Commit Graph

310 Commits

Author SHA1 Message Date
Damien George
76355c8863 py/vm: Make small optimisation of BUILD_SLICE opcode.
No need to call DECODE_UINT since the value will always be either 2 or 3.
2018-09-27 11:22:33 +10:00
Damien George
b735208403 py/vm: Fix handling of finally-return with complex nested finallys.
Back in 8047340d75 basic support was added in
the VM to handle return statements within a finally block.  But it didn't
cover all cases, in particular when some finally's were active and others
inactive when the "return" was executed.

This patch adds further support for return-within-finally by correctly
managing the currently_in_except_block flag, and should fix all cases.  The
main point is that finally handlers remain on the exception stack even if
they are active (currently being executed), and the unwind return code
should only execute those finally's which are inactive.

New tests are added for the cases which now pass.
2018-09-03 13:08:16 +10:00
Damien George
bace1a16d0 py/objtype: Don't expose mp_obj_instance_attr().
mp_obj_is_instance_type() can be used instead to check for instance types.
2018-06-08 11:48:25 +10:00
Damien George
869024dd6e py/vm: Improve performance of opcode dispatch when using switch stmt.
Before this patch, when using the switch statement for dispatch in the VM
(not computed goto) a pending exception check was done after each opcode.
This is not necessary and this patch makes the pending exception check only
happen when explicitly requested by certain opcodes, like jump.  This
improves performance of the VM by about 2.5% when using the switch.
2018-05-18 11:47:03 +10:00
Damien George
46ce395130 py/vm: Use enum names instead of magic numbers in multi-opcode dispatch. 2018-05-18 11:44:26 +10:00
Damien George
1b7487e519 py/vm: Adjust #if logic for gil_divisor so braces are balanced.
Having balanced braces { and } makes it easier to navigate the function.
2018-05-16 12:33:39 +10:00
Damien George
bc36521386 py/vm: Optimise handling of stackless mode when pystack is enabled.
When pystack is enabled mp_obj_fun_bc_prepare_codestate() will always
return a valid pointer, and if there is no more pystack available then it
will raise an exception (a RuntimeError).  So having pystack enabled with
stackless enabled automatically gives strict stackless mode.  There is
therefore no need to have code for strict stackless mode when pystack is
enabled, and this patch optimises the VM for such a case.
2018-04-04 00:51:10 +10:00
Damien George
c7f880eda3 py/vm: Don't do unnecessary updates of ip and sp variables.
Neither the ip nor sp variables are used again after the execution of the
RAISE_VARARGS opcode, so they don't need to be updated.
2018-04-04 00:46:31 +10:00
Damien George
a9f6d49218 py/vm: Simplify handling of special-case STOP_ITERATION in yield from.
There's no need to have MP_OBJ_NULL a special case, the code can re-use
the MP_OBJ_STOP_ITERATION value to signal the special case and the VM can
detect this with only one check (for MP_OBJ_STOP_ITERATION).
2018-02-27 15:48:09 +11:00
Damien George
22ade2f5c4 py/vm: Fix case of handling raised StopIteration within yield from.
This patch concerns the handling of an NLR-raised StopIteration, raised
during a call to mp_resume() which is handling the yield from opcode.

Previously, commit 6738c1dded introduced code
to handle this case, along with a test.  It seems that it was lucky that
the test worked because the code did not correctly handle the stack pointer
(sp).

Furthermore, commit 79d996a57b improved the
way mp_resume() propagated certain exceptions: it changed raising an NLR
value to returning MP_VM_RETURN_EXCEPTION.  This change meant that the
test introduced in gen_yield_from_ducktype.py was no longer hitting the
code introduced in 6738c1dded.

The patch here does two things:

1. Fixes the handling of sp in the VM for the case that yield from is
   interrupted by a StopIteration raised via NLR.

2. Introduces a new test to check this handling of sp and re-covers the
   code in the VM.
2018-02-27 15:39:31 +11:00
Damien George
73d1d20b46 py/objexcept: Remove long-obsolete mp_const_MemoryError_obj.
This constant exception instance was once used by m_malloc_fail() to raise
a MemoryError without allocating memory, but it was made obsolete long ago
by 3556e45711.  The functionality is now
replaced by the use of mp_emergency_exception_obj which lives in the global
uPy state, and which can handle any exception type, not just MemoryError.
2018-02-15 16:50:02 +11:00
Damien George
0c650d4276 py/vm: Simplify stack sentinel values for unwind return and jump.
This patch simplifies how sentinel values are stored on the stack when
doing an unwind return or jump.  Instead of storing two values on the stack
for an unwind jump it now stores only one: a negative small integer means
unwind-return and a non-negative small integer means unwind-jump with the
value being the number of exceptions to unwind.  The savings in code size
are:

