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comparison old-trunk/lwasm/old/insn_rel.c @ 339:eb230fa7d28e

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Prepare for migration to hg
author lost
date Fri, 19 Mar 2010 02:54:14 +0000
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338:e7885b3ee266 339:eb230fa7d28e
1 /*
2 insn_rel.c
3 Copyright © 2009 William Astle
4
5 This file is part of LWASM.
6
7 LWASM is free software: you can redistribute it and/or modify it under the
8 terms of the GNU General Public License as published by the Free Software
9 Foundation, either version 3 of the License, or (at your option) any later
10 version.
11
12 This program is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 more details.
16
17 You should have received a copy of the GNU General Public License along with
18 this program. If not, see <http://www.gnu.org/licenses/>.
19 */
20
21 /*
22 for handling relative mode instructions
23 */
24
25 #define __insn_rel_c_seen__
26 #include <config.h>
27 #include <stdlib.h>
28
29 #include "expr.h"
30 #include "lwasm.h"
31 #include "instab.h"
32
33 OPFUNC(insn_rel8)
34 {
35 int v;
36 lwasm_expr_term_t *t;
37 int r;
38
39 lwasm_emitop(as, l, instab[opnum].ops[0]);
40
41 if (**p == '#')
42 (*p)++;
43
44 if ((r = lwasm_expr_result2(as, l, p, EXPR_SECTCONST, &v, 0)) < 0)
45 v = 0;
46 else
47 {
48 if (as -> passnum == 1)
49 {
50 // need to adjust the expression
51 if (l -> exprs[0])
52 {
53 t = lwasm_expr_term_create_int(as -> addr + 1);
54 lwasm_expr_stack_push(l -> exprs[0], t);
55 lwasm_expr_term_free(t);
56 t = lwasm_expr_term_create_oper(LWASM_OPER_MINUS);
57 lwasm_expr_stack_push(l -> exprs[0], t);
58 lwasm_expr_term_free(t);
59 }
60 else
61 {
62 l -> exprvals[0] -= as -> addr + 1;
63 }
64 }
65 }
66 if (r == 1 && as -> passnum == 2)
67 {
68 register_error(as, l, 2, "Illegal external or intersegment reference");
69 }
70 if (v < -128 || v > 127)
71 register_error(as, l, 2, "Byte overflow");
72 lwasm_emit(as, l, v & 0xff);
73 }
74
75 /*
76 External and intersegment references are adjusted for the relative addressing mode
77 by adjusting the expression on pass 1 and then treated as absolute references later
78 */
79 OPFUNC(insn_rel16)
80 {
81 int v;
82 int r;
83 lwasm_expr_term_t *t;
84
85 lwasm_emitop(as, l, instab[opnum].ops[0]);
86
87 if (**p == '#')
88 (*p)++;
89
90 r = lwasm_expr_result2(as, l, p, EXPR_SECTCONST, &v, 0);
91 if (r < 0)
92 v = 0;
93 else
94 {
95 if (as -> passnum == 1)
96 {
97 // need to adjust the expression
98 if (l -> exprs[0])
99 {
100 t = lwasm_expr_term_create_int(as -> addr + 2);
101 lwasm_expr_stack_push(l -> exprs[0], t);
102 lwasm_expr_term_free(t);
103 t = lwasm_expr_term_create_oper(LWASM_OPER_MINUS);
104 lwasm_expr_stack_push(l -> exprs[0], t);
105 lwasm_expr_term_free(t);
106 }
107 else
108 {
109 l -> exprvals[0] -= as -> addr + 2;
110 }
111 }
112 }
113 if (as -> passnum == 2 && r == 1)
114 {
115 // since we have a reference outside this section, add
116 // a subtract of the section base to get the right value
117 // upon linking
118 t = lwasm_expr_term_create_secbase();
119 lwasm_expr_stack_push(l -> exprs[0], t);
120 lwasm_expr_term_free(t);
121 t = lwasm_expr_term_create_oper(LWASM_OPER_MINUS);
122 lwasm_expr_stack_push(l -> exprs[0], t);
123 lwasm_expr_term_free(t);
124
125 l -> relocoff = as -> addr - l -> codeaddr;
126 }
127 lwasm_emit(as, l, (v >> 8) & 0xff);
128 lwasm_emit(as, l, v & 0xff);
129 }