On Thu, Sep 23, 2010 at 3:48 PM, Chris Conroy <con...@google.com> wrote:
> Why does the compiled size increase from 8 to 9? That would seem to > indicate a bug with the optimizer in that step. > Optimizers don't just reduce code size - they also attempt to improve performance. > On Thu, Sep 23, 2010 at 3:41 PM, Eric Ayers <zun...@google.com> wrote: > >> The attached graph shows an analysis of code size to compile time for >> building a large application. The code size is the total number of bytes >> output for .cache.js files for all permutations added together. >> >> Somewhere between passes 2 to 4 is a "sweet spot", where further >> optimization passes appear to be returning only marginal improvements. At >> 3 optimization passes, Another way to verify that besides just the code >> size metric is to look at the statistics I added in a week ago that show how >> much the tree changes on each pass. When we looked at the same application, >> Changes were measured in the thousands on the first pass or two, then >> trickled down into the tens in later passes. >> >> Previously, I had another implementation of this feature where the >> DataflowOptimizer and SameParameterValueOptimizer were automatically turned >> off until level 6 or higher (you can flip these off with a separate command >> line flag). In that case, code size was nearly the same, and compile time >> was 220 seconds at optimization level 3. >> >> full optimization: 300s >> 3 passes only: 250s >> 3 passes - aggressive optimizations: 220s >> >> -Eric. >> >> On Thu, Sep 23, 2010 at 3:32 PM, <zun...@google.com> wrote: >> >>> Reviewers: scottb, fabbott, Lex, >>> >>> Description: >>> Adds a way to tune the optimization level in steps from >>> draft optimize to full optimization (the current default) >>> >>> Preliminary testing shows that optimization level '3' >>> can give almost as good code size results (within 5%) >>> as full optimization, with about 20% reduction in compile time. >>> >>> >>> Please review this at http://gwt-code-reviews.appspot.com/915802/show >>> >>> Affected files: >>> M dev/core/src/com/google/gwt/dev/Precompile.java >>> M dev/core/src/com/google/gwt/dev/jjs/JJSOptions.java >>> M dev/core/src/com/google/gwt/dev/jjs/JJSOptionsImpl.java >>> M dev/core/src/com/google/gwt/dev/jjs/JavaToJavaScriptCompiler.java >>> M dev/core/src/com/google/gwt/dev/util/arg/ArgHandlerDraftCompile.java >>> A dev/core/src/com/google/gwt/dev/util/arg/ArgHandlerOptimize.java >>> D dev/core/src/com/google/gwt/dev/util/arg/OptionDraftCompile.java >>> A dev/core/src/com/google/gwt/dev/util/arg/OptionOptimize.java >>> >>> >>> >> >> >> -- >> Eric Z. Ayers >> Google Web Toolkit, Atlanta, GA USA >> >> -- >> http://groups.google.com/group/Google-Web-Toolkit-Contributors >> > > -- > http://groups.google.com/group/Google-Web-Toolkit-Contributors -- Eric Z. Ayers Google Web Toolkit, Atlanta, GA USA -- http://groups.google.com/group/Google-Web-Toolkit-Contributors
