313 lines
8.2 KiB
C
313 lines
8.2 KiB
C
/* Target-dependent code for PowerPC systems using the SVR4 ABI
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for GDB, the GNU debugger.
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Copyright 2000, 2001, 2002 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "gdbcore.h"
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#include "inferior.h"
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#include "regcache.h"
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#include "value.h"
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#include "ppc-tdep.h"
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/* round2 rounds x up to the nearest multiple of s assuming that s is a
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power of 2 */
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#undef round2
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#define round2(x,s) ((((long) (x) - 1) & ~(long)((s)-1)) + (s))
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/* Pass the arguments in either registers, or in the stack. Using the
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ppc sysv ABI, the first eight words of the argument list (that might
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be less than eight parameters if some parameters occupy more than one
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word) are passed in r3..r10 registers. float and double parameters are
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passed in fpr's, in addition to that. Rest of the parameters if any
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are passed in user stack.
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If the function is returning a structure, then the return address is passed
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in r3, then the first 7 words of the parametes can be passed in registers,
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starting from r4. */
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CORE_ADDR
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ppc_sysv_abi_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
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int struct_return, CORE_ADDR struct_addr)
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{
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int argno;
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/* Next available general register for non-float, non-vector arguments. */
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int greg;
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/* Next available floating point register for float arguments. */
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int freg;
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/* Next available vector register for vector arguments. */
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int vreg;
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int argstkspace;
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int structstkspace;
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int argoffset;
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int structoffset;
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struct value *arg;
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struct type *type;
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int len;
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char old_sp_buf[4];
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CORE_ADDR saved_sp;
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greg = struct_return ? 4 : 3;
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freg = 1;
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vreg = 2;
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argstkspace = 0;
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structstkspace = 0;
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/* Figure out how much new stack space is required for arguments
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which don't fit in registers. Unlike the PowerOpen ABI, the
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SysV ABI doesn't reserve any extra space for parameters which
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are put in registers. */
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for (argno = 0; argno < nargs; argno++)
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{
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arg = args[argno];
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type = check_typedef (VALUE_TYPE (arg));
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len = TYPE_LENGTH (type);
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if (TYPE_CODE (type) == TYPE_CODE_FLT)
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{
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if (freg <= 8)
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freg++;
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else
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{
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/* SysV ABI converts floats to doubles when placed in
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memory and requires 8 byte alignment */
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if (argstkspace & 0x4)
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argstkspace += 4;
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argstkspace += 8;
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}
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}
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else if (TYPE_CODE (type) == TYPE_CODE_INT && len == 8) /* long long */
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{
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if (greg > 9)
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{
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greg = 11;
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if (argstkspace & 0x4)
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argstkspace += 4;
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argstkspace += 8;
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}
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else
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{
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if ((greg & 1) == 0)
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greg++;
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greg += 2;
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}
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}
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else if (!TYPE_VECTOR (type))
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{
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if (len > 4
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|| TYPE_CODE (type) == TYPE_CODE_STRUCT
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|| TYPE_CODE (type) == TYPE_CODE_UNION)
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{
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/* Rounding to the nearest multiple of 8 may not be necessary,
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but it is safe. Particularly since we don't know the
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field types of the structure */
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structstkspace += round2 (len, 8);
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}
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if (greg <= 10)
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greg++;
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else
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argstkspace += 4;
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}
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else
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{
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if (len == 16
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&& TYPE_CODE (type) == TYPE_CODE_ARRAY
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&& TYPE_VECTOR (type))
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{
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if (vreg <= 13)
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vreg++;
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else
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{
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/* Vector arguments must be aligned to 16 bytes on
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the stack. */
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argstkspace += round2 (argstkspace, 16);
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argstkspace += 16;
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}
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}
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}
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}
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/* Get current SP location */
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saved_sp = read_sp ();
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sp -= argstkspace + structstkspace;
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/* Allocate space for backchain and callee's saved lr */
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sp -= 8;
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/* Make sure that we maintain 16 byte alignment */
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sp &= ~0x0f;
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/* Update %sp before proceeding any further */
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write_register (SP_REGNUM, sp);
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/* write the backchain */
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store_address (old_sp_buf, 4, saved_sp);
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write_memory (sp, old_sp_buf, 4);
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argoffset = 8;
