Commit Graph

75 Commits

Author SHA1 Message Date
Damien George 1762990579 py/bc: Provide separate code-state setup funcs for bytecode and native.
mpy-cross will now generate native code based on the size of
mp_code_state_native_t, and the runtime will use this struct to calculate
the offset of the .state field.  This makes native code generation and
execution (which rely on this struct) independent to the settings
MICROPY_STACKLESS and MICROPY_PY_SYS_SETTRACE, both of which change the
size of the mp_code_state_t struct.

Fixes issue #5059.

Signed-off-by: Damien George <damien@micropython.org>
2022-05-17 14:25:51 +10:00
stijn 594c753c27 py/bc.h: Fix C++20 compilation with "volatile".
C++20 is deprecating several usages of the volatile keyword so remove this
one affected case in the codebase which causes such warning.
2022-03-30 16:29:25 +11:00
Damien George 1692cad673 py/showbc: Remove global variables and make DECODE_PTR work correctly.
The bytecode state variables mp_showbc_code_start and mp_showbc_constants
have been removed and made local variables passed into the various
functions.

As part of this, the DECODE_PTR macro is fixed so it extracts the relevant
pointer from the child_table (a regression introduced in
f2040bfc7e).

Signed-off-by: Damien George <damien@micropython.org>
2022-03-16 11:59:46 +11:00
stijn 795370ca23 py/bc.h: Fix C++ compilation of public API.
Casts between unrelated types must be explicit.  Regression in
f2040bfc7e
2022-03-01 16:17:30 +11:00
Damien George f2040bfc7e py: Rework bytecode and .mpy file format to be mostly static data.
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>
2022-02-24 18:08:43 +11:00
Damien George cfd08448a1 py: Mark unused arguments from bytecode decoding macros.
Signed-off-by: Damien George <damien@micropython.org>
2021-06-25 10:58:22 +10:00
Damien George 85f2b239d8 py/showbc: Pass in an mp_print_t struct to all bytecode-print functions.
So the output can be redirected if needed.

Signed-off-by: Damien George <damien@micropython.org>
2020-09-11 17:22:28 +10:00
stijn 84fa3312cf all: Format code to add space after C++-style comment start.
Note: the uncrustify configuration is explicitly set to 'add' instead of
'force' in order not to alter the comments which use extra spaces after //
as a means of indenting text for clarity.
2020-04-23 11:24:25 +10:00
Damien George 69661f3343 all: Reformat C and Python source code with tools/codeformat.py.
This is run with uncrustify 0.70.1, and black 19.10b0.
2020-02-28 10:33:03 +11:00
Damien George b47e155bd0 py/persistentcode: Add ability to relocate loaded native code.
Implements text, rodata and bss generalised relocations, as well as generic
qstr-object linking.  This allows importing dynamic native modules on all
supported architectures in a unified way.
2019-12-12 20:15:28 +11:00
Damien George c8c0fd4ca3 py: Rework and compress second part of bytecode prelude.
This patch compresses the second part of the bytecode prelude which
contains the source file name, function name, source-line-number mapping
and cell closure information.  This part of the prelude now begins with a
single varible length unsigned integer which encodes 2 numbers, being the
byte-size of the following 2 sections in the header: the "source info
section" and the "closure section".  After decoding this variable unsigned
integer it's possible to skip over one or both of these sections very
easily.

This scheme saves about 2 bytes for most functions compared to the original
format: one in the case that there are no closure cells, and one because
padding was eliminated.
2019-10-01 12:26:22 +10:00
Damien George b5ebfadbd6 py: Compress first part of bytecode prelude.
The start of the bytecode prelude contains 6 numbers telling the amount of
stack needed for the Python values and exceptions, and the signature of the
function.  Prior to this patch these numbers were all encoded one after the
other (2x variable unsigned integers, then 4x bytes), but using so many
bytes is unnecessary.

An entropy analysis of around 150,000 bytecode functions from the CPython
standard library showed that the optimal Shannon coding would need about
7.1 bits on average to encode these 6 numbers, compared to the existing 48
bits.

