This is for efficiency, so we don't need to subtract 1 from the ip
before storing it to code_state->ip. It saves a lot of ROM bytes on
unix and stmhal.
Mirroring ip to a volatile memory variable for each opcode is an expensive
operation. For quite a lot of often executed opcodes like stack manipulation
or jumps, exceptions cannot actually happen. So, record ip only for opcode
where that's possible.
This patch makes the MICROPY_PY_BUILTINS_SLICE compile-time option
fully disable the builtin slice operation (when set to 0). This
includes removing the slice sytanx from the grammar. Now, enabling
slice costs 4228 bytes on unix x64, and 1816 bytes on stmhal.
This patch makes MICROPY_PY_BUILTINS_SET compile-time option fully
disable the builtin set object (when set to 0). This includes removing
set constructor/comprehension from the grammar, the compiler and the
emitters. Now, enabling set costs 8168 bytes on unix x64, and 3576
bytes on stmhal.
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.
This patch gives proper SyntaxError exceptions for bad global/nonlocal
declarations. It also reduces code size: 304 bytes on unix x64, 132
bytes on stmhal.
You can now assign to the range end variable and the for-loop still
works correctly. This fully addresses issue #565.
Also fixed a bug with the stack not being fully popped when breaking out
of an optimised for-loop (and it's actually impossible to write a test
for this case!).
This patch adds a configuration option (MICROPY_CAN_OVERRIDE_BUILTINS)
which, when enabled, allows to override all names within the builtins
module. A builtins override dict is created the first time the user
assigns to a name in the builtins model, and then that dict is searched
first on subsequent lookups. Note that this implementation doesn't
allow deleting of names.
This patch also does some refactoring of builtins code, creating the
modbuiltins.c file.
Addresses issue #959.
The function is modeled after traceback.print_exception(), but unbloated,
and put into existing module to save overhead on adding another module.
Compliant traceback.print_exception() is intended to be implemented in
micropython-lib in terms of sys.print_exception().
This change required refactoring mp_obj_print_exception() to take pfenv_t
interface arguments.
Addresses #751.
mp_obj_int_get_truncated is used as a "fast path" int accessor that
doesn't check for overflow and returns the int truncated to the machine
word size, ie mp_int_t.
Use mp_obj_int_get_truncated to fix struct.pack when packing maximum word
sized values.
Addresses issues #779 and #998.
mp_lexer_t type is exposed, mp_token_t type is removed, and simple lexer
functions (like checking current token kind) are now inlined.
This saves 784 bytes ROM on 32-bit unix, 348 bytes on stmhal, and 460
bytes on bare-arm. It also saves a tiny bit of RAM since mp_lexer_t
is a bit smaller. Also will run a bit more efficiently.
Behaviour of array initialisation is subtly different for bytes,
bytearray and array.array when argument has buffer protocol. This patch
gets us CPython conformant (except we allow initialisation of
array.array by buffer with length not a multiple of typecode).
By using the buffer protocol for these array operations, we now allow
addition of memoryview objects, and objects with "incompatible"
typecodes (in this case it just adds bytes naively). This is an
extension to CPython which seems sensible. It also reduces the code
size.
Before, __repl_print__() used libc printf(), while print() used uPy streams
and own printf() implementation. This led to subtle, but confusing
differences in output when just doing "foo" vs "print(foo)" on interactive
prompt.
Currently compilation sporadically fails, because the automatic
dependency gets created *during* the compilation of objects.
OBJ is a auperset of PY_O and the dependencies apply to all objects.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Going from MICROPY_ERROR_REPORTING_NORMAL to
MICROPY_ERROR_REPORTING_TERSE now saves 2020 bytes ROM for ARM Thumb2,
and 2200 bytes ROM for 32-bit x86.
This is about a 2.5% code size reduction for bare-arm.
When compiler optimization has been turned on, gcc knows that this code
block is not going to be executed. But with -O0 it complains about
path_items being used uninitialized.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
This turns failing assertions to type exceptions for things like
b"123".find(...). We still don't support operations like this on bytes
objects (unlike CPython), but at least it no longer crashes.
Eg b"123" + bytearray(2) now works. This patch actually decreases code
size while adding functionality: 32-bit unix down by 128 bytes, stmhal
down by 84 bytes.
Uninitialised struct members get a default value of 0/false, so this is
not strictly needed. But it actually decreases code size because when
all members are initialised the compiler doesn't need to insert a call
to memset to clear everything. In other words, setting 1 extra member
to 0 uses less code than calling memset.
ROM savings in bytes: 32-bit unix: 100; bare-arm: 44; stmhal: 52.
gc.enable/disable are now the same as CPython: they just control whether
automatic garbage collection is enabled or not. If disabled, you can
still allocate heap memory, and initiate a manual collection.
msvc does not treat 1L a 64bit integer hence all occurences of shifting it left or right
result in undefined behaviour since the maximum allowed shift count for 32bit ints is 31.
Forcing the correct type explicitely, stored in MPZ_LONG_1, solves this.
It should be fair to say that almost in all cases where some API call
expects string, it should be also possible to pass byte string. For example,
it should be open/delete/rename file with name as bytestring. Note that
similar change was done quite a long ago to mp_obj_str_get_data().
