This patch by Tobias fixes PR50561.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2012-02-15 Tobias Grosser <gros...@fim.uni-passau.de>
PR tree-optimization/50561
* graphite-flattening.c (lst_project_loop): Do not
remove old scattering dimensions after flattening.
(lst_do_flatten): Likewise.
* gcc.dg/graphite/pr50561.c: New testcase.
Index: gcc/graphite-flattening.c
===================================================================
*** gcc/graphite-flattening.c (revision 184259)
--- gcc/graphite-flattening.c (working copy)
*************** lst_project_loop (lst_p outer, lst_p inn
*** 277,288 ****
ppl_delete_Linear_Expression (expr);
/* Remove inner loop and the static schedule of its body. */
! ds = XNEWVEC (ppl_dimension_type, 2);
! ds[0] = inner_dim;
! ds[1] = inner_dim + 1;
! ppl_Polyhedron_remove_space_dimensions (poly, ds, 2);
! PBB_NB_SCATTERING_TRANSFORM (pbb) -= 2;
! free (ds);
}
mpz_clear (x);
--- 277,302 ----
ppl_delete_Linear_Expression (expr);
/* Remove inner loop and the static schedule of its body. */
! /* FIXME: As long as we use PPL we are not able to remove the old
! scattering dimensions. The reason is that these dimensions are not
! entirely unused. They are not necessary as part of the scheduling
! vector, as the earlier dimensions already unambiguously define the
! execution time, however they may still be needed to carry modulo
! constraints as introduced e.g. by strip mining. The correct solution
! would be to project these dimensions out of the scattering polyhedra.
! In case they are still required to carry modulo constraints they
should be kept
! internally as existentially quantified dimensions. PPL does only
support
! projection of rational polyhedra, however in this case we need an
integer
! projection. With isl this will be trivial to implement. For now we
just
! leave the dimensions. This is a little ugly, but should be correct. */
! if (0) {
! ds = XNEWVEC (ppl_dimension_type, 2);
! ds[0] = inner_dim;
! ds[1] = inner_dim + 1;
! ppl_Polyhedron_remove_space_dimensions (poly, ds, 2);
! PBB_NB_SCATTERING_TRANSFORM (pbb) -= 2;
! free (ds);
! }
}
mpz_clear (x);
*************** lst_do_flatten (lst_p lst)
*** 412,418 ****
if (LST_LOOP_P (l))
{
res |= lst_flatten_loop (l, zero);
! remove_unused_scattering_dimensions (l);
}
lst_update_scattering (lst);
--- 426,446 ----
if (LST_LOOP_P (l))
{
res |= lst_flatten_loop (l, zero);
!
! /* FIXME: As long as we use PPL we are not able to remove the old
! scattering dimensions. The reason is that these dimensions are not
! entirely unused. They are not necessary as part of the scheduling
! vector, as the earlier dimensions already unambiguously define the
! execution time, however they may still be needed to carry modulo
! constraints as introduced e.g. by strip mining. The correct solution
! would be to project these dimensions out of the scattering polyhedra.
! In case they are still required to carry modulo constraints they
should be kept
! internally as existentially quantified dimensions. PPL does only
support
! projection of rational polyhedra, however in this case we need an
integer
! projection. With isl this will be trivial to implement. For now we
just
! leave the dimensions. This is a little ugly, but should be correct.
*/
! if (0)
! remove_unused_scattering_dimensions (l);
}
lst_update_scattering (lst);
Index: gcc/testsuite/gcc.dg/graphite/pr50561.c
===================================================================
*** gcc/testsuite/gcc.dg/graphite/pr50561.c (revision 0)
--- gcc/testsuite/gcc.dg/graphite/pr50561.c (revision 0)
***************
*** 0 ****
--- 1,9 ----
+ /* { dg-do compile } */
+ /* { dg-options "-O2 -floop-flatten -floop-strip-mine" } */
+
+ void f (unsigned *s)
+ {
+ int n;
+ for (n = 0; n < 256; n++)
+ s[n] = 0;
+ }
