On Tue, Apr 05, 2005 at 07:24:44AM +0300, [EMAIL PROTECTED] wrote:
> Hi guys/ladies,
>
> I'm currently designing an ISA add-on to the MIPS architecture. My
> intention is to use it (it is an algorithm accelerator actually) as a
> COP2 (coprocessor #2). The corresponding microarchitecture is stable
> (works at register-transfer level, not subject to change). Plus, I
> would be happy NOT TO CHANGE my ISA add-on.
>
> My problem is that I would like to access specific indices in the data
> register file of COP2, i.e. registers c2r0 to c2r31. This should be
> done in inline assembly or else I'll have to put down probably 2k-3k
> C-lines in assembly :-)
>
> Is it possible to write down something like this:
>
> asm("cop2a %0, %1;", :: "r" (cp2rb(i)) : "r" (cp2rb(j)));
If GCC knows about the registers on the coprocessor, then you can use
local register variables for this:
long c2r0 asm ("c2r0");
If it doesn't, then you should probably not be telling GCC about them.
Assuming i is constant:
asm volatile ("cop2a c2r" STRINGIFY(i) ", c2r" STRINGIFY(j) );
--
Daniel Jacobowitz
CodeSourcery, LLC
