------- Comment #13 from spop at gcc dot gnu dot org 2007-06-26 16:03 -------
Subject: Re: [4.3 Regression] Complete program optimized away (i686,
-ftree-vectorize)
I just reduced the problem to this snippet: the problem seems to be
that the data dependence analysis is wrong by answering that there is
no dependence on the first loop on RBOUND(N) and RBOUND(N-1) accesses
so I'll have to correct that.
SUBROUTINE KEEL(RBOUND)
REAL, DIMENSION(0:100) :: RBOUND
DO N = 1, NP1
RBOUND(N) = RBOUND(N-1) + 1
END DO
DO N = 1, NS
WRITE (16,'(I5)') SRAD(N)
END DO
END SUBROUTINE KEEL
An auxiliary question, as I'm not programming in FORTRAN, is it okay
to have RBOUND(N-1) for N=1? I thought that the array indices start
from 1, and not from 0. As this is in the polyhedron benchmark, I
would say that it is valid code, but I'm a bit shocked ;-)
Sebastian
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32457
