Commit | Line | Data |
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a85d7ed0 | 1 | /* s390-dis.c -- Disassemble S390 instructions |
4b95cf5c | 2 | Copyright (C) 2000-2014 Free Software Foundation, Inc. |
a85d7ed0 NC |
3 | Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com). |
4 | ||
9b201bb5 | 5 | This file is part of the GNU opcodes library. |
a85d7ed0 | 6 | |
9b201bb5 | 7 | This library is free software; you can redistribute it and/or modify |
a85d7ed0 | 8 | it under the terms of the GNU General Public License as published by |
9b201bb5 NC |
9 | the Free Software Foundation; either version 3, or (at your option) |
10 | any later version. | |
a85d7ed0 | 11 | |
9b201bb5 NC |
12 | It is distributed in the hope that it will be useful, but WITHOUT |
13 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
14 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public | |
15 | License for more details. | |
a85d7ed0 NC |
16 | |
17 | You should have received a copy of the GNU General Public License | |
9b201bb5 NC |
18 | along with this file; see the file COPYING. If not, write to the |
19 | Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston, | |
20 | MA 02110-1301, USA. */ | |
a85d7ed0 | 21 | |
df7b86aa | 22 | #include "sysdep.h" |
a85d7ed0 NC |
23 | #include <stdio.h> |
24 | #include "ansidecl.h" | |
a85d7ed0 | 25 | #include "dis-asm.h" |
112b7c50 | 26 | #include "opintl.h" |
a85d7ed0 NC |
27 | #include "opcode/s390.h" |
28 | ||
29 | static int init_flag = 0; | |
30 | static int opc_index[256]; | |
31 | static int current_arch_mask = 0; | |
32 | ||
44f2a95d KH |
33 | /* Set up index table for first opcode byte. */ |
34 | ||
35 | static void | |
47b0e7ad | 36 | init_disasm (struct disassemble_info *info) |
a85d7ed0 | 37 | { |
9ace48f3 | 38 | int i; |
112b7c50 | 39 | const char *p; |
a85d7ed0 | 40 | |
44f2a95d | 41 | memset (opc_index, 0, sizeof (opc_index)); |
9ace48f3 AA |
42 | |
43 | /* Reverse order, such that each opc_index ends up pointing to the | |
44 | first matching entry instead of the last. */ | |
45 | for (i = s390_num_opcodes; i--; ) | |
46 | opc_index[s390_opcodes[i].opcode[0]] = i; | |
112b7c50 AK |
47 | |
48 | for (p = info->disassembler_options; p != NULL; ) | |
44f2a95d | 49 | { |
112b7c50 AK |
50 | if (CONST_STRNEQ (p, "esa")) |
51 | current_arch_mask = 1 << S390_OPCODE_ESA; | |
52 | else if (CONST_STRNEQ (p, "zarch")) | |
53 | current_arch_mask = 1 << S390_OPCODE_ZARCH; | |
54 | else | |
55 | fprintf (stderr, "Unknown S/390 disassembler option: %s\n", p); | |
56 | ||
57 | p = strchr (p, ','); | |
58 | if (p != NULL) | |
59 | p++; | |
44f2a95d | 60 | } |
112b7c50 AK |
61 | |
62 | if (!current_arch_mask) | |
7d4a7d10 | 63 | current_arch_mask = 1 << S390_OPCODE_ZARCH; |
112b7c50 | 64 | |
a85d7ed0 NC |
65 | init_flag = 1; |
66 | } | |
67 | ||
9ace48f3 AA |
68 | /* Derive the length of an instruction from its first byte. */ |
69 | ||
70 | static inline int | |
71 | s390_insn_length (const bfd_byte *buffer) | |
72 | { | |
