Generally, the documentation doesn't allow for any explicit operands
to be specified with MONITOR/MWAIT. To permit the more legible
overriding of the address size via specifying operands, the option is
being retained even in Intel mode, but operand swapping is being
suppressed by this patch. This is both because it makes no sense here
(all of the operands are inputs) and because, as a result, old gcc
(prior to 4.8) actually expects it this way with -mintel-syntax (and
hence gets fixed by this change rather than, as claimed by a reply in
the bug report, broken).
Conversions which shrink element size and which have a memory source
can't be disambiguated between their 128- and 256-bit variants by
looking at the register operand. "operand size mismatch", however, is a
pretty misleading diagnostic. Generalize the logic introduced for
VFPCLASSP{S,D} such that, with suitable similar adjustments to the
respective templates, it'll cover these cases too.
For VCVTNEPS2BF16 also fold the two previously separate AVX512VL
templates to achieve the intended effect. This is then also accompanied
by a respective addition to the inval-avx512f testcase.
Since SSE3 is independent of SSE4a, don't disable SSE3 when disabling
SSE4a.
* i386-gen.c (cpu_flag_init): Remove CPU_ANY_SSE3_FLAGS from
CPU_ANY_SSE4A_FLAGS.
commit 7deea9aad8 changed nosse4 to include CpuSSE4a. But AMD SSE4a is
a superset of SSE3 and Intel SSE4 is a superset of SSSE3. Disable Intel
SSE4 shouldn't disable AMD SSE4a. This patch restores nosse4. It also
adds .sse4a and nosse4a.
gas/
* config/tc-i386.c (cpu_arch): Add .sse4a and nosse4a. Restore
nosse4.
* doc/c-i386.texi: Document sse4a and nosse4a.
opcodes/
* i386-gen.c (cpu_flag_init): Add CPU_ANY_SSE4A_FLAGS. Remove
CPU_ANY_SSE4_FLAGS.
To help with readability, add the type displaced_step_closure_up, an
alias for std::unique_ptr<displaced_step_closure>, and use it throughout
the code base.
gdb/ChangeLog:
* aarch64-tdep.c (aarch64_displaced_step_copy_insn): Use
displaced_step_closure_up.
* aarch64-tdep.h (aarch64_displaced_step_copy_insn): Likewise.
(struct displaced_step_closure_up):
* amd64-tdep.c (amd64_displaced_step_copy_insn): Likewise.
* amd64-tdep.h (amd64_displaced_step_copy_insn): Likewise.
* arm-linux-tdep.c (arm_linux_displaced_step_copy_insn):
Likewise.
* gdbarch.sh (displaced_step_copy_insn): Likewise.
* gdbarch.c, gdbarch.h: Re-generate.
* i386-linux-tdep.c (i386_linux_displaced_step_copy_insn): Use
displaced_step_closure_up.
* i386-tdep.c (i386_displaced_step_copy_insn): Likewise.
* i386-tdep.h (i386_displaced_step_copy_insn): Likewise.
* infrun.h (displaced_step_closure_up): New type alias.
(struct displaced_step_inferior_state) <step_closure>: Change
type to displaced_step_closure_up.
* rs6000-tdep.c (ppc_displaced_step_copy_insn): Use
displaced_step_closure_up.
* s390-tdep.c (s390_displaced_step_copy_insn): Likewise.
This changes gdbserver so that it no longer builds its own gnulib and
libiberty. Instead, it now relies on the ones that were already built
at the top level.
gdbsupport is still built specially for gdbserver. This is more
complicated and will be tackled in a subsequent patch.
ChangeLog
2020-02-14 Tom Tromey <tom@tromey.com>
* Makefile.in: Rebuild.
* Makefile.def: Make gdbserver require gnulib and libiberty.
gdbserver/ChangeLog
2020-02-14 Tom Tromey <tom@tromey.com>
* acinclude.m4: Don't include acx_configure_dir.m4.
* Makefile.in (LIBIBERTY_BUILDDIR, GNULIB_BUILDDIR): Update.
(SUBDIRS, CLEANDIRS, REQUIRED_SUBDIRS): Remove.
(all, install-only, uninstall, clean-info, clean)
(maintainer-clean): Don't recurse.
(subdir_do, all-lib): Remove.
