test

Sun Studio 12: Fortran Programming Guide

7.6.2.2 Aliasing Introduced With Cray Pointers

This example works only when compiled with -xalias=craypointer, which is the default:


parameter (n=20)
integer a(n)
integer v1(*), v2(*)
pointer (p1,v1)
pointer (p2,v2)
p1 = loc(a)
p2 = loc(a)
a = (/ (i,i=1,n) /)
...
v1(2:n) = v2(1:n-1)
The compiler must assume that these locations can overlap.

Here is an example of Cray pointers that do not overlap. In this case, compile with -xalias=no%craypointer for possibly better performance:


parameter (n=10)
integer a(n+n)
integer v1(n), v2(n)
pointer (p1,v1)
pointer (p2,v2)
p1 = loc(a(1))
p2 = loc(a(n+1))
...
v1(:) = v2(:)
The Cray pointers to not point to overlapping memory areas.