Re: Porting to arm/aarch64

Hi Daniel,

I've read the PORTING file but it's pretty incomplete in describing the 
task. I'm currently stalled trying to figure out how to implement the 
Code_Start function in the translation file. For most of the functions I 
can see where the translation comes from in the output of compiling 
asm_inst.c to assembler, but not for Code_Start -- that seems to depend 
on saving and restoring some registers that Prolog is using, so an 
equivalent cannot be made by the c compiler.

I am using the powerpc_any.c file as a starting point, as I have powerpc 
hardware I can build stuff on and it looks more like a RISC architecture 
so more similar to the ARM than x86.

Also I haven't been able to figure out what registers to use on the ARM, 
as some are call-clobbered and this seems to cause problems for using 
them in assembly language.

Cheers

     Jasper

On 12/06/2020 13:35, Daniel Diaz wrote:
> Hi Jasper,
>
> Sorry for the late reply,
>
> You can have a look at the PORTING file which gives some information 
> about adding a new architecture.
> The main task is to write a mapper from MiniAssembly to Asm. See 
> example files in src/Ma2Asm which contains mapper MA->ASM for various 
> architectures.
> The mappers are written in C (it is a good idea to use another mapper 
> as basis) .Maybe look at the file mips_irix.c file.
> I generally look at the asm generated by gcc (using various 
> optimization flags in order to understand the asm generated, -O0 to -O3).
> For this you can look at src/Ma2Asm/FromC. Do a make (modify Makefile 
> to test with various CFLAGS). It compiles asm_inst.c to asm ; the 
> study of asm_inst.s gives you hints about the translation of MA 
> instructions.
> Maybe you need to adapt the asm_inst.c file.
> Basically it contains C functions whose translation to asm helps you 
> to write the mapper (the name of C functions are useful to know what 
> Ma instruction it corresponds).
>
> Don’t hesitate to write me directly if you need more help (by mail to 
> [email protected]).
>
> Daniel
>
>> Le 30 mai 2020 à 16:39, Jasper Taylor <[email protected] 
>> <mailto:[email protected]>> a écrit :
>>
>> Hi all,
>>
>> I am thinking about trying to port GNU prolog to the ARM architecture 
>> (linux os). Before I get started, has anyone already had a go at 
>> this, if so, how far did you get and what problems did you encounter?
>>
>> Thanks for reading
>>
>>     --Jasper
>>
>>
>>
>