6000 matmuls CG unprec
2000 matmuls CG prec (4000 eo muls)
1050 matmuls PGCR on 16^3 x 32 x 8 m=.01
Substantial effort on timing and logging infrastructure
connect the "Real" default precisoin to a configure flag.
Have RealF, RealD and Real types, where Real is compile target dependent single/double,
RealF is single and RealD is double etc..
but non-identity matrix
l1 0 0 0 ....
0 l2 0 0 ....
0 0 l3 0 ...
. . .
. . .
. . .
And apply the multishift CG to it. Sum the poles and residues.
Insist that this be the same as the exactly taken square root
where l1,l2,l3 >= 0.
