1 /* Print NS 32000 instructions for GDB, the GNU debugger.
2 Copyright 1986, 1988, 1991, 1992, 1994, 1995
3 Free Software Foundation, Inc.
5 This file is part of GDB.
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,
20 Boston, MA 02111-1307, USA. */
25 _initialize_ns32k_tdep (void)
27 tm_print_insn
= print_insn_ns32k
;
30 /* Advance PC across any function entry prologue instructions
31 to reach some "real" code. */
34 merlin_skip_prologue (CORE_ADDR pc
)
36 register int op
= read_memory_integer (pc
, 1);
39 op
= read_memory_integer (pc
+ 2, 1);
42 else if ((op
& 0xc0) == 0x80)
51 umax_skip_prologue (CORE_ADDR pc
)
53 register unsigned char op
= read_memory_integer (pc
, 1);
56 op
= read_memory_integer (pc
+ 2, 1);
59 else if ((op
& 0xc0) == 0x80)
67 /* Return number of args passed to a frame.
68 Can return -1, meaning no way to tell. */
71 merlin_frame_num_args (struct frame_info
*fi
)
79 pc
= FRAME_SAVED_PC (fi
);
80 insn
= read_memory_integer (pc
, 2);
81 addr_mode
= (insn
>> 11) & 0x1f;
83 if ((insn
& 0x7fc) == 0x57c
84 && addr_mode
== 0x14) /* immediate */
86 if (insn
== 0x57c) /* adjspb */
88 else if (insn
== 0x57d) /* adjspw */
90 else if (insn
== 0x57f) /* adjspd */
92 numargs
= read_memory_integer (pc
+ 2, width
);
94 flip_bytes (&numargs
, width
);
95 numargs
= -sign_extend (numargs
, width
* 8) / 4;
103 /* Return number of args passed to a frame.
104 Can return -1, meaning no way to tell.
105 Encore's C compiler often reuses same area on stack for args,
106 so this will often not work properly. If the arg names
107 are known, it's likely most of them will be printed. */
109 umax_frame_num_args (struct frame_info
*fi
)
113 CORE_ADDR enter_addr
;
115 unsigned int addr_mode
;
119 enter_addr
= ns32k_get_enter_addr ((fi
)->pc
);
122 pc
= ((enter_addr
== 1)
123 ? SAVED_PC_AFTER_CALL (fi
)
124 : FRAME_SAVED_PC (fi
));
125 insn
= read_memory_integer (pc
, 2);
126 addr_mode
= (insn
>> 11) & 0x1f;
128 if ((insn
& 0x7fc) == 0x57c
129 && addr_mode
== 0x14) /* immediate */
131 if (insn
== 0x57c) /* adjspb */
133 else if (insn
== 0x57d) /* adjspw */
135 else if (insn
== 0x57f) /* adjspd */
137 numargs
= read_memory_integer (pc
+ 2, width
);
139 flip_bytes (&numargs
, width
);
140 numargs
= -sign_extend (numargs
, width
* 8) / 4;
147 sign_extend (int value
, int bits
)
149 value
= value
& ((1 << bits
) - 1);
150 return (value
& (1 << (bits
- 1))
151 ? value
| (~((1 << bits
) - 1))
156 flip_bytes (char *ptr
, int count
)
163 ptr
[0] = ptr
[count
- 1];
164 ptr
[count
- 1] = tmp
;
170 /* Return the number of locals in the current frame given a pc
171 pointing to the enter instruction. This is used in the macro
172 FRAME_FIND_SAVED_REGS. */
175 ns32k_localcount (CORE_ADDR enter_pc
)
177 unsigned char localtype
;
180 localtype
= read_memory_integer (enter_pc
+ 2, 1);
181 if ((localtype
& 0x80) == 0)
182 localcount
= localtype
;
183 else if ((localtype
& 0xc0) == 0x80)
184 localcount
= (((localtype
& 0x3f) << 8)
185 | (read_memory_integer (enter_pc
+ 3, 1) & 0xff));
187 localcount
= (((localtype
& 0x3f) << 24)
188 | ((read_memory_integer (enter_pc
+ 3, 1) & 0xff) << 16)
189 | ((read_memory_integer (enter_pc
+ 4, 1) & 0xff) << 8)
190 | (read_memory_integer (enter_pc
+ 5, 1) & 0xff));
195 /* Nonzero if instruction at PC is a return instruction. */
198 ns32k_about_to_return (CORE_ADDR pc
)
200 return (read_memory_integer (pc
, 1) == 0x12);
205 * Get the address of the enter opcode for the function
206 * containing PC, if there is an enter for the function,
207 * and if the pc is between the enter and exit.
208 * Returns positive address if pc is between enter/exit,
209 * 1 if pc before enter or after exit, 0 otherwise.
213 ns32k_get_enter_addr (CORE_ADDR pc
)
215 CORE_ADDR enter_addr
;
221 if (ns32k_about_to_return (pc
))
222 return 1; /* after exit */
224 enter_addr
= get_pc_function_start (pc
);
226 if (pc
== enter_addr
)
227 return 1; /* before enter */
229 op
= read_memory_integer (enter_addr
, 1);
232 return 0; /* function has no enter/exit */
234 return enter_addr
; /* pc is between enter and exit */
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