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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 | |
77b2b6d4 AC |
50 | ppc_sysv_abi_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr, |
51 | struct regcache *regcache, CORE_ADDR bp_addr, | |
52 | int nargs, struct value **args, CORE_ADDR sp, | |
53 | int struct_return, CORE_ADDR struct_addr) | |
7b112f9c JT |
54 | { |
55 | int argno; | |
56 | /* Next available general register for non-float, non-vector arguments. */ | |
57 | int greg; | |
58 | /* Next available floating point register for float arguments. */ | |
59 | int freg; | |
60 | /* Next available vector register for vector arguments. */ | |
61 | int vreg; | |
62 | int argstkspace; | |
63 | int structstkspace; | |
64 | int argoffset; | |
65 | int structoffset; | |
7b112f9c JT |
66 | struct type *type; |
67 | int len; | |
68 | char old_sp_buf[4]; | |
69 | CORE_ADDR saved_sp; | |
0a613259 | 70 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
7b112f9c | 71 | |
7a41266b | 72 | greg = 3; |
7b112f9c JT |
73 | freg = 1; |
74 | vreg = 2; | |
75 | argstkspace = 0; | |
76 | structstkspace = 0; | |
77 | ||
7a41266b AC |
78 | /* If the function is returning a `struct', then the first word |
79 | (which will be passed in r3) is used for struct return address. | |
80 | In that case we should advance one word and start from r4 | |
81 | register to copy parameters. */ | |
82 | if (struct_return) | |
83 | { | |
84 | regcache_raw_write_signed (regcache, tdep->ppc_gp0_regnum + greg, | |
85 | struct_addr); | |
86 | greg++; | |
87 | } | |
88 | ||
7b112f9c JT |
89 | /* Figure out how much new stack space is required for arguments |
90 | which don't fit in registers. Unlike the PowerOpen ABI, the | |
91 | SysV ABI doesn't reserve any extra space for parameters which | |
92 | are put in registers. */ | |
93 | for (argno = 0; argno < nargs; argno++) | |
94 | { | |
0a613259 | 95 | struct value *arg = args[argno]; |
7b112f9c JT |
96 | type = check_typedef (VALUE_TYPE (arg)); |
97 | len = TYPE_LENGTH (type); | |
98 | ||
0a613259 AC |
99 | if (TYPE_CODE (type) == TYPE_CODE_FLT |
100 | && ppc_floating_point_unit_p (current_gdbarch)) | |
7b112f9c JT |
101 | { |
102 | if (freg <= 8) | |
103 | freg++; | |
104 | else | |
105 | { | |
106 | /* SysV ABI converts floats to doubles when placed in | |
107 | memory and requires 8 byte alignment */ | |
108 | if (argstkspace & 0x4) | |
109 | argstkspace += 4; | |
110 | argstkspace += 8; | |
111 | } | |
112 | } | |
0a613259 AC |
113 | else if (len == 8 |
114 | && (TYPE_CODE (type) == TYPE_CODE_INT /* long long */ | |
115 | || (!ppc_floating_point_unit_p (current_gdbarch) | |
116 | && TYPE_CODE (type) == TYPE_CODE_FLT))) /* double */ | |
7b112f9c JT |
117 | { |
118 | if (greg > 9) | |
119 | { | |
120 | greg = 11; | |
121 | if (argstkspace & 0x4) | |
122 | argstkspace += 4; | |
123 | argstkspace += 8; | |
124 | } | |
125 | else | |
126 | { | |
127 | if ((greg & 1) == 0) | |
128 | greg++; | |
129 | greg += 2; | |
130 | } | |
131 | } | |
132 | else if (!TYPE_VECTOR (type)) | |
133 | { | |
134 | if (len > 4 | |
135 | || TYPE_CODE (type) == TYPE_CODE_STRUCT | |
136 | || TYPE_CODE (type) == TYPE_CODE_UNION) | |
137 | { | |
138 | /* Rounding to the nearest multiple of 8 may not be necessary, | |
139 | but it is safe. Particularly since we don't know the | |
140 | field types of the structure */ | |
141 | structstkspace += round2 (len, 8); | |
142 | } | |
143 | if (greg <= 10) | |
144 | greg++; | |
145 | else | |
146 | argstkspace += 4; | |
147 | } | |
148 | else | |
149 | { | |
150 | if (len == 16 | |
151 | && TYPE_CODE (type) == TYPE_CODE_ARRAY | |
152 | && TYPE_VECTOR (type)) | |
153 | { | |
154 | if (vreg <= 13) | |
