Commit Graph

88 Commits

Author SHA1 Message Date
Jeff Epler 566688b028
fix mpy magic numbers 2023-09-22 13:50:35 -05:00
Jeff Epler 60fa26022b
build fixes for persistent code 2023-09-22 10:39:41 -05:00
Dan Halbert 2c0fa0f7dc initial merge from v1.20.0; just satisifying conflicts 2023-09-19 11:10:12 -04:00
Jeff Epler 0cab3359df
ignore some cast-align diagnostics 2023-08-20 14:26:48 -05:00
Jeff Epler a94301122a
Make natmods work again.
And put back our magic number, because our bytecode format differs
from upstream

drop btree & framebuf natmods, they had additional problems I didn't
want to fix right now.
2023-08-19 16:59:13 -05:00
Dan Halbert 0d4bc8c163 initial v1.19.1 merge; not compiled yet 2023-08-01 13:50:05 -04:00
Damien George 2283b6d68f py: Pass in address to compiled module instead of returning it.
This change makes it so the compiler and persistent code loader take a
mp_compiled_module_t* as their last argument, instead of returning this
struct.  This eliminates a duplicate context variable for all callers of
these functions (because the context is now stored in the
mp_compiled_module_t by the caller), and also eliminates any confusion
about which context to use after the mp_compile_to_raw_code or
mp_raw_code_load function returns (because there is now only one context,
that stored in mp_compiled_module_t.context).

Reduces code size by 16 bytes on ARM Cortex-based ports.

Signed-off-by: Damien George <damien@micropython.org>
2022-12-08 12:27:23 +11:00
Jim Mussared 1ba0e8ff96 py/persistentcode: Only emit sub-version if generated code has native.
In order for v1.19.1 to load a .mpy, the formerly-feature-flags which are
now used for the sub-version must be zero.

The sub-version is only used to indicate a native version change, so it
should be zero when emitting bytecode-only .mpy files.

This work was funded through GitHub Sponsors.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2022-10-25 14:57:04 +11:00
Dan Halbert 86a0f9a861 save about 112 bytes 2022-10-09 19:22:39 -04:00
Damien George fb77be1506 py: Include filename in errors from loading/saving files via "open".
This improves error messages in mpy-cross:
- When loading a .py file that doesn't exist (or can't be opened) it now
  includes the filename in the OSError.
- When saving a .mpy file that can't be opened it now raises an exception
  (prior, it would silently fail), and includes the filename in the
  OSError.

Signed-off-by: Damien George <damien@micropython.org>
2022-09-19 23:27:08 +10:00
Jim Mussared d94141e147 py/persistentcode: Introduce .mpy sub-version.
The intent is to allow us to make breaking changes to the native ABI (e.g.
changes to dynruntime.h) without needing the bytecode version to increment.

With this commit the two bits previously used for the feature flags (but
now unused as of .mpy version 6) encode a sub-version.  A bytecode-only
.mpy file can be loaded as long as MPY_VERSION matches, but a native .mpy
(i.e. one with an arch set) must also match MPY_SUB_VERSION.  This allows 3
additional updates to the native ABI per bytecode revision.

The sub-version is set to 1 because the previous commits that changed the
layout of mp_obj_type_t have changed the native ABI.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
Signed-off-by: Damien George <damien@micropython.org>
2022-09-19 23:19:55 +10:00
Andrew Leech d521899e18 py/persistentcode: Clarify ValueError when native emitter disabled. 2022-08-29 12:38:49 +10:00
Jim Mussared 3a910b1565 py/objstr: Optimise mp_obj_new_str_from_vstr for known-safe strings.
The new `mp_obj_new_str_from_utf8_vstr` can be used when you know you
already have a unicode-safe string.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2022-08-26 16:44:35 +10:00
Jim Mussared 8a0ee5a5c0 py/objstr: Split mp_obj_str_from_vstr into bytes/str versions.
Previously the desired output type was specified.  Now make the type part
of the function name.  Because this function is used in a few places this
saves code size due to smaller call-site.

This makes `mp_obj_new_str_type_from_vstr` a private function of objstr.c
(which is almost the only place where the output type isn't a compile-time
constant).

