1 /* Target-dependent code for PowerPC systems using the SVR4 ABI
2 for GDB, the GNU debugger.
4 Copyright 2000, 2001, 2002 Free Software Foundation, Inc.
6 This file is part of GDB.
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.
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.
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. */
28 #include "gdb_string.h"
32 /* round2 rounds x up to the nearest multiple of s assuming that s is a
36 #define round2(x,s) ((((long) (x) - 1) & ~(long)((s)-1)) + (s))
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.
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,
50 ppc_sysv_abi_push_arguments (int nargs
, struct value
**args
, CORE_ADDR sp
,
51 int struct_return
, CORE_ADDR struct_addr
)
54 /* Next available general register for non-float, non-vector arguments. */
56 /* Next available floating point register for float arguments. */
58 /* Next available vector register for vector arguments. */
70 greg
= struct_return
? 4 : 3;
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
++)
83 type
= check_typedef (VALUE_TYPE (arg
));
84 len
= TYPE_LENGTH (type
);
86 if (TYPE_CODE (type
) == TYPE_CODE_FLT
)
92 /* SysV ABI converts floats to doubles when placed in
93 memory and requires 8 byte alignment */
94 if (argstkspace
& 0x4)
99 else if (TYPE_CODE (type
) == TYPE_CODE_INT
&& len
== 8) /* long long */
104 if (argstkspace
& 0x4)
115 else if (!TYPE_VECTOR (type
))
118 || TYPE_CODE (type
) == TYPE_CODE_STRUCT
119 || TYPE_CODE (type
) == TYPE_CODE_UNION
)
121 /* Rounding to the nearest multiple of 8 may not be necessary,
122 but it is safe. Particularly since we don't know the
123 field types of the structure */
124 structstkspace
+= round2 (len
, 8);
134 && TYPE_CODE (type
) == TYPE_CODE_ARRAY
135 && TYPE_VECTOR (type
))
141 /* Vector arguments must be aligned to 16 bytes on
143 argstkspace
+= round2 (argstkspace
, 16);
150 /* Get current SP location */
151 saved_sp
= read_sp ();
153 sp
-= argstkspace
+ structstkspace
;
155 /* Allocate space for backchain and callee's saved lr */
158 /* Make sure that we maintain 16 byte alignment */
161 /* Update %sp before proceeding any further */
162 write_register (SP_REGNUM
, sp
);
164 /* write the backchain */
165 store_address (old_sp_buf
, 4, saved_sp
);
166 write_memory (sp
, old_sp_buf
, 4);
169 structoffset
= argoffset
+ argstkspace
;
173 /* Fill in r3 with the return structure, if any */
177 store_address (val_buf
, 4, struct_addr
);
178 memcpy (®isters
[REGISTER_BYTE (greg
)], val_buf
, 4);
181 /* Now fill in the registers and stack... */
182 for (argno
= 0; argno
< nargs
; argno
++)
185 type
= check_typedef (VALUE_TYPE (arg
));
186 len
= TYPE_LENGTH (type
);
188 if (TYPE_CODE (type
) == TYPE_CODE_FLT
)
194 "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno
);
195 memcpy (®isters
[REGISTER_BYTE (FP0_REGNUM
+ freg
)],
196 VALUE_CONTENTS (arg
), len
);
201 /* SysV ABI converts floats to doubles when placed in
202 memory and requires 8 byte alignment */
203 /* FIXME: Convert floats to doubles */
206 write_memory (sp
+ argoffset
, (char *) VALUE_CONTENTS (arg
), len
);
210 else if (TYPE_CODE (type
) == TYPE_CODE_INT
&& len
== 8) /* long long */
217 write_memory (sp
+ argoffset
, (char *) VALUE_CONTENTS (arg
), len
);
225 memcpy (®isters
[REGISTER_BYTE (greg
)],
226 VALUE_CONTENTS (arg
), 4);
227 memcpy (®isters
[REGISTER_BYTE (greg
+ 1)],
228 VALUE_CONTENTS (arg
) + 4, 4);
232 else if (!TYPE_VECTOR (type
))
236 || TYPE_CODE (type
) == TYPE_CODE_STRUCT
237 || TYPE_CODE (type
) == TYPE_CODE_UNION
)
239 write_memory (sp
+ structoffset
, VALUE_CONTENTS (arg
), len
);
240 store_address (val_buf
, 4, sp
+ structoffset
);
241 structoffset
+= round2 (len
, 8);
245 memset (val_buf
, 0, 4);
246 memcpy (val_buf
, VALUE_CONTENTS (arg
), len
);
250 memcpy (®isters
[REGISTER_BYTE (greg
)], val_buf
, 4);
255 write_memory (sp
+ argoffset
, val_buf
, 4);
262 && TYPE_CODE (type
) == TYPE_CODE_ARRAY
263 && TYPE_VECTOR (type
))
265 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
266 char *v_val_buf
= alloca (16);
267 memset (v_val_buf
, 0, 16);
268 memcpy (v_val_buf
, VALUE_CONTENTS (arg
), len
);
271 memcpy (®isters
[REGISTER_BYTE (tdep
->ppc_vr0_regnum
278 write_memory (sp
+ argoffset
, v_val_buf
, 16);
285 target_store_registers (-1);
289 /* Until November 2001, gcc was not complying to the SYSV ABI for
290 returning structures less than or equal to 8 bytes in size. It was
291 returning everything in memory. When this was corrected, it wasn't
292 fixed for native platforms. */
294 ppc_sysv_abi_broken_use_struct_convention (int gcc_p
, struct type
*value_type
)
296 if (TYPE_LENGTH (value_type
) == 16
297 && TYPE_VECTOR (value_type
))
300 return generic_use_struct_convention (gcc_p
, value_type
);
303 /* Structures 8 bytes or less long are returned in the r3 & r4
304 registers, according to the SYSV ABI. */
306 ppc_sysv_abi_use_struct_convention (int gcc_p
, struct type
*value_type
)
308 if (TYPE_LENGTH (value_type
) == 16
309 && TYPE_VECTOR (value_type
))
312 return (TYPE_LENGTH (value_type
) > 8);
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