Commit Graph

271 Commits

Author SHA1 Message Date
Pepijn de Vos 72e9318325 py/emitnative: Explicitly compare comparison ops in binary_op emitter.
Without this it's possible to get a compiler error about the comparison
always being true, because MP_BINARY_OP_LESS is 0.  And it seems that gcc
optimises these 6 equality comparisons into the same size machine code as
before.
2023-02-27 10:25:39 +11:00
Damien George 910f579403 py/emitnative: Initialise locals as Python object type for native code.
In @micropython.native code the types of variables and expressions are
always Python objects, so they can be initialised as such.  This prevents
problems with compiling optimised code like while-loops where a local may
be referenced before it is assigned to.

Signed-off-by: Damien George <damien@micropython.org>
2022-12-16 11:44:10 +11:00
Damien George 0698dd72ea py/emitnative: Ensure load_subscr does not clobber existing REG_ARG_2.
Follow up from a similar fix in 426785a19e

Fixes issue #6314.

Signed-off-by: Damien George <damien@micropython.org>
2022-11-11 12:25:32 +11:00
Jim Mussared 9714a0ead5 py/emitnative: Fix STORE_ATTR viper code-gen when value is not a pyobj.
There was a missing call to MP_F_CONVERT_NATIVE_TO_OBJ.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2022-07-12 17:18:27 +10:00
Damien George a506335524 py/emit: Suppress unreachable bytecode/native code that follows jump.
This new logic tracks when an unconditional jump/raise occurs in the
emitted code stream (bytecode or native machine code) and suppresses all
subsequent code, until a label is assigned.  This eliminates a lot of
cases of dead code, with relatively simple logic.

This commit combined with the previous one (that removed the existing
dead-code finding logic) has the following code size change:

       bare-arm:   -16 -0.028%
    minimal x86:   -60 -0.036%
       unix x64:  -368 -0.070%
    unix nanbox:   -80 -0.017%
          stm32:  -204 -0.052% PYBV10
         cc3200:    +0 +0.000%
        esp8266:  -232 -0.033% GENERIC
          esp32:  -224 -0.015% GENERIC[incl -40(data)]
         mimxrt:  -192 -0.054% TEENSY40
     renesas-ra:  -200 -0.032% RA6M2_EK
            nrf:   +28 +0.015% pca10040
            rp2:  -256 -0.050% PICO
           samd:   -12 -0.009% ADAFRUIT_ITSYBITSY_M4_EXPRESS

Signed-off-by: Damien George <damien@micropython.org>
2022-06-20 22:28:18 +10:00
Damien George e85a096302 py/emit: Remove logic to detect last-emit-was-return-value.
This optimisation to remove dead code is not as good as it could be.

Signed-off-by: Damien George <damien@micropython.org>
2022-06-20 22:28:18 +10:00
Damien George a5324a1074 py/asmthumb: Make ARMv7-M instruction use dynamically selectable.
This commit adjusts the asm_thumb_xxx functions so they can be dynamically
configured to use ARMv7-M instructions or not.  This is available when
MICROPY_DYNAMIC_COMPILER is enabled, and then controlled by the value of
mp_dynamic_compiler.native_arch.

If MICROPY_DYNAMIC_COMPILER is disabled the previous behaviour is retained:
the functions emit ARMv7-M instructions only if MICROPY_EMIT_THUMB_ARMV7M
is enabled.

Signed-off-by: Damien George <damien@micropython.org>
2022-05-23 23:01:12 +10:00
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 7883ae413d py/emitnative: Provide dedicated local for exception unwind handler ptr.
This eliminates the need to save and restore the exception unwind handler
pointer when calling nlr_push.

Signed-off-by: Damien George <damien@micropython.org>
2022-05-19 17:31:56 +10:00
Damien George b608964804 py/emitnative: Simplify generation of code that loads prelude pointer.
It's possible to use REG_PARENT_ARG_1 instead of REG_LOCAL_3.

Signed-off-by: Damien George <damien@micropython.org>
2022-05-19 17:31:56 +10:00
Damien George 8588525868 py/compile: De-duplicate constant objects in module's constant table.
The recent rework of bytecode made all constants global with respect to the
module (previously, each function had its own constant table).  That means
the constant table for a module is shared among all functions/methods/etc
within the module.

This commit add support to the compiler to de-duplicate constants in this
module constant table.  So if a constant is used more than once -- eg 1.0
or (None, None) -- then the same object is reused for all instances.

For example, if there is code like `print(1.0, 1.0)` then the parser will
create two independent constants 1.0 and 1.0.  The compiler will then (with
this commit) notice they are the same and only put one of them in the
constant table.  The bytecode will then reuse that constant twice in the
print expression.  That allows the second 1.0 to be reclaimed by the GC,
also means the constant table has one less entry so saves a word.

Signed-off-by: Damien George <damien@micropython.org>
2022-05-18 15:23:11 +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 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
Damien George b8d959d6cf Revert "py/emitnative: Don't store prelude at end of machine code if..."
This reverts commit 7e8222ae06.

