from Monica:
I ran Scimark2 on the 1P/2C machine (we call it Silver) using 64 bit b76
and found only SparseCompRow to be giving lower scores

from Vladimir:
The regression was introduced after build 48 of 1.6.0 VM which prevents
unrolling of the innermost loop:

/java/re/jdk/1.6.0/promoted/all/b48/binaries/solaris-amd64/bin/java -d64
Sparse matmult (N=1000, nz=5000): 451.5053582898381

/java/re/jdk/1.6.0/promoted/all/b49/binaries/solaris-amd64/bin/java -d64
Sparse matmult (N=1000, nz=5000): 365.7142987543227