Xilinx IP core drivers for RTEMS- diff attached

Jiri Gaisler jiri at gaisler.com
Tue Dec 5 23:22:25 UTC 2006


Keith Robertson wrote:

> To summarise, we are successfully using the virtex ppc405 with:
>
> - no explicit c floating point types
> - no fpu
> - no floating point tasks
> - no -msoft-float
> - with newlib
> - with va_args
> - with rtems' gcc-3.2.3
>
> and I haven't (yet) found any fp instructions being generated.


I think that the compiler version is the catch. gcc-3.2.3 does not
seem to use FPU registers for integer operations, while newer versions
of gcc does. I have seen this on the sparc port, where gcc-3.4.4
uses FPU registers to copy integer data unless -msoft-float is given.

Jiri.



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