[antlr-interest] remove back track from compiler grammar

[Terence Parr]

The initial load time will be big because we have to initialize some DFA (and load lots of classes).
Ter
On Nov 24, 2010, at 4:28 AM, Da Feng wrote:

> Hello everyone:
> I removed back track from openjdk compiler grammar. Though performance is still 
> low, partly it  results from antlr lib loading. I compiled multiple files in a 
> line, and only the first file experience long start up time. I don't have TCK, 
> so the compiler grammar file may still have bugs.
> 
> ==================
> [sunspider at sunspider perfTest]$ rm -r dest/*;time javac -d dest -XDparser=antlr  
> *.java
> 
> real    0m2.212s
> user    0m1.644s
> sys    0m0.190s
> [sunspider at sunspider perfTest]$ rm -r dest/*;time javac -d dest 
> -XDparser=default  *.java
> 
> real    0m1.742s
> user    0m1.204s
> sys    0m0.190s
> 
> ====================
> 
> [sunspider at sunspider perfTest]$ rm -r dest/*;javac -d dest -XDparser=default 
> -XDantlrdebug=true -verbose *.java
> [parsing started Brackets.java]
> [parsing completed 61ms]
> [parsing started ClassLoaderL.java]
> [parsing completed 23ms]
> [parsing started Fragment.java]
> [parsing completed 29ms]
> [parsing started OKWorld.java]
> [parsing completed 2ms]
> [parsing started Regex.java]
> [parsing completed 14ms]
> [parsing started TestClass.java]
> [parsing completed 0ms]
> [parsing started TestFill.java]
> [parsing completed 0ms]
> [parsing started TestRegex2.java]
> [parsing completed 1ms]
> [parsing started TestRemove.java]
> [parsing completed 6ms]
> [parsing started TestThread2.java]
> [parsing completed 4ms]
> [parsing started TestThread.java]
> [parsing completed 12ms]
> [parsing started TestZIPFile.java]
> [parsing completed 2ms]
> [parsing started Text.java]
> [parsing completed 26ms]
> ===============
> [sunspider at sunspider perfTest]$ rm -r dest/*;javac -d dest -XDparser=antlr 
> -XDantlrdebug=true -verbose *.java
> [parsing started Brackets.java]
> Parsing with antlr
> [parsing completed 322ms]
> [parsing started ClassLoaderL.java]
> Parsing with antlr
> [parsing completed 94ms]
> [parsing started Fragment.java]
> Parsing with antlr
> [parsing completed 136ms]
> [parsing started OKWorld.java]
> Parsing with antlr
> [parsing completed 42ms]
> [parsing started Regex.java]
> Parsing with antlr
> [parsing completed 42ms]
> [parsing started TestClass.java]
> Parsing with antlr
> [parsing completed 18ms]
> [parsing started TestFill.java]
> Parsing with antlr
> [parsing completed 10ms]
> [parsing started TestRegex2.java]
> Parsing with antlr
> [parsing completed 10ms]
> [parsing started TestRemove.java]
> Parsing with antlr
> [parsing completed 24ms]
> [parsing started TestThread2.java]
> Parsing with antlr
> [parsing completed 86ms]
> [parsing started TestThread.java]
> Parsing with antlr
> [parsing completed 80ms]
> [parsing started TestZIPFile.java]
> Parsing with antlr
> [parsing completed 14ms]
> [parsing started Text.java]
> Parsing with antlr
> [parsing completed 46ms]
> DaFENG
> Coder
> Telecommunication && Network Industry
> Pudong
> Shanghai
> China
> 
> 
> <Java.g.tar.gz>
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