16-bit external branches in libc/sysdeps/linux/m68k/clone.S

[Richard Sandiford]

Until a few months ago, libc/sysdeps/linux/m68k/clone.S defined
__syscall_error itself.  This local definition was removed in
revision 13305:

http://www.uclibc.org/cgi-bin/viewcvs.cgi/trunk/uClibc/libc/sysdeps/linux/m68k/clone.S?rev=13305&view=log

specifically:

--- trunk/uClibc/libc/sysdeps/linux/m68k/clone.S	2006/01/14 00:58:03	13277
+++ trunk/uClibc/libc/sysdeps/linux/m68k/clone.S	2006/01/14 06:42:52	13305
@@ -55,17 +55,6 @@
 
 	rts
 
-__syscall_error:
-	negl	%d0
-	movel	%d0, %sp at -
-	lea		__errno_location-.-8, %a0
-	jsr		%pc@(%a0)
-	movel	%d0, %a0
-	movel	%sp at +, %a0@
-	moveq	#-1, %d0
-
-	rts
-
 thread_start:
 	/*subl    %fp, %fp*/        /* terminate the stack frame */
 	jsr     (%a0)

However, the clone code uses bcc.w to branch to __syscall_error.
This made sense when there was a local definition, because the
label was guaranteed to be in range.  We can't guarantee that
the external definition will be in range though; it depends on
the order that the objects are linked.

This patch adjusts clone.S to use jbcc instead.  Please install if OK.

Richard


Index: libc/sysdeps/linux/m68k/clone.S
===================================================================
--- libc/sysdeps/linux/m68k/clone.S	(revision 15264)
+++ libc/sysdeps/linux/m68k/clone.S	(working copy)
@@ -21,11 +21,11 @@ clone:
 	movel   4(%sp), %d1             /* no NULL function pointers */
 	movel	%d1, %a0
 	tstl    %d1
-	beq.w   __syscall_error
+	jbeq    __syscall_error
 	movel   8(%sp), %d1             /* no NULL stack pointers */
 	movel	%d1, %a1
 	tstl    %d1
-	beq.w   __syscall_error
+	jbeq    __syscall_error
 
 	/* Allocate space and copy the argument onto the new stack.  */
 	movel   16(%sp), -(%a1)
@@ -50,7 +50,7 @@ clone:
 #endif
 
 	tstl    %d0
-	bmi.w   __syscall_error
+	jbmi    __syscall_error
 	beq.w   thread_start
 
 	rts