Porting libgcj...

Tue Aug 10 08:13:00 GMT 1999

I come out of my lurk...
I have a netwinder (it's Corel Computors' box actually), and an interest in
this project. Not much time, but I would be willing to QA your port and try
porting some of my development code to it.
Let me know.
Rick Graham rick@bitflash.com
 Applications Architect
BitFlash Graphics http//www.bitflash.com/
 Ottawa On, Ca.
scottb wrote:
> > > <scottb@netwinder.org> writes:
> >
> > I'm trying to port libgcj to run on ArmLinux on a NetWinder.
> >
> > It seems that when generating this file, the value for
> > MAX_VALUE is interpreted as a NAN by printf.. I have been
> > looking for the file generation code but have been unable to
> > find it. Could someone point me in the correct direction.
>> Tom Tromey wrote:
> >
> > Most of the headers are generated from class files by a program named
> > "gcjh". It is part of gcc. The source is gcc/java/gjavah.c. You
> > want to look at the function print_field_info().
> >
>> I think I have found the problem (at least for this case). It is the
> WORDS_TO_DOUBLE() macro in javaop.h. The ARM has a funny floating point
> memory layout for doubles. It is the IEEE format in little endian with
> the words swapped. As an example:
>> MAX_DBL = 0xff 0xff 0xff 0xff 0xff 0xff 0xef 0x7f in little endian
> MAX_DBL = 0xff 0xff 0xef 0x7f 0xff 0xff 0xff 0xff on the ARM
>> I updated my gcc-2.95 tree this morning and have a build going to test
> this hypothesis. I have modified WORDS_TO_DOUBLE to be:
>> static inline jdouble
> WORDS_TO_DOUBLE(jword hi, jword lo)
> { union DWord wu;
> #ifdef __arm__
> wu.l = WORDS_TO_LONG(lo,hi);
> #else
> wu.l = WORDS_TO_LONG(hi,lo);
> #endif
> }
>> This is fine to test the code, but not my idea of a decent port. There
> doesn't seem to be any other way of introducing architecture dependent
> code into the tree however. Does anyone have any better suggestions?
>> Scott