[deliverable/binutils-gdb.git] / gdb / ppc-sysv-tdep.c

/* Target-dependent code for PowerPC systems using the SVR4 ABI
   for GDB, the GNU debugger.

   Copyright 2000, 2001, 2002 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "gdbcore.h"
#include "inferior.h"
#include "regcache.h"
#include "value.h"

#include "ppc-tdep.h"

/* round2 rounds x up to the nearest multiple of s assuming that s is a
   power of 2 */

#undef round2
#define round2(x,s) ((((long) (x) - 1) & ~(long)((s)-1)) + (s))

/* Pass the arguments in either registers, or in the stack. Using the
   ppc sysv ABI, the first eight words of the argument list (that might
   be less than eight parameters if some parameters occupy more than one
   word) are passed in r3..r10 registers.  float and double parameters are
   passed in fpr's, in addition to that. Rest of the parameters if any
   are passed in user stack. 

   If the function is returning a structure, then the return address is passed
   in r3, then the first 7 words of the parametes can be passed in registers,
   starting from r4. */

CORE_ADDR
ppc_sysv_abi_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
			     int struct_return, CORE_ADDR struct_addr)
{
  int argno;
  /* Next available general register for non-float, non-vector arguments. */
  int greg;
  /* Next available floating point register for float arguments. */
  int freg;
  /* Next available vector register for vector arguments. */
  int vreg;
  int argstkspace;
  int structstkspace;
  int argoffset;
  int structoffset;
  struct value *arg;
  struct type *type;
  int len;
  char old_sp_buf[4];
  CORE_ADDR saved_sp;

  greg = struct_return ? 4 : 3;
  freg = 1;
  vreg = 2;
  argstkspace = 0;
  structstkspace = 0;

  /* Figure out how much new stack space is required for arguments
     which don't fit in registers.  Unlike the PowerOpen ABI, the
     SysV ABI doesn't reserve any extra space for parameters which
     are put in registers. */
  for (argno = 0; argno < nargs; argno++)
    {
      arg = args[argno];
      type = check_typedef (VALUE_TYPE (arg));
      len = TYPE_LENGTH (type);

      if (TYPE_CODE (type) == TYPE_CODE_FLT)
	{
	  if (freg <= 8)
	    freg++;
	  else
	    {
	      /* SysV ABI converts floats to doubles when placed in
	         memory and requires 8 byte alignment */
	      if (argstkspace & 0x4)
		argstkspace += 4;
	      argstkspace += 8;
	    }
	}
      else if (TYPE_CODE (type) == TYPE_CODE_INT && len == 8)	/* long long */
	{
	  if (greg > 9)
	    {
	      greg = 11;
	      if (argstkspace & 0x4)
		argstkspace += 4;
	      argstkspace += 8;
	    }
	  else
	    {
	      if ((greg & 1) == 0)
		greg++;
	      greg += 2;
	    }
	}
      else if (!TYPE_VECTOR (type))
        {
	  if (len > 4
	      || TYPE_CODE (type) == TYPE_CODE_STRUCT
	      || TYPE_CODE (type) == TYPE_CODE_UNION)
	    {
	      /* Rounding to the nearest multiple of 8 may not be necessary,
		 but it is safe.  Particularly since we don't know the
		 field types of the structure */
	      structstkspace += round2 (len, 8);
	    }
	  if (greg <= 10)
	    greg++;
	  else
	    argstkspace += 4;
    	}
      else
        {
          if (len == 16
	      && TYPE_CODE (type) == TYPE_CODE_ARRAY
	      && TYPE_VECTOR (type))
	    {
	      if (vreg <= 13)
		vreg++;
	      else
		{
		  /* Vector arguments must be aligned to 16 bytes on
                     the stack. */
		  argstkspace += round2 (argstkspace, 16);
		  argstkspace += 16;
		}
	    }
	}
    }

  /* Get current SP location */
  saved_sp = read_sp ();

  sp -= argstkspace + structstkspace;

  /* Allocate space for backchain and callee's saved lr */
  sp -= 8;

  /* Make sure that we maintain 16 byte alignment */
  sp &= ~0x0f;

  /* Update %sp before proceeding any further */
  write_register (SP_REGNUM, sp);