73 | /* 00xxxxxx -> 2, 01xxxxxx/10xxxxxx -> 4, 11xxxxxx -> 6. */ | |
74 | return ((buffer[0] >> 6) + 3) & ~1U; | |
75 | } | |
76 | ||
77 | /* Match the instruction in BUFFER against the given OPCODE, excluding | |
78 | the first byte. */ | |
79 | ||
80 | static inline int | |
81 | s390_insn_matches_opcode (const bfd_byte *buffer, | |
82 | const struct s390_opcode *opcode) | |
83 | { | |
84 | return (buffer[1] & opcode->mask[1]) == opcode->opcode[1] | |
85 | && (buffer[2] & opcode->mask[2]) == opcode->opcode[2] | |
86 | && (buffer[3] & opcode->mask[3]) == opcode->opcode[3] | |
87 | && (buffer[4] & opcode->mask[4]) == opcode->opcode[4] | |
88 | && (buffer[5] & opcode->mask[5]) == opcode->opcode[5]; | |
89 | } | |
90 | ||
91 | union operand_value | |
92 | { | |
93 | int i; | |
94 | unsigned int u; | |
95 | }; | |
96 | ||
a85d7ed0 | 97 | /* Extracts an operand value from an instruction. */ |
7330f9c3 AK |
98 | /* We do not perform the shift operation for larl-type address |
99 | operands here since that would lead to an overflow of the 32 bit | |
100 | integer value. Instead the shift operation is done when printing | |
9ace48f3 | 101 | the operand. */ |
a85d7ed0 | 102 | |
9ace48f3 AA |
103 | static inline union operand_value |
104 | s390_extract_operand (const bfd_byte *insn, | |
105 | const struct s390_operand *operand) | |
a85d7ed0 | 106 | { |
9ace48f3 | 107 | union operand_value ret; |
a85d7ed0 NC |
108 | unsigned int val; |
109 | int bits; | |
110 | ||
44f2a95d KH |
111 | /* Extract fragments of the operand byte for byte. */ |
112 | insn += operand->shift / 8; | |
a85d7ed0 NC |
113 | bits = (operand->shift & 7) + operand->bits; |
114 | val = 0; | |
44f2a95d KH |
115 | do |
116 | { | |
117 | val <<= 8; | |
118 | val |= (unsigned int) *insn++; | |
119 | bits -= 8; | |
120 | } | |
121 | while (bits > 0); | |
a85d7ed0 | 122 | val >>= -bits; |
44f2a95d KH |
123 | val &= ((1U << (operand->bits - 1)) << 1) - 1; |
124 | ||
bac02689 MS |
125 | /* Check for special long displacement case. */ |
126 | if (operand->bits == 20 && operand->shift == 20) | |
127 | val = (val & 0xff) << 12 | (val & 0xfff00) >> 8; | |
128 | ||
9ace48f3 AA |
129 | /* Sign extend value if the operand is signed or pc relative. Avoid |
130 | integer overflows. */ | |
131 | if (operand->flags & (S390_OPERAND_SIGNED | S390_OPERAND_PCREL)) | |
132 | { | |
133 | unsigned int m = 1U << (operand->bits - 1); | |
134 | ||
135 | if (val >= m) | |
136 | ret.i = (int) (val - m) - 1 - (int) (m - 1U); | |
137 | else | |
138 | ret.i = (int) val; | |
139 | } | |
140 | else if (operand->flags & S390_OPERAND_LENGTH) | |
141 | /* Length x in an instruction has real length x + 1. */ | |
142 | ret.u = val + 1; | |
143 | else | |
144 | ret.u = val; | |
145 | ||
146 | return ret; | |
147 | } | |
148 | ||
149 | /* Print the S390 instruction in BUFFER, assuming that it matches the | |
150 | given OPCODE. */ | |
151 | ||
152 | static void | |
153 | s390_print_insn_with_opcode (bfd_vma memaddr, | |
154 | struct disassemble_info *info, | |
155 | const bfd_byte *buffer, | |
