Per Power ISA Version 3.1B 3.3.12, isel uses BC field rather than CRB
field present in binutils sources. Also, per 1.6.2, BC has the same
semantics as BA and BB fields, so this should keep the same flags and
mask, only with the different offset.
opcodes/
* ppc-opc.c
(BC): Define new field, with the same definition as CRB field,
but with the PPC_OPERAND_CR_BIT flag present.
gas/
* testsuite/gas/ppc/476.d: Update.
* testsuite/gas/ppc/a2.d: Update.
* testsuite/gas/ppc/e500.d: Update.
* testsuite/gas/ppc/power7.d: Update.
With the upcoming SVP64 extension[0] to PowerPC architecture, it became
evident that PowerPC operand indices no longer fit 8 bits. This patch
switches the underlying type to uint16_t, also introducing a special
typedef so that any future extension goes even smoother.
[0] https://libre-soc.org
include/
* opcode/ppc.h (ppc_opindex_t): New typedef.
(struct powerpc_opcode): Use it.
(PPC_OPINDEX_MAX): Define.
gas/
* write.h (struct fix): Increase size of fx_pcrel_adjust.
Reorganise.
* config/tc-ppc.c (insn_validate): Use ppc_opindex_t for operands.
(md_assemble): Likewise.
(md_apply_fix): Likewise. Mask fx_pcrel_adjust with PPC_OPINDEX_MAX.
(ppc_setup_opcodes): Adjust opcode index assertion.
opcodes/
* ppc-dis.c (skip_optional_operands): Use ppc_opindex_t for
operand pointer.
(lookup_powerpc, lookup_prefix, lookup_vle, lookup_spe2): Likewise.
(print_insn_powerpc): Likewise.
When running test-case gdb.opt/clobbered-registers-O2.exp with clang 12.0.1, I
get:
...
(gdb) run ^M
Starting program: clobbered-registers-O2 ^M
^M
Program received signal SIGSEGV, Segmentation fault.^M
gen_movsd (operand0=<optimized out>, operand1=<optimized out>) at \
clobbered-registers-O2.c:31^M
31 return *start_sequence(operand0, operand1);^M
(gdb) FAIL: gdb.opt/clobbered-registers-O2.exp: runto: run to start_sequence
...
The problem is that the breakpoint in start_sequence doesn't trigger, because:
- the call to start_sequence in gen_movsd is optimized away, despite the
__attribute__((noinline)), so the actual function start_sequence doesn't get
called, and
- the debug info doesn't contain inlined function info, so there's only one
breakpoint location.
Adding noclone and noipa alongside the noinline attribute doesn't fix this.
Adding the clang-specific attribute optnone in start_sequence does, but since
it inhibits all optimization, that's not a preferred solution in a gdb.opt
test-case, and it would work only for clang and not other compilers that
possibly have the same issue.
Fix this by moving functions start_sequence and gen_movsd into their own
files, as a way of trying harder to enforce noinline/noipa/noclone.
Tested on x86_64-linux.
When running test-case gdb.opt/clobbered-registers-O2.exp with gcc-12, I run
into:
...
(gdb) PASS: gdb.opt/clobbered-registers-O2.exp: backtracing
print operand0^M
$1 = (unsigned int *) 0x7fffffffd070^M
(gdb) print *operand0^M
$2 = 4195541^M
(gdb) FAIL: gdb.opt/clobbered-registers-O2.exp: print operand0
...
The problem is that starting gcc-12, the assignments to x and y in main are
optimized away:
...
int main(void)
{
unsigned x, y;
x = 13;
y = 14;
return (int)gen_movsd (&x, &y);
...
Fix this by making x and y volatile.
Note that the test-case intends to check the handling of debug info for
optimized code in function gen_movsd, so inhibiting optimization in main
doesn't interfere with that.
Tested on x86_64-linux.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29161
LOONGARCH_LINUX_NUM_GREGSET should be defined as 45 (32 + 1 + 1 + 11)
due to reserved 11 for extension in glibc, otherwise when execute:
make check-gdb TESTS="gdb.base/corefile.exp"
there exists the following failed testcase:
(gdb) core-file /home/loongson/build.git/gdb/testsuite/outputs/gdb.base/corefile/corefile.core
[New LWP 7742]
warning: Unexpected size of section `.reg/7742' in core file.
