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8480a37e14
We currently pass frames to function by value, as `frame_info_ptr`.
This is somewhat expensive:
- the size of `frame_info_ptr` is 64 bytes, which is a bit big to pass
by value
- the constructors and destructor link/unlink the object in the global
`frame_info_ptr::frame_list` list. This is an `intrusive_list`, so
it's not so bad: it's just assigning a few points, there's no memory
allocation as if it was `std::list`, but still it's useless to do
that over and over.
As suggested by Tom Tromey, change many function signatures to accept
`const frame_info_ptr &` instead of `frame_info_ptr`.
Some functions reassign their `frame_info_ptr` parameter, like:
void
the_func (frame_info_ptr frame)
{
for (; frame != nullptr; frame = get_prev_frame (frame))
{
...
}
}
I wondered what to do about them, do I leave them as-is or change them
(and need to introduce a separate local variable that can be
re-assigned). I opted for the later for consistency. It might not be
clear why some functions take `const frame_info_ptr &` while others take
`frame_info_ptr`. Also, if a function took a `frame_info_ptr` because
it did re-assign its parameter, I doubt that we would think to change it
to `const frame_info_ptr &` should the implementation change such that
it doesn't need to take `frame_info_ptr` anymore. It seems better to
have a simple rule and apply it everywhere.
Change-Id: I59d10addef687d157f82ccf4d54f5dde9a963fd0
Approved-By: Andrew Burgess <aburgess@redhat.com>
224 lines
6.7 KiB
C
224 lines
6.7 KiB
C
/* Target-dependent code for NetBSD/powerpc.
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Copyright (C) 2002-2024 Free Software Foundation, Inc.
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Contributed by Wasabi Systems, 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 3 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, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "gdbtypes.h"
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#include "osabi.h"
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#include "regcache.h"
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#include "regset.h"
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#include "trad-frame.h"
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#include "tramp-frame.h"
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#include "ppc-tdep.h"
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#include "netbsd-tdep.h"
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#include "ppc-tdep.h"
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#include "solib-svr4.h"
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/* Register offsets from <machine/reg.h>. */
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static ppc_reg_offsets ppcnbsd_reg_offsets;
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/* Core file support. */
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/* NetBSD/powerpc register sets. */
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const struct regset ppcnbsd_gregset =
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{
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&ppcnbsd_reg_offsets,
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ppc_supply_gregset
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};
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const struct regset ppcnbsd_fpregset =
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{
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&ppcnbsd_reg_offsets,
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ppc_supply_fpregset
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};
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/* Iterate over core file register note sections. */
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static void
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ppcnbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
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iterate_over_regset_sections_cb *cb,
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void *cb_data,
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const struct regcache *regcache)
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{
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cb (".reg", 148, 148, &ppcnbsd_gregset, NULL, cb_data);
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cb (".reg2", 264, 264, &ppcnbsd_fpregset, NULL, cb_data);
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}
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/* NetBSD is confused. It appears that 1.5 was using the correct SVR4
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convention but, 1.6 switched to the below broken convention. For
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the moment use the broken convention. Ulgh! */
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static enum return_value_convention
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ppcnbsd_return_value (struct gdbarch *gdbarch, struct value *function,
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struct type *valtype, struct regcache *regcache,
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gdb_byte *readbuf, const gdb_byte *writebuf)
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{
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#if 0
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if ((valtype->code () == TYPE_CODE_STRUCT
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|| valtype->code () == TYPE_CODE_UNION)
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&& !((valtype->length () == 16 || valtype->length () == 8)
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&& valtype->is_vector ())
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&& !(valtype->length () == 1
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|| valtype->length () == 2
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|| valtype->length () == 4
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|| valtype->length () == 8))
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return RETURN_VALUE_STRUCT_CONVENTION;
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else
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#endif
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return ppc_sysv_abi_broken_return_value (gdbarch, function, valtype,
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regcache, readbuf, writebuf);
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}
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/* Signal trampolines. */
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extern const struct tramp_frame ppcnbsd2_sigtramp;
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static void
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ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
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const frame_info_ptr &this_frame,
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struct trad_frame_cache *this_cache,
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CORE_ADDR func)
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{
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struct gdbarch *gdbarch = get_frame_arch (this_frame);
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ppc_gdbarch_tdep *tdep = gdbarch_tdep<ppc_gdbarch_tdep> (gdbarch);
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CORE_ADDR addr, base;
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int i;
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base = get_frame_register_unsigned (this_frame,
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gdbarch_sp_regnum (gdbarch));
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if (self == &ppcnbsd2_sigtramp)
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addr = base + 0x10 + 2 * tdep->wordsize;
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else
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addr = base + 0x18 + 2 * tdep->wordsize;
