From d827c2679c9b13216743c4f7261c369190ba6f20 Mon Sep 17 00:00:00 2001
From: Kirk McKusick <mckusick@ucbvax.Berkeley.EDU>
Date: Mon, 26 Sep 1983 04:18:31 -0800
Subject: [PATCH] fix to insure that overlapping strings are properly handled

SCCS-vsn: lib/libc/vax/string/bcopy.s 4.4
---
 usr/src/lib/libc/vax/string/bcopy.s | 41 ++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 6 deletions(-)

diff --git a/usr/src/lib/libc/vax/string/bcopy.s b/usr/src/lib/libc/vax/string/bcopy.s
index dea0e1b1ef..ec495e3a8d 100644
--- a/usr/src/lib/libc/vax/string/bcopy.s
+++ b/usr/src/lib/libc/vax/string/bcopy.s
@@ -1,18 +1,47 @@
-/* @(#)bcopy.s	4.3 %G% */
+/* @(#)bcopy.s	4.4 %G% */
 /* bcopy(from, to, size) */
 
 #include "DEFS.h"
 
-ENTRY(bcopy)
+	.globl	_bcopy
+_bcopy:
+	.word	0x0040
+#ifdef PROF
+	.data; 1:; .long 0; .text; moval 1b,r0; jsb mcount
+#endif PROF
 	movl	4(ap),r1
 	movl	8(ap),r3
-	jbr	2f
+	movl	12(ap),r6
+	cmpl	r1,r3
+	bgtr	2f		# normal forward case
+	blss	3f		# overlapping, must do backwards
+	ret			# equal, nothing to do
 1:
-	subl2	r0,12(ap)
+	subl2	r0,r6
 	movc3	r0,(r1),(r3)
 2:
 	movzwl	$65535,r0
-	cmpl	12(ap),r0
+	cmpl	r6,r0
 	jgtr	1b
-	movc3	12(ap),(r1),(r3)
+	movc3	r6,(r1),(r3)
+	ret
+3:
+	addl2	r6,r1
+	addl2	r6,r3
+	movzwl	$65535,r0
+	jbr	5f
+4:
+	subl2	r0,r6
+	subl2	r0,r1
+	subl2	r0,r3
+	movc3	r0,(r1),(r3)
+	movzwl	$65535,r0
+	subl2	r0,r1
+	subl2	r0,r3
+5:
+	cmpl	r6,r0
+	jgtr	4b
+	subl2	r6,r1
+	subl2	r6,r3
+	movc3	r6,(r1),(r3)
 	ret
-- 
2.20.1