# HG changeset patch
# User William Astle <lost@l-w.ca>
# Date 1436844834 21600
# Node ID 2abcd82b455f107daeb073dfe6738f755b49f6da
# Parent  221b5f58d8adb609524736169eca8a64d89d7ae6
Make TFM complain if invalid registers are used

TFM can only accept 5 pointer registers as source/dest. Complain if anything
else is used.

Thanks to Erik G <erik@6809.org> for the patch.

diff -r 221b5f58d8ad -r 2abcd82b455f lwasm/insn_tfm.c
--- a/lwasm/insn_tfm.c	Mon Jul 13 21:32:39 2015 -0600
+++ b/lwasm/insn_tfm.c	Mon Jul 13 21:33:54 2015 -0600
@@ -34,7 +34,7 @@
 	c = strchr(reglist, toupper(*(*p)++));
 	if (!c)
 	{
-		lwasm_register_error(as, l, E_UNKNOWN_OPERATION);
+		lwasm_register_error(as, l, E_REGISTER_BAD);
 		return;
 	}
 	r0 = c - reglist;
@@ -56,7 +56,7 @@
 	c = strchr(reglist, toupper(*(*p)++));
 	if (!c)
 	{
-		lwasm_register_error(as, l, E_UNKNOWN_OPERATION);
+		lwasm_register_error(as, l, E_REGISTER_BAD);
 		return;
 	}
 	r1 = c - reglist;
@@ -77,7 +77,13 @@
 		lwasm_register_error(as, l, E_OPERAND_BAD);
 		return;
 	}
-			
+	/* only D, X, Y, U, S are valid tfm registers */
+	if (r0 > 4 || r1 > 4)
+	{
+		if (r0 < r1) r0 = r1;
+		lwasm_register_error2(as, l, E_REGISTER_BAD, "'%c'", reglist[r0]);
+	}
+
 	// valid values of tfm here are:
 	// 1: r0+,r1 (2)
 	// 4: r0,r1+ (3)