This patch attempts to get close to this optimal value by packing the 6
numbers into a single, varible-length unsigned integer via bit-wise
interleaving.  The interleaving scheme is chosen to minimise the average
number of bytes needed, and at the same time keep the scheme simple enough
so it can be implemented without too much overhead in code size or speed.
The scheme requires about 10.5 bits on average to store the 6 numbers.

As a result most functions which originally took 6 bytes to encode these 6
numbers now need only 1 byte (in 80% of cases).
2019-10-01 12:26:22 +10:00
Damien George 81d04a0200 py: Add n_state to mp_code_state_t struct.
This value is used often enough that it is better to cache it instead of
decode it each time.
2019-10-01 12:26:22 +10:00
Damien George 4c5e1a0368 py/bc: Change mp_code_state_t.exc_sp to exc_sp_idx.
Change from a pointer to an index, to make space in mp_code_state_t.
2019-10-01 12:26:22 +10:00
Damien George 1d7afcce49 py/bc: Remove comments referring to obsolete currently_in_except_block.
It was made obsolete in 6f9e3ff719
2019-10-01 12:26:22 +10:00
Damien George 1f7202d122 py/bc: Replace big opcode format table with simple macro. 2019-09-26 15:27:11 +10:00
Milan Rossa 310b3d1b81 py: Integrate sys.settrace feature into the VM and runtime.
This commit adds support for sys.settrace, allowing to install Python
handlers to trace execution of Python code.  The interface follows CPython
as closely as possible.  The feature is disabled by default and can be
enabled via MICROPY_PY_SYS_SETTRACE.
2019-08-30 16:44:12 +10:00
Damien George dbf35d3da3 py/bc: Factor out code to get bytecode line number info into new func. 2019-08-30 16:43:46 +10:00
Paul Sokolovsky 016d9a40fe various: Add and update my copyright line based on git history.
For modules I initially created or made substantial contributions to.
2019-05-17 18:04:15 +10:00
Damien George 992a6e1dea py/persistentcode: Pack qstrs directly in bytecode to reduce mpy size.
Instead of emitting two bytes in the bytecode for where the linked qstr
should be written to, it is now replaced by the actual qstr data, or a
reference into the qstr window.

Reduces mpy file size by about 10%.
2019-03-05 16:27:34 +11:00
Damien George a3dc1b1957 all: Remove inclusion of internal py header files.
Header files that are considered internal to the py core and should not
normally be included directly are:
    py/nlr.h - internal nlr configuration and declarations
    py/bc0.h - contains bytecode macro definitions
    py/runtime0.h - contains basic runtime enums

Instead, the top-level header files to include are one of:
    py/obj.h - includes runtime0.h and defines everything to use the
        mp_obj_t type
    py/runtime.h - includes mpstate.h and hence nlr.h, obj.h, runtime0.h,
        and defines everything to use the general runtime support functions

Additional, specific headers (eg py/objlist.h) can be included if needed.
2017-10-04 12:37:50 +11:00
Alexander Steffen 55f33240f3 all: Use the name MicroPython consistently in comments
There were several different spellings of MicroPython present in comments,
when there should be only one.
2017-07-31 18:35:40 +10:00
Alexander Steffen 299bc62586 all: Unify header guard usage.
The code conventions suggest using header guards, but do not define how
those should look like and instead point to existing files. However, not
all existing files follow the same scheme, sometimes omitting header guards
altogether, sometimes using non-standard names, making it easy to
accidentally pick a "wrong" example.

This commit ensures that all header files of the MicroPython project (that
were not simply copied from somewhere else) follow the same pattern, that
was already present in the majority of files, especially in the py folder.

The rules are as follows.