Core was generated by `/home/loongson/build.git/gdb/testsuite/outputs/gdb.base/corefile/corefile'.
Program terminated with signal SIGABRT, Aborted.
warning: Unexpected size of section `.reg/7742' in core file.
#0 0x000000fff76f4e24 in raise () from /lib/loongarch64-linux-gnu/libc.so.6
(gdb) FAIL: gdb.base/corefile.exp: core-file warning-free
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
This small patch adds support for TYPE_CODE_DECFLOAT in
aapcs_is_vfp_call_or_return_candidate_1 and pass_in_v_vfp_candidate,
so that GDB for AArch64 knows how to pass DFP parameters and how to
read DFP results when calling a function.
Tested on aarch64-linux-gnu, with a GCC with DFP support in the PATH,
all of GDB's DFP tests pass.
The fix here is to pass "section" down to read_and_display_attr_value.
The test in read_and_display_attr_value is a little bit of hardening.
PR 29171
* dwarf.c (display_debug_macro, display_debug_names): Pass section
to read_and_display_attr_value2.
(read_and_display_attr_value): Don't attempt to check for .dwo
section name when section is NULL.
Move the specialization into an explicit std namespace to workaround a
bug in older compilers. GCC 6.4.1 at least fails to compile the previous
version with the following error:
gdb/arch/aarch64.h:48:13: error: specialization of 'template<class _Tp> struct std::hash' in different namespace [-fpermissive]
struct std::hash<aarch64_features>
Define a constant for the number of registers stored in a register set
and use this with register_size to compute the size of the
general-purpose register set in core dumps.
This also fixes the build on hosts such as FreeBSD that do not define
an elf_gregset_t type.
When execute the following command on LoongArch:
make check-gdb TESTS="gdb.base/auxv.exp"
there exist the following unsupported and failed testcases:
UNSUPPORTED: gdb.base/auxv.exp: gcore
FAIL: gdb.base/auxv.exp: load core file for info auxv on native core dump
FAIL: gdb.base/auxv.exp: info auxv on native core dump
FAIL: gdb.base/auxv.exp: matching auxv data from live and core
UNSUPPORTED: gdb.base/auxv.exp: info auxv on gcore-created dump
UNSUPPORTED: gdb.base/auxv.exp: matching auxv data from live and gcore
we can see the following messages in gdb/testsuite/gdb.log:
gcore /home/loongson/build.git/gdb/testsuite/outputs/gdb.base/auxv/auxv.gcore
Target does not support core file generation.
(gdb) UNSUPPORTED: gdb.base/auxv.exp: gcore
In order to fix the above issues, implement the iterate_over_regset_sections
gdbarch method to iterate over core file register note sections on LoongArch.
By the way, with this patch, the failed testcases in gdb.base/corefile.exp
and gdb.base/gcore.exp can also be fixed.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
With check-read1 I run into:
...
[infrun] maybe_set_commit_resumed_all_targets: not requesting
commit-resumed for target native, no resumed threads^M
(gdb) FAIL: gdb.base/ui-redirect.exp: debugging: continue
[infrun] fetch_inferior_event: exit^M
...
The problem is that proc gdb_test doesn't pass down the -prompt option to proc
gdb_test_multiple, due to a typo making this lappend without effect:
...
set opts {}
lappend "-prompt $prompt"
...
Fix this by actually appending to opts.
Tested on x86_64-linux.
When building gdb with -fsanitize=undefined, I run into:
...
(gdb) PASS: gdb.ada/access_to_packed_array.exp: set logging enabled on
maint print symbols^M
print-utils.cc:281:29:runtime error: negation of -9223372036854775808 cannot \
be represented in type 'long int'; cast to an unsigned type to negate this \
value to itself
(gdb) FAIL: gdb.ada/access_to_packed_array.exp: maint print symbols
...
By running in a debug session, we find that this happens during printing of:
...
typedef system.storage_elements.storage_offset: \
range -9223372036854775808 .. 9223372036854775807;
...
Possibly, an ada test-case could be created that exercises this in isolation.
The problem is here in int_string, where we negate a val with type LONGEST:
...
return decimal2str ("-", -val, width);
...
