PowerPC code generation

Franz Sirl Franz.Sirl-kernel@lauterbach.com
Wed Jul 5 13:53:00 GMT 2000


At 22:26 05.07.00, Geoff Keating wrote:
>"David J Schinsing" <dxs@pt.com> writes:
>
> >    What can I do to get gcc to generate byte-reversed loads and stores
> > (like the lwbrx instruction, for example).  Perhaps there's a way to define
> > a structure so as to generate them?
>
>You can use asm statements, like
>
>asm ("lwbrx %0, 0, %1" : "=r"(result) : "r"(&input), "X"(input));
>
>at present, there is no way to have gcc generate such code without
>using asm statements.

Just out of interest, if I would implement __attribute__((little_endian)) 
and __attribute__((big_endian)) for MEM's, basically the major work would 
be to create something like a "revmovsi" pattern in the .md and tell 
compiler how to use it, or? Which pass of the compiler would be responsible 
for that? reload?

Franz.



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