--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lwasm/insn_bitbit.c	Fri Jan 30 04:01:55 2009 +0000
@@ -0,0 +1,137 @@
+/*
+insn_bitbit.c
+Copyright © 2009 William Astle
+
+This file is part of LWASM.
+
+LWASM is free software: you can redistribute it and/or modify it under the
+terms of the GNU General Public License as published by the Free Software
+Foundation, either version 3 of the License, or (at your option) any later
+version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+more details.
+
+You should have received a copy of the GNU General Public License along with
+this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+for handling inherent mode instructions
+*/
+
+#define __insn_bitbit_c_seen__
+
+#include <stdlib.h>
+
+#include "lwasm.h"
+#include "instab.h"
+#include "expr.h"
+
+// these instructions cannot tolerate external references
+OPFUNC(insn_bitbit)
+{
+	int r;
+	lwasm_expr_stack_t *s;
+	int v1;
+	int tv;
+
+	lwasm_emitop(as, l, instab[opnum].ops[0]);
+	
+	r = toupper(*(*p)++);
+	if (r == 'A')
+		r = 1;
+	else if (r == 'B')
+		r = 2;
+	else if (r == 'C' && toupper(**p) == 'C')
+	{
+		r = 0;
+		(*p)++;
+	}
+	else
+	{
+		register_error(as, l, 1, "Bad register");
+		return;
+	}
+	if (*(*p)++ != ',')
+	{
+		register_error(as, l, 1, "Bad operand");
+		return;
+	}
+	s = lwasm_evaluate_expr(as, l, *p, NULL, 0);
+	if (!s)
+	{
+		register_error(as, l, 1, "Bad operand");
+		return;
+	}
+	if (!lwasm_expr_is_constant(s))
+	{
+		register_error(as, l, 2, "Incomplete reference");
+	}
+	v1 = lwasm_expr_get_value(s);
+	lwasm_expr_stack_free(s);
+	if (v1 < 0 || v1 > 7)
+	{
+		register_error(as, l, 2, "Invalid bit number");
+		v1 = 0;
+	}
+	if (*(*p)++ != ',')
+	{
+		register_error(as, l, 1, "Bad operand");
+		return;
+	}
+	r = (r << 6) | (v1 << 3);
+
+	s = lwasm_evaluate_expr(as, l, *p, NULL, 0);
+	if (!s)
+	{
+		register_error(as, l, 1, "Bad operand");
+		return;
+	}
+	if (!lwasm_expr_is_constant(s))
+	{
+		register_error(as, l, 1, "Incomplete reference");
+	}
+	v1 = lwasm_expr_get_value(s);
+	lwasm_expr_stack_free(s);
+	if (v1 < 0 || v1 > 7)
+	{
+		register_error(as, l, 2, "Invalid bit number");
+		v1 = 0;
+	}
+	if (*(*p)++ != ',')
+	{
+		register_error(as, l, 1, "Bad operand");
+		return;
+	}
+	r |= v1;
+	
+	lwasm_emit(as, l, r);
+			
+	// ignore base page address modifier
+	if (**p == '<')
+		(*p)++;
+			
+	s = lwasm_evaluate_expr(as, l, *p, NULL, 0);
+	if (!s)
+	{
+		register_error(as, l, 1, "Bad operand");
+		return;
+	}
+	if (!lwasm_expr_is_constant(s))
+	{
+		register_error(as, l, 1, "Incomplete reference");
+	}
+	v1 = lwasm_expr_get_value(s);
+	lwasm_expr_stack_free(s);
+	v1 &= 0xFFFF;
+
+	tv = v1 - ((as -> dpval) << 8);
+	if (tv > 0xFF || tv < 0)
+	{
+		register_error(as, l, 2, "Byte overflow");
+	}
+	lwasm_emit(as, l, tv & 0xff);
+}