--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lwasm/insn_rel.c	Wed Jan 19 22:27:17 2011 -0700
@@ -0,0 +1,116 @@
+/*
+insn_rel.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 relative mode instructions
+*/
+
+#include <stdlib.h>
+
+#include <lw_expr.h>
+
+#include "lwasm.h"
+#include "instab.h"
+
+PARSEFUNC(insn_parse_rel8)
+{
+	int v;
+	lw_expr_t t, e1, e2;
+	int r;
+
+	// sometimes there is a "#", ignore if there
+	if (**p == '#')
+		(*p)++;
+
+	t = lwasm_parse_expr(as, p);
+	if (!t)
+	{
+		lwasm_register_error(as, l, "Bad operand");
+		return;
+	}
+	l -> len = OPLEN(instab[l -> insn].ops[0]) + 1;
+	
+	e1 = lw_expr_build(lw_expr_type_special, lwasm_expr_linelen, l);
+	e2 = lw_expr_build(lw_expr_type_oper, lw_expr_oper_plus, e1, l -> addr);
+	lw_expr_destroy(e1);
+	e1 = lw_expr_build(lw_expr_type_oper, lw_expr_oper_minus, t, e2);
+	lw_expr_destroy(e2);
+	lwasm_save_expr(l, 0, e1);
+}
+
+EMITFUNC(insn_emit_rel8)
+{
+	lw_expr_t e;
+	int offs;
+	
+	e = lwasm_fetch_expr(l, 0);
+	if (!lw_expr_istype(e, lw_expr_type_int))
+	{
+		lwasm_register_error(as, l, "Illegal non-constant expression");
+		return;
+	}
+	
+	offs = lw_expr_intval(e);
+	if (offs < -128 || offs > 127)
+	{
+		lwasm_register_error(as, l, "Byte overflow");
+		return;
+	}
+	
+	lwasm_emitop(l, instab[l -> insn].ops[0]);
+	lwasm_emit(l, offs);
+}
+
+PARSEFUNC(insn_parse_rel16)
+{
+	int v;
+	lw_expr_t t, e1, e2;
+	int r;
+
+	// sometimes there is a "#", ignore if there
+	if (**p == '#')
+		(*p)++;
+
+	t = lwasm_parse_expr(as, p);
+	if (!t)
+	{
+		lwasm_register_error(as, l, "Bad operand");
+		return;
+	}
+	l -> len = OPLEN(instab[l -> insn].ops[0]) + 2;
+	
+	e1 = lw_expr_build(lw_expr_type_special, lwasm_expr_linelen, l);
+	e2 = lw_expr_build(lw_expr_type_oper, lw_expr_oper_plus, e1, l -> addr);
+	lw_expr_destroy(e1);
+	e1 = lw_expr_build(lw_expr_type_oper, lw_expr_oper_minus, t, e2);
+	lw_expr_destroy(e2);
+	lwasm_save_expr(l, 0, e1);
+}
+
+EMITFUNC(insn_emit_rel16)
+{
+	lw_expr_t e;
+	int offs;
+	
+	e = lwasm_fetch_expr(l, 0);
+	
+	lwasm_emitop(l, instab[l -> insn].ops[0]);
+	lwasm_emitexpr(l, e, 2);
+}