1 /* s390-dis.c -- Disassemble S390 instructions
2 Copyright 2000, 2001 Free Software Foundation, Inc.
3 Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
5 This file is part of GDB, GAS and the GNU binutils.
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.
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.
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
26 #include "opcode/s390.h"
28 static int init_flag = 0;
29 static int opc_index[256];
30 static int current_arch_mask = 0;
32 static void init_disasm PARAMS ((struct disassemble_info *));
33 static unsigned int s390_extract_operand
34 PARAMS ((unsigned char *, const struct s390_operand *));
36 /* Set up index table for first opcode byte. */
40 struct disassemble_info *info;
42 const struct s390_opcode *opcode;
43 const struct s390_opcode *opcode_end;
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++)
49 opc_index[(int) opcode->opcode[0]] = opcode - s390_opcodes;
50 while ((opcode < opcode_end) &&
51 (opcode[1].opcode[0] == opcode->opcode[0]))
56 case bfd_mach_s390_esa:
57 current_arch_mask = 1 << S390_OPCODE_ESA;
59 case bfd_mach_s390_esame:
60 current_arch_mask = 1 << S390_OPCODE_ESAME;
68 /* Extracts an operand value from an instruction. */
70 static inline unsigned int
71 s390_extract_operand (insn, operand)
73 const struct s390_operand *operand;
78 /* Extract fragments of the operand byte for byte. */
79 insn += operand->shift / 8;
80 bits = (operand->shift & 7) + operand->bits;
85 val |= (unsigned int) *insn++;
90 val &= ((1U << (operand->bits - 1)) << 1) - 1;
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;
97 /* Double value if the operand is pc relative. */
98 if (operand->flags & S390_OPERAND_PCREL)
101 /* Length x in an instructions has real length x+1. */
102 if (operand->flags & S390_OPERAND_LENGTH)
107 /* Print a S390 instruction. */
110 print_insn_s390 (memaddr, info)
112 struct disassemble_info *info;
115 const struct s390_opcode *opcode;
116 const struct s390_opcode *opcode_end;
118 int status, opsize, bufsize;
124 /* The output looks better if we put 6 bytes on a line. */
125 info->bytes_per_line = 6;
127 /* Every S390 instruction is max 6 bytes long. */
128 memset (buffer, 0, 6);
129 status = (*info->read_memory_func) (memaddr, buffer, 6, info);
132 for (bufsize = 0; bufsize < 6; bufsize++)
133 if ((*info->read_memory_func) (memaddr, buffer, bufsize + 1, info) != 0)
137 (*info->memory_error_func) (status, memaddr, info);
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;
149 opsize = ((((buffer[0] >> 6) + 1) >> 1) + 1) << 1;
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]);
160 const struct s390_operand *operand;
161 const unsigned char *opindex;
163 /* Check architecture. */
164 if (!(opcode->architecture & current_arch_mask))
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])
174 /* The instruction is valid. */
175 if (opcode->operands[0] != 0)
176 (*info->fprintf_func) (info->stream, "%s\t", opcode->name);
178 (*info->fprintf_func) (info->stream, "%s", opcode->name);
180 /* Extract the operands. */
182 for (opindex = opcode->operands; *opindex != 0; opindex++)
186 operand = s390_operands + *opindex;
187 value = s390_extract_operand (buffer, operand);
189 if ((operand->flags & S390_OPERAND_INDEX) && value == 0)
191 if ((operand->flags & S390_OPERAND_BASE) &&
192 value == 0 && separator == '(')
199 (*info->fprintf_func) (info->stream, "%c", separator);
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);
214 (*info->fprintf_func) (info->stream, "%i", value);
216 if (operand->flags & S390_OPERAND_DISP)
220 else if (operand->flags & S390_OPERAND_BASE)
222 (*info->fprintf_func) (info->stream, ")");
229 /* Found instruction, printed it, return its size. */
232 /* No matching instruction found, fall through to hex print. */
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);
244 else if (bufsize >= 2)
246 value = (unsigned int) buffer[0];
247 value = (value << 8) + (unsigned int) buffer[1];
248 (*info->fprintf_func) (info->stream, ".short\t0x%04x", value);
253 value = (unsigned int) buffer[0];
254 (*info->fprintf_func) (info->stream, ".byte\t0x%02x", value);