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for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
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{
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int regnum = i + tdep->ppc_gp0_regnum;
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trad_frame_set_reg_addr (this_cache, regnum, addr);
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}
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trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, addr);
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addr += tdep->wordsize;
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trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, addr);
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addr += tdep->wordsize;
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trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, addr);
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addr += tdep->wordsize;
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trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, addr);
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addr += tdep->wordsize;
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trad_frame_set_reg_addr (this_cache, gdbarch_pc_regnum (gdbarch),
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addr); /* SRR0? */
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addr += tdep->wordsize;
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/* Construct the frame ID using the function start. */
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trad_frame_set_id (this_cache, frame_id_build (base, func));
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}
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static const struct tramp_frame ppcnbsd_sigtramp =
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{
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SIGTRAMP_FRAME,
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4,
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{
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{ 0x3821fff0, ULONGEST_MAX }, /* add r1,r1,-16 */
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{ 0x4e800021, ULONGEST_MAX }, /* blrl */
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{ 0x38610018, ULONGEST_MAX }, /* addi r3,r1,24 */
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{ 0x38000127, ULONGEST_MAX }, /* li r0,295 */
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{ 0x44000002, ULONGEST_MAX }, /* sc */
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{ 0x38000001, ULONGEST_MAX }, /* li r0,1 */
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{ 0x44000002, ULONGEST_MAX }, /* sc */
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{ TRAMP_SENTINEL_INSN, ULONGEST_MAX }
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},
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ppcnbsd_sigtramp_cache_init
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};
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/* NetBSD 2.0 introduced a slightly different signal trampoline. */
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const struct tramp_frame ppcnbsd2_sigtramp =
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{
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SIGTRAMP_FRAME,
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4,
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{
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{ 0x3821fff0, ULONGEST_MAX }, /* add r1,r1,-16 */
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{ 0x4e800021, ULONGEST_MAX }, /* blrl */
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{ 0x38610010, ULONGEST_MAX }, /* addi r3,r1,16 */
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{ 0x38000127, ULONGEST_MAX }, /* li r0,295 */
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{ 0x44000002, ULONGEST_MAX }, /* sc */
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{ 0x38000001, ULONGEST_MAX }, /* li r0,1 */
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{ 0x44000002, ULONGEST_MAX }, /* sc */
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{ TRAMP_SENTINEL_INSN, ULONGEST_MAX }
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},
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ppcnbsd_sigtramp_cache_init
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};
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static void
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ppcnbsd_init_abi (struct gdbarch_info info,
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struct gdbarch *gdbarch)
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{
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nbsd_init_abi (info, gdbarch);
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/* For NetBSD, this is an on again, off again thing. Some systems
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do use the broken struct convention, and some don't. */
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set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
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/* NetBSD uses SVR4-style shared libraries. */
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set_solib_svr4_fetch_link_map_offsets
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(gdbarch, svr4_ilp32_fetch_link_map_offsets);
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set_gdbarch_iterate_over_regset_sections
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(gdbarch, ppcnbsd_iterate_over_regset_sections);
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tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
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tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd2_sigtramp);
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}
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void _initialize_ppcnbsd_tdep ();
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void
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_initialize_ppcnbsd_tdep ()
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{
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gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD,
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ppcnbsd_init_abi);
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/* Avoid initializing the register offsets again if they were
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already initialized by ppc-netbsd-nat.c. */
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if (ppcnbsd_reg_offsets.pc_offset == 0)
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{
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/* General-purpose registers. */
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ppcnbsd_reg_offsets.r0_offset = 0;
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ppcnbsd_reg_offsets.gpr_size = 4;
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ppcnbsd_reg_offsets.xr_size = 4;
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ppcnbsd_reg_offsets.lr_offset = 128;
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ppcnbsd_reg_offsets.cr_offset = 132;
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ppcnbsd_reg_offsets.xer_offset = 136;
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ppcnbsd_reg_offsets.ctr_offset = 140;
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ppcnbsd_reg_offsets.pc_offset = 144;
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ppcnbsd_reg_offsets.ps_offset = -1;
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ppcnbsd_reg_offsets.mq_offset = -1;
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/* Floating-point registers. */
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ppcnbsd_reg_offsets.f0_offset = 0;
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ppcnbsd_reg_offsets.fpscr_offset = 256;
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ppcnbsd_reg_offsets.fpscr_size = 4;
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}
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}
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