($(LIBGNU) $(LIBIBERTY) $(GNULIB_H)): Remove rule.
(GNULIB_H): Remove.
(generated_files): Update.
($(GNULIB_BUILDDIR)/Makefile): Remove rule.
* configure: Rebuild.
* configure.ac: Don't configure gnulib or libiberty.
(GNULIB): Update.
gdbsupport/ChangeLog
2020-02-14 Tom Tromey <tom@tromey.com>
* common-defs.h: Change path to gnulib/config.h.
Change-Id: I469cbbf5db2ab37109c058e9e3a1e4f4dabdfc98
While looking at the output of "maint info bfd" with multiple
inferiors, I noticed that there were duplicate entries for
.gnu_debugdata.
There is no reason to re-create this BFD each time it is needed. This
patch arranges to share the data.
gdb/ChangeLog
2020-02-14 Tom Tromey <tom@tromey.com>
* minidebug.c (gnu_debug_key): New global.
(find_separate_debug_file_in_section): Use it.
Change-Id: If139f89f0f07db33f399afdbcfbf5aaeffe4de46
This updates the gdb testsuite to look for gdbserver in its new
location. The old location is also checked for, on the theory that
perhaps someone sets GDB to a full path for install testing.
gdb/testsuite/ChangeLog
2020-02-14 Tom Tromey <tom@tromey.com>
* lib/gdbserver-support.exp (find_gdbserver): Find gdbserver in
build directory.
* boards/gdbserver-base.exp: Update path to gdbserver.
Change-Id: If03db762ba53882ddfaf2d2d516de14c3fa03938
This callback dynamically allocates a specialized displaced_step_closure, and
gives the ownership of the object to its caller. So I think it would make
sense for the callback to return an std::unique_ptr, this is what this patch
implements.
gdb/ChangeLog:
* gdbarch.sh (displaced_step_copy_insn): Change return type to an
std::unique_ptr.
* gdbarch.c: Re-generate.
* gdbarch.h: Re-generate.
* infrun.c (displaced_step_prepare_throw): Adjust to std::unique_ptr
change.
* aarch64-tdep.c (aarch64_displaced_step_copy_insn): Change return
type to std::unique_ptr.
* aarch64-tdep.h (aarch64_displaced_step_copy_insn): Likewise.
* amd64-tdep.c (amd64_displaced_step_copy_insn): Likewise.
* amd64-tdep.h (amd64_displaced_step_copy_insn): Likewise.
* arm-linux-tdep.c (arm_linux_displaced_step_copy_insn): Likewise.
* i386-linux-tdep.c (i386_linux_displaced_step_copy_insn): Likewise.
* i386-tdep.c (i386_displaced_step_copy_insn): Likewise.
* i386-tdep.h (i386_displaced_step_copy_insn): Likewise.
* rs6000-tdep.c (ppc_displaced_step_copy_insn): Likewise.
* s390-tdep.c (s390_displaced_step_copy_insn): Likewise.
displaced_step_inferior_state::reset and displaced_step_clear appear to
have the same goal, but they don't do the same thing.
displaced_step_inferior_state::reset clears more things than
displaced_step_clear, but it misses free'ing the closure, which
displaced_step_clear does.
This patch replaces displaced_step_clear's implementation with just a call to
displaced_step_inferior_state::reset. It then changes
displaced_step_inferior_state::step_closure to be a unique_ptr, to indicate the
fact that displaced_step_inferior_state owns the closure (and so that it is
automatically freed when the field is reset).
The test gdb.base/step-over-syscall.exp caught a problem when doing this, which
I consider to be a latent bug which my cleanup exposes. In
handle_inferior_event, in the TARGET_WAITKIND_FORKED case, if we displaced-step
over a fork syscall, we make sure to restore the memory that we used as a
displaced-stepping buffer in the child. We do so using the
displaced_step_inferior_state of the parent. However, we do it after calling
displaced_step_fixup for the parent, which clears the information in the
parent's displaced_step_inferior_state. It worked fine before, because
displaced_step_clear didn't completely clear the displaced_step_inferior_state
structure, so the required information (in this case the gdbarch) was
still available after clearing.