156 | const struct s390_opcode *opcode) | |
157 | { | |
158 | const unsigned char *opindex; | |
159 | char separator; | |
160 | ||
161 | /* Mnemonic. */ | |
162 | info->fprintf_func (info->stream, "%s", opcode->name); | |
163 | ||
164 | /* Operands. */ | |
165 | separator = '\t'; | |
166 | for (opindex = opcode->operands; *opindex != 0; opindex++) | |
167 | { | |
168 | const struct s390_operand *operand = s390_operands + *opindex; | |
169 | union operand_value val = s390_extract_operand (buffer, operand); | |
170 | unsigned long flags = operand->flags; | |
171 | ||
172 | if ((flags & S390_OPERAND_INDEX) && val.u == 0) | |
173 | continue; | |
174 | if ((flags & S390_OPERAND_BASE) && | |
175 | val.u == 0 && separator == '(') | |
176 | { | |
177 | separator = ','; | |
178 | continue; | |
179 | } | |
180 | ||
181 | info->fprintf_func (info->stream, "%c", separator); | |
182 | ||
183 | if (flags & S390_OPERAND_GPR) | |
184 | info->fprintf_func (info->stream, "%%r%u", val.u); | |
185 | else if (flags & S390_OPERAND_FPR) | |
186 | info->fprintf_func (info->stream, "%%f%u", val.u); | |
187 | else if (flags & S390_OPERAND_AR) | |
188 | info->fprintf_func (info->stream, "%%a%u", val.u); | |
189 | else if (flags & S390_OPERAND_CR) | |
190 | info->fprintf_func (info->stream, "%%c%u", val.u); | |
191 | else if (flags & S390_OPERAND_PCREL) | |
192 | info->print_address_func (memaddr + val.i + val.i, info); | |
193 | else if (flags & S390_OPERAND_SIGNED) | |
194 | info->fprintf_func (info->stream, "%i", val.i); | |
195 | else | |
196 | info->fprintf_func (info->stream, "%u", val.u); | |
197 | ||
198 | if (flags & S390_OPERAND_DISP) | |
199 | separator = '('; | |
200 | else if (flags & S390_OPERAND_BASE) | |
201 | { | |
202 | info->fprintf_func (info->stream, ")"); | |
203 | separator = ','; | |
204 | } | |
205 | else | |
206 | separator = ','; | |
207 | } | |
208 | } | |
209 | ||
210 | /* Check whether opcode A's mask is more specific than that of B. */ | |
44f2a95d | 211 | |
9ace48f3 AA |
212 | static int |
213 | opcode_mask_more_specific (const struct s390_opcode *a, | |
214 | const struct s390_opcode *b) | |
215 | { | |
216 | return (((int) a->mask[0] + a->mask[1] + a->mask[2] | |
217 | + a->mask[3] + a->mask[4] + a->mask[5]) | |
218 | > ((int) b->mask[0] + b->mask[1] + b->mask[2] | |
219 | + b->mask[3] + b->mask[4] + b->mask[5])); | |
a85d7ed0 NC |
220 | } |
221 | ||
222 | /* Print a S390 instruction. */ | |
223 | ||
224 | int | |
47b0e7ad | 225 | print_insn_s390 (bfd_vma memaddr, struct disassemble_info *info) |
a85d7ed0 NC |
226 | { |
227 | bfd_byte buffer[6]; | |
9ace48f3 | 228 | const struct s390_opcode *opcode = NULL; |
a85d7ed0 NC |
229 | unsigned int value; |
230 | int status, opsize, bufsize; | |
a85d7ed0 NC |
231 | |
232 | if (init_flag == 0) | |
44f2a95d | 233 | init_disasm (info); |
a85d7ed0 NC |
234 | |
235 | /* The output looks better if we put 6 bytes on a line. */ | |
236 | info->bytes_per_line = 6; | |
237 | ||
238 | /* Every S390 instruction is max 6 bytes long. */ | |
