On Sat, Jan 14, 2006 at 02:21:20AM +0100, Philippe De Muyter wrote: > For an embedded mmu-less m68k target, I would like to generate code > that will always run at a fixed place in memory, thus not needing to be PIC, > but that would access a data+bss segment that could be anywhere in memory, > thus needing accesses to the data segment via %a5 and an offset table. > > 1. Does that possibility already exist in gcc (I did not find it) ? > -msep-data currently does PI-text + PI-data.
AFAICT, this doesn't exist within mainline GCC. The AmigaOS port (which isn't part of the official sources) implements this scheme, either with 16bit or 32bit displacements. The latter requires a 68020 or better. Note, you need binutils support as well. > 2. If it does not exist, I plan to integrate it. > - From which release or branch should I start ? > I'd like to work on something that is stable except for my changes. You have to use current mainlines sources. > - How is it currently possible in the gcc internals to know if a > SYMBOL_REF points to the .text or .rodata segments ? The AmigaOS port uses SYMBOL_REF_FLAG to record this information. I believe SYMBOL_REF_FLAG is deprecated and there is a newer functionality to achieve the same. Gunther
