01.11.2017 10:46, Sven Barth via fpc-devel wrote:
Am 01.11.2017 05:58 schrieb "J. Gareth Moreton" <gar...@moreton-family.com <mailto:gar...@moreton-family.com>>:Would it be worth opening up a bug report for this, with the attached assembler routines as suggestions? I haven't worked out how to implement internal functions into the compiler yet, and I rather clear it with you guys first before I make such an addition. I had a thought that the simple routines above could be used for when compiling for small code size, while larger, more advanced ones are used for when compiling for speed. Improvements like these are always welcome. Two points however:The Fill* routines are not part of the compiler, but of the RTL (the Pascal routines are in rtl/inc/generic.inc, the assembly ones reside in rtl/CPU/CPU.inc) and they aren't handled differently depending on the current optimization flags, so a one-size-fits-all is needed (look at e.g. the i386 ones). I also think that you might need to handle memory that isn't correctly aligned for the assembler instructions (I didn't look at your routines in detail so I don't know whether they'd need to be adjusted for that). A check of the i386 routines will probably help here as well.
Another important thing to note is that all modifications to stack pointer and nonvolatile registers on x86_64 need SEH annotations in win64 and CFI annotations on linux/bsd. The former is available only in AT&T syntax, the latter is not supported. This requierment, together with different parameter locations, makes writing assembler routines for x86_64 much more complicated than for i386. For this reason, existing assembler routines in RTL avoid using nonvolatile registers as much as possible.
Regards, Sergei _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