I fixed it by making GDB restore the child's memory before calling the
displaced_step_fixup on the parent. This way, the data in the
displaced_step_inferior_state structure is still valid when we use it for the
child. This is the error you would get in
gdb.base/step-over-syscall.exp without this fix:
/home/smarchi/src/binutils-gdb/gdb/gdbarch.c:3911: internal-error: ULONGEST gdbarch_max_insn_length(gdbarch*): Assertion `gdbarch != NULL' failed.
gdb/ChangeLog:
* infrun.c (get_displaced_step_closure_by_addr): Adjust to
std::unique_ptr.
(displaced_step_clear): Rename to...
(displaced_step_reset): ... this. Just call displaced->reset ().
(displaced_step_clear_cleanup): Rename to...
(displaced_step_reset_cleanup): ... this.
(displaced_step_prepare_throw): Adjust to std::unique_ptr.
(displaced_step_fixup): Likewise.
(resume_1): Likewise.
(handle_inferior_event): Restore child's memory before calling
displaced_step_fixup on the parent.
* infrun.h (displaced_step_inferior_state) <reset>: Adjust
to std::unique_ptr.
<step_closure>: Change type to std::unique_ptr.
For a fix I intend to submit, I would need a function that counts the
number of set bits in a word. There is __builtin_popcount that is
supported by gcc and clang, but there is also a gnulib module that wraps
that and provides a fallback for other compilers, so I think it would be
good to use it.
I also noticed that there is a bitcount function in arch/arm.c, so I
thought that as a first step I would replace that one with the gnulib
count-one-bits module. This is what this patch does.
The gnulib module provides multiple functions, with various parameter
length (unsigned int, unsigned long int, unsigned long long int), I
chose the one that made sense for each call site based on the argument
type.
gnulib/ChangeLog:
* update-gnulib.sh (IMPORTED_GNULIB_MODULES): Import
count-one-bits module.
* configure: Re-generate.
* aclocal.m4: Re-generate.
* Makefile.in: Re-generate.
* import/count-one-bits.c: New file.
* import/count-one-bits.h: New file.
* import/Makefile.am: Re-generate.
* import/Makefile.in: Re-generate.
* import/m4/gnulib-cache.m4: Re-generate.
* import/m4/gnulib-comp.m4: Re-generate.
* import/m4/count-one-bits.m4: New file.
gdb/ChangeLog:
* arm-tdep.c: Include count-one-bits.h.
(cleanup_block_store_pc): Use count_one_bits.
(cleanup_block_load_pc): Use count_one_bits.
(arm_copy_block_xfer): Use count_one_bits.
(thumb2_copy_block_xfer): Use count_one_bits.
(thumb_copy_pop_pc_16bit): Use count_one_bits.
* arch/arm-get-next-pcs.c: Include count-one-bits.h.
(thumb_get_next_pcs_raw): Use count_one_bits.
(arm_get_next_pcs_raw): Use count_one_bits_l.
* arch/arm.c (bitcount): Remove.
* arch/arm.h (bitcount): Remove.
call_site_find_chain returns a pointer that the caller must
deallocate. It seemed better here to return a unique_xmalloc_ptr
instead.
gdb/ChangeLog
2020-02-14 Tom Tromey <tromey@adacore.com>
* dwarf2/frame-tailcall.c (dwarf2_tailcall_sniffer_first):
Update.
* dwarf2/loc.h (call_site_find_chain): Return unique_xmalloc_ptr.
* dwarf2/loc.c (call_site_find_chain_1): Return
unique_xmalloc_ptr.
(call_site_find_chain): Likewise.
Since movsx and movzx are valid mnemonic in AT&T syntax, remove Intel
syntax comments on movsx and movzx to avoid confusing other readers.
* i386-opc.tbl (movsx): Remove Intel syntax comments.
(movzx): Likewise.
For these to get treatment consistent with other operand size checking
the special logic shouldn't live in md_assemble(), but process_suffix().
And there's more logic involved than simply zapping the suffix.
Note however that MOVS[BW]* and MOVZ[BW]* still won't be fully
consistent, due to the objection to fold MOVS* templates just like was
done for MOVZ* in c07315e0c6 ("x86: allow suffix-less movzw and 64-bit
movzb").
Note further that it is against my own intentions to have MOVSX/MOVZX
silently default to a byte source in AT&T mode. This should happen only
when the destination register is a 16-bit one. In all other cases there
is an ambiguity, and the user should be warned. But it was explicitly
requested for this to be done in a way inconsistent with everything
else.
