Re: Embedding data in the code stream

[Paul Cercueil]

Why don't you simply malloc your object, and tell Lightning to emit 
code at offset (e.g.) 0x100? Then your first 0x100 bytes would be for 
meta-data use.

Cheers,
-Paul

Le jeu., août 11 2022 at 12:44:08 +0200, Marc Nieper-Wißkirchen 
<marc.nieper+gnu@gmail.com> a écrit :
> Am Do., 11. Aug. 2022 um 12:28 Uhr schrieb Paul Cercueil 
> <paul@crapouillou.net>:
> > Hi Marc,
> >
> >  Obvious questions first: why would you do that?
>
> Say, I want to implement a VM using GNU lightning.  Code objects 
> would be first-class objects.  Some information (e.g. for the garbage 
> collector) would need to be attached to such code objects to remove 
> the need for an extra pointer indirection.
>
> An example:
>
> jit_align (16);
> jit_data_ui (meta_information);
> jit_align (16);
> entry = label_indirect ();
> /* the actual code */
> ...
> unsigned char *addr = jit_address (entry);
> unsigned int info = * (unsigned int *) (addr - 16);