Background: .mpy files are precompiled .py files, built using mpy-cross,
that contain compiled bytecode functions (and can also contain machine
code). The benefit of using an .mpy file over a .py file is that they are
faster to import and take less memory when importing. They are also
smaller on disk.
But the real benefit of .mpy files comes when they are frozen into the
firmware. This is done by loading the .mpy file during compilation of the
firmware and turning it into a set of big C data structures (the job of
mpy-tool.py), which are then compiled and downloaded into the ROM of a
device. These C data structures can be executed in-place, ie directly from
ROM. This makes importing even faster because there is very little to do,
and also means such frozen modules take up much less RAM (because their
bytecode stays in ROM).
The downside of frozen code is that it requires recompiling and reflashing
the entire firmware. This can be a big barrier to entry, slows down
development time, and makes it harder to do OTA updates of frozen code
(because the whole firmware must be updated).
This commit attempts to solve this problem by providing a solution that
sits between loading .mpy files into RAM and freezing them into the
firmware. The .mpy file format has been reworked so that it consists of
data and bytecode which is mostly static and ready to run in-place. If
these new .mpy files are located in flash/ROM which is memory addressable,
the .mpy file can be executed (mostly) in-place.
With this approach there is still a small amount of unpacking and linking
of the .mpy file that needs to be done when it's imported, but it's still
much better than loading an .mpy from disk into RAM (although not as good
as freezing .mpy files into the firmware).
The main trick to make static .mpy files is to adjust the bytecode so any
qstrs that it references now go through a lookup table to convert from
local qstr number in the module to global qstr number in the firmware.
That means the bytecode does not need linking/rewriting of qstrs when it's
loaded. Instead only a small qstr table needs to be built (and put in RAM)
at import time. This means the bytecode itself is static/constant and can
be used directly if it's in addressable memory. Also the qstr string data
in the .mpy file, and some constant object data, can be used directly.
Note that the qstr table is global to the module (ie not per function).
In more detail, in the VM what used to be (schematically):
qst = DECODE_QSTR_VALUE;
is now (schematically):
idx = DECODE_QSTR_INDEX;
qst = qstr_table[idx];
That allows the bytecode to be fixed at compile time and not need
relinking/rewriting of the qstr values. Only qstr_table needs to be linked
when the .mpy is loaded.
Incidentally, this helps to reduce the size of bytecode because what used
to be 2-byte qstr values in the bytecode are now (mostly) 1-byte indices.
If the module uses the same qstr more than two times then the bytecode is
smaller than before.
The following changes are measured for this commit compared to the
previous (the baseline):
- average 7%-9% reduction in size of .mpy files
- frozen code size is reduced by about 5%-7%
- importing .py files uses about 5% less RAM in total
- importing .mpy files uses about 4% less RAM in total
- importing .py and .mpy files takes about the same time as before
The qstr indirection in the bytecode has only a small impact on VM
performance. For stm32 on PYBv1.0 the performance change of this commit
is:
