> [ you seem to be living some hors ahead in time ] Yep, sorry about that.
> The problem stays the same: spilling processors to parrot's or > parrots to array. > Thinking a bit more about it, now I believe that the best way to do it would be: (1) First, do a register allocation for machine registers, assuming that there are N machine registers and infinite parrot registers. (2) Second, do a register allocation for parrot registers, using an array as spill area. The first step assures us that we generate code that always puts data in the availabe machine registers, and tries to minimize moves between registers and the physical memory. The second step tries to put all the data in parrot registers, and if it is not able to do that in the parrot spilling area (currently an PerlArray) For example, code generated by (1) would look like: set m3, 1 # m3 is the machine 3d register add m3, m3, 1 print m3 set $I1, m3 # $I1 is a parrot virtual register etc... Then we would do register allocation for the virtual $I1 registers, hoping to be able to put them all in the 32 parrot registers. I believe this would be the optimal way to do it, because it actually models our priorities: first to put all data in physical registers, otherwise try do it in parrot registers. This is better than reserving the machine registers for the most used parrot registers (your original proposal) or doing a pyhsical register allocation and assuming that we have an infinite number of parrot registers (my original proposal). Hope that it know make more sense, -angel