This saves ~140 bytes on PYBV11.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2022-08-26 16:43:55 +10:00
David Lechner a98aa66df6 py/persistentcode: Use MP_REGISTER_ROOT_POINTER().
This uses MP_REGISTER_ROOT_POINTER() to register track_reloc_code_list
instead of using a conditional inside of mp_state_vm_t.

Signed-off-by: David Lechner <david@pybricks.com>
2022-07-18 13:52:01 +10:00
Damien George 627ba38154 py/parsenum: Optimise when building with complex disabled.
To reduce code size when MICROPY_PY_BUILTINS_COMPLEX is disabled.

Signed-off-by: Damien George <damien@micropython.org>
2022-06-23 11:46:47 +10:00
Damien George b37b578214 py/persistentcode: Remove remaining native qstr linking support.
Support for architecture-specific qstr linking was removed in
d4d53e9e11, where native code was changed to
access qstr values via qstr_table.  The only remaining use for the special
qstr link table in persistentcode.c is to support native module written in
C, linked via mpy_ld.py.  But native modules can also use the standard
module-level qstr_table (and obj_table) which was introduced in the .mpy
file reworking in f2040bfc7e.

This commit removes the remaining native qstr liking support in
persistentcode.c's load_raw_code function, and adds two new relocation
options for constants.qstr_table and constants.obj_table.  mpy_ld.py is
updated to use these relocations options instead of the native qstr link
table.

Signed-off-by: Damien George <damien@micropython.org>
2022-06-07 13:19:55 +10:00
Scott Shawcroft 9d10a3da66
Conditionalize LTO 2022-05-27 12:59:54 -07:00
Damien George d4d53e9e11 py/emitnative: Access qstr values using indirection table qstr_table.
This changes the native emitter to access qstr values using the qstr
indirection table qstr_table, but only when generating native code that
will be saved to a .mpy file.  This makes the resulting native code fully
static, ie it does not require any fix-ups or rewriting when it is
imported.

The performance of native code is more or less unchanged.  Benchmark
results on PYBv1.0 (using --via-mpy and --emit native) are:

N=100 M=100          baseline -> this-commit     diff      diff% (error%)
bm_chaos.py            407.16 ->     411.85 :   +4.69 =  +1.152% (+/-0.01%)
bm_fannkuch.py         100.89 ->     101.20 :   +0.31 =  +0.307% (+/-0.01%)
bm_fft.py             3521.17 ->    3441.72 :  -79.45 =  -2.256% (+/-0.00%)
bm_float.py           6707.29 ->    6644.83 :  -62.46 =  -0.931% (+/-0.00%)
bm_hexiom.py            55.91 ->      55.41 :   -0.50 =  -0.894% (+/-0.00%)
bm_nqueens.py         5343.54 ->    5326.17 :  -17.37 =  -0.325% (+/-0.00%)
bm_pidigits.py         603.89 ->     632.79 :  +28.90 =  +4.786% (+/-0.33%)
core_qstr.py            64.18 ->      64.09 :   -0.09 =  -0.140% (+/-0.01%)
core_yield_from.py     313.61 ->     311.11 :   -2.50 =  -0.797% (+/-0.03%)
misc_aes.py            654.29 ->     659.75 :   +5.46 =  +0.834% (+/-0.02%)
misc_mandel.py        4205.10 ->    4272.08 :  +66.98 =  +1.593% (+/-0.01%)
misc_pystone.py       3077.79 ->    3128.39 :  +50.60 =  +1.644% (+/-0.01%)
misc_raytrace.py       388.45 ->     393.71 :   +5.26 =  +1.354% (+/-0.01%)
viper_call0.py         576.83 ->     566.76 :  -10.07 =  -1.746% (+/-0.05%)
viper_call1a.py        550.39 ->     540.12 :  -10.27 =  -1.866% (+/-0.11%)
viper_call1b.py        438.32 ->     432.09 :   -6.23 =  -1.421% (+/-0.11%)
viper_call1c.py        442.96 ->     436.11 :   -6.85 =  -1.546% (+/-0.08%)
viper_call2a.py        536.31 ->     527.37 :   -8.94 =  -1.667% (+/-0.04%)
viper_call2b.py        378.99 ->     377.50 :   -1.49 =  -0.393% (+/-0.08%)

Signed-off-by: Damien George <damien@micropython.org>
2022-05-23 15:43:06 +10:00
Damien George 1fb01bd6c5 py/emitnative: Put a pointer to the native prelude in child_table array.
Some architectures (like esp32 xtensa) cannot read byte-wise from
executable memory.  This means the prelude for native functions -- which is
usually located after the machine code for the native function -- must be
placed in separate memory that can be read byte-wise.  Prior to this commit
this was achieved by enabling N_PRELUDE_AS_BYTES_OBJ for the emitter and
MICROPY_EMIT_NATIVE_PRELUDE_AS_BYTES_OBJ for the runtime.  The prelude was
then placed in a bytes object, pointed to by the module's constant table.

