This should fix PR53616, loop distribution can change partition
ordering when merging non-builtin partitions again, not honoring
read-after-write dependences. The patch simply avoids any change
in ordering.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2012-07-23 Richard Guenther <rguent...@suse.de>
PR tree-optimization/53616
* tree-loop-distribution.c (ldist_gen): Do not change
partition ordering when merging partitions.
Index: gcc/tree-loop-distribution.c
===================================================================
*** gcc/tree-loop-distribution.c (revision 189777)
--- gcc/tree-loop-distribution.c (working copy)
*************** ldist_gen (struct loop *loop, struct gra
*** 1289,1304 ****
nbp = 0;
goto ldist_done;
}
! for (i = 0; VEC_iterate (partition_t, partitions, i, into); ++i)
! if (!partition_builtin_p (into))
! break;
! for (++i; VEC_iterate (partition_t, partitions, i, partition); ++i)
! if (!partition_builtin_p (partition))
! {
! bitmap_ior_into (into->stmts, partition->stmts);
! VEC_ordered_remove (partition_t, partitions, i);
! i--;
! }
}
else
{
--- 1289,1313 ----
nbp = 0;
goto ldist_done;
}
! /* Only fuse adjacent non-builtin partitions, see PR53616.
! ??? Use dependence information to improve partition ordering. */
! i = 0;
! do
! {
! for (; VEC_iterate (partition_t, partitions, i, into); ++i)
! if (!partition_builtin_p (into))
! break;
! for (++i; VEC_iterate (partition_t, partitions, i, partition); ++i)
! if (!partition_builtin_p (partition))
! {
! bitmap_ior_into (into->stmts, partition->stmts);
! VEC_ordered_remove (partition_t, partitions, i);
! i--;
! }
! else
! break;
! }
! while ((unsigned) i < VEC_length (partition_t, partitions));
}
else
{