Naming convention:
* start with the words MICROPY_INCLUDED
* contain the full path to the file
* replace special characters with _

In addition, there are no empty lines before #ifndef, between #ifndef and
one empty line before #endif. #endif is followed by a comment containing
the name of the guard macro.

py/grammar.h cannot use header guards by design, since it has to be
included multiple times in a single C file. Several other files also do not
need header guards as they are only used internally and guaranteed to be
included only once:
* MICROPY_MPHALPORT_H
* mpconfigboard.h
* mpconfigport.h
* mpthreadport.h
* pin_defs_*.h
* qstrdefs*.h
2017-07-18 11:57:39 +10:00
Damien George a8a5d1e8c8 py: Provide mp_decode_uint_skip() to help reduce stack usage.
Taking the address of a local variable leads to increased stack usage, so
the mp_decode_uint_skip() function is added to reduce the need for taking
addresses.  The changes in this patch reduce stack usage of a Python call
by 8 bytes on ARM Thumb, by 16 bytes on non-windowing Xtensa archs, and by
16 bytes on x86-64.  Code size is also slightly reduced on most archs by
around 32 bytes.
2017-06-09 13:36:33 +10:00
Damien George 5640e6dacd py: Provide mp_decode_uint_value to help optimise stack usage.
This has a noticeable improvement on x86-64 and Thumb2 archs, where stack
usage is reduced by 2 machine words in the VM.
2017-03-17 16:50:19 +11:00
Damien George 71a3d6ec3b py: Reduce size of mp_code_state_t structure.
Instead of caching data that is constant (code_info, const_table and
n_state), store just a pointer to the underlying function object from which
this data can be derived.

This helps reduce stack usage for the case when the mp_code_state_t
structure is stored on the stack, as well as heap usage when it's stored
on the heap.

The downside is that the VM becomes a little more complex because it now
needs to derive the data from the underlying function object.  But this
doesn't impact the performance by much (if at all) because most of the
decoding of data is done outside the main opcode loop.  Measurements using
pystone show that little to no performance is lost.

This patch also fixes a nasty bug whereby the bytecode can be reclaimed by
the GC during execution.  With this patch there is always a pointer to the
function object held by the VM during execution, since it's stored in the
mp_code_state_t structure.
2017-03-17 16:39:13 +11:00
Damien George cc4c1adf6e py/showbc: Make sure to set the const_table before printing bytecode. 2017-01-27 12:34:09 +11:00
Damien George f4ee9f8853 py/bc.h: Rename _mp_code_state to _mp_code_state_t.
This rename was missed in the previous patch.
2016-08-27 23:23:51 +10:00
Damien George 581a59a456 py: Rename struct mp_code_state to mp_code_state_t.
Also at _t to mp_exc_stack pre-declaration in struct typedef.
2016-08-27 23:21:00 +10:00
Damien George 1d899e1783 py/bc: Use size_t instead of mp_uint_t to count size of state and args. 2015-12-17 12:33:42 +00:00
Damien George 999cedb90f py: Wrap all obj-ptr conversions in MP_OBJ_TO_PTR/MP_OBJ_FROM_PTR.
This allows the mp_obj_t type to be configured to something other than a
pointer-sized primitive type.