Note finally that the assembler change points out (and this patch fixes)
a wrong Intel syntax test introduced by bc31405ebb ("x86-64: Properly
encode and decode movsxd"): When source code specifies a 16-bit
destination register, disassembly expectations shouldn't have been to
find a 32-bit one.
Since we already suppress the prefix altogether when it's the default
one for the chosen addressing mode, let's do so also when instruction
prefix and override specified with the memory operand match. (Note that
insn prefix specified segment overrides never get discarded.)
For one both possible forms should be warned about. And then, to guard
against future surprises, qualify the original opcode check by excluding
VEX/EVEX-like templates.
Document different mnemonics of movsx, movsxd and movzx in AT&T syntax.
PR gas/25438
* doc/c-i386.texi: Document movsx, movsxd and movzx for AT&T
syntax.
gdbserver/ChangeLog
2020-02-14 Eli Zaretskii <eliz@gnu.org>
* win32-low.c (create_process): Prepend PROGRAM to ARGS when
preparing the command line for CreateProcess.
(win32_create_inferior): Reflect the program name in debugging
output that shows the process and its command line.
I see for some program at gdb startup:
...
Samples: 102K of event 'cycles:pu', Event count (approx.): 91710925103
Overhead Command Shared Object Symbol
15.21% gdb gdb [.]
lnp_state_machine::handle_special
...
where the divisions are the places we stall. The following
micro-optimizes things but it smells like m_line_header->line_range
is constant, likewise probably m_line_header->maximum_ops_per_instruction
so eventually the divisions could be avoided completely with some
lookup table.
Well. Micro-optimizing with this patch improves things
(don't expect [load] CSE over the gdbarch_adjust_dwarf2_line call).
Build and reg-tested on x86_64-linux.
gdb/ChangeLog:
2020-02-14 Richard Biener <rguenther@suse.de>
* dwarf2/read.c (lnp_state_machine::handle_special_opcode): Apply CSE
on expression with division operators.
Since PLT entry isn't needed for branch to local symbol, we can resolve
R_386_PLT32/R_X86_64_PLT32 relocation aganst local symbol to section,
similar to R_386_PC32/R_X86_64_PC32.
2020-02-13 Fangrui Song <maskray@google.com>
H.J. Lu <hongjiu.lu@intel.com>
PR gas/25551
* config/tc-i386.c (tc_i386_fix_adjustable): Don't check
BFD_RELOC_386_PLT32 nor BFD_RELOC_X86_64_PLT32.
* testsuite/gas/i386/i386.exp: Run relax-5 and x86-64-relax-4.
* testsuite/gas/i386/relax-5.d: New file.
* testsuite/gas/i386/relax-5.s: Likewise.
* testsuite/gas/i386/x86-64-relax-4.d: Likewise.
* testsuite/gas/i386/x86-64-relax-4.s: Likewise.
For the same reasons outlined in the previous patch, this patch renames
gdbserver source files to .cc.
I have moved the "-x c++" switch to only those rules that require it.
gdbserver/ChangeLog:
* Makefile.in: Rename source files from .c to .cc.
* %.c: Rename to %.cc.
* configure.ac: Rename server.c to server.cc.
* configure: Re-generate.
This patch renames the .c source files in gdbsupport to .cc.
In the gdb directory, there is an argument against renaming the source
files, which is that it makes using some git commands more difficult to
do archeology. Some commands have some kind of "follow" option that
makes git try to follow renames, but it doesn't work in all situations.
Given that we have just moved the gdbsupport directory, that argument
doesn't hold for source files in that directory. I therefore suggest
renaming them to .cc, so that they are automatically recognized as C++
by various tools and editors.
The original motivation behind this is that when building gdbsupport
with clang, I get:
CC agent.o
clang: error: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Werror,-Wdeprecated]
In the gdb/ directory, we make clang happy by passing "-x c++". We
could do this in gdbsupport too, but I think that renaming the files is
a better long-term solution.
gdbserver still does its own build of gdbsupport, so a few changes in
its Makefile are necessary.
gdbsupport/ChangeLog:
* Makefile.am: Rename source files from .c to .cc.
(CC, CFLAGS): Don't override.
(AM_CFLAGS): Rename to ...
(AM_CXXFLAGS): ... this.
