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7b112f9c JT |
1 | /* Target-dependent code for PowerPC systems using the SVR4 ABI |
2 | for GDB, the GNU debugger. | |
3 | ||
4 | Copyright 2000, 2001, 2002 Free Software Foundation, Inc. | |
5 | ||
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 59 Temple Place - Suite 330, | |
21 | Boston, MA 02111-1307, USA. */ | |
22 | ||
23 | #include "defs.h" | |
24 | #include "gdbcore.h" | |
25 | #include "inferior.h" | |
26 | #include "regcache.h" | |
27 | #include "value.h" | |
bdf64bac | 28 | #include "gdb_string.h" |
7b112f9c JT |
29 | |
30 | #include "ppc-tdep.h" | |
31 | ||
32 | /* round2 rounds x up to the nearest multiple of s assuming that s is a | |
33 | power of 2 */ | |
34 | ||
35 | #undef round2 | |
36 | #define round2(x,s) ((((long) (x) - 1) & ~(long)((s)-1)) + (s)) | |
37 | ||
38 | /* Pass the arguments in either registers, or in the stack. Using the | |
39 | ppc sysv ABI, the first eight words of the argument list (that might | |
40 | be less than eight parameters if some parameters occupy more than one | |
41 | word) are passed in r3..r10 registers. float and double parameters are | |
42 | passed in fpr's, in addition to that. Rest of the parameters if any | |
43 | are passed in user stack. | |
44 | ||
45 | If the function is returning a structure, then the return address is passed | |
46 | in r3, then the first 7 words of the parametes can be passed in registers, | |
47 | starting from r4. */ | |
48 | ||
49 | CORE_ADDR | |
50 | ppc_sysv_abi_push_arguments (int nargs, struct value **args, CORE_ADDR sp, | |
51 | int struct_return, CORE_ADDR struct_addr) | |
52 | { | |
53 | int argno; | |
54 | /* Next available general register for non-float, non-vector arguments. */ | |
55 | int greg; | |
56 | /* Next available floating point register for float arguments. */ | |
57 | int freg; | |
58 | /* Next available vector register for vector arguments. */ | |
59 | int vreg; | |
60 | int argstkspace; | |
61 | int structstkspace; | |
62 | int argoffset; | |
63 | int structoffset; | |
7b112f9c JT |
64 | struct type *type; |
65 | int len; | |
66 | char old_sp_buf[4]; | |
67 | CORE_ADDR saved_sp; | |
0a613259 | 68 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
7b112f9c JT |
69 | |
70 | greg = struct_return ? 4 : 3; | |
71 | freg = 1; | |
72 | vreg = 2; | |
73 | argstkspace = 0; | |
74 | structstkspace = 0; | |
75 | ||
76 | /* Figure out how much new stack space is required for arguments | |
77 | which don't fit in registers. Unlike the PowerOpen ABI, the | |
78 | SysV ABI doesn't reserve any extra space for parameters which | |
79 | are put in registers. */ | |
80 | for (argno = 0; argno < nargs; argno++) | |
81 | { | |
0a613259 | 82 | struct value *arg = args[argno]; |
7b112f9c JT |
83 | type = check_typedef (VALUE_TYPE (arg)); |
84 | len = TYPE_LENGTH (type); | |
85 | ||
0a613259 AC |
86 | if (TYPE_CODE (type) == TYPE_CODE_FLT |
87 | && ppc_floating_point_unit_p (current_gdbarch)) | |
7b112f9c JT |
88 | { |
89 | if (freg <= 8) | |
90 | freg++; | |
91 | else | |
92 | { | |
93 | /* SysV ABI converts floats to doubles when placed in | |
94 | memory and requires 8 byte alignment */ | |
95 | if (argstkspace & 0x4) | |
96 | argstkspace += 4; | |
97 | argstkspace += 8; | |
98 | } | |
99 | } | |
0a613259 AC |
100 | else if (len == 8 |
101 | && (TYPE_CODE (type) == TYPE_CODE_INT /* long long */ | |
102 | || (!ppc_floating_point_unit_p (current_gdbarch) | |
103 | && TYPE_CODE (type) == TYPE_CODE_FLT))) /* double */ | |
7b112f9c JT |
104 | { |
105 | if (greg > 9) | |
106 | { | |
107 | greg = 11; | |
108 | if (argstkspace & 0x4) | |
109 | argstkspace += 4; | |
110 | argstkspace += 8; | |
111 | } | |
112 | else | |
113 | { | |
114 | if ((greg & 1) == 0) | |
115 | greg++; | |
116 | greg += 2; | |
117 | } | |
118 | } | |
119 | else if (!TYPE_VECTOR (type)) | |