Fix this by, as recommend, using "-(ULONGEST)val" instead.
Tested on x86_64-linux.
When building gdb with -fsanitize=undefined, I run into:
...
$ gdb -q -batch -ex "p -(-0x7fffffffffffffff - 1)"
src/gdb/valarith.c:1385:10: runtime error: signed integer overflow: \
0 - -9223372036854775808 cannot be represented in type 'long int'
$1 = -9223372036854775808
...
Fix this by performing the substraction in scalar_binop using unsigned types.
Tested on x86_64-linux.
This test in test-case gdb.ada/dynamic-iface.exp passes with gcc 8:
...
(gdb) print obj^M
$1 = (n => 3, a => "ABC", value => 93)^M
(gdb) PASS: gdb.ada/dynamic-iface.exp: print local as interface
...
but fails with gcc 7:
...
(gdb) print obj^M
$1 = ()^M
(gdb) FAIL: gdb.ada/dynamic-iface.exp: print local as interface
...
More concretely, we have trouble finding the type of obj. With gcc 8:
...
$ gdb -q -batch main -ex "b concrete.adb:20" -ex run -ex "ptype obj"
...
type = <ref> new concrete.intermediate with record
value: integer;
end record
...
and with gcc 7:
...
type = <ref> tagged record null; end record
...
The translation from tagged type to "full view" type happens in
ada_tag_value_at_base_address, where we hit this code:
...
/* Storage_Offset'Last is used to indicate that a dynamic offset to
top is used. In this situation the offset is stored just after
the tag, in the object itself. */
if (offset_to_top == last)
{
struct value *tem = value_addr (tag);
tem = value_ptradd (tem, 1);
tem = value_cast (ptr_type, tem);
offset_to_top = value_as_long (value_ind (tem));
}
...
resulting in an offset_to_top for gcc 8:
...
(gdb) p offset_to_top
$1 = -16
...
and for gcc 7:
...
(gdb) p offset_to_top
$1 = 16
...
The difference is expected, it bisects to gcc commit d0567dc0dbf ("[multiple
changes]") which mentions this change.
There's some code right after the code quoted above that deals with this
change:
...
else if (offset_to_top > 0)
{
/* OFFSET_TO_TOP used to be a positive value to be subtracted
from the base address. This was however incompatible with
C++ dispatch table: C++ uses a *negative* value to *add*
to the base address. Ada's convention has therefore been
changed in GNAT 19.0w 20171023: since then, C++ and Ada
use the same convention. Here, we support both cases by
checking the sign of OFFSET_TO_TOP. */
offset_to_top = -offset_to_top;
}
...
but it's not activated because of the 'else'.
Fix this by removing the 'else'.
Tested on x86_64-linux, with gcc 7.5.0.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29057
In test-case gdb.base/parse_number.exp, we skip architecture auto in the
$supported_archs loop, to prevent duplicate testing.
Likewise, skip language auto and its alias local in the $::all_languages
loop. This reduces the number of tests from 17744 to 15572.
Tested on x86_64-linux, with a build with --enable-targets=all.
Currently GDB is not able to debug (Binary generated with Clang) variables
present in shared/private clause of OpenMP Task construct. Please note that
LLVM debugger LLDB is able to debug.
In case of OpenMP, compilers generate artificial functions which are not
present in actual program. This is done to apply parallelism to block of
code.
For non-artifical functions, DW_AT_name attribute should contains the name
exactly as present in actual program.
(Ref# http://wiki.dwarfstd.org/index.php?title=Best_Practices)
Since artificial functions are not present in actual program they not having
DW_AT_name and having DW_AT_linkage_name instead should be fine.
Currently GDB is invalidating any function not havnig DW_AT_name which is why
it is not able to debug OpenMP (Clang).
It should be fair to fallback to check DW_AT_linkage_name in case DW_AT_name
is absent.
Even after the previous patches reworking the inheritance of several
breakpoint types, the present breakpoint hierarchy looks a bit
surprising, as we have "breakpoint" as the superclass, and then
"base_breakpoint" inherits from "breakpoint". Like so, simplified:
breakpoint
base_breakpoint
ordinary_breakpoint
internal_breakpoint
momentary_breakpoint
ada_catchpoint
exception_catchpoint
tracepoint
watchpoint
catchpoint
exec_catchpoint
...
