Re: [PATCH, pretty-ipa] Fix wave ICE in SRA

[Richard Guenther <richard dot guenther at gmail dot com>]

2009/4/29 Martin Jambor <mjambor@suse.cz>:
> Hi,
>
> the patch ?below fixes ?an ICE on ?assert in intra-SRA ?when compiling
> boost (this issue is already fixed in the trunk patch).
>
> The problem is that I wrongly assumed that in an assignment in between
> types ?conforming ?to useless_type_conversion_p() ?the ?sizes of ?both
> sides would be the same. ?Obviously ?they need not to be. ?In fact the

Err ...

> RHS ?was ?substantially ?bigger ?in ?this case, ?which ?might ?confuse
> propagating accesses.

... can you share this case?  It looks bogus.

Richard.

> ? I try to ?be as bold ?as I can and ?only limit
> propagation of sub-accesses that would be outside their new base.
>
> The following patch does just ?that, fixes the issue and bootstraps on
> trunk. ?Pretty-ipa ?branch does not bootstrap for ?me, I'll bootstrap,
> test and commit the patch once it does.
>
>
> Thanks,
>
> Martin
>
> 2009-04-29 ?Martin Jambor ?<mjambor@suse.cz>
>
> ? ? ? ?* ipa-sra.c (propagate_subacesses_accross_link): Check that
> ? ? ? ?new sub-accesses would not be outside of their new base.
> ? ? ? ?(build_accesses_from_assign): Remove size equality assert.
>
>
> Index: isra/gcc/ipa-sra.c
> ===================================================================
> --- isra.orig/gcc/ipa-sra.c
> +++ isra/gcc/ipa-sra.c
> @@ -1309,7 +1309,6 @@ build_accesses_from_assign (gimple *stmt
> ? ? {
> ? ? ? struct assign_link *link;
>
> - ? ? ?gcc_assert (lacc->size == racc->size);
> ? ? ? link = (struct assign_link *) pool_alloc (link_pool);
> ? ? ? memset (link, 0, sizeof (struct assign_link));
>
> @@ -3008,19 +3007,19 @@ propagate_subacesses_accross_link (struc
> ?{
> ? struct access *rchild;
> ? HOST_WIDE_INT norm_delta = lacc->offset - racc->offset;
> + ?HOST_WIDE_INT lbase_size = tree_low_cst (DECL_SIZE (lacc->base), 1);
> ? bool ret = false;
>
> - ?if (is_sra_scalar_type (lacc->type) && lacc->grp_unscalarizable_region)
> + ?if (is_sra_scalar_type (lacc->type) || lacc->grp_unscalarizable_region)
> ? ? return false;
>
> - ?gcc_assert (lacc->size == racc->size);
> -
> ? for (rchild = racc->first_child; rchild; rchild = rchild->next_sibling)
> ? ? {
> ? ? ? struct access *new_acc = NULL;
> ? ? ? HOST_WIDE_INT norm_offset = rchild->offset + norm_delta;
>
> - ? ? ?if (rchild->grp_unscalarizable_region)
> + ? ? ?if (rchild->grp_unscalarizable_region
> + ? ? ? ? || norm_offset + rchild->size > lbase_size)
> ? ? ? ?continue;
>
> ? ? ? if (child_would_conflict_in_lacc (lacc, norm_offset, rchild->size,
>