120 | { | |
121 | if (len > 4 | |
122 | || TYPE_CODE (type) == TYPE_CODE_STRUCT | |
123 | || TYPE_CODE (type) == TYPE_CODE_UNION) | |
124 | { | |
125 | /* Rounding to the nearest multiple of 8 may not be necessary, | |
126 | but it is safe. Particularly since we don't know the | |
127 | field types of the structure */ | |
128 | structstkspace += round2 (len, 8); | |
129 | } | |
130 | if (greg <= 10) | |
131 | greg++; | |
132 | else | |
133 | argstkspace += 4; | |
134 | } | |
135 | else | |
136 | { | |
137 | if (len == 16 | |
138 | && TYPE_CODE (type) == TYPE_CODE_ARRAY | |
139 | && TYPE_VECTOR (type)) | |
140 | { | |
141 | if (vreg <= 13) | |
142 | vreg++; | |
143 | else | |
144 | { | |
145 | /* Vector arguments must be aligned to 16 bytes on | |
146 | the stack. */ | |
147 | argstkspace += round2 (argstkspace, 16); | |
148 | argstkspace += 16; | |
149 | } | |
150 | } | |
0a613259 AC |
151 | else if (len == 8 |
152 | && TYPE_CODE (type) == TYPE_CODE_ARRAY | |
153 | && TYPE_VECTOR (type)) | |
154 | { | |
155 | if (greg <= 10) | |
156 | greg++; | |
157 | else | |
158 | { | |
159 | /* Vector arguments must be aligned to 8 bytes on | |
160 | the stack. */ | |
161 | argstkspace += round2 (argstkspace, 8); | |
162 | argstkspace += 8; | |
163 | } | |
164 | } | |
7b112f9c JT |
165 | } |
166 | } | |
167 | ||
168 | /* Get current SP location */ | |
169 | saved_sp = read_sp (); | |
170 | ||
171 | sp -= argstkspace + structstkspace; | |
172 | ||
173 | /* Allocate space for backchain and callee's saved lr */ | |
174 | sp -= 8; | |
175 | ||
176 | /* Make sure that we maintain 16 byte alignment */ | |
177 | sp &= ~0x0f; | |
178 | ||
179 | /* Update %sp before proceeding any further */ | |
180 | write_register (SP_REGNUM, sp); | |
181 | ||
182 | /* write the backchain */ | |
183 | store_address (old_sp_buf, 4, saved_sp); | |
184 | write_memory (sp, old_sp_buf, 4); | |
185 | ||
186 | argoffset = 8; | |
187 | structoffset = argoffset + argstkspace; | |
188 | freg = 1; | |
189 | greg = 3; | |
190 | vreg = 2; | |
0a613259 | 191 | |
7b112f9c JT |
192 | /* Fill in r3 with the return structure, if any */ |
193 | if (struct_return) | |
194 | { | |
0a613259 | 195 | write_register (tdep->ppc_gp0_regnum + greg, struct_addr); |
7b112f9c JT |
196 | greg++; |
197 | } | |
0a613259 | 198 | |
7b112f9c JT |
199 | /* Now fill in the registers and stack... */ |
200 | for (argno = 0; argno < nargs; argno++) | |
201 | { | |
0a613259 AC |
202 | struct value *arg = args[argno]; |
203 | char *val = VALUE_CONTENTS (arg); | |
7b112f9c JT |
204 | type = check_typedef (VALUE_TYPE (arg)); |
205 | len = TYPE_LENGTH (type); | |
206 | ||
0a613259 AC |
207 | if (TYPE_CODE (type) == TYPE_CODE_FLT |
208 | && ppc_floating_point_unit_p (current_gdbarch)) | |
7b112f9c JT |
209 | { |
210 | if (freg <= 8) | |
211 | { | |
0a613259 | 212 | ULONGEST regval; |
7b112f9c JT |
213 | if (len > 8) |
214 | printf_unfiltered ( | |
215 | "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno); | |
0a613259 AC |
216 | regval = extract_unsigned_integer (val, len); |
217 | write_register (FP0_REGNUM + freg, regval); | |
7b112f9c JT |
218 | freg++; |
219 | } | |
220 | else | |
221 | { | |
222 | /* SysV ABI converts floats to doubles when placed in | |
223 | memory and requires 8 byte alignment */ | |
224 | /* FIXME: Convert floats to doubles */ | |
225 | if (argoffset & 0x4) | |
226 | argoffset += 4; | |
0a613259 | 227 | write_memory (sp + argoffset, val, len); |
7b112f9c JT |
228 | argoffset += 8; |
229 | } | |
230 | } | |
0a613259 AC |
231 | else if (len == 8 |
232 | && (TYPE_CODE (type) == TYPE_CODE_INT /* long long */ | |
233 | || (!ppc_floating_point_unit_p (current_gdbarch) | |
234 | && TYPE_CODE (type) == TYPE_CODE_FLT))) /* double */ | |
7b112f9c JT |
235 | { |
236 | if (greg > 9) | |
237 | { | |
238 | greg = 11; | |
239 | if (argoffset & 0x4) | |
