source: trunk/binutils/opcodes/s390-dis.c@ 2784

Last change on this file since 2784 was 607, checked in by bird, 22 years ago

Initial revision
  • Property cvs2svn:cvs-rev set to 1.1
  • Property svn:eol-style set to native
  • Property svn:executable set to *
File size: 7.4 KB
Line 
1/* s390-dis.c -- Disassemble S390 instructions
2 Copyright 2000, 2001, 2002 Free Software Foundation, Inc.
3 Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
4
5 This file is part of GDB, GAS and the GNU binutils.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
21
22#include <stdio.h>
23#include "ansidecl.h"
24#include "sysdep.h"
25#include "dis-asm.h"
26#include "opcode/s390.h"
27
28static int init_flag = 0;
29static int opc_index[256];
30static int current_arch_mask = 0;
31
32static void init_disasm PARAMS ((struct disassemble_info *));
33static unsigned int s390_extract_operand
34 PARAMS ((unsigned char *, const struct s390_operand *));
35
36/* Set up index table for first opcode byte. */
37
38static void
39init_disasm (info)
40 struct disassemble_info *info;
41{
42 const struct s390_opcode *opcode;
43 const struct s390_opcode *opcode_end;
44
45 memset (opc_index, 0, sizeof (opc_index));
46 opcode_end = s390_opcodes + s390_num_opcodes;
47 for (opcode = s390_opcodes; opcode < opcode_end; opcode++)
48 {
49 opc_index[(int) opcode->opcode[0]] = opcode - s390_opcodes;
50 while ((opcode < opcode_end) &&
51 (opcode[1].opcode[0] == opcode->opcode[0]))
52 opcode++;
53 }
54 switch (info->mach)
55 {
56 case bfd_mach_s390_31:
57 current_arch_mask = 1 << S390_OPCODE_ESA;
58 break;
59 case bfd_mach_s390_64:
60 current_arch_mask = 1 << S390_OPCODE_ZARCH;
61 break;
62 default:
63 abort ();
64 }
65 init_flag = 1;
66}
67
68/* Extracts an operand value from an instruction. */
69
70static inline unsigned int
71s390_extract_operand (insn, operand)
72 unsigned char *insn;
73 const struct s390_operand *operand;
74{
75 unsigned int val;
76 int bits;
77
78 /* Extract fragments of the operand byte for byte. */
79 insn += operand->shift / 8;
80 bits = (operand->shift & 7) + operand->bits;
81 val = 0;
82 do
83 {
84 val <<= 8;
85 val |= (unsigned int) *insn++;
86 bits -= 8;
87 }
88 while (bits > 0);
89 val >>= -bits;
90 val &= ((1U << (operand->bits - 1)) << 1) - 1;
91
92 /* Sign extend value if the operand is signed or pc relative. */
93 if ((operand->flags & (S390_OPERAND_SIGNED | S390_OPERAND_PCREL))
94 && (val & (1U << (operand->bits - 1))))
95 val |= (-1U << (operand->bits - 1)) << 1;
96
97 /* Double value if the operand is pc relative. */
98 if (operand->flags & S390_OPERAND_PCREL)
99 val <<= 1;
100
101 /* Length x in an instructions has real length x+1. */
102 if (operand->flags & S390_OPERAND_LENGTH)
103 val++;
104 return val;
105}
106
107/* Print a S390 instruction. */
108
109int
110print_insn_s390 (memaddr, info)
111 bfd_vma memaddr;
112 struct disassemble_info *info;
113{
114 bfd_byte buffer[6];
115 const struct s390_opcode *opcode;
116 const struct s390_opcode *opcode_end;
117 unsigned int value;
118 int status, opsize, bufsize;
119 char separator;
120
121 if (init_flag == 0)
122 init_disasm (info);
123
124 /* The output looks better if we put 6 bytes on a line. */
125 info->bytes_per_line = 6;
126
127 /* Every S390 instruction is max 6 bytes long. */
128 memset (buffer, 0, 6);
129 status = (*info->read_memory_func) (memaddr, buffer, 6, info);
130 if (status != 0)
131 {
132 for (bufsize = 0; bufsize < 6; bufsize++)
133 if ((*info->read_memory_func) (memaddr, buffer, bufsize + 1, info) != 0)
134 break;
135 if (bufsize <= 0)
136 {
137 (*info->memory_error_func) (status, memaddr, info);
138 return -1;
139 }
