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 2020-11-21T04:33:39+00:00 Dan Halbert halbert@halwitz.org 2020-11-21T04:33:39+00:00 urn:sha1:e4c66990e27779f43f4901d431b6c61f8da85f51 2020-10-12T02:18:03+00:00 Jeff Epler jepler@gmail.com 2020-10-11T21:03:46+00:00 urn:sha1:479552ce564410f2d96855f5dbca223317c4cbe0 This gets a further speedup of about 2s (12s -> 9.5s elapsed build time) for stm32f405_feather For what are probably historical reasons, the qstr process involves preprocessing a large number of source files into a single "qstr.i.last" file, then reading this and splitting it into one "qstr" file for each original source ("*.c") file. By eliminating the step of writing qstr.i.last as well as making the regular-expression-matching part be parallelized, build speed is further improved. Because the step to build QSTR_DEFS_COLLECTED does not access qstr.i.last, the path is replaced with "-" in the Makefile. 2020-10-12T01:19:59+00:00 Jeff Epler jepler@gmail.com 2020-10-11T20:19:55+00:00 urn:sha1:607e4a905ae8654bd8450ae137ffa24367039277 Rather than simply invoking gcc in preprocessor mode with a list of files, use a Python script with the (python3) ThreadPoolExecutor to invoke the preprocessor in parallel. The amount of concurrency is the number of system CPUs, not the makefile "-j" parallelism setting, because there is no simple and correct way for a Python program to correctly work together with make's idea of parallelism. This reduces the build time of stm32f405 feather (a non-LTO build) from 16s to 12s on my 16-thread Ryzen machine.