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[binutils.git] / opcodes / s390-dis.c
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1 /* s390-dis.c -- Disassemble S390 instructions
2 Copyright 2000, 2001, 2002, 2003, 2005, 2007 Free Software Foundation, Inc.
3 Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
5 This file is part of the GNU opcodes library.
7 This library 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 3, or (at your option)
10 any later version.
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.
17 You should have received a copy of the GNU General Public License
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. */
22 #include <stdio.h>
23 #include "ansidecl.h"
24 #include "sysdep.h"
25 #include "dis-asm.h"
26 #include "opintl.h"
27 #include "opcode/s390.h"
29 static int init_flag = 0;
30 static int opc_index[256];
31 static int current_arch_mask = 0;
33 /* Set up index table for first opcode byte. */
35 static void
36 init_disasm (struct disassemble_info *info)
38 const struct s390_opcode *opcode;
39 const struct s390_opcode *opcode_end;
40 const char *p;
42 memset (opc_index, 0, sizeof (opc_index));
43 opcode_end = s390_opcodes + s390_num_opcodes;
44 for (opcode = s390_opcodes; opcode < opcode_end; opcode++)
46 opc_index[(int) opcode->opcode[0]] = opcode - s390_opcodes;
47 while ((opcode < opcode_end) &&
48 (opcode[1].opcode[0] == opcode->opcode[0]))
49 opcode++;
52 for (p = info->disassembler_options; p != NULL; )
54 if (CONST_STRNEQ (p, "esa"))
55 current_arch_mask = 1 << S390_OPCODE_ESA;
56 else if (CONST_STRNEQ (p, "zarch"))
57 current_arch_mask = 1 << S390_OPCODE_ZARCH;
58 else
59 fprintf (stderr, "Unknown S/390 disassembler option: %s\n", p);
61 p = strchr (p, ',');
62 if (p != NULL)
63 p++;
66 if (!current_arch_mask)
67 switch (info->mach)
69 case bfd_mach_s390_31:
70 current_arch_mask = 1 << S390_OPCODE_ESA;
71 break;
72 case bfd_mach_s390_64:
73 current_arch_mask = 1 << S390_OPCODE_ZARCH;
74 break;
75 default:
76 abort ();
79 init_flag = 1;
82 /* Extracts an operand value from an instruction. */
84 static inline unsigned int
85 s390_extract_operand (unsigned char *insn, const struct s390_operand *operand)
87 unsigned int val;
88 int bits;
90 /* Extract fragments of the operand byte for byte. */
91 insn += operand->shift / 8;
92 bits = (operand->shift & 7) + operand->bits;
93 val = 0;
96 val <<= 8;
97 val |= (unsigned int) *insn++;
98 bits -= 8;
100 while (bits > 0);
101 val >>= -bits;
102 val &= ((1U << (operand->bits - 1)) << 1) - 1;
104 /* Check for special long displacement case. */
105 if (operand->bits == 20 && operand->shift == 20)
106 val = (val & 0xff) << 12 | (val & 0xfff00) >> 8;
108 /* Sign extend value if the operand is signed or pc relative. */
109 if ((operand->flags & (S390_OPERAND_SIGNED | S390_OPERAND_PCREL))
110 && (val & (1U << (operand->bits - 1))))
111 val |= (-1U << (operand->bits - 1)) << 1;
113 /* Double value if the operand is pc relative. */
114 if (operand->flags & S390_OPERAND_PCREL)
115 val <<= 1;
117 /* Length x in an instructions has real length x + 1. */
118 if (operand->flags & S390_OPERAND_LENGTH)
119 val++;
120 return val;
123 /* Print a S390 instruction. */
126 print_insn_s390 (bfd_vma memaddr, struct disassemble_info *info)
128 bfd_byte buffer[6];
129 const struct s390_opcode *opcode;
130 const struct s390_opcode *opcode_end;
131 unsigned int value;
132 int status, opsize, bufsize;
133 char separator;
135 if (init_flag == 0)
136 init_disasm (info);
138 /* The output looks better if we put 6 bytes on a line. */
139 info->bytes_per_line = 6;
141 /* Every S390 instruction is max 6 bytes long. */
142 memset (buffer, 0, 6);
143 status = (*info->read_memory_func) (memaddr, buffer, 6, info);
144 if (status != 0)
146 for (bufsize = 0; bufsize < 6; bufsize++)
147 if ((*info->read_memory_func) (memaddr, buffer, bufsize + 1, info) != 0)
148 break;
149 if (bufsize <= 0)