155 | vreg++; | |
156 | else | |
157 | { | |
158 | /* Vector arguments must be aligned to 16 bytes on | |
159 | the stack. */ | |
160 | argstkspace += round2 (argstkspace, 16); | |
161 | argstkspace += 16; | |
162 | } | |
163 | } | |
0a613259 AC |
164 | else if (len == 8 |
165 | && TYPE_CODE (type) == TYPE_CODE_ARRAY | |
166 | && TYPE_VECTOR (type)) | |
167 | { | |
168 | if (greg <= 10) | |
169 | greg++; | |
170 | else | |
171 | { | |
172 | /* Vector arguments must be aligned to 8 bytes on | |
173 | the stack. */ | |
174 | argstkspace += round2 (argstkspace, 8); | |
175 | argstkspace += 8; | |
176 | } | |
177 | } | |
7b112f9c JT |
178 | } |
179 | } | |
180 | ||
181 | /* Get current SP location */ | |
182 | saved_sp = read_sp (); | |
183 | ||
184 | sp -= argstkspace + structstkspace; | |
185 | ||
186 | /* Allocate space for backchain and callee's saved lr */ | |
187 | sp -= 8; | |
188 | ||
189 | /* Make sure that we maintain 16 byte alignment */ | |
190 | sp &= ~0x0f; | |
191 | ||
33a7c2fc AC |
192 | /* Update %sp before proceeding any further. */ |
193 | regcache_raw_write_signed (regcache, SP_REGNUM, sp); | |
7b112f9c JT |
194 | |
195 | /* write the backchain */ | |
fbd9dcd3 | 196 | store_unsigned_integer (old_sp_buf, 4, saved_sp); |
7b112f9c JT |
197 | write_memory (sp, old_sp_buf, 4); |
198 | ||
199 | argoffset = 8; | |
200 | structoffset = argoffset + argstkspace; | |
201 | freg = 1; | |
202 | greg = 3; | |
203 | vreg = 2; | |
0a613259 | 204 | |
7b112f9c JT |
205 | /* Fill in r3 with the return structure, if any */ |
206 | if (struct_return) | |
207 | { | |
0a613259 | 208 | write_register (tdep->ppc_gp0_regnum + greg, struct_addr); |
7b112f9c JT |
209 | greg++; |
210 | } | |
0a613259 | 211 | |
7b112f9c JT |
212 | /* Now fill in the registers and stack... */ |
213 | for (argno = 0; argno < nargs; argno++) | |
214 | { | |
0a613259 AC |
215 | struct value *arg = args[argno]; |
216 | char *val = VALUE_CONTENTS (arg); | |
7b112f9c JT |
217 | type = check_typedef (VALUE_TYPE (arg)); |
218 | len = TYPE_LENGTH (type); | |
219 | ||
0a613259 AC |
220 | if (TYPE_CODE (type) == TYPE_CODE_FLT |
221 | && ppc_floating_point_unit_p (current_gdbarch)) | |
7b112f9c JT |
222 | { |
223 | if (freg <= 8) | |
224 | { | |
0a613259 | 225 | ULONGEST regval; |
7b112f9c JT |
226 | if (len > 8) |
227 | printf_unfiltered ( | |
228 | "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno); | |
0a613259 AC |
229 | regval = extract_unsigned_integer (val, len); |
230 | write_register (FP0_REGNUM + freg, regval); | |
7b112f9c JT |
231 | freg++; |
232 | } | |
233 | else | |
234 | { | |
235 | /* SysV ABI converts floats to doubles when placed in | |
236 | memory and requires 8 byte alignment */ | |
237 | /* FIXME: Convert floats to doubles */ | |
238 | if (argoffset & 0x4) | |
239 | argoffset += 4; | |
0a613259 | 240 | write_memory (sp + argoffset, val, len); |
7b112f9c JT |
241 | argoffset += 8; |
242 | } | |
243 | } | |
0a613259 AC |
244 | else if (len == 8 |
245 | && (TYPE_CODE (type) == TYPE_CODE_INT /* long long */ | |
246 | || (!ppc_floating_point_unit_p (current_gdbarch) | |
247 | && TYPE_CODE (type) == TYPE_CODE_FLT))) /* double */ | |
7b112f9c JT |
248 | { |
249 | if (greg > 9) | |
250 | { | |
251 | greg = 11; | |
252 | if (argoffset & 0x4) | |
253 | argoffset += 4; | |
0a613259 | 254 | write_memory (sp + argoffset, val, len); |
7b112f9c JT |
255 | argoffset += 8; |
256 | } | |
257 | else | |
258 | { | |
0a613259 | 259 | ULONGEST regval; |
7b112f9c JT |
260 | if ((greg & 1) == 0) |
261 | greg++; | |
0a613259 AC |
262 | regval = extract_unsigned_integer (val, 4); |
263 | write_register (tdep->ppc_gp0_regnum + greg, regval); | |