140 /* Opsize calculation looks strange but it works
141 00xxxxxx -> 2 bytes, 01xxxxxx/10xxxxxx -> 4 bytes,
142 11xxxxxx -> 6 bytes. */
143 opsize = ((((buffer[0] >> 6) + 1) >> 1) + 1) << 1;
144 status = opsize > bufsize;
145 }
146 else
147 {
148 bufsize = 6;
149 opsize = ((((buffer[0] >> 6) + 1) >> 1) + 1) << 1;
150 }
151
152 if (status == 0)
153 {
154 /* Find the first match in the opcode table. */
155 opcode_end = s390_opcodes + s390_num_opcodes;
156 for (opcode = s390_opcodes + opc_index[(int) buffer[0]];
157 (opcode < opcode_end) && (buffer[0] == opcode->opcode[0]);
158 opcode++)
159 {
160 const struct s390_operand *operand;
161 const unsigned char *opindex;
162
163 /* Check architecture. */
164 if (!(opcode->modes & current_arch_mask))
165 continue;
166 /* Check signature of the opcode. */
167 if ((buffer[1] & opcode->mask[1]) != opcode->opcode[1]
168 || (buffer[2] & opcode->mask[2]) != opcode->opcode[2]
169 || (buffer[3] & opcode->mask[3]) != opcode->opcode[3]
170 || (buffer[4] & opcode->mask[4]) != opcode->opcode[4]
171 || (buffer[5] & opcode->mask[5]) != opcode->opcode[5])
172 continue;
173
174 /* The instruction is valid. */
175 if (opcode->operands[0] != 0)
176 (*info->fprintf_func) (info->stream, "%s\t", opcode->name);
177 else
178 (*info->fprintf_func) (info->stream, "%s", opcode->name);
179
180 /* Extract the operands. */
181 separator = 0;
182 for (opindex = opcode->operands; *opindex != 0; opindex++)
183 {
184 unsigned int value;
185
186 operand = s390_operands + *opindex;
187 value = s390_extract_operand (buffer, operand);
188
189 if ((operand->flags & S390_OPERAND_INDEX) && value == 0)
190 continue;
191 if ((operand->flags & S390_OPERAND_BASE) &&
192 value == 0 && separator == '(')
193 {
194 separator = ',';
195 continue;
196 }
197
198 if (separator)
199 (*info->fprintf_func) (info->stream, "%c", separator);
200
201 if (operand->flags & S390_OPERAND_GPR)
202 (*info->fprintf_func) (info->stream, "%%r%i", value);
203 else if (operand->flags & S390_OPERAND_FPR)
204 (*info->fprintf_func) (info->stream, "%%f%i", value);
205 else if (operand->flags & S390_OPERAND_AR)
206 (*info->fprintf_func) (info->stream, "%%a%i", value);
207 else if (operand->flags & S390_OPERAND_CR)
208 (*info->fprintf_func) (info->stream, "%%c%i", value);
209 else if (operand->flags & S390_OPERAND_PCREL)
210 (*info->print_address_func) (memaddr + (int) value, info);
211 else if (operand->flags & S390_OPERAND_SIGNED)
212 (*info->fprintf_func) (info->stream, "%i", (int) value);
213 else
214 (*info->fprintf_func) (info->stream, "%i", value);
215
216 if (operand->flags & S390_OPERAND_DISP)
217 {
218 separator = '(';
219 }
220 else if (operand->flags & S390_OPERAND_BASE)
221 {
222 (*info->fprintf_func) (info->stream, ")");
223 separator = ',';
224 }
225 else
226 separator = ',';
227 }
228
229 /* Found instruction, printed it, return its size. */
230 return opsize;
231 }
232 /* No matching instruction found, fall through to hex print. */
233 }
234
235 if (bufsize >= 4)
236 {
237 value = (unsigned int) buffer[0];
238 value = (value << 8) + (unsigned int) buffer[1];
239 value = (value << 8) + (unsigned int) buffer[2];
240 value = (value << 8) + (unsigned int) buffer[3];
241 (*info->fprintf_func) (info->stream, ".long\t0x%08x", value);
242 return 4;
243 }
244 else if (bufsize >= 2)
245 {
246 value = (unsigned int) buffer[0];
247 value = (value << 8) + (unsigned int) buffer[1];
248 (*info->fprintf_func) (info->stream, ".short\t0x%04x", value);
249 return 2;
250 }
251 else
252 {
253 value = (unsigned int) buffer[0];
254 (*info->fprintf_func) (info->stream, ".byte\t0x%02x", value);
255 return 1;
256 }
257}
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