--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lwasm/insn_rel.c	Fri Jan 30 04:01:55 2009 +0000
@@ -0,0 +1,123 @@
+/*
+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
+*/
+
+#define __insn_rel_c_seen__
+
+#include <stdlib.h>
+
+#include "expr.h"
+#include "lwasm.h"
+#include "instab.h"
+
+OPFUNC(insn_rel8)
+{
+	int v;
+	lwasm_expr_term_t *t;
+	int r;
+	
+	lwasm_emitop(as, l, instab[opnum].ops[0]);
+
+	if ((r = lwasm_expr_result2(as, l, p, EXPR_SECTCONST, &v, 0)) < 0)
+		v = 0;
+	else
+	{
+		if (as -> passnum == 1)
+		{
+			// need to adjust the expression
+			if (l -> exprs[0])
+			{
+				t = lwasm_expr_term_create_int(as -> addr + 1);
+				lwasm_expr_stack_push(l -> exprs[0], t);
+				lwasm_expr_term_free(t);
+				t = lwasm_expr_term_create_oper(LWASM_OPER_MINUS);
+				lwasm_expr_stack_push(l -> exprs[0], t);
+				lwasm_expr_term_free(t);
+			}
+			else
+			{
+				l -> exprvals[0] -= as -> addr + 1;
+			}
+		}
+	}
+	if (r == 1 && as -> passnum == 2)
+	{
+		register_error(as, l, 2, "Illegal external or intersegment reference");
+	}
+	if (v < -128 || v > 127)
+		register_error(as, l, 2, "Byte overflow");
+	lwasm_emit(as, l, v & 0xff);
+}
+
+/*
+External and intersegment references are adjusted for the relative addressing mode
+by adjusting the expression on pass 1 and then treated as absolute references later
+*/
+OPFUNC(insn_rel16)
+{
+	int v;
+	int r;
+	lwasm_expr_term_t *t;
+	
+	lwasm_emitop(as, l, instab[opnum].ops[0]);
+	
+	r = lwasm_expr_result2(as, l, p, EXPR_SECTCONST, &v, 0);
+	if (r < 0)
+		v = 0;
+	else
+	{
+		if (as -> passnum == 1)
+		{
+			// need to adjust the expression
+			if (l -> exprs[0])
+			{
+				t = lwasm_expr_term_create_int(as -> addr + 2);
+				lwasm_expr_stack_push(l -> exprs[0], t);
+				lwasm_expr_term_free(t);
+				t = lwasm_expr_term_create_oper(LWASM_OPER_MINUS);
+				lwasm_expr_stack_push(l -> exprs[0], t);
+				lwasm_expr_term_free(t);
+			}
+			else
+			{
+				l -> exprvals[0] -= as -> addr + 2;
+			}
+		}
+	}
+	if (as -> passnum == 2 && r == 1)
+	{
+		// since we have a reference outside this section, add
+		// a subtract of the section base to get the right value
+		// upon linking
+		t = lwasm_expr_term_create_secbase();
+		lwasm_expr_stack_push(l -> exprs[0], t);
+		lwasm_expr_term_free(t);
+		t = lwasm_expr_term_create_oper(LWASM_OPER_MINUS);
+		lwasm_expr_stack_push(l -> exprs[0], t);
+		lwasm_expr_term_free(t);
+
+		l -> relocoff = as -> addr - l -> codeaddr;
+	}
+	lwasm_emit(as, l, (v >> 8) & 0xff);
+	lwasm_emit(as, l, v & 0xff);
+}