[fpc-devel] FPC-JVM: Status report on Android

[Sven Barth]

Am 29.08.2011 10:58, schrieb Jonas Maebe:
>
> On 29 Aug 2011, at 09:58, Michael Schnell wrote:
>
>> How did you manage to move from the 8 bit SUN Java bytecode to the 16
>> bit Android /Dalvik code ?
>
> You are thinking of 8 and 16 bit in the wrong way. Those are simply
> details of the respective byte code instruction formats. For example,
> it's about whether an "add" instruction is encoded using 1 byte or using
> 2 bytes. It has nothing to do with the width of the executed operations
> (the JVM byte code instruction set includes 64 bit integer and floating
> point operations). Also note that this is only about the instruction
> opcodes: if you include the operands then several JVM byte code
> instructions are wider than 8 bit.

But there is a significant difference between the JVM bytecode and the 
Dalvik one and perhaps Michael thought of that when writing his question:
The JVM bytecode is a pure stackbased one while the Dalvik one uses 
registers.

Regards,
Sven