diff of scores (higher is better)
N=100 M=100 baseline -> this-commit diff diff% (error%)
bm_chaos.py 371.07 -> 357.39 : -13.68 = -3.687% (+/-0.02%)
bm_fannkuch.py 78.72 -> 77.49 : -1.23 = -1.563% (+/-0.01%)
bm_fft.py 2591.73 -> 2539.28 : -52.45 = -2.024% (+/-0.00%)
bm_float.py 6034.93 -> 5908.30 : -126.63 = -2.098% (+/-0.01%)
bm_hexiom.py 48.96 -> 47.93 : -1.03 = -2.104% (+/-0.00%)
bm_nqueens.py 4510.63 -> 4459.94 : -50.69 = -1.124% (+/-0.00%)
bm_pidigits.py 650.28 -> 644.96 : -5.32 = -0.818% (+/-0.23%)
core_import_mpy_multi.py 564.77 -> 581.49 : +16.72 = +2.960% (+/-0.01%)
core_import_mpy_single.py 68.67 -> 67.16 : -1.51 = -2.199% (+/-0.01%)
core_qstr.py 64.16 -> 64.12 : -0.04 = -0.062% (+/-0.00%)
core_yield_from.py 362.58 -> 354.50 : -8.08 = -2.228% (+/-0.00%)
misc_aes.py 429.69 -> 405.59 : -24.10 = -5.609% (+/-0.01%)
misc_mandel.py 3485.13 -> 3416.51 : -68.62 = -1.969% (+/-0.00%)
misc_pystone.py 2496.53 -> 2405.56 : -90.97 = -3.644% (+/-0.01%)
misc_raytrace.py 381.47 -> 374.01 : -7.46 = -1.956% (+/-0.01%)
viper_call0.py 576.73 -> 572.49 : -4.24 = -0.735% (+/-0.04%)
viper_call1a.py 550.37 -> 546.21 : -4.16 = -0.756% (+/-0.09%)
viper_call1b.py 438.23 -> 435.68 : -2.55 = -0.582% (+/-0.06%)
viper_call1c.py 442.84 -> 440.04 : -2.80 = -0.632% (+/-0.08%)
viper_call2a.py 536.31 -> 532.35 : -3.96 = -0.738% (+/-0.06%)
viper_call2b.py 382.34 -> 377.07 : -5.27 = -1.378% (+/-0.03%)
And for unix on x64:
diff of scores (higher is better)
N=2000 M=2000 baseline -> this-commit diff diff% (error%)
bm_chaos.py 13594.20 -> 13073.84 : -520.36 = -3.828% (+/-5.44%)
bm_fannkuch.py 60.63 -> 59.58 : -1.05 = -1.732% (+/-3.01%)
bm_fft.py 112009.15 -> 111603.32 : -405.83 = -0.362% (+/-4.03%)
bm_float.py 246202.55 -> 247923.81 : +1721.26 = +0.699% (+/-2.79%)
bm_hexiom.py 615.65 -> 617.21 : +1.56 = +0.253% (+/-1.64%)
bm_nqueens.py 215807.95 -> 215600.96 : -206.99 = -0.096% (+/-3.52%)
bm_pidigits.py 8246.74 -> 8422.82 : +176.08 = +2.135% (+/-3.64%)
misc_aes.py 16133.00 -> 16452.74 : +319.74 = +1.982% (+/-1.50%)
misc_mandel.py 128146.69 -> 130796.43 : +2649.74 = +2.068% (+/-3.18%)
misc_pystone.py 83811.49 -> 83124.85 : -686.64 = -0.819% (+/-1.03%)
misc_raytrace.py 21688.02 -> 21385.10 : -302.92 = -1.397% (+/-3.20%)
The code size change is (firmware with a lot of frozen code benefits the
most):
bare-arm: +396 +0.697%
minimal x86: +1595 +0.979% [incl +32(data)]
unix x64: +2408 +0.470% [incl +800(data)]
unix nanbox: +1396 +0.309% [incl -96(data)]
stm32: -1256 -0.318% PYBV10
cc3200: +288 +0.157%
esp8266: -260 -0.037% GENERIC
esp32: -216 -0.014% GENERIC[incl -1072(data)]
nrf: +116 +0.067% pca10040
rp2: -664 -0.135% PICO
samd: +844 +0.607% ADAFRUIT_ITSYBITSY_M4_EXPRESS
As part of this change the .mpy file format version is bumped to version 6.
And mpy-tool.py has been improved to provide a good visualisation of the
contents of .mpy files.
In summary: this commit changes the bytecode to use qstr indirection, and
reworks the .mpy file format to be simpler and allow .mpy files to be
executed in-place. Performance is not impacted too much. Eventually it
will be possible to store such .mpy files in a linear, read-only, memory-
mappable filesystem so they can be executed from flash/ROM. This will
essentially be able to replace frozen code for most applications.
Signed-off-by: Damien George <damien@micropython.org>
This allows the compiler to merge strings: e.g. "update",
"difference_update" and "symmetric_difference_update" will all point to the
same memory.
No functional change.
