From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <16c90927387c0a9664e3f4c14e0736b3@felloff.net>
Date: Fri, 17 Jan 2014 21:07:45 +0100
From: cinap_lenrek@felloff.net
To: quanstro@labs.coraid.com
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Cc: 9fans@9fans.net
Subject: [9fans] MOVLQSX wrong operand order
Topicbox-Message-UUID: b3c6653a-ead8-11e9-9d60-3106f5b1d025

just disassembled some code generated by 6c
and found something funny. the debugger seems
to print the operands of MOVLQSX in the wrong
order.

output of 6c -S:

	MOVLQSX	BP,CX
	ADDQ	CX,AX
	RET	,

output of acid:

foo+0x1a 0x00200042	MOVLQSX	CX,BP
foo+0x1d 0x00200045	ADDQ	CX,AX
foo+0x20 0x00200048	RET

fix:

diff -r 4e094627d459 sys/src/libmach/8db.c
--- a/sys/src/libmach/8db.c	Tue Jan 14 00:22:13 2014 +0100
+++ b/sys/src/libmach/8db.c	Fri Jan 17 21:06:42 2014 +0100
@@ -1223,7 +1223,7 @@
 [0xfd]	0,0,		"STD",
 [0xfe]	RMOPB,0,	optabFE,
 [0xff]	RMOP,0,		optabFF,
-[0x100]	RM,0,		"MOVLQSX	%r,%e",
+[0x100]	RM,0,		"MOVLQSX	%e,%r",
 };

--
cinap