  /* write the backchain */
  store_address (old_sp_buf, 4, saved_sp);
  write_memory (sp, old_sp_buf, 4);

  argoffset = 8;
  structoffset = argoffset + argstkspace;
  freg = 1;
  greg = 3;
  vreg = 2;
  /* Fill in r3 with the return structure, if any */
  if (struct_return)
    {
      char val_buf[4];
      store_address (val_buf, 4, struct_addr);
      memcpy (&registers[REGISTER_BYTE (greg)], val_buf, 4);
      greg++;
    }
  /* Now fill in the registers and stack... */
  for (argno = 0; argno < nargs; argno++)
    {
      arg = args[argno];
      type = check_typedef (VALUE_TYPE (arg));
      len = TYPE_LENGTH (type);

      if (TYPE_CODE (type) == TYPE_CODE_FLT)
	{
	  if (freg <= 8)
	    {
	      if (len > 8)
		printf_unfiltered (
				   "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno);
	      memcpy (&registers[REGISTER_BYTE (FP0_REGNUM + freg)],
		      VALUE_CONTENTS (arg), len);
	      freg++;
	    }
	  else
	    {
	      /* SysV ABI converts floats to doubles when placed in
	         memory and requires 8 byte alignment */
	      /* FIXME: Convert floats to doubles */
	      if (argoffset & 0x4)
		argoffset += 4;
	      write_memory (sp + argoffset, (char *) VALUE_CONTENTS (arg), len);
	      argoffset += 8;
	    }
	}
      else if (TYPE_CODE (type) == TYPE_CODE_INT && len == 8)	/* long long */
	{
	  if (greg > 9)
	    {
	      greg = 11;
	      if (argoffset & 0x4)
		argoffset += 4;
	      write_memory (sp + argoffset, (char *) VALUE_CONTENTS (arg), len);
	      argoffset += 8;
	    }
	  else
	    {
	      if ((greg & 1) == 0)
		greg++;

	      memcpy (&registers[REGISTER_BYTE (greg)],
		      VALUE_CONTENTS (arg), 4);
	      memcpy (&registers[REGISTER_BYTE (greg + 1)],
		      VALUE_CONTENTS (arg) + 4, 4);
	      greg += 2;
	    }
	}
      else if (!TYPE_VECTOR (type))
	{
	  char val_buf[4];
	  if (len > 4
	      || TYPE_CODE (type) == TYPE_CODE_STRUCT
	      || TYPE_CODE (type) == TYPE_CODE_UNION)
	    {
	      write_memory (sp + structoffset, VALUE_CONTENTS (arg), len);
	      store_address (val_buf, 4, sp + structoffset);
	      structoffset += round2 (len, 8);
	    }
	  else
	    {
	      memset (val_buf, 0, 4);
	      memcpy (val_buf, VALUE_CONTENTS (arg), len);
	    }
	  if (greg <= 10)
	    {
	      memcpy (&registers[REGISTER_BYTE (greg)], val_buf, 4);
	      greg++;
	    }
	  else
	    {
	      write_memory (sp + argoffset, val_buf, 4);
	      argoffset += 4;
	    }
	}
      else
	{
	  if (len == 16
	      && TYPE_CODE (type) == TYPE_CODE_ARRAY
	      && TYPE_VECTOR (type))
	    {
	      struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
	      char *v_val_buf = alloca (16);
	      memset (v_val_buf, 0, 16);
	      memcpy (v_val_buf, VALUE_CONTENTS (arg), len);
	      if (vreg <= 13)
		{
		  memcpy (&registers[REGISTER_BYTE (tdep->ppc_vr0_regnum
						    + vreg)],
			  v_val_buf, 16);
		  vreg++;
		}
	      else
		{
		  write_memory (sp + argoffset, v_val_buf, 16);
		  argoffset += 16;
		}
	    }
        }
    }

  target_store_registers (-1);
  return sp;
}

/* Until November 2001, gcc was not complying to the SYSV ABI for 
   returning structures less than or equal to 8 bytes in size.  It was
   returning everything in memory.  When this was corrected, it wasn't
   fixed for native platforms.  */
int     
ppc_sysv_abi_broken_use_struct_convention (int gcc_p, struct type *value_type)
{  
  if (TYPE_LENGTH (value_type) == 16 
      && TYPE_VECTOR (value_type))
    return 0;                            

  return generic_use_struct_convention (gcc_p, value_type);
}

/* Structures 8 bytes or less long are returned in the r3 & r4
   registers, according to the SYSV ABI. */
int
ppc_sysv_abi_use_struct_convention (int gcc_p, struct type *value_type)
{
  if (TYPE_LENGTH (value_type) == 16
      && TYPE_VECTOR (value_type))
    return 0;

