File: /usr/src/linux/arch/ppc/xmon/ppc-dis.c
1 /*
2 * BK Id: SCCS/s.ppc-dis.c 1.5 05/17/01 18:14:23 cort
3 */
4 /* ppc-dis.c -- Disassemble PowerPC instructions
5 Copyright 1994 Free Software Foundation, Inc.
6 Written by Ian Lance Taylor, Cygnus Support
7
8 This file is part of GDB, GAS, and the GNU binutils.
9
10 GDB, GAS, and the GNU binutils are free software; you can redistribute
11 them and/or modify them under the terms of the GNU General Public
12 License as published by the Free Software Foundation; either version
13 2, or (at your option) any later version.
14
15 GDB, GAS, and the GNU binutils are distributed in the hope that they
16 will be useful, but WITHOUT ANY WARRANTY; without even the implied
17 warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
18 the GNU General Public License for more details.
19
20 You should have received a copy of the GNU General Public License
21 along with this file; see the file COPYING. If not, write to the Free
22 Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
23
24 #include "nonstdio.h"
25 #include "ansidecl.h"
26 #include "ppc.h"
27
28 static int print_insn_powerpc PARAMS ((FILE *, unsigned long insn,
29 unsigned memaddr, int dialect));
30
31 extern void print_address PARAMS((unsigned memaddr));
32
33 /* Print a big endian PowerPC instruction. For convenience, also
34 disassemble instructions supported by the Motorola PowerPC 601. */
35
36 int
37 print_insn_big_powerpc (FILE *out, unsigned long insn, unsigned memaddr)
38 {
39 return print_insn_powerpc (out, insn, memaddr,
40 PPC_OPCODE_PPC | PPC_OPCODE_601);
41 }
42
43 /* Print a PowerPC or POWER instruction. */
44
45 static int
46 print_insn_powerpc (FILE *out, unsigned long insn, unsigned memaddr,
47 int dialect)
48 {
49 const struct powerpc_opcode *opcode;
50 const struct powerpc_opcode *opcode_end;
51 unsigned long op;
52
53 /* Get the major opcode of the instruction. */
54 op = PPC_OP (insn);
55
56 /* Find the first match in the opcode table. We could speed this up
57 a bit by doing a binary search on the major opcode. */
58 opcode_end = powerpc_opcodes + powerpc_num_opcodes;
59 for (opcode = powerpc_opcodes; opcode < opcode_end; opcode++)
60 {
61 unsigned long table_op;
62 const unsigned char *opindex;
63 const struct powerpc_operand *operand;
64 int invalid;
65 int need_comma;
66 int need_paren;
67
68 table_op = PPC_OP (opcode->opcode);
69 if (op < table_op)
70 break;
71 if (op > table_op)
72 continue;
73
74 if ((insn & opcode->mask) != opcode->opcode
75 || (opcode->flags & dialect) == 0)
76 continue;
77
78 /* Make two passes over the operands. First see if any of them
79 have extraction functions, and, if they do, make sure the
80 instruction is valid. */
81 invalid = 0;
82 for (opindex = opcode->operands; *opindex != 0; opindex++)
83 {
84 operand = powerpc_operands + *opindex;
85 if (operand->extract)
86 (*operand->extract) (insn, &invalid);
87 }
88 if (invalid)
89 continue;
90
91 /* The instruction is valid. */
92 fprintf(out, "%s", opcode->name);
93 if (opcode->operands[0] != 0)
94 fprintf(out, "\t");
95
96 /* Now extract and print the operands. */
97 need_comma = 0;
98 need_paren = 0;
99 for (opindex = opcode->operands; *opindex != 0; opindex++)
100 {
101 long value;
102
103 operand = powerpc_operands + *opindex;
104
105 /* Operands that are marked FAKE are simply ignored. We
106 already made sure that the extract function considered
107 the instruction to be valid. */
108 if ((operand->flags & PPC_OPERAND_FAKE) != 0)
109 continue;
110
111 /* Extract the value from the instruction. */
112 if (operand->extract)
113 value = (*operand->extract) (insn, (int *) 0);
114 else
115 {
116 value = (insn >> operand->shift) & ((1 << operand->bits) - 1);
117 if ((operand->flags & PPC_OPERAND_SIGNED) != 0
118 && (value & (1 << (operand->bits - 1))) != 0)
119 value -= 1 << operand->bits;
120 }
121
122 /* If the operand is optional, and the value is zero, don't
123 print anything. */
124 if ((operand->flags & PPC_OPERAND_OPTIONAL) != 0
125 && (operand->flags & PPC_OPERAND_NEXT) == 0
126 && value == 0)
127 continue;
128
129 if (need_comma)
130 {
131 fprintf(out, ",");
132 need_comma = 0;
133 }
134
135 /* Print the operand as directed by the flags. */
136 if ((operand->flags & PPC_OPERAND_GPR) != 0)
137 fprintf(out, "r%ld", value);
138 else if ((operand->flags & PPC_OPERAND_FPR) != 0)
139 fprintf(out, "f%ld", value);
140 else if ((operand->flags & PPC_OPERAND_RELATIVE) != 0)
141 print_address (memaddr + value);
142 else if ((operand->flags & PPC_OPERAND_ABSOLUTE) != 0)
143 print_address (value & 0xffffffff);
144 else if ((operand->flags & PPC_OPERAND_CR) == 0
145 || (dialect & PPC_OPCODE_PPC) == 0)
146 fprintf(out, "%ld", value);
147 else
148 {
149 if (operand->bits == 3)
150 fprintf(out, "cr%d", value);
151 else
152 {
153 static const char *cbnames[4] = { "lt", "gt", "eq", "so" };
154 int cr;
155 int cc;
156
157 cr = value >> 2;
158 if (cr != 0)
159 fprintf(out, "4*cr%d", cr);
160 cc = value & 3;
161 if (cc != 0)
162 {
163 if (cr != 0)
164 fprintf(out, "+");
165 fprintf(out, "%s", cbnames[cc]);
166 }
167 }
168 }
169
170 if (need_paren)
171 {
172 fprintf(out, ")");
173 need_paren = 0;
174 }
175
176 if ((operand->flags & PPC_OPERAND_PARENS) == 0)
177 need_comma = 1;
178 else
179 {
180 fprintf(out, "(");
181 need_paren = 1;
182 }
183 }
184
185 /* We have found and printed an instruction; return. */
186 return 4;
187 }
188
189 /* We could not find a match. */
190 fprintf(out, ".long 0x%lx", insn);
191
192 return 4;
193 }
194