* Makefile.in: Re-generate.
* %.c: Rename to %.cc.
gdbserver/ChangeLog:
* Makefile.in: Rename gdbsupport source files from .c to .cc.
When running test-case gdb.ada/ptype_tagged_param.exp, I get:
...
PASS: gdb.ada/ptype_tagged_param.exp: compilation foo.adb
...
However, when I then de-install gnatmake and run again, I get the same result.
This is due to a stale exec. After removing the stale exec, I get:
...
UNSUPPORTED: gdb.ada/ptype_tagged_param.exp: compilation foo.adb
...
Fix this removing the stale exec in gdb_compile_ada before compilation.
Tested on x86_64-linux.
gdb/testsuite/ChangeLog:
2020-02-13 Tom de Vries <tdevries@suse.de>
* lib/ada.exp (gdb_compile_ada): Delete stale exec before compilation.
If I de-install gnatbind, I run into:
...
FAIL: gdb.ada/catch_ex_std.exp: gnatbind foo
...
Fix this by marking the test unsupported instead:
...
UNSUPPORTED: gdb.ada/catch_ex_std.exp: gnatbind foo
...
Likewise for gnatlink.
Tested on x86_64-linux, with and without gnatbind/gnatlink installed.
gdb/testsuite/ChangeLog:
2020-02-13 Tom de Vries <tdevries@suse.de>
* gdb.ada/catch_ex_std.exp: Indicate unsupported if gnatbind/gnatlink
are missing.
try_load_plugin is updated to take either plugin name or plugin entry.
load_plugin is updated to search bfd-plugins directories first to build
a list of plugins and call try_load_plugin with each plugin on the list.
When --plugin is used, the plugin list only has one entry.
* plugin.c (try_load_plugin): Make plugin_list_iter an argument
and use it if it isn't NULL. Remove has_plugin_p argument. Add
a build_list_p argument. Don't search plugin_list. Short circuit
when building the plugin list.
(has_plugin): Renamed to has_plugin_list.
(bfd_plugin_set_plugin): Don't set has_plugin.
(bfd_plugin_specified_p): Check plugin_list instead.
(build_plugin_list): New function.
(load_plugin): Call build_plugin_list and use plugin_list.
After de-installing gnatmake, I get:
...
Running src/gdb/testsuite/gdb.ada/rename_subscript_param.exp ...
ERROR: tcl error sourcing src/gdb/testsuite/gdb.ada/rename_subscript_param.exp.
ERROR: couldn't execute "gnatmake": no such file or directory
while executing
"exec $gnatmake --version"
(procedure "gnatmake_version_at_least" line 4)
...
Fix this by wrapping the exec call in a catch call.
Tested with and withouth gnatmake installed on x86_64-linux.
gdb/testsuite/ChangeLog:
2020-02-13 Tom de Vries <tdevries@suse.de>
* lib/ada.exp (gnatmake_version_at_least): Wrap exec call in a catch
call.
This removes some dead code from event-loop.c.
This patch is from my old series to merge the gdb and gdbserver event
loops; but since it is just removing dead code, it seemed simple to
commit it separately.
gdb/ChangeLog
2020-02-12 Tom Tromey <tom@tromey.com>
* event-loop.c (event_data, gdb_event, event_handler_func):
Remove.
Now that comp_unit and the remaining frame data are all independent of
the objfile, it can all be stored on the BFD and shared across
inferiors.
As with other code doing this same thing, care must be taken to not
share the data when the objfile requires relocations. So, two keys
are used: one for the BFD and one for the objfile, and
gdb_bfd_requires_relocations is used to differentiate between the two
cases.
gdb/ChangeLog
2020-02-12 Tom Tromey <tom@tromey.com>
* dwarf2/frame.c (dwarf2_frame_bfd_data): New global.
(dwarf2_frame_objfile_data): Add comment.
(find_comp_unit, set_comp_unit): New functions.
(dwarf2_frame_find_fde): Use find_comp_unit.
(dwarf2_build_frame_info): Use set_comp_unit.
This removes the objfile backlink from comp_unit. The only remaining
uses involved fetching the text offset from the objfile. However,
this is already conveniently computed at all the sites that call
execute_cfa_program, and so it can simply be passed in.
gdb/ChangeLog
2020-02-12 Tom Tromey <tom@tromey.com>
* dwarf2/frame.c (struct comp_unit) <objfile>: Remove.