   bare-arm:   -56
minimal x86:   -68
   unix x64:   -80
unix nanbox:    -4
      stm32:   -56
     cc3200:   -64
    esp8266:   -76
      esp32:  -156
2018-02-08 13:30:33 +11:00
Damien George
30fd8484eb py/runtime: Use the Python stack when building *arg and **kwarg state.
With MICROPY_ENABLE_PYSTACK enabled the following language constructs no
longer allocate on the heap: f(*arg), f(**kwarg).
2017-12-11 13:49:09 +11:00
Damien George
1e5a33df41 py: Convert all uses of alloca() to use new scoped allocation API. 2017-12-11 13:49:09 +11:00
Damien George
5b8998da6d py/runtime: Move mp_exc_recursion_depth to runtime and rename to raise.
For consistency this helper function is renamed to match the other
exception helpers, and moved to their location in runtime.c.
2017-12-11 13:49:09 +11:00
Paul Sokolovsky
d72370def7 py/objfun, vm: Add comments on codestate allocation in stackless mode. 2017-12-09 11:01:34 +02:00
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
Damien George
e2ba45c35f py/vm: Use lowercase letter at start of exception message.
For consistency with all the other exception messages.
2017-09-22 11:28:45 +10:00
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
Damien George
016325dd0a py/vm: Make n_state variable local to just set-up part of VM.
It's not used anywhere else in the VM loop, and clashes with (is shadowed
by) the n_state variable that's redeclared towards the end of the
mp_execute_bytecode function.  Code size is unchanged.
2017-07-18 16:17:23 +10:00
Damien George
9ed5e80eea py/vm: Make "if" control flow more obvious in YIELD_FROM opcode. 2017-07-04 02:14:25 +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
Ville Skyttä
ca16c38210 various: Spelling fixes 2017-05-29 11:36:05 +03:00
Damien George
04d05db27e py/vm: Fix bug with unwind jump popping the iterator from a for loop.
This patch fixes a regression introduced by
088740ecc4
2017-05-25 20:39:08 +10:00
Damien George
68e71eacb8 py/vm: Fix bug with stackless mode and unwinding of exceptions.
This patch fixes a regression introduced by
71a3d6ec3b

Previous to this patch the n_state variable was referring to that computed
at the very start of the mp_execute_bytecode function.  This patch fixes it
so that n_state is recomputed when the code_state changes.
2017-05-25 20:35:57 +10:00
Damien George
dd11af209d py: Add LOAD_SUPER_METHOD bytecode to allow heap-free super meth calls.
This patch allows the following code to run without allocating on the heap:

    super().foo(...)

Before this patch such a call would allocate a super object on the heap and
then load the foo method and call it right away.  The super object is only
needed to perform the lookup of the method and not needed after that.  This
patch makes an optimisation to allocate the super object on the C stack and
discard it right after use.

Changes in code size due to this patch are:

   bare-arm: +128
    minimal: +232
   unix x64: +416
unix nanbox: +364
     stmhal: +184
    esp8266: +340
     cc3200: +128
2017-04-22 23:39:20 +10:00
Damien George
a0973b09ce py/vm: Fix VM opcode tracing to print correct stack pointer.
Also const_table is now moved to the code_state->fun_bc structure.
2017-03-27 10:52:04 +11:00
Damien George
707f16b05c py: Use mp_locals/mp_globals accessor funcs instead of MP_STATE_CTX.
To improve maintainability of the code.
2017-03-24 18:41:11 +11:00
Damien George
60656eaea4 py: Define and use MP_OBJ_ITER_BUF_NSLOTS to get size of stack iter buf.
It improves readability of code and reduces the chance to make a mistake.

This patch also fixes a bug with nan-boxing builds by rounding up the
calculation of the new NSLOTS variable, giving the correct number of slots
(being 4) even if mp_obj_t is larger than the native machine size.
2017-03-23 16:36:08 +11:00
Damien George
1a5c8d1053 py/vm: Don't release the GIL if the scheduler is locked.
The scheduler being locked general means we are running a scheduled
function, and switching to another thread violates that, so don't switch in
such a case (even though we technically could).

