On Monday 28 June 2004 12:44, Mircea Namolaru wrote:
We started to implement IPA constant propagation
(see http://gcc.gnu.org/ml/gcc/2004-06/msg00518.html) and also look
into
some related IPA alias analysis issues.
As we understand it, your proposal targets static variables only.
Extending
the analysis to reference formal arguments may detect aliasing
introduced
by
parameter passing (in Fortran this is the only way two variables can
alias).
No they can't. Aliasing of variables through procedure arguments is
prohibited
by the standard.
For example the following program is illegal:
subroutine foo (a, b)
integer a, b
! This invokes undefined behaviour if the same actual argument
! is passed for a and b
a = 1
print *, b
end subroutine
program illegal
integer i
call foo (i, i)
end program