Source module last modified on Thu, 2 Jul 1998, 23:17;
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for2html on Sun, 23 Jun 2002, 15:10.
subroutine dcopy(n,dx,incx,dy,incy)
#
# copies a vector, x, to a vector, y.
# uses unrolled loops for increments equal to one.
# jack dongarra, linpack, 3/11/78.
# modified 12/3/93, array(1) declarations changed to array(*)
#
double precision dx(*),dy(*)
integer i,incx,incy,ix,iy,m,mp1,n
#
if(n<=0)return
if(incx==1&&incy==1)go to 20
#
# code for unequal increments or equal increments
# not equal to 1
#
ix = 1
iy = 1
if(incx<0)ix = (-n+1)*incx + 1
if(incy<0)iy = (-n+1)*incy + 1
do 10 i = 1,n
dy(iy) = dx(ix)
ix = ix + incx
iy = iy + incy
10 continue
return
#
# code for both increments equal to 1
#
#
# clean-up loop
#
20 m = mod(n,7)
if( m == 0 ) go to 40
do 30 i = 1,m
dy(i) = dx(i)
30 continue
if( n < 7 ) return
40 mp1 = m + 1
do 50 i = mp1,n,7
dy(i) = dx(i)
dy(i + 1) = dx(i + 1)
dy(i + 2) = dx(i + 2)
dy(i + 3) = dx(i + 3)
dy(i + 4) = dx(i + 4)
dy(i + 5) = dx(i + 5)
dy(i + 6) = dx(i + 6)
50 continue
return
end