[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 "gdb_string.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 type *type;
  int len;
  char old_sp_buf[4];
  CORE_ADDR saved_sp;
  struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);

  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++)
    {
      struct value *arg = args[argno];
      type = check_typedef (VALUE_TYPE (arg));
      len = TYPE_LENGTH (type);

      if (TYPE_CODE (type) == TYPE_CODE_FLT
          && ppc_floating_point_unit_p (current_gdbarch))
	{
	  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 (len == 8 
               && (TYPE_CODE (type) == TYPE_CODE_INT /* long long */
                   || (!ppc_floating_point_unit_p (current_gdbarch)
                       && TYPE_CODE (type) == TYPE_CODE_FLT))) /* double */
	{
	  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;
		}
	    }
          else if (len == 8 
                   && TYPE_CODE (type) == TYPE_CODE_ARRAY
                   && TYPE_VECTOR (type))
            {
              if (greg <= 10)
                greg++;
              else
                {
                  /* Vector arguments must be aligned to 8 bytes on
                     the stack. */
                  argstkspace += round2 (argstkspace, 8);
                  argstkspace += 8;
                }
            }
	}
    }

  /* 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_unsigned_integer (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)
    {
      write_register (tdep->ppc_gp0_regnum + greg, struct_addr);
      greg++;
    }

  /* Now fill in the registers and stack... */
  for (argno = 0; argno < nargs; argno++)
    {
      struct value *arg = args[argno];
      char *val = VALUE_CONTENTS (arg);
      type = check_typedef (VALUE_TYPE (arg));
      len = TYPE_LENGTH (type);

      if (TYPE_CODE (type) == TYPE_CODE_FLT
          && ppc_floating_point_unit_p (current_gdbarch))
	{
	  if (freg <= 8)
	    {
	      ULONGEST regval;
	      if (len > 8)
		printf_unfiltered (
				   "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno);
              regval = extract_unsigned_integer (val, len);
              write_register (FP0_REGNUM + freg, regval);
	      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, val, len);
	      argoffset += 8;
	    }
	}
      else if (len == 8 
               && (TYPE_CODE (type) == TYPE_CODE_INT /* long long */
                   || (!ppc_floating_point_unit_p (current_gdbarch)
                        && TYPE_CODE (type) == TYPE_CODE_FLT))) /* double */
	{
	  if (greg > 9)
	    {
	      greg = 11;
	      if (argoffset & 0x4)
		argoffset += 4;
	      write_memory (sp + argoffset, val, len);
	      argoffset += 8;
	    }
	  else
	    {
	      ULONGEST regval;
	      if ((greg & 1) == 0)
		greg++;
              regval = extract_unsigned_integer (val, 4);
              write_register (tdep->ppc_gp0_regnum + greg, regval);
              regval = extract_unsigned_integer (val + 4, 4);
              write_register (tdep->ppc_gp0_regnum + greg + 1, regval);
	      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, val, len);
	      store_unsigned_integer (val_buf, 4, sp + structoffset);
	      structoffset += round2 (len, 8);
	    }
	  else
	    {
	      memset (val_buf, 0, 4);
	      memcpy (val_buf, val, len);
	    }
	  if (greg <= 10)
	    {
              ULONGEST regval = extract_unsigned_integer (val_buf, 4);
              write_register (tdep->ppc_gp0_regnum + greg, regval);
	      greg++;
	    }
	  else
	    {
	      write_memory (sp + argoffset, val_buf, 4);
	      argoffset += 4;
	    }
	}
      else
	{
	  if (len == 16
	      && TYPE_CODE (type) == TYPE_CODE_ARRAY
	      && TYPE_VECTOR (type))
	    {
	      char *v_val_buf = alloca (16);
	      memset (v_val_buf, 0, 16);
	      memcpy (v_val_buf, val, len);
	      if (vreg <= 13)
		{
		  regcache_cooked_write (current_regcache,
					 tdep->ppc_vr0_regnum + vreg,
					 v_val_buf);
		  vreg++;
		}
	      else
		{
		  write_memory (sp + argoffset, v_val_buf, 16);
		  argoffset += 16;
		}
	    }
          else if (len == 8 
		   && TYPE_CODE (type) == TYPE_CODE_ARRAY
		   && TYPE_VECTOR (type))
            {
              char *v_val_buf = alloca (8);
              memset (v_val_buf, 0, 8);
              memcpy (v_val_buf, val, len);
              if (greg <= 10)
                {
		  regcache_cooked_write (current_regcache,
					 tdep->ppc_ev0_regnum + greg,
					 v_val_buf);
                  greg++;
                }
              else
                {
                  write_memory (sp + argoffset, v_val_buf, 8);
                  argoffset += 8;
                }
            }
        }
    }

  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_LENGTH (value_type) == 8)
      && 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_LENGTH (value_type) == 8)
      && 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"
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
0a613259 AC	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 */
fbd9dcd3	183	store_unsigned_integer (old_sp_buf, 4, saved_sp);
7b112f9c JT	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++;
7b112f9c JT	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];
0a613259 AC	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
0a613259 AC	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);
0a613259 AC	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)
7b112f9c JT	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);
fbd9dcd3	264	store_unsigned_integer (val_buf, 4, sp + structoffset);
7b112f9c JT	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);
0a613259 AC	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);
7b112f9c JT	291	memset (v_val_buf, 0, 16);
0a613259	292	memcpy (v_val_buf, val, len);
7b112f9c JT	293	if (vreg <= 13)
7b112f9c JT	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	}