44f2a95d | 239 | memset (buffer, 0, 6); |
9ace48f3 | 240 | status = info->read_memory_func (memaddr, buffer, 6, info); |
44f2a95d KH |
241 | if (status != 0) |
242 | { | |
243 | for (bufsize = 0; bufsize < 6; bufsize++) | |
9ace48f3 | 244 | if (info->read_memory_func (memaddr, buffer, bufsize + 1, info) != 0) |
44f2a95d KH |
245 | break; |
246 | if (bufsize <= 0) | |
247 | { | |
9ace48f3 | 248 | info->memory_error_func (status, memaddr, info); |
44f2a95d KH |
249 | return -1; |
250 | } | |
9ace48f3 | 251 | opsize = s390_insn_length (buffer); |
44f2a95d KH |
252 | status = opsize > bufsize; |
253 | } | |
254 | else | |
255 | { | |
256 | bufsize = 6; | |
9ace48f3 | 257 | opsize = s390_insn_length (buffer); |
44f2a95d KH |
258 | } |
259 | ||
260 | if (status == 0) | |
261 | { | |
02cbf767 AK |
262 | const struct s390_opcode *op; |
263 | ||
9ace48f3 AA |
264 | /* Find the "best match" in the opcode table. */ |
265 | for (op = s390_opcodes + opc_index[buffer[0]]; | |
266 | op != s390_opcodes + s390_num_opcodes | |
267 | && op->opcode[0] == buffer[0]; | |
268 | op++) | |
44f2a95d | 269 | { |
9ace48f3 AA |
270 | if ((op->modes & current_arch_mask) |
271 | && s390_insn_matches_opcode (buffer, op) | |
272 | && (opcode == NULL | |
273 | || opcode_mask_more_specific (op, opcode))) | |
274 | opcode = op; | |
44f2a95d | 275 | } |
44f2a95d KH |
276 | } |
277 | ||
9ace48f3 AA |
278 | if (opcode != NULL) |
279 | { | |
280 | /* The instruction is valid. Print it and return its size. */ | |
281 | s390_print_insn_with_opcode (memaddr, info, buffer, opcode); | |
282 | return opsize; | |
283 | } | |
284 | ||
285 | /* Fall back to hex print. */ | |
44f2a95d KH |
286 | if (bufsize >= 4) |
287 | { | |
288 | value = (unsigned int) buffer[0]; | |
289 | value = (value << 8) + (unsigned int) buffer[1]; | |
290 | value = (value << 8) + (unsigned int) buffer[2]; | |
291 | value = (value << 8) + (unsigned int) buffer[3]; | |
9ace48f3 | 292 | info->fprintf_func (info->stream, ".long\t0x%08x", value); |
44f2a95d KH |
293 | return 4; |
294 | } | |
295 | else if (bufsize >= 2) | |
296 | { | |
297 | value = (unsigned int) buffer[0]; | |
298 | value = (value << 8) + (unsigned int) buffer[1]; | |
9ace48f3 | 299 | info->fprintf_func (info->stream, ".short\t0x%04x", value); |
44f2a95d | 300 | return 2; |
a85d7ed0 | 301 | } |
44f2a95d KH |
302 | else |
303 | { | |
304 | value = (unsigned int) buffer[0]; | |
9ace48f3 | 305 | info->fprintf_func (info->stream, ".byte\t0x%02x", value); |
44f2a95d | 306 | return 1; |
a85d7ed0 | 307 | } |
a85d7ed0 | 308 | } |
112b7c50 AK |
309 | |
310 | void | |
311 | print_s390_disassembler_options (FILE *stream) | |
312 | { | |
313 | fprintf (stream, _("\n\ | |
314 | The following S/390 specific disassembler options are supported for use\n\ | |
315 | with the -M switch (multiple options should be separated by commas):\n")); | |
316 | ||
317 | fprintf (stream, _(" esa Disassemble in ESA architecture mode\n")); | |
318 | fprintf (stream, _(" zarch Disassemble in z/Architecture mode\n")); | |
319 | } |