You can disassemble LLVM bitcode with llvm-dis, might help figure out which flags can help here.
- Alon On Sun, Feb 15, 2015 at 3:55 PM, Alecazam <[email protected]> wrote: > I'm suggesting reducing the volume of debug info with any optimizations > (f.e. -O2) and -g4. There's currently too much data (a 22x increase in .bc > files). There are clang flags for this -flimit-debug-info. I tried > passing those, but the .bc files were unchanged. It's hard to tell from > disassembling the .bc files what is in the file, and what is just the > verbose display of data from llvm. With relative paths and lines > embedded, turning on -g4 to get to source maps shouldn't need that much > more space over -g3. It feels like something is too verbose in the g4 > setting. > > On Sunday, February 15, 2015 at 12:21:47 PM UTC-8, Alon Zakai wrote: >> >> Fastcomp is the backend, "native optimizer" is something that runs after >> it. We disable the latter, not the former, when using source maps. >> >> I think emscripten also disables debug info by default, except at -O0. >> >> - Alon >> >> >> On Fri, Feb 13, 2015 at 2:50 PM, Alecazam <[email protected]> wrote: >> >>> If emcc -g4 is using clang, then experimenting with the clang flags >>> might do the trick (-gline-tables-only and/or -flimit-debug-info). It >>> seems that Darwin clang defaults to disabling optimizing debug info except >>> at -O0. See thread here: >>> >>> http://llvm.org/klaus/clang/commit/c44757105021d1429f9430d5ff0da4 >>> 5b02b9f741/ >>> >>> >>> On Friday, February 13, 2015 at 2:30:47 PM UTC-8, Alecazam wrote: >>>> >>>> >>>> 1. We cannot use the fast native optimizer when emitting source maps >>>>>> >>>>> >>>> Does that mean fastcomp isn't used? I re-read about fastcomp, but >>>> there wasn't any mention of source maps disabling it. Indeed turning on >>>> -g4 generates 443MB of bc data, where -g3 only generates 20MB. That's a >>>> 22x increase in bc data, and it's not suprising the linker slows >>>> dramatically from parsing 2.2GB of data. The final js output is a few MB. >>>> >>>> It seems like -g3 should be most of the data needed, and there should >>>> only be a small addition from adding file/line directives to the source. >>>> It's not like it's copying the source into the .bc files, just a source >>>> marker. We're looking at the .bc data, but it feels like there may be too >>>> much data requested on the part of emcc (type info?). The linker is having >>>> to toss out all this unneeded data. >>>> >>> -- >>> 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. > -- 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.