(comp_unit): Don't initialize objfile.
(execute_cfa_program): Add text_offset parameter.
(execute_cfa_program_test, dwarf2_fetch_cfa_info)
(dwarf2_frame_cache): Update.
(dwarf2_build_frame_info): Don't set "objfile" member.
The DWARF frame comp_unit object still has a backlink to the objfile.
In order to be truly objfile-independent, this must be removed.
This patch removes one such use, by passing the gdbarch to
decode_frame_entry directly.
gdb/ChangeLog
2020-02-12 Tom Tromey <tom@tromey.com>
* dwarf2/frame.c (decode_frame_entry_1): Add gdbarch parameter.
(decode_frame_entry): Likewise.
(dwarf2_build_frame_info): Update.
This adds an auto_obstack to the DWARF frame comp_unit object, and
then changes the remaining code here to use the comp_unit obstack
rather than the objfile obstack.
At this point, all the storage for frame data is self-contained --
that is, it is independent of the objfile.
gdb/ChangeLog
2020-02-12 Tom Tromey <tom@tromey.com>
* dwarf2/frame.c (struct comp_unit) <obstack>: New member.
(decode_frame_entry_1): Use the comp_unit obstack.
This changes the DWARF frame code to store the comp_unit on the
objfile, rather than storing the FDE table. It also changes the
comp_unit to be heap-allocated using "new".
This change makes it simpler for a later patch to add a field to the
comp_unit, and to have deallaction work properly. This in turn is
important for making the frame data be independent of the objfile.
gdb/ChangeLog
2020-02-12 Tom Tromey <tom@tromey.com>
* dwarf2/frame.c (struct comp_unit): Add initializers and
constructor.
(dwarf2_frame_objfile_data): Store a comp_unit.
(dwarf2_frame_find_fde): Update.
(dwarf2_build_frame_info): Use "new".
This removes struct dwarf2_fde_table, replacing it with a typedef of
std::vector. This simplifies the code somewhat.
gdb/ChangeLog
2020-02-12 Tom Tromey <tom@tromey.com>
* dwarf2/frame.c (struct dwarf2_fde_table): Remove.
(dwarf2_fde_table): Typedef for std::vector.
(dwarf2_frame_objfile_data): Remove the deleter. Now static.
(dwarf2_frame_find_fde, add_fde, decode_frame_entry_1)
(decode_frame_entry): Update.
(dwarf2_build_frame_info): Use "new".
I am keeping the (int) casts because a future patch will change the type
to bool.
gdb/ChangeLog:
2020-02-12 Christian Biesinger <cbiesinger@google.com>
* arm-tdep.c (arm_dump_tdep): Print more fields of tdep.
The type dwarf_expr_baton is unused and can be removed.
gdb/ChangeLog
2020-02-12 Tom Tromey <tom@tromey.com>
* dwarf2/loc.c (struct dwarf_expr_baton): Remove.
Change-Id: Id8342da31398b9b4b08f31be7c3d612e9590bbbf
handle_v_kill uses signal_pid because win32 doesn't support multi-process.
Without this gdb just refuses to kill the process:
(gdb) kill
Kill the program being debugged? (y or n) y
Sending packet: $vKill;a410#33...Packet received: E01
Packet vKill (kill) is supported
Can't kill process
gdbserver/ChangeLog:
2020-02-12 Hannes Domani <ssbssa@yahoo.de>
* win32-low.c (win32_create_inferior): Set signal_pid.
With AVX512VL disabled (e.g. when writing code for the Knights family
of processors) these insns aren't ambiguous when used with a memory
source, and hence should be accepted without suffix or operand size
specifier. When AVX512VL is enabled, to be consistent with this as
well as other ambiguous operand size handling it would seem better to
just warn about the ambiguity in AT&T mode, and still default to 512-bit
operands (on the assumption that the code may have been written without
AVX512VL in mind yet), but it was requested to leave AT&T syntax mode
alone here.
Now that the AMD64 check in match_template() applies to 64-bit code
only, the non-64-bit and the Amd64 template can be folded, as being
otherwise compatible with one another. (Oddly enough the same doesn't
apply to CALL, due to the suffixes it permits, while JMP doesn't
allow for any.)
