On Tue, 3 Jan 2012, Jakub Jelinek wrote:
> Hi!
>
> My previous patch apparently wasn't enough. If at add_mem_*
> time mem_elt is still its own canonical cselib_val, but only afterwards
> new_elt_loc_list adds a new canonical cselib_val to it (and moves
Hm, shouldn't an existing cselib_val be always the canonical one?
> over its locs), then we can still crash in cselib_invalidate_mem.
> This patch ensures that new_elt_loc_list when moving over the locs also
> adds the canonical cselib_val to first_containing_mem list if it
> wasn't already there and the old val was (it would be better to
> remove it, but the chain is only single linked list and it would be
> expensive to remove it there - the next cselib_invalidate_mem
> will handle it automatically, as non-canonical values don't have any mem
> locs and thus are removed from the chain).
> In cselib_invalidate_mem it needs to call canonical_cselib_val on the
> addr_list chain elts (those aren't canonicalized by anything).
> There is no need to call canonical_cselib_val on v, the new_elt_loc_list
> change ensures that the canonical value is in the list always too
> and non-canonical values don't have MEM locs.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, tested with
> cross jc1 to ia64-linux on gnu-CORBA.list compilation. Ok for trunk?
>
> 2012-01-03 Jakub Jelinek <ja...@redhat.com>
>
> PR bootstrap/51725
> * cselib.c (new_elt_loc_list): When moving locs from one
> cselib_val to its new canonical_cselib_val and the
> cselib_val was in first_containing_mem chain, but
> the canonical_cselib_val was not, add the latter into the
> chain.
> (cselib_invalidate_mem): Compare canonical_cselib_val of
> addr_list chain elt with v.
>
> --- gcc/cselib.c.jj 2012-01-03 16:22:48.000000000 +0100
> +++ gcc/cselib.c 2012-01-03 17:29:10.096229315 +0100
> @@ -277,6 +277,12 @@ new_elt_loc_list (cselib_val *val, rtx l
> }
> el->next = val->locs;
> next = val->locs = CSELIB_VAL_PTR (loc)->locs;
> + if (CSELIB_VAL_PTR (loc)->next_containing_mem != NULL
> + && val->next_containing_mem == NULL)
> + {
> + val->next_containing_mem = first_containing_mem;
> + first_containing_mem = val;
> + }
> }
>
> /* Chain LOC back to VAL. */
> @@ -2211,7 +2217,7 @@ cselib_invalidate_mem (rtx mem_rtx)
> mem_chain = &addr->addr_list;
> for (;;)
> {
> - if ((*mem_chain)->elt == v)
> + if (canonical_cselib_val ((*mem_chain)->elt) == v)
> {
> unchain_one_elt_list (mem_chain);
> break;
>
> Jakub
>
>
--
Richard Guenther <rguent...@suse.de>
SUSE / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
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