The prelude data must exist somewhere in the native code so load_raw_code
and mpy-tool.py can access and parse it.

Signed-off-by: Damien George <damien@micropython.org>
2022-04-14 14:06:38 +10:00
David Lechner 1e99d29f36 py/runtime: Allow multiple **args in a function call.
This is a partial implementation of PEP 448 to allow multiple ** unpackings
when calling a function or method.

The compiler is modified to encode the argument as a None: obj key-value
pair (similar to how regular keyword arguments are encoded as str: obj
pairs).  The extra object that was pushed on the stack to hold a single **
unpacking object is no longer used and is removed.

The runtime is modified to decode this new format.

Signed-off-by: David Lechner <david@pybricks.com>
2022-03-31 16:54:00 +11:00
Damien George 7e8222ae06 py/emitnative: Don't store prelude at end of machine code if not needed.
Signed-off-by: Damien George <damien@micropython.org>
2022-03-30 16:32:17 +11:00
Damien George 538c3c0a55 py: Change jump opcodes to emit 1-byte jump offset when possible.
This commit introduces changes:

- All jump opcodes are changed to have variable length arguments, of either
  1 or 2 bytes (previously they were fixed at 2 bytes).  In most cases only
  1 byte is needed to encode the short jump offset, saving bytecode size.

- The bytecode emitter now selects 1 byte jump arguments when the jump
  offset is guaranteed to fit in 1 byte.  This is achieved by checking if
  the code size changed during the last pass and, if it did (if it shrank),
  then requesting that the compiler make another pass to get the correct
  offsets of the now-smaller code.  This can continue multiple times until
  the code stabilises.  The code can only ever shrink so this iteration is
  guaranteed to complete.  In most cases no extra passes are needed, the
  original 4 passes are enough to get it right by the 4th pass (because the
  2nd pass computes roughly the correct labels and the 3rd pass computes
  the correct size for the jump argument).

This change to the jump opcode encoding reduces .mpy files and RAM usage
(when bytecode is in RAM) by about 2% on average.

The performance of the VM is not impacted, at least within measurment of
the performance benchmark suite.

Code size is reduced for builds that include a decent amount of frozen
bytecode.  ARM Cortex-M builds without any frozen code increase by about
350 bytes.

Signed-off-by: Damien George <damien@micropython.org>
2022-03-28 15:41:38 +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 426785a19e py/emitnative: Ensure load_subscr does not clobber existing REG_RET.
Fixes issue #7782, and part of issue #6314.

Signed-off-by: Damien George <damien@micropython.org>
2021-09-13 22:30:24 +10:00
Jim Mussared 0e3752e82a py/emitnative: Ensure stack settling is safe mid-branch.
And add a test for the case where REG_RET could be in use.

Fixes #7523.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2021-07-19 23:18:59 +10:00
Damien George d0227d5862 py/emitnative: Reuse need_reg_all func in need_stack_settled.
To reduce code size and code duplication.

Signed-off-by: Damien George <damien@micropython.org>
2021-07-19 23:18:13 +10:00
Damien George 5176a2d732 py/emitnative: Fix x86-64 emitter to generate correct 8/16-bit stores.
Fixes issue #6643.

Signed-off-by: Damien George <damien@micropython.org>
2021-05-20 23:43:25 +10:00
graham sanderson 794df0f1d5 py/emitnative: Support binary ops on ARMv6M without use of ite instr. 2021-01-29 23:57:10 +11:00
Damien George c9f4c5acd6 py/emitnative: Ensure encoding to load prelude_offset doesn't change sz.
Based on change made by Graham Sanderson.

Signed-off-by: Damien George <damien@micropython.org>
2021-01-29 23:57:10 +11:00
Damien George 41fa8b5482 py/emitnative: Implement binary operations for viper uint operands.
uint types in viper mode can now be used for all binary operators except
floor-divide and modulo.

Fixes issue #1847 and issue #6177.

