subroutinesscalf(n,sa,sx,incx)
c
cscalesavectorbyaconstant.
cusesunrolledloopsforincrementequalto1.
cjackdongarra,linpack,3/11/78.
cmodified3/93toreturnifincx.le.0.
cmodified12/3/93,array(1)declarationschangedtoarray(*)
c
realsa,sx(*)
integeri,incx,m,mp1,n,nincx
c
if(n.le.0.or.incx.le.0)return
if(incx.eq.1)go to20
c
ccodeforincrementnotequalto1
c
nincx=n*incx
do10i=1,nincx,incx
sx(i)=sa*sx(i)
10continue
return
c
ccodeforincrementequalto1
c
c
cclean-uploop
c
20m=mod(n,5)
if(m.eq.0)go to40
do30i=1,m
sx(i)=sa*sx(i)
30continue
if(n.lt.5)return
40mp1=m+1
do50i=mp1,n,5
sx(i)=sa*sx(i)
sx(i+1)=sa*sx(i+1)
sx(i+2)=sa*sx(i+2)
sx(i+3)=sa*sx(i+3)
sx(i+4)=sa*sx(i+4)
50continue
return
end