151 (*info->memory_error_func) (status, memaddr, info);
152 return -1;
154 /* Opsize calculation looks strange but it works
155 00xxxxxx -> 2 bytes, 01xxxxxx/10xxxxxx -> 4 bytes,
156 11xxxxxx -> 6 bytes. */
157 opsize = ((((buffer[0] >> 6) + 1) >> 1) + 1) << 1;
158 status = opsize > bufsize;
160 else
162 bufsize = 6;
163 opsize = ((((buffer[0] >> 6) + 1) >> 1) + 1) << 1;
166 if (status == 0)
168 /* Find the first match in the opcode table. */
169 opcode_end = s390_opcodes + s390_num_opcodes;
170 for (opcode = s390_opcodes + opc_index[(int) buffer[0]];
171 (opcode < opcode_end) && (buffer[0] == opcode->opcode[0]);
172 opcode++)
174 const struct s390_operand *operand;
175 const unsigned char *opindex;
177 /* Check architecture. */
178 if (!(opcode->modes & current_arch_mask))
179 continue;
180 /* Check signature of the opcode. */
181 if ((buffer[1] & opcode->mask[1]) != opcode->opcode[1]
182 || (buffer[2] & opcode->mask[2]) != opcode->opcode[2]
183 || (buffer[3] & opcode->mask[3]) != opcode->opcode[3]
184 || (buffer[4] & opcode->mask[4]) != opcode->opcode[4]
185 || (buffer[5] & opcode->mask[5]) != opcode->opcode[5])
186 continue;
188 /* The instruction is valid. */
189 if (opcode->operands[0] != 0)
190 (*info->fprintf_func) (info->stream, "%s\t", opcode->name);
191 else
192 (*info->fprintf_func) (info->stream, "%s", opcode->name);
194 /* Extract the operands. */
195 separator = 0;
196 for (opindex = opcode->operands; *opindex != 0; opindex++)
198 unsigned int value;
200 operand = s390_operands + *opindex;
201 value = s390_extract_operand (buffer, operand);
203 if ((operand->flags & S390_OPERAND_INDEX) && value == 0)
204 continue;
205 if ((operand->flags & S390_OPERAND_BASE) &&
206 value == 0 && separator == '(')
208 separator = ',';
209 continue;
212 if (separator)
213 (*info->fprintf_func) (info->stream, "%c", separator);
215 if (operand->flags & S390_OPERAND_GPR)
216 (*info->fprintf_func) (info->stream, "%%r%i", value);
217 else if (operand->flags & S390_OPERAND_FPR)
218 (*info->fprintf_func) (info->stream, "%%f%i", value);
219 else if (operand->flags & S390_OPERAND_AR)
220 (*info->fprintf_func) (info->stream, "%%a%i", value);
221 else if (operand->flags & S390_OPERAND_CR)
222 (*info->fprintf_func) (info->stream, "%%c%i", value);
223 else if (operand->flags & S390_OPERAND_PCREL)
224 (*info->print_address_func) (memaddr + (int) value, info);
225 else if (operand->flags & S390_OPERAND_SIGNED)
226 (*info->fprintf_func) (info->stream, "%i", (int) value);
227 else
228 (*info->fprintf_func) (info->stream, "%u", value);
230 if (operand->flags & S390_OPERAND_DISP)
232 separator = '(';
234 else if (operand->flags & S390_OPERAND_BASE)
236 (*info->fprintf_func) (info->stream, ")");
237 separator = ',';
239 else
240 separator = ',';
243 /* Found instruction, printed it, return its size. */
244 return opsize;
246 /* No matching instruction found, fall through to hex print. */
249 if (bufsize >= 4)
251 value = (unsigned int) buffer[0];
252 value = (value << 8) + (unsigned int) buffer[1];
253 value = (value << 8) + (unsigned int) buffer[2];
254 value = (value << 8) + (unsigned int) buffer[3];
255 (*info->fprintf_func) (info->stream, ".long\t0x%08x", value);
256 return 4;
258 else if (bufsize >= 2)
260 value = (unsigned int) buffer[0];
261 value = (value << 8) + (unsigned int) buffer[1];
262 (*info->fprintf_func) (info->stream, ".short\t0x%04x", value);
263 return 2;
265 else
267 value = (unsigned int) buffer[0];
268 (*info->fprintf_func) (info->stream, ".byte\t0x%02x", value);
269 return 1;
273 void
274 print_s390_disassembler_options (FILE *stream)
276 fprintf (stream, _("\n\
277 The following S/390 specific disassembler options are supported for use\n\
278 with the -M switch (multiple options should be separated by commas):\n"));
280 fprintf (stream, _(" esa Disassemble in ESA architecture mode\n"));
281 fprintf (stream, _(" zarch Disassemble in z/Architecture mode\n"));