Re: Porting to arm/aarch64

This just got a bit more urgent as Apple announced that new Macs will use ARM rather than Intel processors!

On 15 Jun 2020 10:51 am, Jasper Taylor <[email protected]> wrote:



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] > 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