  return (TYPE_LENGTH (value_type) > 8);
}
Commit	Line	Data
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"
	28
	29	#include "ppc-tdep.h"
	30
	31	/* round2 rounds x up to the nearest multiple of s assuming that s is a
	32	power of 2 */
	33
	34	#undef round2
	35	#define round2(x,s) ((((long) (x) - 1) & ~(long)((s)-1)) + (s))
	36
	37	/* Pass the arguments in either registers, or in the stack. Using the
	38	ppc sysv ABI, the first eight words of the argument list (that might
	39	be less than eight parameters if some parameters occupy more than one
	40	word) are passed in r3..r10 registers. float and double parameters are
	41	passed in fpr's, in addition to that. Rest of the parameters if any
	42	are passed in user stack.
	43
	44	If the function is returning a structure, then the return address is passed
	45	in r3, then the first 7 words of the parametes can be passed in registers,
	46	starting from r4. */
	47
	48	CORE_ADDR
	49	ppc_sysv_abi_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
	50	int struct_return, CORE_ADDR struct_addr)
	51	{
	52	int argno;
	53	/* Next available general register for non-float, non-vector arguments. */
	54	int greg;
	55	/* Next available floating point register for float arguments. */
	56	int freg;
	57	/* Next available vector register for vector arguments. */
	58	int vreg;
	59	int argstkspace;
	60	int structstkspace;
	61	int argoffset;
	62	int structoffset;
	63	struct value *arg;
	64	struct type *type;
65	int len;
66	char old_sp_buf[4];
67	CORE_ADDR saved_sp;
68
69	greg = struct_return ? 4 : 3;
70	freg = 1;
71	vreg = 2;
72	argstkspace = 0;
73	structstkspace = 0;
74
75	/* Figure out how much new stack space is required for arguments
76	which don't fit in registers. Unlike the PowerOpen ABI, the
77	SysV ABI doesn't reserve any extra space for parameters which
78	are put in registers. */
79	for (argno = 0; argno < nargs; argno++)
80	{
81	arg = args[argno];
82	type = check_typedef (VALUE_TYPE (arg));
83	len = TYPE_LENGTH (type);
84
85	if (TYPE_CODE (type) == TYPE_CODE_FLT)
86	{
87	if (freg <= 8)
88	freg++;
89	else
90	{
91	/* SysV ABI converts floats to doubles when placed in
92	memory and requires 8 byte alignment */
93	if (argstkspace & 0x4)
94	argstkspace += 4;
95	argstkspace += 8;
96	}
97	}
98	else if (TYPE_CODE (type) == TYPE_CODE_INT && len == 8) /* long long */
99	{
100	if (greg > 9)
101	{
102	greg = 11;
103	if (argstkspace & 0x4)
104	argstkspace += 4;
105	argstkspace += 8;
106	}
107	else
108	{
109	if ((greg & 1) == 0)
110	greg++;
111	greg += 2;
112	}
113	}
114	else if (!TYPE_VECTOR (type))
115	{
116	if (len > 4
117	\|\| TYPE_CODE (type) == TYPE_CODE_STRUCT
118	\|\| TYPE_CODE (type) == TYPE_CODE_UNION)
119	{
120	/* Rounding to the nearest multiple of 8 may not be necessary,
121	but it is safe. Particularly since we don't know the
122	field types of the structure */
123	structstkspace += round2 (len, 8);
124	}
125	if (greg <= 10)
126	greg++;
127	else
128	argstkspace += 4;
129	}
130	else
131	{
132	if (len == 16
133	&& TYPE_CODE (type) == TYPE_CODE_ARRAY
134	&& TYPE_VECTOR (type))
135	{
136	if (vreg <= 13)
137	vreg++;
138	else
139	{
140	/* Vector arguments must be aligned to 16 bytes on
141	the stack. */
142	argstkspace += round2 (argstkspace, 16);
143	argstkspace += 16;
144	}
145	}
146	}
147	}
148
149	/* Get current SP location */
150	saved_sp = read_sp ();
151
152	sp -= argstkspace + structstkspace;
153
154	/* Allocate space for backchain and callee's saved lr */
155	sp -= 8;
156
157	/* Make sure that we maintain 16 byte alignment */
158	sp &= ~0x0f;
159
160	/* Update %sp before proceeding any further */
161	write_register (SP_REGNUM, sp);
162
163	/* write the backchain */
164	store_address (old_sp_buf, 4, saved_sp);