And if we are running a scheduled function then we want to finish it ASAP,
so we shouldn't switch to another thread.

Furthermore, ports with threading enabled will lock the scheduler during a
hard IRQ, and this patch to the VM will make sure that threads are not
switched during a hard IRQ (which would crash the VM).
2017-03-20 18:42:27 +11:00
Damien George
6e74d24f30 py: Add micropython.schedule() function and associated runtime code. 2017-03-20 15:20:26 +11:00
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
088740ecc4 py: Optimise storage of iterator so it takes only 4 slots on Py stack. 2017-02-16 18:38:06 +11:00
Damien George
6e769da0da py: Make FOR_ITER opcode pop 1+4 slots from the stack when finished.
The extra 4 slots correspond to the iterator object stored on the stack.
2017-02-16 18:38:06 +11:00
Damien George
f4df3aaa72 py: Allow bytecode/native to put iter_buf on stack for simple for loops.
So that the "for x in it: ..." statement can now work without using the
heap (so long as the iterator argument fits in an iter_buf structure).
2017-02-16 18:38:06 +11:00
Damien George
ae8d867586 py: Add iter_buf to getiter type method.
Allows to iterate over the following without allocating on the heap:
- tuple
- list
- string, bytes
- bytearray, array
- dict (not dict.keys, dict.values, dict.items)
- set, frozenset

Allows to call the following without heap memory:
- all, any, min, max, sum

TODO: still need to allocate stack memory in bytecode for iter_buf.
2017-02-16 18:38:06 +11:00
Damien George
101886f529 py/vm: Convert mp_uint_t to size_t where appropriate. 2017-02-16 16:51:17 +11:00
Damien George
f6c22a0679 py/vm: Add MICROPY_PY_THREAD_GIL_VM_DIVISOR option.
This improves efficiency of GIL release within the VM, by only doing the
release after a fixed number of jump-opcodes have executed in the current
thread.
2017-02-15 11:28:15 +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
71fec076dc py/vm: Use MP_OBJ_FROM_PTR to cast a type to an object. 2016-09-27 13:21:23 +10:00
Damien George
f040685b0c py: Only store the exception instance on Py stack in bytecode try block.
When an exception is raised and is to be handled by the VM, it is stored
on the Python value stack so the bytecode can access it.  CPython stores
3 objects on the stack for each exception: exc type, exc instance and
traceback.  uPy followed this approach, but it turns out not to be
necessary.  Instead, it is enough to store just the exception instance on
the Python value stack.  The only place where the 3 values are needed
explicitly is for the __exit__ handler of a with-statement context, but
for these cases the 3 values can be extracted from the single exception
instance.

This patch removes the need to store 3 values on the stack, and instead
just stores the exception instance.

Code size is reduced by about 50-100 bytes, the compiler and VM are
slightly simpler, generate bytecode is smaller (by 2 bytes for each try
block), and the Python value stack is reduced in size for functions that
handle exceptions.
2016-09-27 12:37:21 +10:00
Damien George
adaf0d865c py: Combine 3 comprehension opcodes (list/dict/set) into 1.
With the previous patch combining 3 emit functions into 1, it now makes
sense to also combine the corresponding VM opcodes, which is what this
patch does.  This eliminates 2 opcodes which simplifies the VM and reduces
code size, in bytes: bare-arm:44, minimal:64, unix(NDEBUG,x86-64):272,
stmhal:92, esp8266:200.  Profiling (with a simple script that creates many
list/dict/set comprehensions) shows no measurable change in performance.
2016-09-19 12:28:03 +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
4cec63a9db py: Implement a simple global interpreter lock.
This makes the VM/runtime thread safe, at the cost of not being able to
run code in parallel.
2016-06-28 11:28:50 +01:00
Paul Sokolovsky
eff85bb1dc py/vm: "yield from" didn't handle MP_OBJ_STOP_ITERATION optimization.
E.g. crashed when yielding from already stopped generators.
2016-04-28 02:08:43 +03:00
Damien George
40d8430ee3 py/vm: Add macros to hook into various points in the VM.
These can be used to insert arbitrary checks, polling, etc into the VM.
They are left general because the VM is a highly tuned loop and it should
be up to a given port how that port wants to modify the VM internals.

