4f
+
+	tst	#0x03,r0
+	bt	2f
+	tst	#0x01,r0	! not bit 0 -> T
+	mov	#0,r0
+	rts
+	 addc	r1,r0		! 0 + r1 + T -> r0
+
+2:	tst	#0x04,r0
+	mov	#2,r0
+	rts
+	 addc	r1,r0
+
+4:	tst	#0x30,r0
+	bt	6f
+	tst	#0x10,r0
+	mov	#4,r0
+	rts
+	 addc	r1,r0
+
+6:	tst	#0x40,r0
+	mov	#6,r0
+	rts
+	 addc	r1,r0
+
+Lzero:	rts
+	 nop