Mainline space problem

[Robert Dewar]

James E Wilson wrote:

> What I said, in both previous messages, is that we have too
> many pseudo regs.  The common case is a small enough number of pseudos
> such that the quadratic memory allocation here isn't a problem.

I absolutely agree that the problem is too many pseudo-registers.
There is no justification for the large number we see here.

When you have performance of N**2/K

increasing K by a small factor is likely to be much less
significant than reducing N or the 2. Now it is true that using
a sparse matrix representation would indeed reduce the 2, but
I agree with JW that this would likely introduce unacceptable
overhead.