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comparison lwasm/insn_rel.c @ 357:0cf4948d53b4

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Checkpoint - adding actual cpu instructions
author lost@starbug
date Wed, 31 Mar 2010 20:12:20 -0600
parents old-trunk/lwasm/old/insn_rel.c@eb230fa7d28e
children 9c24d9d485b9
comparison
equal deleted inserted replaced
356:7166254491ed 357:0cf4948d53b4
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 #include <config.h>
26 #include <stdlib.h>
27
28 #include <lw_expr.h>
29
30 #include "lwasm.h"
31 #include "instab.h"
32
33 PARSEFUNC(insn_parse_rel8)
34 {
35 int v;
36 lw_expr_t t, e1, e2;
37 int r;
38
39 // sometimes there is a "#", ignore if there
40 if (**p == '#')
41 (*p)++;
42
43 t = lwasm_parse_expr(as, p);
44 if (!t)
45 {
46 lwasm_register_error(as, l, "Bad operand");
47 return;
48 }
49 l -> len = OPLEN(instab[l -> insn].ops[0]) + 1;
50
51 e1 = lw_expr_build(lw_expr_type_special, lwasm_expr_linelen, l);
52 e2 = lw_expr_build(lw_expr_type_oper, lw_expr_oper_plus, e1, l -> addr);
53 lw_expr_destroy(e1);
54 e1 = lw_expr_build(lw_expr_type_oper, lw_expr_oper_minus, t, e2);
55 lw_expr_destroy(e2);
56 lwasm_save_expr(l, 0, e2);
57 }
58
59 EMITFUNC(insn_emit_rel8)
60 {
61 lw_expr_t e;
62 int offs;
63
64 e = lwasm_fetch_expr(l, 0);
65 if (!lw_expr_istype(e, lw_expr_type_int))
66 {
67 lwasm_register_error(as, l, "Illegal non-constant expression");
68 return;
69 }
70
71 offs = lw_expr_intval(e);
72 if (offs < -128 || offs > 127)
73 {
74 lwasm_register_error(as, l, "Byte overflow");
75 return;
76 }
77
78 lwasm_emitop(l, instab[l -> insn].ops[0]);
79 lwasm_emit(l, offs);
80 }
81
82 PARSEFUNC(insn_parse_rel16)
83 {
84 int v;
85 lw_expr_t t, e1, e2;
86 int r;
87
88 // sometimes there is a "#", ignore if there
89 if (**p == '#')
90 (*p)++;
91
92 t = lwasm_parse_expr(as, p);
93 if (!t)
94 {
95 lwasm_register_error(as, l, "Bad operand");
96 return;
97 }
98 l -> len = OPLEN(instab[l -> insn].ops[0]) + 2;
99
100 e1 = lw_expr_build(lw_expr_type_special, lwasm_expr_linelen, l);
101 e2 = lw_expr_build(lw_expr_type_oper, lw_expr_oper_plus, e1, l -> addr);
102 lw_expr_destroy(e1);
103 e1 = lw_expr_build(lw_expr_type_oper, lw_expr_oper_minus, t, e2);
104 lw_expr_destroy(e2);
105 lwasm_save_expr(l, 0, e2);
106 }
107
108 EMITFUNC(insn_emit_rel16)
109 {
110 lw_expr_t e;
111 int offs;
112
113 e = lwasm_fetch_expr(l, 0);
114
115 lwasm_emitop(l, instab[l -> insn].ops[0]);
116 lwasm_emitexpr(l, e, 2);
117 }