The surprising part to me is having "base_breakpoint" being a subclass
of "breakpoint". I'm just refering to naming here -- I mean, you'd
expect that it would be the top level baseclass that would be called
"base".
Just flipping the names of breakpoint and base_breakpoint around
wouldn't be super great for us, IMO, given we think of every type of
*point as a breakpoint at the user visible level. E.g., "info
breakpoints" shows watchpoints, tracepoints, etc. So it makes to call
the top level class breakpoint.
Instead, I propose renaming base_breakpoint to code_breakpoint. The
previous patches made sure that all code breakpoints inherit from
base_breakpoint, so it's fitting. Also, "code breakpoint" contrasts
nicely with a watchpoint also being typically known as a "data
breakpoint".
After this commit, the resulting hierarchy looks like:
breakpoint
code_breakpoint
ordinary_breakpoint
internal_breakpoint
momentary_breakpoint
ada_catchpoint
exception_catchpoint
tracepoint
watchpoint
catchpoint
exec_catchpoint
...
... which makes a lot more sense to me.
I've left this patch as last in the series in case people want to
bikeshed on the naming.
"code" has a nice property that it's exactly as many letters as
"base", so this patch didn't require any reindentation. :-)
Change-Id: Id8dc06683a69fad80d88e674f65e826d6a4e3f66
To look for code paths that lead to create_breakpoints_sal creating
multiple breakpoints, I ran the whole testsuite with this hack:
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -8377,8 +8377,7 @@ create_breakpoints_sal (struct gdbarch *gdbarch,
int from_tty,
int enabled, int internal, unsigned flags)
{
- if (canonical->pre_expanded)
- gdb_assert (canonical->lsals.size () == 1);
+ gdb_assert (canonical->lsals.size () == 1);
surprisingly, the assert never failed...
The way to get to create_breakpoints_sal with multiple lsals is to use
"set multiple-symbols ask" and then select multiple options from the
menu, like so:
(gdb) set multiple-symbols ask
(gdb) b overload1arg
[0] cancel
[1] all
[2] /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc:foo::overload1arg()
[3] /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc:foo::overload1arg(char)
[4] /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc:foo::overload1arg(double)
[5] /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc:foo::overload1arg(float)
[6] /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc:foo::overload1arg(int)
[7] /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc:foo::overload1arg(long)
[8] /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc:foo::overload1arg(short)
[9] /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc:foo::overload1arg(signed char)
[10] /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc:foo::overload1arg(unsigned char)
[11] /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc:foo::overload1arg(unsigned int)
[12] /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc:foo::overload1arg(unsigned long)
[13] /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc:foo::overload1arg(unsigned short)
> 2-3
Breakpoint 2 at 0x1532: file /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc, line 107.
Breakpoint 3 at 0x154b: file /home/pedro/gdb/binutils-gdb/src/gdb/testsuite/gdb.cp/ovldbreak.cc, line 110.
warning: Multiple breakpoints were set.
Use the "delete" command to delete unwanted breakpoints.
... which would trigger the assert.
This commit makes gdb.cp/ovldbreak.exp test this scenario. It does
that by making set_bp_overloaded take a list of expected created
breakpoints rather than just one breakpoint. It converts the
procedure to use gdb_test_multiple instead of send_gdb/gdb_expect
along the way.
Change-Id: Id87d1e08feb6670440d926f5344e5081f5e37c8e
This adds a new ctor to momentary_breakpoints with a few parameters
that are always necessary for momentary breakpoints.
In particular, I noticed that set_std_terminate_breakpoint doesn't
make the breakpoint be thread specific, which looks like a bug to me.
The point of that breakpoint is to intercept std::terminate calls that
happen as result of the called thread throwing an exception that won't
be caught by the dummy frame. If some other thread calls
std::terminate, IMO, it's no different from some other thread calling
exit/_exit, for example.
Change-Id: Ifc5ff4a6d6e58b8c4854d00b86725382d38a1a02
Momentary breakpoints have no breakpoint number, their breakpoint
number should be always 0, to avoid constantly incrementing (or
decrementing) the internal breakpoint count.
Indeed, set_momentary_breakpoint installs the created breakpoint
without a number.