This patch also includes additional changes to allow the code to compile
when sizeof(mp_uint_t) != sizeof(void*), such as using size_t instead of
mp_uint_t, and various casts.
2015-11-29 14:25:35 +00:00
Damien George 254cfa6c31 py: Use uintptr_t instead of mp_uint_t in MP_TAGPTR_* macros. 2015-11-29 14:25:04 +00:00
Damien George 9f6976b74e py: Make mp_setup_code_state take concrete pointer for func arg. 2015-11-29 14:25:04 +00:00
Damien George d8c834c95d py: Add MICROPY_PERSISTENT_CODE_LOAD/SAVE to load/save bytecode.
MICROPY_PERSISTENT_CODE must be enabled, and then enabling
MICROPY_PERSISTENT_CODE_LOAD/SAVE (either or both) will allow loading
and/or saving of code (at the moment just bytecode) from/to a .mpy file.
2015-11-13 12:49:18 +00:00
Damien George 713ea1800d py: Add constant table to bytecode.
Contains just argument names at the moment but makes it easy to add
arbitrary constants.
2015-11-13 12:49:18 +00:00
Damien George 3a3db4dcf0 py: Put all bytecode state (arg count, etc) in bytecode. 2015-11-13 12:49:18 +00:00
Damien George 9b7f583b0c py: Reorganise bytecode layout so it's more structured, easier to edit. 2015-11-13 12:49:18 +00:00
Paul Sokolovsky 2039757b85 vm: Initial support for calling bytecode functions w/o C stack ("stackless"). 2015-04-03 00:03:07 +03:00
Paul Sokolovsky 53e5e0fa28 py: Make old_globals part of mp_code_state structure.
Conceptually it is part of code state, so let it be allocated in the same way
as the rest of state.
2015-02-15 19:24:15 +03:00
Damien George 51dfcb4bb7 py: Move to guarded includes, everywhere in py/ core.
Addresses issue #1022.
2015-01-01 20:32:09 +00:00
Paul Sokolovsky 343266ea51 showbc: Refactor to allow inline instruction printing. 2014-12-27 05:01:21 +02:00
Damien George 74eb44c392 py: Reduce size of VM exception stack element by 1 machine word.
This optimisation reduces the VM exception stack element (mp_exc_stack_t)
by 1 word, by using bit 1 of a pointer to store whether the opcode was a
FINALLY or WITH opcode.  This optimisation was pending, waiting for
maturity of the exception handling code, which has now proven itself.

Saves 1 machine word RAM for each exception (4->3 words per exception).
Increases stmhal code by 4 bytes, and decreases unix x64 code by 32
bytes.
2014-12-22 12:49:57 +00:00
Damien George 1084b0f9c2 py: Store bytecode arg names in bytecode (were in own array).
This saves a lot of RAM for 2 reasons:

1. For functions that don't have default values, var args or var kw
args (which is a large number of functions in the general case), the
mp_obj_fun_bc_t type now fits in 1 GC block (previously needed 2 because
of the extra pointer to point to the arg_names array).  So this saves 16
bytes per function (32 bytes on 64-bit machines).

2. Combining separate memory regions generally saves RAM because the
unused bytes at the end of the GC block are saved for 1 of the blocks
(since that block doesn't exist on its own anymore).  So generally this
saves 8 bytes per function.

Tested by importing lots of modules:

- 64-bit Linux gave about an 8% RAM saving for 86k of used RAM.
- pyboard gave about a 6% RAM saving for 31k of used RAM.
2014-10-25 20:23:13 +01:00
Damien George 39dc145478 py: Change [u]int to mp_[u]int_t in qstr.[ch], and some other places.
This should pretty much resolve issue #50.
2014-10-03 19:52:22 +01:00
Damien George 42f3de924b py: Convert [u]int to mp_[u]int_t where appropriate.
Addressing issue #50.
2014-10-03 17:44:14 +00:00
Damien George b534e1b9f1 py: Use variable length encoded uints in more places in bytecode.
Code-info size, block name, source name, n_state and n_exc_stack now use
variable length encoded uints.  This saves 7-9 bytes per bytecode
function for most functions.
2014-09-04 14:44:01 +01:00
Damien George 3c658a4e75 py: Fix bug where GC collected native/viper/asm function data.
Because (for Thumb) a function pointer has the LSB set, pointers to
dynamic functions in RAM (eg native, viper or asm functions) were not
being traced by the GC.  This patch is a comprehensive fix for this.

Addresses issue #820.
2014-08-24 16:28:17 +01:00
Damien George 40f3c02682 Rename machine_(u)int_t to mp_(u)int_t.
See discussion in issue #50.
2014-07-03 13:25:24 +01:00
Paul Sokolovsky f77d0c5bb3 objgenerator: First iteration of refactor to use mp_setup_code_state(). 2014-06-11 20:43:47 +03:00
Damien George aabd83ea20 py: Merge mp_execute_bytecode into fun_bc_call.
This reduces stack usage by 16 words (64 bytes) for stmhal/ port.

See issue #640.
2014-06-07 14:16:08 +01:00