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Re: Vectorizing HIRLAM 1: This dependence is determinable.
- From: Toon Moene <toon at moene dot indiv dot nluug dot nl>
- To: DORIT at il dot ibm dot com, toon at moene dot indiv dot nluug dot nl
- Cc: fortran at gcc dot gnu dot org, gcc at gcc dot gnu dot org
- Date: Sat, 22 Oct 2005 12:12:23 +0200
- Subject: Re: Vectorizing HIRLAM 1: This dependence is determinable.
This one does get vectorized with autovect-branch:
[ example with source and destination array exactly overlapping ]
~/autovect_cvs/bin/gfortran -O3 -ftree-vectorize -maltivec
-ftree-vectorizer-verbose=4 -S hilaram1.f90
hilaram1.f90:5: note: dependence distance = 0.
hilaram1.f90:5: note: accesses have the same alignment.
hilaram1.f90:5: note: dependence distance modulo vf == 0 between
(*a_25)[D.949_60] and (*a_25)[D.949_60]
hilaram1.f90:5: note: Alignment of access forced using peeling.
hilaram1.f90:5: note: Vectorizing an unaligned access.
hilaram1.f90:5: note: LOOP VECTORIZED.
hilaram1.f90:9: note: vectorized 1 loops in function.
dorit
Indeed, it works on x86_64-unknown-linux-gnu too, with the
autovect branch.
> L.S.,
>
> This code:
>
> SUBROUTINE S(N, M)
> DIMENSION A(N, M), B(N, M)
> READ*,A,B
> DO J = 1, M
> DO I = 1, N
> A(I, J) = A(I, J) + B(I, J)
> ENDDO
> ENDDO
> PRINT*,A
> END
Unfortunately, it's only this example that works. I still see
a lot of cases when using the autovect branch compiler on HIRLAM.
I'll try to distill another example.
Kind regards,
--
Toon Moene - e-mail: toon@moene.indiv.nluug.nl - phone: +31 346 214290
Saturnushof 14, 3738 XG Maartensdijk, The Netherlands
A maintainer of GNU Fortran 95: http://gcc.gnu.org/fortran/