This behaviour is changed by this commit so that a pointer to the prelude
is stored either in mp_obj_fun_bc_t.child_table, or in
mp_obj_fun_bc_t.child_table[num_children] if num_children > 0.  The reasons
for doing this are:

1. It decouples the native emitter from runtime requirements, the emitted
   code no longer needs to know if the system it runs on can/can't read
   byte-wise from executable memory.

2. It makes all ports have the same emitter behaviour, there is no longer
   the N_PRELUDE_AS_BYTES_OBJ option.

3. The module's constant table is now used only for actual constants in the
   Python code.  This allows further optimisations to be done with the
   constants (eg constant deduplication).

Code size change for those ports that enable the native emitter:
   unix x64:   +80 +0.015%
      stm32:   +24 +0.004% PYBV10
    esp8266:   +88 +0.013% GENERIC
      esp32:   -20 -0.002% GENERIC[incl -112(data)]
        rp2:   +32 +0.005% PICO

Signed-off-by: Damien George <damien@micropython.org>
2022-05-17 16:44:49 +10:00
Damien George b295b6f1f3 py/persistentcode: Remove obsolete comment about qstr window size.
This was made obsolete in f2040bfc7e

Signed-off-by: Damien George <damien@micropython.org>
2022-05-17 12:51:54 +10:00
Damien George 4ca96983ff py/persistentcode: Support loading and saving tuples in .mpy files.
Signed-off-by: Damien George <damien@micropython.org>
2022-04-14 23:52:14 +10:00
Damien George 42d0bd2c17 py/persistentcode: Define enum values for obj types instead of letters.
To keep the separate parts of the code that use these values in sync.  And
make it easier to add new object types.

Signed-off-by: Damien George <damien@micropython.org>
2022-04-14 22:44:04 +10:00
David Lechner 768879f999 py/smallint: Introduce MP_SMALL_INT_BITS macro.
This adds a new MP_SMALL_INT_BITS macro that is a compile-time constant
that contains the number of bits available in an MP_SMALL_INT.

We can use this in place of the runtime function mp_small_int_bits().

Signed-off-by: David Lechner <david@pybricks.com>
2022-03-25 12:23:43 +11:00
Damien George 962ad8622e py/parse: Handle check for target small-int size in parser.
This means that all constants for EMIT_ARG(load_const_obj, obj) are created
in the parser (rather than some in the compiler).

Signed-off-by: Damien George <damien@micropython.org>
2022-03-16 00:41:10 +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
James Carr 61a7212b28
Update comment in persistentcode.c
Update comment in mp_raw_code_save so that it matches the code.
2021-05-23 08:57:41 +01:00
Scott Shawcroft 966d25c6a5
Merge MicroPython v1.15 into CircuitPython 2021-05-12 17:51:42 -07:00
Scott Shawcroft e02a26453c
Merge MicroPython 1.14 into CircuitPython 2021-05-11 15:07:40 -07:00
Scott Shawcroft 42f4065c8a
Merge remote-tracking branch 'adafruit/main' into merge_1.13 2021-05-06 11:17:53 -07:00
Scott Shawcroft 3fda0c0a1b
Fix board builds and use MP_ERROR_TEXT in py and extmod 2021-05-05 17:51:52 -07:00
Jeff Epler ef3ec93c8b Change the first byte of CircuitPython 'mpy' files to "C"
.. and also distinguish CircuitPython better in `mpy-cross --version`
2021-05-05 18:06:06 -05:00
Scott Shawcroft f0bb26d70f
Merge MicroPython 1.13 into CircuitPython 2021-05-04 18:06:33 -07:00
Scott Shawcroft b35fa44c8a
Merge MicroPython 1.12 into CircuitPython 2021-05-03 14:01:18 -07:00
Jeff Epler dfa7c3d32d codeformat: Fix handling of `**`
After discussing with danh, I noticed that `a/**/b` would not match `a/b`.