264 | regval = extract_unsigned_integer (val + 4, 4); | |
265 | write_register (tdep->ppc_gp0_regnum + greg + 1, regval); | |
7b112f9c JT |
266 | greg += 2; |
267 | } | |
268 | } | |
269 | else if (!TYPE_VECTOR (type)) | |
270 | { | |
271 | char val_buf[4]; | |
272 | if (len > 4 | |
273 | || TYPE_CODE (type) == TYPE_CODE_STRUCT | |
274 | || TYPE_CODE (type) == TYPE_CODE_UNION) | |
275 | { | |
0a613259 | 276 | write_memory (sp + structoffset, val, len); |
fbd9dcd3 | 277 | store_unsigned_integer (val_buf, 4, sp + structoffset); |
7b112f9c JT |
278 | structoffset += round2 (len, 8); |
279 | } | |
280 | else | |
281 | { | |
282 | memset (val_buf, 0, 4); | |
0a613259 | 283 | memcpy (val_buf, val, len); |
7b112f9c JT |
284 | } |
285 | if (greg <= 10) | |
286 | { | |
0a613259 AC |
287 | ULONGEST regval = extract_unsigned_integer (val_buf, 4); |
288 | write_register (tdep->ppc_gp0_regnum + greg, regval); | |
7b112f9c JT |
289 | greg++; |
290 | } | |
291 | else | |
292 | { | |
293 | write_memory (sp + argoffset, val_buf, 4); | |
294 | argoffset += 4; | |
295 | } | |
296 | } | |
297 | else | |
298 | { | |
299 | if (len == 16 | |
300 | && TYPE_CODE (type) == TYPE_CODE_ARRAY | |
301 | && TYPE_VECTOR (type)) | |
302 | { | |
7b112f9c JT |
303 | char *v_val_buf = alloca (16); |
304 | memset (v_val_buf, 0, 16); | |
0a613259 | 305 | memcpy (v_val_buf, val, len); |
7b112f9c JT |
306 | if (vreg <= 13) |
307 | { | |
0a613259 AC |
308 | regcache_cooked_write (current_regcache, |
309 | tdep->ppc_vr0_regnum + vreg, | |
310 | v_val_buf); | |
7b112f9c JT |
311 | vreg++; |
312 | } | |
313 | else | |
314 | { | |
315 | write_memory (sp + argoffset, v_val_buf, 16); | |
316 | argoffset += 16; | |
317 | } | |
318 | } | |
0a613259 AC |
319 | else if (len == 8 |
320 | && TYPE_CODE (type) == TYPE_CODE_ARRAY | |
321 | && TYPE_VECTOR (type)) | |
322 | { | |
323 | char *v_val_buf = alloca (8); | |
324 | memset (v_val_buf, 0, 8); | |
325 | memcpy (v_val_buf, val, len); | |
326 | if (greg <= 10) | |
327 | { | |
328 | regcache_cooked_write (current_regcache, | |
329 | tdep->ppc_ev0_regnum + greg, | |
330 | v_val_buf); | |
331 | greg++; | |
332 | } | |
333 | else | |
334 | { | |
335 | write_memory (sp + argoffset, v_val_buf, 8); | |
336 | argoffset += 8; | |
337 | } | |
338 | } | |
7b112f9c JT |
339 | } |
340 | } | |
341 | ||
e56a0ecc AC |
342 | /* Point the inferior function call's return address at the dummy's |
343 | breakpoint. */ | |
344 | regcache_raw_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr); | |
345 | ||
7b112f9c JT |
346 | target_store_registers (-1); |
347 | return sp; | |
348 | } | |
349 | ||
350 | /* Until November 2001, gcc was not complying to the SYSV ABI for | |
351 | returning structures less than or equal to 8 bytes in size. It was | |
352 | returning everything in memory. When this was corrected, it wasn't | |
353 | fixed for native platforms. */ | |
354 | int | |
355 | ppc_sysv_abi_broken_use_struct_convention (int gcc_p, struct type *value_type) | |
356 | { | |
0a613259 | 357 | if ((TYPE_LENGTH (value_type) == 16 || TYPE_LENGTH (value_type) == 8) |
7b112f9c JT |
358 | && TYPE_VECTOR (value_type)) |
359 | return 0; | |
360 | ||
361 | return generic_use_struct_convention (gcc_p, value_type); | |
362 | } | |
363 | ||
364 | /* Structures 8 bytes or less long are returned in the r3 & r4 | |
365 | registers, according to the SYSV ABI. */ | |
366 | int | |
367 | ppc_sysv_abi_use_struct_convention (int gcc_p, struct type *value_type) | |
368 | { | |
0a613259 | 369 | if ((TYPE_LENGTH (value_type) == 16 || TYPE_LENGTH (value_type) == 8) |
7b112f9c JT |
370 | && TYPE_VECTOR (value_type)) |
371 | return 0; | |
372 | ||
373 | return (TYPE_LENGTH (value_type) > 8); | |
374 | } |