However, momentary_breakpoint_from_master incorrectly gives an
internal breakpoint number to the new breakpoint. This commit fixes
that.
Change-Id: Iedcae5432cdf232db9e9a6e1a646d358abd34f95
This tweaks the intro comments of the following classes:
internal_breakpoint
momentary_breakpoint
breakpoint
base_breakpoint
watchpoint
catchpoint
Change-Id: If6b31f51ebbb81705fbe5b8435f60ab2c88a98c8
After the previous patches, only base_breakpoint subclasses use
add_location(sal), so we can move it to base_breakpoint (a.k.a. base
class for code breakpoints).
This requires a few casts here and there, but always at spots where
you can see from context what the breakpoint's type actually is.
I inlined new_single_step_breakpoint into its only caller exactly for
this reason.
I did try to propagate more use of base_breakpoint to avoid casts, but
that turned out unwieldy for this patch.
Change-Id: I49d959322b0fdce5a88a216bb44730fc5dd7c6f8
Move common bits of catchpoint and exception_catchpoint to
breakpoint's ctor, to avoid duplicating code.
Change-Id: I3a115180f4d496426522f1d89a3875026aea3cf2
struct catchpoint's ctor currently calls init_raw_breakpoint, which is
a bit weird, as that ctor-like function takes a sal argument, but
catchpoints don't have code locations.
Instead, make struct catchpoint's ctor add the catchpoint's dummy
location using add_dummy_location.
init_raw_breakpoint uses add_location under the hood, and with a dummy
sal it would ultimately use the breakpoint's gdbarch for the
location's gdbarch, so replace the references to loc->gdbarch (which
is now NULL) in syscall_catchpoint to references to the catchpoint's
gdbarch.
struct catchpoint's ctor was the last user of init_raw_breakpoint, so
this commit eliminates the latter.
Since catchpoint locations aren't code locations, make struct
catchpoint inherit struct breakpoint instead of base_breakpoint. This
let's us delete the tracepoint::re_set override too.
Change-Id: Ib428bf71efb09fdaf399c56e4372b0f41d9c5869
Software watchpoints allocate a special dummy location using
software_watchpoint_add_no_memory_location, and then
breakpoint_address_bits checks whether the location is that special
location to decide whether the location has a meaninful address to
print.
Introduce a new bp_loc_software_watchpoint location kind, and make
breakpoint_address_bits use bl_address_is_meaningful instead, which
returns false for bp_loc_other, which is in accordance with we
document for bp_location::address:
/* (... snip ...) Valid for all types except
bp_loc_other. */
CORE_ADDR address = 0;
Rename software_watchpoint_add_no_memory_location to
add_dummy_location, and simplify it. This will be used by catchpoints
too in a following patch.
Note that neither "info breakpoints" nor "maint info breakpoints"
actually prints the addresses of watchpoints, but I think it would be
useful to do so in "maint info breakpoints". This approach let's us
implement that in the future.
Change-Id: I50e398f66ef618c31ffa662da755eaba6295aed7
exception_catchpoint is really a code breakpoint, with locations set
by sals, re-set like other code breakpoints, etc., so make it inherit
base_breakpoint.
This adds a bit of duplicated code to exception_catchpoint's ctor
(copied from struct catchpoint's ctor), but it will be eliminated in a
following patch.
Change-Id: I9fbb2927491120e9744a4f5e5cb5e6870ca07009
This commit makes set_momentary_breakpoint allocate the breakpoint
type without relying on set_raw_breakpoint, and similarly,
momentary_breakpoint_from_master not rely on
set_raw_breakpoint_without_location. This will let us convert
init_raw_breakpoint to a ctor in a following patch.
The comment about set_raw_breakpoint being used in gdbtk sources is
stale. gdbtk no longer uses it.
Change-Id: Ibbf77731e4b22e18ccebc1b5799bbec0aff28c8a
This moves initialization of internal_breakpoint's breakpoint fields
to internal_breakpoint's ctor, and stops using
new_breakpoint_from_type for internal_breakpoint breakpoints.
Change-Id: I898ed0565f47cb00e4429f1c6446e6f9a385a78d
Currently, init_ada_exception_catchpoint is defined in breakpoint.c, I
presume so it can call the static describe_other_breakpoints function.