The size reduction depends on the number of qstrs in the build. The change
this commit brings is:
bare-arm: -4 -0.007%
minimal x86: +150 +0.092% [incl +48(data)]
unix x64: -608 -0.118%
unix nanbox: -572 -0.126% [incl +32(data)]
stm32: -1392 -0.352% PYBV10
cc3200: -448 -0.244%
esp8266: -1208 -0.173% GENERIC
esp32: -1028 -0.068% GENERIC[incl -1020(data)]
nrf: -440 -0.252% pca10040
rp2: -1072 -0.217% PICO
samd: -368 -0.264% ADAFRUIT_ITSYBITSY_M4_EXPRESS
Performance is also improved (on bare metal at least) for the
core_import_mpy_multi.py, core_import_mpy_single.py and core_qstr.py
performance benchmarks.
Originally at adafruit#4583
Signed-off-by: Artyom Skrobov <tyomitch@gmail.com>
The inclusion of `umachine` in the list of built-in modules is now done
centrally in py/objmodule.c. Enabling MICROPY_PY_MACHINE will include this
module.
As part of this, all ports now have `umachine` as the core module name
(previously some had only `machine` as the name).
Signed-off-by: Damien George <damien@micropython.org>
The new test has an .exp file, because it is not compatible with Python 3.9
and lower.
See CPython version of the issue at https://bugs.python.org/issue27772
Signed-off-by: Jeff Epler <jepler@gmail.com>
The qstr_last_chunk is not collected by the garbage collector. This relies
on the assertion that qstr_pool_t also references the qstr_last_chunk. If
an exception is raised while allocating the qstr_pool_t, qstr_last_chunk
has to be invalidated not to become a dangling reference at the next
garbage collection.
Signed-off-by: Emilie Feral <emilie.feral@numworks.com>
In commit 86ce442607 the '.frozen' entry was
added at the start of sys.path, to allow control over when frozen modules
are searched during import, and retain existing behaviour whereby frozen
was searched before the filesystem.
But Python semantics of sys.path require sys.path[0] to be the directory of
the currently executing script, or ''.
This commit moves the '.frozen' entry to second place in sys.path, so
sys.path[0] retains its correct value (described above).
Signed-off-by: Damien George <damien@micropython.org>
This commit makes sure that the value zero is always encoded in an mpz_t as
neg=0 and len=0 (previously it was just len=0).
This invariant is needed for some of the bitwise operations that operate on
negative numbers, because they cannot handle -0. For example
(-((1<<100)-(1<<100)))|1 was being computed as -65535, instead of 1.
Fixes issue #8042.
Signed-off-by: Damien George <damien@micropython.org>
The mp_sys_path_obj and mp_sys_argv_obj objects are only used by the
runtime and accessible from Python if MICROPY_PY_SYS is enabled. So
exclude them from the runtime state if this option is disabled.
Signed-off-by: Damien George <damien@micropython.org>
If MICROPY_PY_SYS_PATH_ARGV_DEFAULTS is enabled (which it is by default)
then sys.path and sys.argv will be initialised and populated with default
values. This keeps all bare-metal ports aligned.
Signed-off-by: Damien George <damien@micropython.org>
This ensures MICROPY_QSTR_EXTRA_POOL and MICROPY_MODULE_FROZEN_MPY are set
if necessary before the CFLAGS are extracted for QSTR generation.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
This changes makemanifest.py & mpy-tool.py to merge string and mpy names
into the same list (now mp_frozen_names).
The various paths for loading a frozen module (mp_find_frozen_module) and
checking existence of a frozen module (mp_frozen_stat) use a common
function that searches this list.
In addition, the frozen lookup will now only take place if the path starts
with ".frozen", which needs to be added to sys.path.
This fixes issues #1804, #2322, #3509, #6419.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
This feature is not enabled on any port, it's not in CPython's io module,
and functionality is better suited to the micropython-lib implementation of
pkg_resources.
Make it possible to proceed to a regular lookup in locals_dict if the
custom type->attr fails. This allows type->attr to extend rather than
completely replace the lookup in locals_dict.
This is useful for custom builtin classes that have mostly regular methods
but just a few special attributes/properties. This way, type->attr needs
to deal with the special cases only and the default lookup will be used for
generic methods.
Signed-off-by: Laurens Valk <laurens@pybricks.com>
This makes it possible for cooperative multitasking systems to keep running
event loops during garbage collector operations.
For example, this can be used to ensure that a motor control loop runs
approximately each 5 ms. Without this hook, the loop time can jump to
about 15 ms.
Addresses #3475.
