From 4464fee50386ebff4d8a1e9f4e28917f1791918a Mon Sep 17 00:00:00 2001
From: "Kenneth D. Merry" <ken@FreeBSD.org>
Date: Wed, 4 Apr 2001 22:50:57 +0000
Subject: [PATCH] Don't allow immediate values of 0 for operations that can
 take either an immediate value or the accumulator.  0 is the chip's internal
 representation for the accumulator, and so 0 is an invalid immediate value
 when the accumulator can also be specified as an argument.

Submitted by:	gibbs
---
 sys/dev/aic7xxx/aicasm/aicasm_gram.y | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sys/dev/aic7xxx/aicasm/aicasm_gram.y b/sys/dev/aic7xxx/aicasm/aicasm_gram.y
index d0bc6714acdc..91425f38c30a 100644
--- a/sys/dev/aic7xxx/aicasm/aicasm_gram.y
+++ b/sys/dev/aic7xxx/aicasm/aicasm_gram.y
@@ -623,6 +623,11 @@ immediate_or_a:
 	expression
 	{
 		$$ = $1;
+		if ($$.value == 0) {
+			stop("Immediate value of 0 not valid for opcode",
+			     EX_DATAERR);
+			/* NOTREACHED */
+		}
 	}
 |	T_A
 	{