Commit Graph

65 Commits

Author SHA1 Message Date
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
Paul Sokolovsky a4ac5b9f05 showbc: Make sure it's possible to trace MAKE_FUNCTION arg to actual bytecode. 2014-06-03 01:26:51 +03:00
Paul Sokolovsky b4ebad3310 vm: Factor out structure with code execution state and pass it around.
This improves stack usage in callers to mp_execute_bytecode2, and is step
forward towards unifying execution interface for function and generators
(which is important because generators don't even support full forms
of arguments passing (keywords, etc.)).
2014-05-31 18:22:01 +03:00
Damien George 3417bc2f25 py: Rename byte_code to bytecode everywhere.
bytecode is the more widely used.  See issue #590.
2014-05-10 10:36:38 +01:00
Damien George 04b9147e15 Add license header to (almost) all files.
Blanket wide to all .c and .h files.  Some files originating from ST are
difficult to deal with (license wise) so it was left out of those.

Also merged modpyb.h, modos.h, modstm.h and modtime.h in stmhal/.
2014-05-03 23:27:38 +01:00
Paul Sokolovsky c5e32c6995 vm: Add rudimentary bytecode execution tracing capability. 2014-04-23 03:46:00 +03:00
Paul Sokolovsky f39d3b93da py: Implement support for generalized generator protocol.
Iterators and ducktype objects can now be arguments of yield from.
2014-03-30 23:30:16 +03:00
Damien George 89f94b51ab py: Rename mp_exc_stack to mp_exc_stack_t. 2014-03-30 00:57:09 +00:00
Paul Sokolovsky 0c904df8e6 vm: Save current active exception on opening new try block.
Required to reraise correct exceptions in except block, regardless if more
try blocks with active exceptions happen in the same except block.

P.S. This "automagic reraise" appears to be quite wasteful feature of Python
- we need to save pending exception just in case it *might* be reraised.
Instead, programmer could explcitly capture exception to a variable using
"except ... as var", and reraise that. So, consider disabling argless raise
support as an optimization.
2014-03-30 01:01:35 +02:00
Damien George bee17b00e3 py: Put n_state for bytecode in the bytecode prelude.
Rationale: setting up the stack (state for locals and exceptions) is
really part of the "code", it's the prelude of the function.  For
example, native code adjusts the stack pointer on entry to the function.
Native code doesn't need to know n_state for any other reason.  So
putting the state size in the bytecode prelude is sensible.

It reduced ROM usage on STM by about 30 bytes :)  And makes it easier to
pass information about the bytecode between functions.
2014-03-27 11:07:04 +00:00
Paul Sokolovsky 1673420053 vm: Abstract working with tagged pointers in VM using macro accessors.
Based on issues raised during recent review and inconsistency of different
implementations.
2014-03-23 21:41:29 +02:00