Optimisation work on Zero/ARM

[Matthias Klose]

Xerxes Rånby schrieb:
> Greetings Ed!
> 
> I have been trying to compile the "BIG ASM" interpreter today in order
> to check if something needs changing before moving your work into Icedtea.
> 
> Edward Nevill skrev:
>>> I peeked at the sourcecode and it looks great!
>>> Your changes are most portable for inclusion into Icedtea6/OpenJDK since
>>> they are already contained in separate patches against the Icedtea6 tree
>>>     
>> >from 23 june 2009 in the debian/patches directory, fantastic.
>>
>> Would you be happy to review the changes for inclusion into IcedTea.
>>
>> === zero-asm-port.diff
>>
>> This contains the diffs to the ports/... part of IcedTea. The diffs are
>> quite small (141 line) and are there mainly to provide hooks for the asm
>> interpreter. The files affected are
>>
>> - zero.make
>>
>> Adds cppInterpreter_arm.o and rules to build it.
>>   
> I have found this line of zero.make in my way:
> 
> zero-asm-port.diff:+CFLAGS += -DHOTSPOT_ASM -DHW_NULL_PTR_CHECK
> -march=armv5t -mtune=cortex-a8 -O2 -falign-functions=64 -falign-loops=8 -g0
> 
> I think it are causing my crosscompile build for my armv5te system to
> fail with this error:

[...]
this requires http://sourceware.org/ml/binutils/2009-06/msg00289.html

> Are any of the cflags
> -march=armv5t -mtune=cortex-a8 -O2 -falign-functions=64 -falign-loops=8 -g0
>  crucial or just optimization related?

I didn't run tests for armv4 yet.

> Most ARM Linux distributions will supply the correct CFLAGS so i dont
> think we should have these turned on as default.

Yes, these could be set in the packaging as well.

  Matthias