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structoffset = argoffset + argstkspace;
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freg = 1;
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greg = 3;
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vreg = 2;
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/* Fill in r3 with the return structure, if any */
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if (struct_return)
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{
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char val_buf[4];
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store_address (val_buf, 4, struct_addr);
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memcpy (®isters[REGISTER_BYTE (greg)], val_buf, 4);
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greg++;
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}
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/* Now fill in the registers and stack... */
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for (argno = 0; argno < nargs; argno++)
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{
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arg = args[argno];
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type = check_typedef (VALUE_TYPE (arg));
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len = TYPE_LENGTH (type);
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if (TYPE_CODE (type) == TYPE_CODE_FLT)
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{
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if (freg <= 8)
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{
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if (len > 8)
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printf_unfiltered (
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"Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno);
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memcpy (®isters[REGISTER_BYTE (FP0_REGNUM + freg)],
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VALUE_CONTENTS (arg), len);
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freg++;
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}
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else
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{
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/* SysV ABI converts floats to doubles when placed in
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memory and requires 8 byte alignment */
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/* FIXME: Convert floats to doubles */
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if (argoffset & 0x4)
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argoffset += 4;
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write_memory (sp + argoffset, (char *) VALUE_CONTENTS (arg), len);
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argoffset += 8;
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}
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}
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else if (TYPE_CODE (type) == TYPE_CODE_INT && len == 8) /* long long */
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{
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if (greg > 9)
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{
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greg = 11;
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if (argoffset & 0x4)
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argoffset += 4;
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write_memory (sp + argoffset, (char *) VALUE_CONTENTS (arg), len);
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argoffset += 8;
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}
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else
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{
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if ((greg & 1) == 0)
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greg++;
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memcpy (®isters[REGISTER_BYTE (greg)],
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VALUE_CONTENTS (arg), 4);
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memcpy (®isters[REGISTER_BYTE (greg + 1)],
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VALUE_CONTENTS (arg) + 4, 4);
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greg += 2;
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}
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}
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else if (!TYPE_VECTOR (type))
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{
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char val_buf[4];
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if (len > 4
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|| TYPE_CODE (type) == TYPE_CODE_STRUCT
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|| TYPE_CODE (type) == TYPE_CODE_UNION)
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{
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write_memory (sp + structoffset, VALUE_CONTENTS (arg), len);
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store_address (val_buf, 4, sp + structoffset);
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structoffset += round2 (len, 8);
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}
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else
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{
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memset (val_buf, 0, 4);
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memcpy (val_buf, VALUE_CONTENTS (arg), len);
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}
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if (greg <= 10)
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{
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memcpy (®isters[REGISTER_BYTE (greg)], val_buf, 4);
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greg++;
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}
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else
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{
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write_memory (sp + argoffset, val_buf, 4);
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argoffset += 4;
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}
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}
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else
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{
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if (len == 16
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&& TYPE_CODE (type) == TYPE_CODE_ARRAY
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&& TYPE_VECTOR (type))
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
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char *v_val_buf = alloca (16);
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memset (v_val_buf, 0, 16);
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memcpy (v_val_buf, VALUE_CONTENTS (arg), len);
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if (vreg <= 13)
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{
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memcpy (®isters[REGISTER_BYTE (tdep->ppc_vr0_regnum
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+ vreg)],
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v_val_buf, 16);
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vreg++;
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}
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else
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{
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write_memory (sp + argoffset, v_val_buf, 16);
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argoffset += 16;
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}
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}
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}
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}
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target_store_registers (-1);
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return sp;
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}
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/* Until November 2001, gcc was not complying to the SYSV ABI for
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returning structures less than or equal to 8 bytes in size. It was
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returning everything in memory. When this was corrected, it wasn't
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fixed for native platforms. */
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int
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ppc_sysv_abi_broken_use_struct_convention (int gcc_p, struct type *value_type)
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{
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if (TYPE_LENGTH (value_type) == 16
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&& TYPE_VECTOR (value_type))
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return 0;
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return generic_use_struct_convention (gcc_p, value_type);
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}
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/* Structures 8 bytes or less long are returned in the r3 & r4
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registers, according to the SYSV ABI. */
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int
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ppc_sysv_abi_use_struct_convention (int gcc_p, struct type *value_type)
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{
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if (TYPE_LENGTH (value_type) == 16
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&& TYPE_VECTOR (value_type))
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return 0;
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return (TYPE_LENGTH (value_type) > 8);
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}
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