After correcting this and re-running "pre-commit run --all", additional
files were reindented, including the codeformat script itself.
2021-04-30 15:30:13 -05:00
Scott Shawcroft 76033d5115
Merge MicroPython v1.11 into CircuitPython 2021-04-26 15:47:41 -07:00
microDev a52eb88031
run code formatting script 2021-03-15 19:27:36 +05:30
Damien George ad4656b861 all: Rename BYTES_PER_WORD to MP_BYTES_PER_OBJ_WORD.
The "word" referred to by BYTES_PER_WORD is actually the size of mp_obj_t
which is not always the same as the size of a pointer on the target
architecture.  So rename this config value to better reflect what it
measures, and also prefix it with MP_.

For uses of BYTES_PER_WORD in setting the stack limit this has been
changed to sizeof(void *), because the stack usually grows with
machine-word sized values (eg an nlr_buf_t has many machine words in it).

Signed-off-by: Damien George <damien@micropython.org>
2021-02-04 22:46:42 +11:00
David CARLIER cb30928ac8 py/persistentcode: Introduce MICROPY_PERSISTENT_CODE_SAVE_FILE option.
This should be enabled when the mp_raw_code_save_file function is needed.

It is enabled for mpy-cross, and a check for defined(__APPLE__) is added to
cover Mac M1 systems.
2021-01-30 15:13:24 +11:00
Damien George 9883d8e818 py/persistentcode: Maintain root ptr list of imported native .mpy code.
On ports where normal heap memory can contain executable code (eg ARM-based
ports such as stm32), native code loaded from an .mpy file may be reclaimed
by the GC because there's no reference to the very start of the native
machine code block that is reachable from root pointers (only pointers to
internal parts of the machine code block are reachable, but that doesn't
help the GC find the memory).

This commit fixes this issue by maintaining an explicit list of root
pointers pointing to native code that is loaded from an .mpy file.  This
is not needed for all ports so is selectable by the new configuration
option MICROPY_PERSISTENT_CODE_TRACK_RELOC_CODE.  It's enabled by default
if a port does not specify any special functions to allocate or commit
executable memory.

A test is included to test that native code loaded from an .mpy file does
not get reclaimed by the GC.

Fixes #6045.

Signed-off-by: Damien George <damien@micropython.org>
2020-08-02 22:34:09 +10:00
Diego Elio Pettenò 34b4993d63 Add license to some obvious files. 2020-07-06 19:16:25 +01:00
Jim Mussared def76fe4d9 all: Use MP_ERROR_TEXT for all error messages. 2020-04-05 15:02:06 +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
David Lechner 62537a18e3 py: Release GIL during syscalls in reader and writer code.
This releases the GIL during POSIX system calls that could block.
2020-01-26 23:26:31 +11:00
Damien George 0bd7d1f7f0 py/persistentcode: Move loading of rodata/bss to before obj/raw-code.
This makes the loading of viper-code-with-relocations a bit neater and
easier to understand, by treating the rodata/bss like a special object to
be loaded into the constant table (which is how it behaves).
2019-12-17 13:22:11 +11:00
Damien George 9ac949cdbd py/persistentcode: Make ARM Thumb archs support multiple sub-archs. 2019-12-12 20:15:28 +11:00
Damien George 360d972c16 py/nativeglue: Add new header file with native function table typedef. 2019-12-12 20:15:28 +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 f4601af10a py/persistentcode: Move declarations for .mpy header from .c to .h file. 2019-11-04 16:00:05 +11:00
Damien George 23f0691fdd py/persistentcode: Make .mpy more compact with qstr directly in prelude.
Instead of encoding 4 zero bytes as placeholders for the simple_name and
source_file qstrs, and storing the qstrs after the bytecode, store the
qstrs at the location of these 4 bytes.  This saves 4 bytes per bytecode
function stored in a .mpy file (for example lcd160cr.mpy drops by 232
bytes, 4x 58 functions).  And resulting code size is slightly reduced on
ports that use this feature.
2019-10-15 16:56:27 +11:00