Why does the compiled size increase from 8 to 9? That would seem to indicate
a bug with the optimizer in that step.

On Thu, Sep 23, 2010 at 3:41 PM, Eric Ayers <[email protected]> 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, <[email protected]> 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
>

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