Vector Update: 2D Form

With DAXPY operation in the inner loop, we should consider further optimization with outer loop unrolling and blocking.
- hand tuning was necessary
- compiler would not implement loop interchange because in the original code the loops are not properly nested
- With the DAXPY formulation, we can consider 2-dimensional implementation of that code:

real*8 dp(ni,nj), p(ni,nib)

ndb1=nmb1/2

nde1=nme1/2

id1 =nma1+(i-1)*nru+(l-1)*nra*nrub

do jj=nde1,nj

do n=ndb1,nib

dp_temp=dp(n,jj-nde1)

do ii=1,ni

dp(ii,jj)=dp(ii,jj)+p(ii,jj)*dp_temp

end do

With DAXPY operation in the inner loop, we should consider further optimization with outer loop unrolling and blocking.