Support for packages as argument not implemented, but otherwise error and
exit handling should be correct. This for example will allow to do:
pip-micropython install micropython-test.pystone
micropython -m test.pystone
This allows to implement KeyboardInterrupt on unix, and a much safer
ctrl-C in stmhal port. First ctrl-C is a soft one, with hope that VM
will notice it; second ctrl-C is a hard one that kills anything (for
both unix and stmhal).
One needs to check for a pending exception in the VM only for jump
opcodes. Others can't produce an infinite loop (infinite recursion is
caught by stack check).
There is a lot potential in compress bytecodes and make more use of the
coding space. This patch introduces "multi" bytecodes which have their
argument included in the bytecode (by addition).
UNARY_OP and BINARY_OP now no longer take a 1 byte argument for the
opcode. Rather, the opcode is included in the first byte itself.
LOAD_FAST_[0,1,2] and STORE_FAST_[0,1,2] are removed in favour of their
multi versions, which can take an argument between 0 and 15 inclusive.
The majority of LOAD_FAST/STORE_FAST codes fit in this range and so this
saves a byte for each of these.
LOAD_CONST_SMALL_INT_MULTI is used to load small ints between -16 and 47
inclusive. Such ints are quite common and now only need 1 byte to
store, and now have much faster decoding.
In all this patch saves about 2% RAM for typically bytecode (1.8% on
64-bit test, 2.5% on pyboard test). It also reduces the binary size
(because bytecodes are simplified) and doesn't harm performance.
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.
This makes open() and _io.FileIO() more CPython compliant.
The mode kwarg is fully iplemented.
The encoding kwarg is allowed but not implemented; mainly to allow
the tests to specify encoding for CPython, see #874
Also, usocket.readinto(). Known issue is that .readinto() should be available
only for binary files, but micropython uses single method table for both
binary and text files.
Just like they handled in other read*(). Note that behavior of readline()
in case there's no data when it's called is underspecified in Python lib
spec, implemented to behave as read() - return None.
With this patch a port can enable module weak link support and provide
a dict of qstr->module mapping. This mapping is looked up only if an
import fails to find the requested module in the filesystem.
This allows to have the builtin module named, eg, usocket, and provide
a weak link of "socket" to the same module, but this weak link can be
overridden if a file by the name "socket.py" is found in the import
path.
This has benefits all round: code factoring for parse/compile/execute,
proper context save/restore for exec, allow to sepcify globals/locals
for eval, and reduced ROM usage by >100 bytes on stmhal and unix.
Also, the call to mp_parse_compile_execute is tail call optimised for
the import code, so it doesn't increase stack memory usage.
In CPython IOError (and EnvironmentError) is deprecated and aliased to
OSError. All modules that used to raise IOError now raise OSError (or a
derived exception).
In Micro Python we never used IOError (except 1 place, incorrectly) and
so don't need to keep it.
See http://legacy.python.org/dev/peps/pep-3151/ for background.
Viper can now do the following:
def store(p:ptr8, c:int):
p[0] = c
This does a store of c to the memory pointed to by p using a machine
instructions inline in the code.
It seems most sensible to use size_t for measuring "number of bytes" in
malloc and vstr functions (since that's what size_t is for). We don't
use mp_uint_t because malloc and vstr are not Micro Python specific.
mp_parse_node_free now frees the memory associated with non-interned
strings. And the parser calls mp_parse_node_free when discarding a
non-used node (such as a doc string).
Also, the compiler now frees the parse tree explicitly just before it
exits (as opposed to relying on the caller to do this).
Addresses issue #708 as best we can.
Stack is full descending and must be 8-byte aligned. It must start off
pointing to just above the last byte of RAM.
Previously, stack started pointed to last byte of RAM (eg 0x2001ffff)
and so was not 8-byte aligned. This caused a bug in combination with
alloca.
This patch also updates some debug printing code.
Addresses issue #872 (among many other undiscovered issues).
Heap RAM was being allocated to print dicts and do some other types of
iterating. Now these iterations use 1 word of state on the stack.
Deleting elements from a dict was not allowing the value to be reclaimed
by the GC. This is now fixed.
sys.exit always raises SystemExit so doesn't need a special
implementation for each port. If C exit() is really needed, use the
standard os._exit function.
Also initialise mp_sys_path and mp_sys_argv in teensy port.
Eventually, viper wants to be able to use raw pointers to strings and
arrays for efficient access. But for now, let's just load strings as a
Python object so they can be used as normal. This will anyway be
compatible with eventual intended viper behaviour.
Addresses issue #857.
Type representing signed size doesn't have to be int, so use special value
which defaults to SSIZE_MAX, but as it's not defined by C standard (but rather
by POSIX), allow ports to set it.
Previously, mpz was restricted to using at most 15 bits in each digit,
where a digit was a uint16_t.
With this patch, mpz can use all 16 bits in the uint16_t (improvement
to mpn_div was required). This gives small inprovements in speed and
RAM usage. It also yields savings in ROM code size because all of the
digit masking operations become no-ops.
