--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lwasm/insn_bitbit.c	Wed Jan 19 22:27:17 2011 -0700
@@ -0,0 +1,146 @@
+/*
+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/>.
+*/
+
+#include <stdlib.h>
+
+#include <lw_expr.h>
+
+#include "lwasm.h"
+#include "instab.h"
+
+// these instructions cannot tolerate external references
+PARSEFUNC(insn_parse_bitbit)
+{
+	int r;
+	lw_expr_t e;
+	int v1;
+	int tv;
+
+	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
+	{
+		lwasm_register_error(as, l, "Bad register");
+		return;
+	}
+	
+	if (*(*p)++ != ',')
+	{
+		lwasm_register_error(as, l, "Bad operand");
+		return;
+	}
+	e = lwasm_parse_expr(as, p);
+	if (!e)
+	{
+		lwasm_register_error(as, l, "Bad operand");
+		return;
+	}
+	lwasm_save_expr(l, 0, e);
+	if (*(*p)++ != ',')
+	{
+		lwasm_register_error(as, l, "Bad operand");
+		return;
+	}
+
+	e = lwasm_parse_expr(as, p);
+	if (!e)
+	{
+		lwasm_register_error(as, l, "Bad operand");
+		return;
+	}
+	lwasm_save_expr(l, 1, e);
+
+	if (*(*p)++ != ',')
+	{
+		lwasm_register_error(as, l, "Bad operand");
+		return;
+	}
+
+	// ignore base page address modifier
+	if (**p == '<')
+		(*p)++;
+			
+	e = lwasm_parse_expr(as, p);
+	if (!e)
+	{
+		lwasm_register_error(as, l, "Bad operand");
+		return;
+	}
+	lwasm_save_expr(l, 2, e);
+
+	l -> lint = r;
+	l -> len = OPLEN(instab[l -> insn].ops[0]) + 2;
+}
+
+EMITFUNC(insn_emit_bitbit)
+{
+	int v1, v2;
+	lw_expr_t e;
+	
+	e = lwasm_fetch_expr(l, 0);
+	if (!lw_expr_istype(e, lw_expr_type_int))
+	{
+		lwasm_register_error(as, l, "Bit number must be fully resolved");
+		return;
+	}
+	v1 = lw_expr_intval(e);
+	if (v1 < 0 || v1 > 7)
+	{
+		lwasm_register_error(as, l, "Invalid bit number");
+		v1 = 0;
+	}
+
+	e = lwasm_fetch_expr(l, 1);
+	if (!lw_expr_istype(e, lw_expr_type_int))
+	{
+		lwasm_register_error(as, l, "Bit number must be fully resolved");
+		return;
+	}
+	v2 = lw_expr_intval(e);
+	if (v2 < 0 || v2 > 7)
+	{
+		lwasm_register_error(as, l, "Invalid bit number");
+		v2 = 0;
+	}
+	l -> pb = (l -> lint << 6) | (v1 << 3) | v2;
+	
+	e = lwasm_fetch_expr(l, 2);
+	if (lw_expr_istype(e, lw_expr_type_int))
+	{
+		v1 = lw_expr_intval(e) & 0xFFFF;
+		v2 = v1 - ((l -> dpval) << 8);
+		if (v2 > 0xFF || v2 < 0)
+		{
+			lwasm_register_error(as, l, "Byte overflow");
+			return;
+		}
+	}
+	lwasm_emitop(l, instab[l -> insn].ops[0]);
+	lwasm_emit(l, l -> pb);
+	lwasm_emitexpr(l, e, 1);
+}