[GOOGLE] Fix AutoFDO LIPO ICE due to eliminated abstract origin

[Teresa Johnson]

The ICE is, because we create a new node when querying the node during
symtab_remove_unreachable_nodes after LIPO linking is complete, and
then try to access its resolved node, for which there is none. Trunk
has the same code in these two locations, but the creation of a new
node after deleting the first does not cause any problems.
Teresa

On Sat, Aug 23, 2014 at 11:50 AM, Xinliang David Li <davidxl@google.com> wrote:
> Is it a problem specific to LIPO?
>
> David
>
> On Sat, Aug 23, 2014 at 11:41 AM, Teresa Johnson <tejohnson@google.com> wrote:
>> This patch ensures we don't prematurely delete an abstract origin node, leading
>> to creating a new one after LIPO linking when we invoke similar handling in
>> symtab_remove_unreachable_nodes, which then does not have a resolved node. It
>> makes the handling of such nodes equivalent to that in
>> symtab_remove_unreachable_nodes.
>>
>> Tested with regression tests and internal benchmarks. Ok for google/4_9
>>
>> 2014-08-23  Teresa Johnson  <tejohnson@google.com>
>>
>>         Google ref b/16731481
>>         * cgraphunit.c (analyze_functions): Don't remove origin node.
>>
>> Index: cgraphunit.c
>> ===================================================================
>> --- cgraphunit.c        (revision 214320)
>> +++ cgraphunit.c        (working copy)
>> @@ -1051,6 +1051,7 @@ analyze_functions (void)
>>                   struct cgraph_node *origin_node
>>                   = cgraph_get_node (DECL_ABSTRACT_ORIGIN (decl));
>>                   origin_node->used_as_abstract_origin = true;
>> +                 enqueue_node (origin_node);
>>                 }
>>             }
>>           else
>>
>> --
>> Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413



-- 
Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413