One common use would be to insert a polling check, but only done after
a certain number of opcodes were executed, so as not to slow down the VM
too much.  For example:

 #define MICROPY_VM_HOOK_COUNT (30)
 #define MICROPY_VM_HOOK_INIT static uint vm_hook_divisor = MICROPY_VM_HOOK_COUNT
 #define MICROPY_VM_HOOK_POLL if (--vm_hook_divisor == 0) { \
     vm_hook_divisor = MICROPY_VM_HOOK_COUNT;
     extern void vm_hook_function(void);
     vm_hook_function();
 }
 #define MICROPY_VM_HOOK_LOOP MICROPY_VM_HOOK_POLL
 #define MICROPY_VM_HOOK_RETURN MICROPY_VM_HOOK_POLL
2016-02-17 09:02:19 +00:00
Damien George
93bb7dffd2 py/vm: Fix popping of exception block in UNWIND_JUMP opcode.
Fixes issue #1812.
2016-02-01 16:07:21 +00:00
Damien George
3d2daa2d03 py: Change exception traceback data to use size_t instead of mp_uint_t.
The traceback array stores qstrs and line numbers.  qstrs are typed as
size_t, and line numbers should safely fit in size_t as well.
2016-01-02 22:04:12 +00:00
Damien George
8047340d75 py: Handle case of return within the finally block of try-finally.
Addresses issue #1636.
2015-12-24 12:47:39 +00:00
Damien George
7a30e87d2b py: Fix MICROPY_STACKLESS mode to compile with MICROPY_OBJ_REPR_D. 2015-12-17 12:32:41 +00:00
Damien George
bdbe8c9ae2 py: Make UNARY_OP_NOT a first-class op, to agree with Py not semantics.
Fixes #1684 and makes "not" match Python semantics.  The code is also
simplified (the separate MP_BC_NOT opcode is removed) and the patch saves
68 bytes for bare-arm/ and 52 bytes for minimal/.

Previously "not x" was implemented as !mp_unary_op(x, MP_UNARY_OP_BOOL),
so any given object only needs to implement MP_UNARY_OP_BOOL (and the VM
had a special opcode to do the ! bit).

With this patch "not x" is implemented as mp_unary_op(x, MP_UNARY_OP_NOT),
but this operation is caught at the start of mp_unary_op and dispatched as
!mp_obj_is_true(x).  mp_obj_is_true has special logic to test for
truthness, and is the correct way to handle the not operation.
2015-12-10 22:19:48 +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
c8e9c0d89a py: Add MICROPY_PERSISTENT_CODE so code can persist beyond the runtime.
Main changes when MICROPY_PERSISTENT_CODE is enabled are:

- qstrs are encoded as 2-byte fixed width in the bytecode
- all pointers are removed from bytecode and put in const_table (this
  includes const objects and raw code pointers)

Ultimately this option will enable persistence for not just bytecode but
also native code.
2015-11-13 12:49:18 +00:00
Damien George
4bf3f2d3c0 py: Fix with+for+return bug by popping for-iter when unwinding exc stack.
Addresses issue #1182.
2015-10-15 17:48:28 +01:00
Paul Sokolovsky
2ff2ea5f3b vm: Handle "raise X from Y" statements the best way we can.
By issuing a warning that exception chaining is not supported, and ignoring
"from Y" argument.
2015-09-01 10:39:04 +03:00
Damien George
59fba2d6ea py: Remove mp_load_const_bytes and instead load precreated bytes object.
Previous to this patch each time a bytes object was referenced a new
instance (with the same data) was created.  With this patch a single
bytes object is created in the compiler and is loaded directly at execute
time as a true constant (similar to loading bignum and float objects).
This saves on allocating RAM and means that bytes objects can now be
used when the memory manager is locked (eg in interrupts).

The MP_BC_LOAD_CONST_BYTES bytecode was removed as part of this.

Generated bytecode is slightly larger due to storing a pointer to the
bytes object instead of the qstr identifier.

Code size is reduced by about 60 bytes on Thumb2 architectures.
2015-06-25 14:42:13 +00:00
Damien George
ed570e4b2a py: Remove mp_load_const_str and replace uses with inlined version. 2015-06-25 13:58:41 +00:00
Damien George
c5029bcbf3 py: Add MP_BINARY_OP_DIVMOD to simplify and consolidate divmod builtin. 2015-06-13 23:36:30 +01:00
Damien George
c2a4e4effc py: Convert hash API to use MP_UNARY_OP_HASH instead of ad-hoc function.
Hashing is now done using mp_unary_op function with MP_UNARY_OP_HASH as
the operator argument.  Hashing for int, str and bytes still go via
fast-path in mp_unary_op since they are the most common objects which
need to be hashed.

