Is there a way to tell emcc / whatever to pre-build this or tell it to use a pre-built copy?
When emcc builds things as part of a compilation run, it is tough for a build system to handle the case where those things don't exist and we have multiple simultaneous invocations of emcc in a parallel build ... - Bruce On Thu, Dec 18, 2014 at 2:46 AM, Alon Zakai <[email protected]> wrote: > > I just merged code to enable the new native optimizer by default. This > means that the "js opts" phase in -O2 and above will use new C++ code > instead of the old JS code. This generally speeds up that phase by more > than 3x, and since this phase is often the slowest, can have a significant > positive effect on -O2 and above build times. > > In the big picture, this concludes the 2nd of two major code upgrades this > year - first to replace the JS compiler with an LLVM backend in C++, and > now to replace the JS optimizer. > > The native optimizer code is written in c++11, and depends on having a > c++11 compiler and runtime library. This might not be available everywhere; > if building it fails, emcc will automatically use the old optimizer. You > can see messages regarding that in debug mode output (EMCC_DEBUG=1 in the > environment). > > I believe we saw that the native optimizer wouldn't build on the windows > bot, and clb disabled the test verifying build success on it > (other.test_native_optimizer). We should probably look more into why it > fails now. > > I added a new test mode, asm2nn, which runs the non-native optimizer (i.e. > the old one), to keep test coverage of the case where the native optimizer > can't be built. To offset the extra bot test time, I disabled slow2asm, > which tested the old pre-fastcomp compiler in asm.js mode. I'm not aware of > anyone using that mode - let me know if disabling those tests concerns you. > Note that bot test times should improve since all the other optimized test > modes will use the native optimizer, which is faster. > > Please test this on your codebases! :) All you need to do is pull latest > incoming (on all 3 repos), which is version 1.28.2, and use that - the > native optimizer will be utilized by default. Check in EMCC_DEBUG=1 output > if it says, somewhere after "running js post-opts", something like "js > optimizer using native". That implies the native optimizer is used. > Otherwise, you might see a warning message. > > You can manually disable the native optimizer, if you want, with > EMCC_NATIVE_OPTIMIZER=0 in the env. However, as mentioned before, emcc will > fall back to the JS optimizer if it fails to build the native optimizer, so > you shouldn't need to do so (unless perhaps you find a bug in the native > optimizer?). > > - Alon > > P.S. The native optimizer parses asm.js code, optimizes it, and emits that > asm.js code. To parse and unparse, I wrote a new standalone library for > that purpose, called cashew, > > https://github.com/kripken/cashew > > It might be useful if you want a C++ library for parsing asm.js code. > > -- > You received this message because you are subscribed to the Google Groups > "emscripten-discuss" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "emscripten-discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