Signed-off-by: Laurens Valk <laurens@pybricks.com>
This is an stm32-specific feature that's accessed via the pyb module, so
not something that will be widely enabled.
Signed-off-by: Damien George <damien@micropython.org>
Some of these will later be moved to CORE or BASIC, but EXTRA is a good
starting point based on what stm32 uses.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
This commit removes all parts of code associated with the existing
MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE optimisation option, including the
-mcache-lookup-bc option to mpy-cross.
This feature originally provided a significant performance boost for Unix,
but wasn't able to be enabled for MCU targets (due to frozen bytecode), and
added significant extra complexity to generating and distributing .mpy
files.
The equivalent performance gain is now provided by the combination of
MICROPY_OPT_LOAD_ATTR_FAST_PATH and MICROPY_OPT_MAP_LOOKUP_CACHE (which has
been enabled on the unix port in the previous commit).
It's hard to provide precise performance numbers, but tests have been run
on a wide variety of architectures (x86-64, ARM Cortex, Aarch64, RISC-V,
xtensa) and they all generally agree on the qualitative improvements seen
by the combination of MICROPY_OPT_LOAD_ATTR_FAST_PATH and
MICROPY_OPT_MAP_LOOKUP_CACHE.
For example, on a "quiet" Linux x64 environment (i3-5010U @ 2.10GHz) the
change from CACHE_MAP_LOOKUP_IN_BYTECODE, to LOAD_ATTR_FAST_PATH combined
with MAP_LOOKUP_CACHE is:
diff of scores (higher is better)
N=2000 M=2000 bccache -> attrmapcache diff diff% (error%)
bm_chaos.py 13742.56 -> 13905.67 : +163.11 = +1.187% (+/-3.75%)
bm_fannkuch.py 60.13 -> 61.34 : +1.21 = +2.012% (+/-2.11%)
bm_fft.py 113083.20 -> 114793.68 : +1710.48 = +1.513% (+/-1.57%)
bm_float.py 256552.80 -> 243908.29 : -12644.51 = -4.929% (+/-1.90%)
bm_hexiom.py 521.93 -> 625.41 : +103.48 = +19.826% (+/-0.40%)
bm_nqueens.py 197544.25 -> 217713.12 : +20168.87 = +10.210% (+/-3.01%)
bm_pidigits.py 8072.98 -> 8198.75 : +125.77 = +1.558% (+/-3.22%)
misc_aes.py 17283.45 -> 16480.52 : -802.93 = -4.646% (+/-0.82%)
misc_mandel.py 99083.99 -> 128939.84 : +29855.85 = +30.132% (+/-5.88%)
misc_pystone.py 83860.10 -> 82592.56 : -1267.54 = -1.511% (+/-2.27%)
misc_raytrace.py 21490.40 -> 22227.23 : +736.83 = +3.429% (+/-1.88%)
This shows that the new optimisations are at least as good as the existing
inline-bytecode-caching, and are sometimes much better (because the new
ones apply caching to a wider variety of map lookups).
The new optimisations can also benefit code generated by the native
emitter, because they apply to the runtime rather than the generated code.
The improvement for the native emitter when LOAD_ATTR_FAST_PATH and
MAP_LOOKUP_CACHE are enabled is (same Linux environment as above):
diff of scores (higher is better)
N=2000 M=2000 native -> nat-attrmapcache diff diff% (error%)
bm_chaos.py 14130.62 -> 15464.68 : +1334.06 = +9.441% (+/-7.11%)
bm_fannkuch.py 74.96 -> 76.16 : +1.20 = +1.601% (+/-1.80%)
bm_fft.py 166682.99 -> 168221.86 : +1538.87 = +0.923% (+/-4.20%)
bm_float.py 233415.23 -> 265524.90 : +32109.67 = +13.756% (+/-2.57%)
bm_hexiom.py 628.59 -> 734.17 : +105.58 = +16.796% (+/-1.39%)
bm_nqueens.py 225418.44 -> 232926.45 : +7508.01 = +3.331% (+/-3.10%)
bm_pidigits.py 6322.00 -> 6379.52 : +57.52 = +0.910% (+/-5.62%)
misc_aes.py 20670.10 -> 27223.18 : +6553.08 = +31.703% (+/-1.56%)
misc_mandel.py 138221.11 -> 152014.01 : +13792.90 = +9.979% (+/-2.46%)
misc_pystone.py 85032.14 -> 105681.44 : +20649.30 = +24.284% (+/-2.25%)
misc_raytrace.py 19800.01 -> 23350.73 : +3550.72 = +17.933% (+/-2.79%)
In summary, compared to MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE, the new
MICROPY_OPT_LOAD_ATTR_FAST_PATH and MICROPY_OPT_MAP_LOOKUP_CACHE options:
- are simpler;
- take less code size;
- are faster (generally);
- work with code generated by the native emitter;
- can be used on embedded targets with a small and constant RAM overhead;
- allow the same .mpy bytecode to run on all targets.