This lead to quite a bit of code cleanup, and should be more efficient
if anything.  It saves 176 bytes code space on Thumb2, and 360 bytes on
x86.

The only loss is that the error message "unhashable type" is now the
more generic "unsupported type for __hash__".
2015-05-12 22:46:02 +01:00
Paul Sokolovsky
6738c1dded vm: Properly handle StopIteration raised in user instance iterator.
I.e. in bytecode Python functions.
2015-05-11 23:57:42 +01:00
Paul Sokolovsky
a7c02c4538 vm: Null pointer test when checking for StopIteration optimizations.
When generator raises exception, it is automatically terminated (by setting
its code_state.ip to 0), which interferes with this check.

Triggered in particular by CPython's test_pep380.py.
2015-05-10 17:20:46 +03:00
Damien George
8872abcbc4 py: Remove LOAD_CONST_ELLIPSIS bytecode, use LOAD_CONST_OBJ instead.
Ellipsis constant is rarely used so no point having an extra bytecode
for it.
2015-05-05 22:15:42 +01:00
Paul Sokolovsky
ae2c81ff38 vm: On exiting except block, clear sys.exc_info() value.
This doesn't handle case fo enclosed except blocks, but once again,
sys.exc_info() support is a workaround for software which uses it
instead of properly catching exceptions via variable in except clause.
2015-04-26 01:40:37 +03:00
Paul Sokolovsky
8b85d14b92 modsys: Add basic sys.exc_info() implementation.
The implementation is very basic and non-compliant and provided solely for
CPython compatibility. The function itself is bad Python2 heritage, its
usage is discouraged.
2015-04-25 03:49:23 +03:00
Damien George
8c1d23a0e2 py: Modify bytecode "with" behaviour so it doesn't use any heap.
Before this patch a "with" block needed to create a bound method object
on the heap for the __exit__ call.  Now it doesn't because we use
load_method instead of load_attr, and save the method+self on the stack.
2015-04-24 01:52:28 +01:00
Damien George
b1bbe966c4 py: Combine load_attr and store_attr type methods into one (attr).
This simplifies the API for objects and reduces code size (by around 400
bytes on Thumb2, and around 2k on x86).  Performance impact was measured
with Pystone score, but change was barely noticeable.
2015-04-11 16:54:37 +01:00
Damien George
4dea922610 py: Adjust some spaces in code style/format, purely for consistency. 2015-04-09 15:29:54 +00:00
stijn
36cc84a2a9 py: Fix msvc warning '*/ found outside of comment'
Also prevents some of the weaker syntax parsers out there treating the whole
'*/*const*/' part as a comment
2015-04-09 12:40:38 +02:00
Damien George
12a5e17afb py: Add finer configuration of static funcs when not in stackless mode.
Also rename call_args_t to mp_call_args_t.
2015-04-02 22:56:58 +01:00
Paul Sokolovsky
7f1c98177b vm: Support strict stackless mode, with proper exception reporting.
I.e. in this mode, C stack will never be used to call a Python function,
but if there's no free heap for a call, it will be reported as
RuntimeError (as expected), not MemoryError.
2015-04-03 00:26:47 +03:00
Paul Sokolovsky
f0a8f21190 vm: Implement stackless for CALL_FUNCTION_VAR_KW & CALL_METHOD_VAR_KW. 2015-04-03 00:03:07 +03:00
Paul Sokolovsky
390e92688c vm: Stackless support for MP_BC_CALL_METHOD. 2015-04-03 00:03:07 +03:00
Paul Sokolovsky
332a909d44 vm: If there's no heap to call function in stackless manner, call via C stack. 2015-04-03 00:03:07 +03:00
Paul Sokolovsky
2039757b85 vm: Initial support for calling bytecode functions w/o C stack ("stackless"). 2015-04-03 00:03:07 +03:00
stijn
28fa84b445 py: Add optional support for descriptors' __get__ and __set__ methods.
Disabled by default.  Enabled on unix and windows ports.
2015-03-26 23:55:14 +00:00
Damien George
5e1d993f54 py: Clean up some logic in VM to remove assert(0)'s.
Saves around 30 bytes code on Thumb2 archs.
2015-03-25 22:20:37 +00:00
Damien George
12d6d777e1 py: Small optimisation of logic flow in BC_WITH_CLEANUP bytecode.
Slightly smaller code, and does not need to use C stack to save
temporaries.
2015-02-26 17:54:50 +00:00
Damien George
596f41da04 py: Reuse value stack in VM WITH_CLEANUP opcode to reduce C-stack size.
Saves 8 bytes C-stack on stmhal and 16 bytes on unix x86.
2015-02-10 13:21:42 +00:00
Damien George
7d414a1b52 py: Parse big-int/float/imag constants directly in parser.
Previous to this patch, a big-int, float or imag constant was interned
(made into a qstr) and then parsed at runtime to create an object each
time it was needed.  This is wasteful in RAM and not efficient.  Now,
these constants are parsed straight away in the parser and turned into
objects.  This allows constants with large numbers of digits (so
addresses issue #1103) and takes us a step closer to #722.
2015-02-08 01:57:40 +00:00
Damien George
dab1385177 py: Add load_const_obj to emitter, add LOAD_CONST_OBJ to bytecode.
This allows to directly load a Python object to the Python stack.  See
issue #722 for background.
2015-01-13 15:55:54 +00:00
Damien George
7ee91cf861 py: Add option to cache map lookup results in bytecode.
This is a simple optimisation inspired by JITing technology: we cache in
the bytecode (using 1 byte) the offset of the last successful lookup in
a map. This allows us next time round to check in that location in the
hash table (mp_map_t) for the desired entry, and if it's there use that
entry straight away.  Otherwise fallback to a normal map lookup.

