1 /* Print NS 32000 instructions for GDB, the GNU debugger.
2 Copyright 1986, 1988, 1991, 1992, 1994, 1995, 1998, 1999, 2000, 2001
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. */
26 static int sign_extend (int value
, int bits
);
29 _initialize_ns32k_tdep (void)
31 tm_print_insn
= print_insn_ns32k
;
34 /* Advance PC across any function entry prologue instructions
35 to reach some "real" code. */
38 merlin_skip_prologue (CORE_ADDR pc
)
40 register int op
= read_memory_integer (pc
, 1);
43 op
= read_memory_integer (pc
+ 2, 1);
46 else if ((op
& 0xc0) == 0x80)
55 umax_skip_prologue (CORE_ADDR pc
)
57 register unsigned char op
= read_memory_integer (pc
, 1);
60 op
= read_memory_integer (pc
+ 2, 1);
63 else if ((op
& 0xc0) == 0x80)
71 /* Return number of args passed to a frame.
72 Can return -1, meaning no way to tell. */
75 merlin_frame_num_args (struct frame_info
*fi
)
83 pc
= FRAME_SAVED_PC (fi
);
84 insn
= read_memory_integer (pc
, 2);
85 addr_mode
= (insn
>> 11) & 0x1f;
87 if ((insn
& 0x7fc) == 0x57c
88 && addr_mode
== 0x14) /* immediate */
90 if (insn
== 0x57c) /* adjspb */
92 else if (insn
== 0x57d) /* adjspw */
94 else if (insn
== 0x57f) /* adjspd */
97 internal_error (__FILE__
, __LINE__
, "bad else");
98 numargs
= read_memory_integer (pc
+ 2, width
);
100 flip_bytes (&numargs
, width
);
101 numargs
= -sign_extend (numargs
, width
* 8) / 4;
109 /* Return number of args passed to a frame.
110 Can return -1, meaning no way to tell.
111 Encore's C compiler often reuses same area on stack for args,
112 so this will often not work properly. If the arg names
113 are known, it's likely most of them will be printed. */
115 umax_frame_num_args (struct frame_info
*fi
)
119 CORE_ADDR enter_addr
;
121 unsigned int addr_mode
;
125 enter_addr
= ns32k_get_enter_addr ((fi
)->pc
);
128 pc
= ((enter_addr
== 1)
129 ? SAVED_PC_AFTER_CALL (fi
)
130 : FRAME_SAVED_PC (fi
));
131 insn
= read_memory_integer (pc
, 2);
132 addr_mode
= (insn
>> 11) & 0x1f;
134 if ((insn
& 0x7fc) == 0x57c
135 && addr_mode
== 0x14) /* immediate */
137 if (insn
== 0x57c) /* adjspb */
139 else if (insn
== 0x57d) /* adjspw */
141 else if (insn
== 0x57f) /* adjspd */
144 internal_error (__FILE__
, __LINE__
, "bad else");
145 numargs
= read_memory_integer (pc
+ 2, width
);
147 flip_bytes (&numargs
, width
);
148 numargs
= -sign_extend (numargs
, width
* 8) / 4;
156 sign_extend (int value
, int bits
)
158 value
= value
& ((1 << bits
) - 1);
159 return (value
& (1 << (bits
- 1))
160 ? value
| (~((1 << bits
) - 1))
165 flip_bytes (void *p
, int count
)
173 ptr
[0] = ptr
[count
- 1];
174 ptr
[count
- 1] = tmp
;
180 /* Return the number of locals in the current frame given a pc
181 pointing to the enter instruction. This is used in the macro
182 FRAME_FIND_SAVED_REGS. */
185 ns32k_localcount (CORE_ADDR enter_pc
)
187 unsigned char localtype
;
190 localtype
= read_memory_integer (enter_pc
+ 2, 1);
191 if ((localtype
& 0x80) == 0)
192 localcount
= localtype
;
193 else if ((localtype
& 0xc0) == 0x80)
194 localcount
= (((localtype
& 0x3f) << 8)
195 | (read_memory_integer (enter_pc
+ 3, 1) & 0xff));
197 localcount
= (((localtype
& 0x3f) << 24)
198 | ((read_memory_integer (enter_pc
+ 3, 1) & 0xff) << 16)
199 | ((read_memory_integer (enter_pc
+ 4, 1) & 0xff) << 8)
200 | (read_memory_integer (enter_pc
+ 5, 1) & 0xff));
205 /* Nonzero if instruction at PC is a return instruction. */
208 ns32k_about_to_return (CORE_ADDR pc
)
210 return (read_memory_integer (pc
, 1) == 0x12);
215 * Get the address of the enter opcode for the function
216 * containing PC, if there is an enter for the function,
217 * and if the pc is between the enter and exit.
218 * Returns positive address if pc is between enter/exit,
219 * 1 if pc before enter or after exit, 0 otherwise.
223 ns32k_get_enter_addr (CORE_ADDR pc
)
225 CORE_ADDR enter_addr
;
231 if (ns32k_about_to_return (pc
))
232 return 1; /* after exit */
234 enter_addr
= get_pc_function_start (pc
);
236 if (pc
== enter_addr
)
237 return 1; /* before enter */
239 op
= read_memory_integer (enter_addr
, 1);
242 return 0; /* function has no enter/exit */
244 return enter_addr
; /* pc is between enter and exit */
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