Also, mpz can now use a uint32_t as the digit type, and hence use 32
bits per digit. This will give decent improvements in mpz speed on
64-bit machines.
Test for big integer division added.
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.
This way, the native glue code is only compiled if native code is
enabled (which makes complete sense; thanks to Paul Sokolovsky for
the idea).
Should fix issue #834.
The heap allocation is now exactly as it was before the "faster gc
alloc" patch, but it's still nearly as fast. It is fixed by being
careful to always update the "last free block" pointer whenever the heap
changes (eg free or realloc).
Tested on all tests by enabling EXTENSIVE_HEAP_PROFILING in py/gc.c:
old and new allocator have exactly the same behaviour, just the new one
is much faster.
Recent speed up of GC allocation made the GC have a fragmented heap.
This patch restores "original fragmentation behaviour" whilst still
retaining relatively fast allocation. This patch works because there is
always going to be a single block allocated now and then, which advances
the gc_last_free_atb_index pointer often enough so that the whole heap
doesn't need scanning.
Should address issue #836.
With a file with 1 line (and an error on that line), used to show the
line as number 0. Now shows it correctly as line number 1.
But, when line numbers are disabled, it now prints line number 1 for any
line that has an error (instead of 0 as previously). This might end up
being confusing, but requires extra RAM and/or hack logic to make it
print something special in the case of no line numbers.
These functions are generally 1 machine instruction, and are used in
critical code, so makes sense to have them inline.
Also leave these functions uninverted (ie 0 means enable, 1 means
disable) and provide macro constants if you really need to distinguish
the states. This makes for smaller code as well (combined with
inlining).
Applied to teensy port as well.
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.
This simple patch gives a very significant speed up for memory allocation
with the GC.
Eg, on PYBv1.0:
tests/basics/dict_del.py: 3.55 seconds -> 1.19 seconds
tests/misc/rge_sm.py: 15.3 seconds -> 2.48 seconds
Multiplication of a tuple, list, str or bytes now yields an empty
sequence (instead of crashing). Addresses issue #799
Also added ability to mult bytes on LHS by integer.
Can now index ranges with integers and slices, and reverse ranges
(although reversing is not very efficient).
Not sure how useful this stuff is, but gets us closer to having all of
Python's builtins.
reversed function now implemented, and works for tuple, list, str, bytes
and user objects with __len__ and __getitem__.
Renamed mp_builtin_len to mp_obj_len to make it publically available (eg
for reversed).
This happens for example for zero-size arrays. As .get_buffer() method now
has explicit return value, it's enough to distinguish success vs failure
of getting buffer.
This was a nasty bug to track down. It only had consequences when the
heap size was just the right size to expose the rounding error in the
calculation of the finaliser table size. And, a script had to allocate
a small (1 or 2 cell) object at the very end of the heap. And, this
object must not have a finaliser. And, the initial state of the heap
must have been all bits set to 1. All these conspire on the pyboard,
but only if your run the script fresh (so unused memory is all 1's),
and if your script allocates a lot of small objects (eg 2-char strings
that are not interned).
qstr_init is always called exactly before mp_init, so makes sense to
just have mp_init call it. Similarly with
mp_init_emergency_exception_buf. Doing this makes the ports simpler and
less error prone (ie they can no longer forget to call these).
Reduces by about a factor of 10 on average the amount of RAM needed to
store the line-number to bytecode map in the bytecode prelude.
Using CPython3.4's stdlib for statistics: previously, an average of
13 bytes were used per (bytecode offset, line-number offset) pair, and
now with this improvement, that's down to 1.3 bytes on average.
Large RAM usage before was due to some very large steps in line numbers,
both from the start of the first line in a function way down in the
file, and also functions that have big comments and/or big strings in
them (both cases were significant).
Although the savings are large on average for the CPython stdlib, it
won't have such a big effect for small scripts used in embedded
programming.
Addresses issue #648.
This removes mpz_as_int, since that was a terrible function (it
implemented saturating conversion).
Use mpz_as_int_checked and mpz_as_uint_checked. These now work
correctly (they previously had wrong overflow checking, eg
print(chr(10000000000000)) on 32-bit machine would incorrectly convert
this large number to a small int).
Many OSes/CPUs have affinity to put "user" data into lower half of address
space. Take advantage of that and remap such addresses into full small int
range (including negative part).
If address is from upper half, long int will be used. Previously, small
int was returned for lower quarter of address space, and upper quarter. For
2 middle quarters, long int was used, which is clearly worse schedule than
the above.
The user code should call micropython.alloc_emergency_exception_buf(size)
where size is the size of the buffer used to print the argument
passed to the exception.
With the test code from #732, and a call to
micropython.alloc_emergenncy_exception_buf(100) the following error is
now printed:
```python
>>> import heartbeat_irq
Uncaught exception in Timer(4) interrupt handler
Traceback (most recent call last):
File "0://heartbeat_irq.py", line 14, in heartbeat_cb
NameError: name 'led' is not defined
```
Damien George
Paul Sokolovsky
stijn
Sven Wegener
Dave Hylands
Fabian Vogt
bvernoux