Works for LOAD_NAME, LOAD_GLOBAL, LOAD_ATTR and STORE_ATTR opcodes.

On a few tests it gives >90% cache hit and greatly improves speed of
code.

Disabled by default.  Enabled for unix and stmhal ports.
2015-01-07 21:07:23 +00:00
Damien George
b4b10fd350 py: Put all global state together in state structures.
This patch consolidates all global variables in py/ core into one place,
in a global structure.  Root pointers are all located together to make
GC tracing easier and more efficient.
2015-01-07 20:33:00 +00:00
Damien George
51dfcb4bb7 py: Move to guarded includes, everywhere in py/ core.
Addresses issue #1022.
2015-01-01 20:32:09 +00:00
Damien George
f89d659e3b py: In VM, for selective ip saving, store 1 byte past last opcode.
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.
2014-12-29 00:29:59 +00:00
Paul Sokolovsky
749575097f vm: Record exception ip only for instructions where exceptions may happen.
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.
2014-12-28 07:37:04 +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
7764f163fa py: Fix label printing in showbc; print sp in vm trace. 2014-12-12 17:18:56 +00:00
Damien George
cd97a43f8d py, vm: Make unum a local variable for each opcode that uses it.
This makes no change to the generated code, but it's now easier to
understand since unum is not a "global" variable anymore.
2014-12-02 19:25:10 +00:00
Damien George
b0b0012fd8 py: Fix VM dispatch following a pending exception check. 2014-10-26 00:33:23 +01:00
Damien George
124df6f8d0 py: Add mp_pending_exception global variable, for VM soft interrupt.
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).
2014-10-25 23:37:57 +01:00
Damien George
8456cc017b py: Compress load-int, load-fast, store-fast, unop, binop bytecodes.
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.
2014-10-25 20:23:13 +01:00
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
b427d6ae86 py: Fix line number printing for file with 1 line.
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.
2014-08-26 23:35:57 +01:00
Damien George
4747becc64 py: Improve encoding scheme for line-number to bytecode map.
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.
2014-07-31 16:12:01 +00:00
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
Damien George
df896eceef Merge branch 'alloca' of github.com:marcusva/micropython into marcusva-alloca 2014-06-08 13:18:14 +01:00
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
Marcus von Appen
0c90eb1658 - FreeBSD provides alloca() via stdlib.h, in contrast to Linux and Windows
- Move the includes for alloca() intp mpconfigport.h
2014-06-07 09:36:04 +02:00
Paul Sokolovsky
411732e93b vm: If there's no lineno info, set lineno in traceback to 0, not 1.
To clearly signify that lineno is not known.
2014-06-03 12:32:59 +03:00