See #7680 for further discussion. And see also #7653 for a discussion
about simplifying mpy-cross options.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
The existing inline bytecode caching optimisation, selected by
MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE, reserves an extra byte in the
bytecode after certain opcodes, which at runtime stores a map index of the
likely location of this field when looking up the qstr. This scheme is
incompatible with bytecode-in-ROM, and doesn't work with native generated
code. It also stores bytecode in .mpy files which is of a different format
to when the feature is disabled, making generation of .mpy files more
complex.
This commit provides an alternative optimisation via an approach that adds
a global cache for map offsets, then all mp_map_lookup operations use it.
It's less precise than bytecode caching, but allows the cache to be
independent and external to the bytecode that is executing. It also works
for the native emitter and adds a similar performance boost on top of the
gain already provided by the native emitter.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
When the LOAD_ATTR opcode is executed there are quite a few different cases
that have to be handled, but the common case is accessing a member on an
instance type. Typically, built-in types provide methods which is why this
is common.
Fortunately, for this specific case, if the member is found in the member
map then there's no further processing.
This optimisation does a relatively cheap check (type is instance) and then
forwards directly to the member map lookup, falling back to the regular
path if necessary.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
This is the beginning of a set of changes to simplify enabling/disabling
features. The goals are:
- Remove redundancy from mpconfigport.h (never set a value to the default
-- make it clear exactly what's being enabled).
- Improve consistency between ports. All "similar" ports (i.e. approx same
flash size) should get the same features.
- Simplify mpconfigport.h -- just get default/sensible options for the size
of the port.
- Make it easy for defining constrained boards (e.g. STM32F0/L0), they can
just set a lower level.
This commit makes a step towards this and defines the "core" level as the
current default feature set, and a "minimal" level to turn off everything.
And a few placeholder levels are added for where the other ports will
roughly land.
This is a no-op change for all ports.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
This commit simplifies and optimises the parse tree in-memory
representation of lists of expressions, for tuples and lists, and when
tuples are used on the left-hand-side of assignments and within del
statements. This reduces memory usage of the parse tree when such code is
compiled, and also reduces the size of the compiler.
For example, (1,) was previously the following parse tree:
expr_stmt(5) (n=2)
atom_paren(45) (n=1)
testlist_comp(146) (n=2)
int(1)
testlist_comp_3b(149) (n=1)
NULL
NULL
and with this commit is now:
expr_stmt(5) (n=2)
atom_paren(45) (n=1)
testlist_comp(146) (n=1)
int(1)
NULL
Similarly, (1, 2, 3) was previously:
expr_stmt(5) (n=2)
atom_paren(45) (n=1)
testlist_comp(146) (n=2)
int(1)
testlist_comp_3c(150) (n=2)
int(2)
int(3)
NULL
and is now:
expr_stmt(5) (n=2)
atom_paren(45) (n=1)
testlist_comp(146) (n=3)
int(1)
int(2)
int(3)
NULL
Signed-off-by: Damien George <damien@micropython.org>
This commit refactors machine.PWM and creates extmod/machine_pwm.c. The
esp8266, esp32 and rp2 ports all use this and provide implementations of
the required PWM functionality. This helps to reduce code duplication and
keep the same Python API across ports.
This commit does not make any functional changes.
Signed-off-by: Damien George <damien@micropython.org>
The zephyr port doesn't support SoftI2C so it's not enabled, and the legacy
I2C constructor check can be removed.
Signed-off-by: Damien George <damien@micropython.org>
