CircuitPython - a Python implementation for teaching coding with microcontrollers https://git.suspectdevices.com/suspect-devices/circuitpython/atom?h=main 2021-03-15T13:57:36+00:00 2021-03-15T13:57:36+00:00 microDev 70126934+microDev1@users.noreply.github.com 2021-03-15T13:57:36+00:00 urn:sha1:a52eb88031620a81521b937f2a0651dbac2bb350 2020-09-12T19:07:23+00:00 Jeff Epler jepler@gmail.com 2020-09-12T18:57:31+00:00 urn:sha1:54d97251fe2dd4939652a186bf703885e654b4d1 While checking whether we can enable -Wimplicit-fallthrough, I encountered a diagnostic in mp_binary_set_val_array_from_int which led to discovering the following bug: ``` >>> struct.pack("xb", 3) b'\x03\x03' ``` That is, the next value (3) was used as the value of a padding byte, while standard Python always fills "x" bytes with zeros. I initially thought this had to do with the unintentional fallthrough, but it doesn't. Instead, this code would relate to an array.array with a typecode of padding ('x'), which is ALSO not desktop Python compliant: ``` >>> array.array('x', (1, 2, 3)) array('x', [1, 0, 0]) ``` Possibly this is dead code that used to be shared between struct-setting and array-setting, but it no longer is. I also discovered that the argument list length for struct.pack and struct.pack_into were not checked, and that the length of binary data passed to array.array was not checked to be a multiple of the element size. I have corrected all of these to conform more closely to standard Python and revised some tests where necessary. Some tests for micropython-specific behavior that does not conform to standard Python and is not present in CircuitPython was deleted outright. 2018-07-11T20:45:30+00:00 Dan Halbert halbert@halwitz.org 2018-07-11T20:45:30+00:00 urn:sha1:7c219600a246d8956d0b23ea3f5d125a820e6b6a 2018-06-08T02:12:08+00:00 Damien George damien.p.george@gmail.com 2018-05-25T07:09:54+00:00 urn:sha1:36c105218321167d47b0fb67575a7cddc36d17e7 This patch is a code optimisation, trading text bytes for speed. On pyboard it's an increase of 0.06% in code size for a gain (in pystone performance) of roughly 6.5%. The patch optimises load/store/delete of attributes in user defined classes by not looking up special accessors (@property, __get__, __delete__, __set__, __setattr__ and __getattr_) if they are guaranteed not to exist in the class. Currently, if you do my_obj.foo() then the runtime has to do a few checks to see if foo is a property or has __get__, and if so delegate the call. And for stores things like my_obj.foo = 1 has to first check if foo is a property or has __set__ defined on it. Doing all those checks each and every time the attribute is accessed has a performance penalty. This patch eliminates all those checks for cases when it's guaranteed that the checks will always fail, ie no attributes are properties nor have any special accessor methods defined on them. To make this guarantee it checks all attributes of a user-defined class when it is first created. If any of the attributes of the user class are properties or have special accessors, or any of the base classes of the user class have them, then it sets a flag in the class to indicate that special accessors must be checked for. Then in the load/store/delete code it checks this flag to see if it can take the shortcut and optimise the lookup. It's an optimisation that's pretty widely applicable because it improves lookup performance for all methods of user defined classes, and stores of attributes, at least for those that don't have special accessors. And, it allows to enable descriptors with minimal additional runtime overhead if they are not used for a particular user class. There is one restriction on dynamic class creation that has been introduced by this patch: a user-defined class cannot go from zero special accessors to one special accessor (or more) after that class has been subclassed. If the script attempts this an AttributeError is raised (see addition to tests/misc/non_compliant.py for an example of this case). The cost in code space bytes for the optimisation in this patch is: unix x64: +528 unix nanbox: +508 stm32: +192 cc3200: +200 esp8266: +332 esp32: +244 Performance tests that were done: - on unix x86-64, pystone improved by about 5% - on pyboard, pystone improved by about 6.5%, from 1683 up to 1794 - on pyboard, bm_chaos (from CPython benchmark suite) improved by about 5% - on esp32, pystone improved by about 30% (but there are caching effects) - on esp32, bm_chaos improved by about 11% 2017-12-14T01:25:30+00:00 Damien George damien.p.george@gmail.com 2017-12-14T01:25:30+00:00 urn:sha1:36f79523abe8d79fec1cc7af41e8e96e8ceb2cc4 2017-10-25T05:31:16+00:00 Scott Shawcroft scott.shawcroft@gmail.com 2017-10-25T05:31:16+00:00 urn:sha1:73c15dcf8b1b927757a595a867334b38355ddb8f This is prep for merging in the NRF5 pull request. 2017-10-18T19:50:20+00:00 Michael McWethy mrmcwethy@yahoo.com 2017-10-18T19:50:20+00:00 urn:sha1:b41cbe9256d3f7105a70ad3d2e4fb64180f81e09 Added struct module to shared-bindings and shared-module. removed ustruct 2017-10-03T06:56:27+00:00 Damien George damien.p.george@gmail.com 2017-10-03T06:56:27+00:00 urn:sha1:2ac1364688cd3ee313661e82a336663551986fc8 CPython docs explicitly state that the RHS of a set/frozenset binary op must be a set to prevent user errors. It also preserves commutativity of the ops, eg: "abc" & set() is a TypeError, and so should be set() & "abc". This change actually decreases unix (x64) code by 160 bytes; it increases stm32 by 4 bytes and esp8266 by 28 bytes (but previous patch already introduced a much large saving). 2017-06-10T17:34:38+00:00 Paul Sokolovsky pfalcon@users.sourceforge.net 2017-06-10T17:14:16+00:00 urn:sha1:85d809d1f4e35a511e0a56b3411126e05a31c01b 2017-03-11T00:17:02+00:00 Paul Sokolovsky pfalcon@users.sourceforge.net 2017-03-11T00:16:26+00:00 urn:sha1:3e321f1724b4e2deae2a7750c789c6423f5201c2