240 | argoffset += 4; | |
0a613259 | 241 | write_memory (sp + argoffset, val, len); |
7b112f9c JT |
242 | argoffset += 8; |
243 | } | |
244 | else | |
245 | { | |
0a613259 | 246 | ULONGEST regval; |
7b112f9c JT |
247 | if ((greg & 1) == 0) |
248 | greg++; | |
0a613259 AC |
249 | regval = extract_unsigned_integer (val, 4); |
250 | write_register (tdep->ppc_gp0_regnum + greg, regval); | |
251 | regval = extract_unsigned_integer (val + 4, 4); | |
252 | write_register (tdep->ppc_gp0_regnum + greg + 1, regval); | |
7b112f9c JT |
253 | greg += 2; |
254 | } | |
255 | } | |
256 | else if (!TYPE_VECTOR (type)) | |
257 | { | |
258 | char val_buf[4]; | |
259 | if (len > 4 | |
260 | || TYPE_CODE (type) == TYPE_CODE_STRUCT | |
261 | || TYPE_CODE (type) == TYPE_CODE_UNION) | |
262 | { | |
0a613259 | 263 | write_memory (sp + structoffset, val, len); |
7b112f9c JT |
264 | store_address (val_buf, 4, sp + structoffset); |
265 | structoffset += round2 (len, 8); | |
266 | } | |
267 | else | |
268 | { | |
269 | memset (val_buf, 0, 4); | |
0a613259 | 270 | memcpy (val_buf, val, len); |
7b112f9c JT |
271 | } |
272 | if (greg <= 10) | |
273 | { | |
0a613259 AC |
274 | ULONGEST regval = extract_unsigned_integer (val_buf, 4); |
275 | write_register (tdep->ppc_gp0_regnum + greg, regval); | |
7b112f9c JT |
276 | greg++; |
277 | } | |
278 | else | |
279 | { | |
280 | write_memory (sp + argoffset, val_buf, 4); | |
281 | argoffset += 4; | |
282 | } | |
283 | } | |
284 | else | |
285 | { | |
286 | if (len == 16 | |
287 | && TYPE_CODE (type) == TYPE_CODE_ARRAY | |
288 | && TYPE_VECTOR (type)) | |
289 | { | |
7b112f9c JT |
290 | char *v_val_buf = alloca (16); |
291 | memset (v_val_buf, 0, 16); | |
0a613259 | 292 | memcpy (v_val_buf, val, len); |
7b112f9c JT |
293 | if (vreg <= 13) |
294 | { | |
0a613259 AC |
295 | regcache_cooked_write (current_regcache, |
296 | tdep->ppc_vr0_regnum + vreg, | |
297 | v_val_buf); | |
7b112f9c JT |
298 | vreg++; |
299 | } | |
300 | else | |
301 | { | |
302 | write_memory (sp + argoffset, v_val_buf, 16); | |
303 | argoffset += 16; | |
304 | } | |
305 | } | |
0a613259 AC |
306 | else if (len == 8 |
307 | && TYPE_CODE (type) == TYPE_CODE_ARRAY | |
308 | && TYPE_VECTOR (type)) | |
309 | { | |
310 | char *v_val_buf = alloca (8); | |
311 | memset (v_val_buf, 0, 8); | |
312 | memcpy (v_val_buf, val, len); | |
313 | if (greg <= 10) | |
314 | { | |
315 | regcache_cooked_write (current_regcache, | |
316 | tdep->ppc_ev0_regnum + greg, | |
317 | v_val_buf); | |
318 | greg++; | |
319 | } | |
320 | else | |
321 | { | |
322 | write_memory (sp + argoffset, v_val_buf, 8); | |
323 | argoffset += 8; | |
324 | } | |
325 | } | |
7b112f9c JT |
326 | } |
327 | } | |
328 | ||
329 | target_store_registers (-1); | |
330 | return sp; | |
331 | } | |
332 | ||
333 | /* Until November 2001, gcc was not complying to the SYSV ABI for | |
334 | returning structures less than or equal to 8 bytes in size. It was | |
335 | returning everything in memory. When this was corrected, it wasn't | |
336 | fixed for native platforms. */ | |
337 | int | |
338 | ppc_sysv_abi_broken_use_struct_convention (int gcc_p, struct type *value_type) | |
339 | { | |
0a613259 | 340 | if ((TYPE_LENGTH (value_type) == 16 || TYPE_LENGTH (value_type) == 8) |
7b112f9c JT |
341 | && TYPE_VECTOR (value_type)) |
342 | return 0; | |
343 | ||
344 | return generic_use_struct_convention (gcc_p, value_type); | |
345 | } | |
346 | ||
347 | /* Structures 8 bytes or less long are returned in the r3 & r4 | |
348 | registers, according to the SYSV ABI. */ | |
349 | int | |
350 | ppc_sysv_abi_use_struct_convention (int gcc_p, struct type *value_type) | |
351 | { | |
0a613259 | 352 | if ((TYPE_LENGTH (value_type) == 16 || TYPE_LENGTH (value_type) == 8) |
7b112f9c JT |
353 | && TYPE_VECTOR (value_type)) |
354 | return 0; | |
355 | ||
356 | return (TYPE_LENGTH (value_type) > 8); | |
357 | } |