On 06/14/2017 12:41 PM, Thomas Koenig wrote: > Hello world, > > the attached patch implements a blocked algorithm for > improving the speed of cshift for dim > 1. > > It uses the fact that > > integer, dimension (n1,n2,n3) :: a, b > > b = cshift(a,shift,3) > > is identical, as far as the memory locations is concerned. > > integer, dimension (n1*n2*n3) :: c, d > d = cshift(c, shift*n1*n2, 1) > > The speedup is quite large; from being really slow for > dim > 1, this patch makes it go even faster. > > Below there are some comparisons for the attached benchmark, > do-1.f90. gfortran-7 uses the old library version. > > Interestingly, the library version is also much faster > than an implementation of straight DO loops. > > Regression-tested. OK for trunk? >
OK for trunk. Thanks, Jerry