I think this is a dependency inversion.
init_ada_exception_catchpoint, being code specific to Ada catchpoints,
should be in ada-lang.c, and describe_other_breakpoints, a core
function, should be exported.
And then, we can convert init_ada_exception_catchpoint to an
ada_catchpoint ctor.
Change-Id: I07695572dabc5a75d3d3740fd9b95db1529406a1
This commit changes ada_catchpoint_location's ctor from:
ada_catchpoint_location (breakpoint *owner)
to:
ada_catchpoint_location (ada_catchpoint *owner)
just to make the code better document intention.
To do this, we need to move the ada_catchpoint_location type's
definition to after ada_catchpoint is defined, otherwise the compiler
doesn't know that ada_catchpoint is convertible to struct breakpoint.
Change-Id: Id908b2e38bde30b262381e00c5637adb9bf0129d
This converts init_breakpoint_sal to a base_breakpoint constructor.
It removes a use of init_raw_breakpoint.
To avoid manually adding a bunch of parameters to
new_breakpoint_from_type, and manually passing them down to the
constructors of a number of different base_breakpoint subclasses, make
new_breakpoint_from_type a variable template function.
Change-Id: I4cc24133ac4c292f547289ec782fc78e5bbe2510
None of init_breakpoint_sal, create_breakpoint_sal, and
strace_marker_create_breakpoints_sal make use of their "internal"
parameter, so remove it.
Change-Id: I943f3bb44717ade7a7b7547edf8f3ff3c37da435
This makes tracepoints inherit from base_breakpoint, since their
locations are code locations. If we do that, then we can eliminate
tracepoint::re_set and tracepoint::decode_location, as they are doing
the same as the base_breakpoint implementations.
With this, all breakpoint types created by new_breakpoint_from_type
are code breakpoints, i.e., base_breakpoint subclasses, and thus we
can make it return a base_breakpoint pointer.
Finally, init_breakpoint_sal can take a base_breakpoint pointer as
"self" pointer too. This will let us convert this function to a
base_breakpoint ctor in a following patch.
Change-Id: I3a4073ff1a4c865f525588095c18dc42b744cb54
This commit replaces a chunk of code in break_range_command by an
equivalent call to install_breakpoint.
Change-Id: I31c06cabd36f5be91740aab029265f678aa78e35
ranged_breakpoint's ctor already sets the breakpoint's type to
bp_hardware_breakpoint.
Since this is a "regular" breakpoint, b->pspace should remain NULL.
Thus, the only thing init_raw_breakpoint is needed for, is to add the
breakpoint's location. Do that directly.
Change-Id: I1505de94c3919881c2b300437e2c0da9b05f76bd
Make add_location_to_breakpoint be a method of struct breakpoint.
A patch later in the series will move this to base_breakpoint, but for
now, it needs to be here.
Change-Id: I5bdc2ec1a7c2d66f26f51bf6f6adc8384a90b129
The .quad statement stores the 64-bit hex value in Endian order. When used
to store a 64-bit prefix instructions on Big Endian (BE) systems, the .quad
statement stores the 32-bit suffix followed by the 32-bit prefix rather
than the expected order of prefix word followed by the suffix word. GDB
fetches 32-bits at a time when disassembling instructions. The disassembly
on BE gets messed up since GDB fetches the suffix first and interprets it
as a word instruction not a prefixed instruction. When gdb fetches the
prefix part of the instruction, following the initial suffix word, gdb
associates the prefix word incorrectly with the following 32-bits as the
suffix for the instruction when in fact it is the following instruction.
For example on BE we have two prefixed instructions stored using the
.quad statement as follows:
addr word GDB action
---------------------------------------------
1 suffix inst A <- GDB interprets as a word instruction
2 prefix inst A <- GDB uses this prefix with
3 suffix inst B <- this suffix rather than the suffix at addr 1.
4 prefix inst B
This patch changes the .quad statement into two .longs to explicitly store
the prefix followed by the suffix of the instruction.
The patch rearranges the instructions to put all of the word instructions
together followed by the prefix instructions for clarity.
The patch has been tested on Power 10 and Power 7 BE and LE to verify
the change works as expected.
The documentation says that -enable-pretty-printing is experimental in
7.0 and may change -- that's long enough ago that I think we can say
that this text is no longer correct or useful.
