[Bug java/30588] New: gcj compiler large jars much slower

["mark at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

An example from frysk:

$ /usr/bin/gcj -v
Using built-in specs.
Reading specs from /usr/lib/gcc/x86_64-redhat-linux/4.1.1/libgcj.spec
rename spec startfile to startfileorig
rename spec lib to liborig
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-libgcj-multifile
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk
--disable-dssi --enable-plugin
--with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --with-cpu=generic
--host=x86_64-redhat-linux
Thread model: posix
gcc version 4.1.1 20070105 (Red Hat 4.1.1-51)

$ /home/mark/src/gcc-install/bin/gcj -v
Using built-in specs.
Reading specs from
/home/mark/src/gcc-install/lib/gcc/x86_64-unknown-linux-gnu/4.3.0/../../../libgcj.spec
rename spec startfile to startfileorig
rename spec lib to liborig
Target: x86_64-unknown-linux-gnu
Configured with: /home/mark/src/gcc/configure
--prefix=/home/mark/src/gcc-install --enable-java-awt=gtk --disable-bootstrap
--disable-checking --enable-plugin --enable-languages=c,c++,java
Thread model: posix
gcc version 4.3.0 20070125 (experimental)


$ time /usr/bin/gcj -I../../frysk/frysk-imports -I. -Igetopt.jar -Ijunit.jar
-Werror -Wall -fPIC  -g -O -fjni -c antlr.jar

real    0m36.455s
user    0m35.666s
sys     0m0.644s

$ time /home/mark/src/gcc-install/bin/gcj -I../../frysk/frysk-imports -I.
-Igetopt.jar -Ijunit.jar -Werror -Wall -fPIC  -g -O -fjni -c antlr.jar

real    0m51.691s
user    0m50.643s
sys     0m0.760s

Compiling with -ftime-report gives a hint where this might come from:
4.3 (trunk):
tree PTA              :   3.80 ( 8%) usr   0.02 ( 1%) sys   3.79 ( 7%) wall  
25485 kB ( 2%) ggc
tree alias analysis   :  10.41 (21%) usr   0.50 (21%) sys  10.83 (21%) wall 
600226 kB (42%) ggc

With 4.1.1 it is:
tree PTA              :   5.80 (17%) usr   0.05 ( 3%) sys   5.54 (15%) wall  
45994 kB ( 5%) ggc
tree alias analysis   :   1.48 ( 4%) usr   0.37 (21%) sys   1.90 ( 5%) wall  
16749 kB ( 2%) ggc


-- 
           Summary: gcj compiler large jars much slower
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: java
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mark at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30588