Signed-off-by: Damien George <damien@micropython.org>
2020-06-27 00:24:04 +10:00
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
Damien George a1b18b3ba7 py: Removing dangling "else" to improve code format consistency. 2020-02-28 10:29:27 +11:00
Jim Mussared 888ddb81dd py/emitnative: Stop after finding an unwind target.
The loop searches backwards for a target, but doesn't stop after finding
the first result, meaning that it'll always end up at the outermost
exception handler.
2020-01-27 13:22:03 +11:00
Jim Mussared 0de304e7da py/emitnative: Use NULL for pending exception (not None).
This previously made the native emitter incompatible with the bytecode
emitter, and mp_resume (and subsequently mp_obj_generator_resume) expects
the bytecode emitter behavior (i.e. throw==NULL).
2020-01-27 13:21:49 +11:00
Damien George 360d972c16 py/nativeglue: Add new header file with native function table typedef. 2019-12-12 20:15:28 +11:00
Thea Flowers f0e4677f0d py/emitnative: Fix typo, REG_PARENT_ARG_RET should be REG_PARENT_RET. 2019-11-07 12:30:47 +11:00
Damien George 9adedce42e py: Add new Xtensa-Windowed arch for native emitter.
Enabled via the configuration MICROPY_EMIT_XTENSAWIN.
2019-10-05 13:44:53 +10:00
Damien George 306ec5369a py/emitnative: Add support for archs that cannot read executable data.
In which case place the native function prelude in a bytes object, linked
from the const_table of that function.  An architecture should define
N_PRELUDE_AS_BYTES_OBJ to 1 before including py/emitnative.c to emit
correct machine code, then enable MICROPY_EMIT_NATIVE_PRELUDE_AS_BYTES_OBJ
so the runtime can correctly handle the prelude being in a bytes object.
2019-10-05 13:42:39 +10:00
Damien George 3504edc804 py/emitnative: Add support for using setjmp with native emitter.
To enable this feature the N_NLR_SETJMP macro should be set to 1 before
including py/emitnative.c.
2019-10-05 13:41:58 +10:00
Damien George 4107597b84 py/emitnative: Add support for archs with windowed registers.
Such that args/return regs for the parent are different to args/return regs
for child calls.  For an architecture to use this feature it should define
the REG_PARENT_xxx macros before including py/emitnative.c.
2019-10-05 13:41:14 +10:00
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 b596638b9b mpy-cross: Set number of registers in nlr_buf_t based on native arch.
Fixes #5059.  Done in collaboration with Jim Mussared.
2019-09-26 15:53:05 +10:00
Damien George 74503107a7 py/emitnative: Factor sizeof/offsetof calculations to macros. 2019-09-26 15:52:19 +10:00
Damien George a4f1d82757 py/nativeglue: Remove dependency on mp_fun_table in dyn-compiler mode.
mpy-cross uses MICROPY_DYNAMIC_COMPILER and MICROPY_EMIT_NATIVE but does
not actually need to execute native functions, and does not need
mp_fun_table.  This commit makes it so mp_fun_table and all its entries are
not built when MICROPY_DYNAMIC_COMPILER is enabled, significantly reducing
the size of the mpy-cross executable and allowing it to be built on more
machines/OS's.
2019-05-29 21:17:29 +10:00
Jun Wu 089c9b71d1 py: remove "if (0)" and "if (false)" branches.
Prior to this commit, building the unix port with `DEBUG=1` and
`-finstrument-functions` the compilation would fail with an error like
"control reaches end of non-void function".  This change fixes this by
removing the problematic "if (0)" branches.  Not all branches affect
compilation, but they are all removed for consistency.
2019-05-06 18:28:28 +10:00
Damien George 5ea38e4d74 py/native: Improve support for bool type in viper functions.
Variables with type bool now act more like an int, and there is proper
casting to/from Python objects.
2019-05-03 23:18:30 +10:00
Damien George d9d92f27d7 py/compile: Add support to select the native emitter at runtime. 2019-03-14 12:22:25 +11:00
Damien George 3b973a5658 py: Move mp_native_type_from_qstr() from emitnative.c to nativeglue.c. 2019-03-14 12:22:25 +11:00
Damien George 1396a026be py: Add support to save native, viper and asm code to .mpy files.
This commit adds support for saving and loading .mpy files that contain
native code (native, viper and inline-asm).  A lot of the ground work was
already done for this in the form of removing pointers from generated
native code.  The changes here are mainly to link in qstr values to the
native code, and change the format of .mpy files to contain native code
blocks (possibly mixed with bytecode).

A top-level summary:

- @micropython.native, @micropython.viper and @micropython.asm_thumb/
  asm_xtensa are now allowed in .py files when compiling to .mpy, and they
  work transparently to the user.

- Entire .py files can be compiled to native via mpy-cross -X emit=native
  and for the most part the generated .mpy files should work the same as
  their bytecode version.

- The .mpy file format is changed to 1) specify in the header if the file
  contains native code and if so the architecture (eg x86, ARMV7M, Xtensa);
  2) for each function block the kind of code is specified (bytecode,
  native, viper, asm).

- When native code is loaded from a .mpy file the native code must be
  modified (in place) to link qstr values in, just like bytecode (see
  py/persistentcode.c:arch_link_qstr() function).

In addition, this now defines a public, native ABI for dynamically loadable
native code generated by other languages, like C.
2019-03-08 15:53:05 +11:00
Damien George 3986820912 py/emitnative: Adjust accounting of size of const_table.
n_obj no longer includes a count for mp_fun_table to make it a bit simpler.
2019-03-08 15:53:04 +11:00
Damien George 205edb4305 py/emitnative: Provide concentrated points of qstr emit. 2019-03-08 15:53:04 +11:00
Damien George 01a1f31f67 py/emitnative: Consolidate where HASCONSTS is set to load-const-obj fun.
Simplifies the code and fixes handling of the Ellipsis const in native code
generation (which also needs the constant table so must set this flag).
2019-03-08 15:53:04 +11:00