165	write_memory (sp, old_sp_buf, 4);
166
167	argoffset = 8;
168	structoffset = argoffset + argstkspace;
169	freg = 1;
170	greg = 3;
171	vreg = 2;
172	/* Fill in r3 with the return structure, if any */
173	if (struct_return)
174	{
175	char val_buf[4];
176	store_address (val_buf, 4, struct_addr);
177	memcpy (&registers[REGISTER_BYTE (greg)], val_buf, 4);
178	greg++;
179	}
180	/* Now fill in the registers and stack... */
181	for (argno = 0; argno < nargs; argno++)
182	{
183	arg = args[argno];
184	type = check_typedef (VALUE_TYPE (arg));
185	len = TYPE_LENGTH (type);
186
187	if (TYPE_CODE (type) == TYPE_CODE_FLT)
188	{
189	if (freg <= 8)
190	{
191	if (len > 8)
192	printf_unfiltered (
193	"Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno);
194	memcpy (&registers[REGISTER_BYTE (FP0_REGNUM + freg)],
195	VALUE_CONTENTS (arg), len);
196	freg++;
197	}
198	else
199	{
200	/* SysV ABI converts floats to doubles when placed in
201	memory and requires 8 byte alignment */
202	/* FIXME: Convert floats to doubles */
203	if (argoffset & 0x4)
204	argoffset += 4;
205	write_memory (sp + argoffset, (char *) VALUE_CONTENTS (arg), len);
206	argoffset += 8;
207	}
208	}
209	else if (TYPE_CODE (type) == TYPE_CODE_INT && len == 8) /* long long */
210	{
211	if (greg > 9)
212	{
213	greg = 11;
214	if (argoffset & 0x4)
215	argoffset += 4;
216	write_memory (sp + argoffset, (char *) VALUE_CONTENTS (arg), len);
217	argoffset += 8;
218	}
219	else
220	{
221	if ((greg & 1) == 0)
222	greg++;
223
224	memcpy (&registers[REGISTER_BYTE (greg)],
225	VALUE_CONTENTS (arg), 4);
226	memcpy (&registers[REGISTER_BYTE (greg + 1)],
227	VALUE_CONTENTS (arg) + 4, 4);
228	greg += 2;
229	}
230	}
231	else if (!TYPE_VECTOR (type))
232	{
233	char val_buf[4];
234	if (len > 4
235	\|\| TYPE_CODE (type) == TYPE_CODE_STRUCT
236	\|\| TYPE_CODE (type) == TYPE_CODE_UNION)
237	{
238	write_memory (sp + structoffset, VALUE_CONTENTS (arg), len);
239	store_address (val_buf, 4, sp + structoffset);
240	structoffset += round2 (len, 8);
241	}
242	else
243	{
244	memset (val_buf, 0, 4);
245	memcpy (val_buf, VALUE_CONTENTS (arg), len);
246	}
247	if (greg <= 10)
248	{
249	memcpy (&registers[REGISTER_BYTE (greg)], val_buf, 4);
250	greg++;
251	}
252	else
253	{
254	write_memory (sp + argoffset, val_buf, 4);
255	argoffset += 4;
256	}
257	}
258	else
259	{
260	if (len == 16
261	&& TYPE_CODE (type) == TYPE_CODE_ARRAY
262	&& TYPE_VECTOR (type))
263	{
264	struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
265	char *v_val_buf = alloca (16);
266	memset (v_val_buf, 0, 16);
267	memcpy (v_val_buf, VALUE_CONTENTS (arg), len);
268	if (vreg <= 13)
269	{
270	memcpy (&registers[REGISTER_BYTE (tdep->ppc_vr0_regnum
271	+ vreg)],
272	v_val_buf, 16);
273	vreg++;
274	}
275	else
276	{
277	write_memory (sp + argoffset, v_val_buf, 16);
278	argoffset += 16;
279	}
280	}
281	}
282	}
283
284	target_store_registers (-1);
285	return sp;
286	}
287
288	/* Until November 2001, gcc was not complying to the SYSV ABI for
289	returning structures less than or equal to 8 bytes in size. It was
290	returning everything in memory. When this was corrected, it wasn't
291	fixed for native platforms. */
292	int
293	ppc_sysv_abi_broken_use_struct_convention (int gcc_p, struct type *value_type)
294	{
295	if (TYPE_LENGTH (value_type) == 16
296	&& TYPE_VECTOR (value_type))
297	return 0;
298
299	return generic_use_struct_convention (gcc_p, value_type);
300	}
301
302	/* Structures 8 bytes or less long are returned in the r3 & r4
303	registers, according to the SYSV ABI. */
304	int
305	ppc_sysv_abi_use_struct_convention (int gcc_p, struct type *value_type)
306	{
307	if (TYPE_LENGTH (value_type) == 16
308	&& TYPE_VECTOR (value_type))
309	return 0;
310
311	return (TYPE_LENGTH (value_type) > 8);
312	}