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subroutine mxv(a,ncol,b,nrow,c)
C$Id: mxv_daxpy1.f,v 1.2 1995-02-02 23:24:19 d3g681 Exp $
implicit double precision (a-h, o-z)
dimension a(ncol, nrow), b(nrow), c(ncol)
parameter (nchunk = 800)
c
c matrix vector product stripmined to optimize cache usage
c when inner loop is replaced with a daxpy that uses pipelined
c loads for a to avoid writing over c in the cache.
c
do 10 ilo = 1, ncol, nchunk
ihi = min(ncol, ilo+nchunk-1)
ndo = ihi - ilo + 1
do 20 i = ilo, ihi
c(i) = 0.0d0
20 continue
do 30 j = 1, nrow
c do 40 i = ilo, ihi
c c(i) = c(i) + a(i,j)*b(j)
c40 continue
call daxpy1(ndo, b(j), a(ilo, j), c(ilo))
30 continue
10 continue
c
end
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