The situation you described is worse -- hopefully it will be addressed
in the next version of lipo.
The change is ok.
David
On Tue, Oct 29, 2013 at 10:08 AM, Dehao Chen <de...@google.com> wrote:
> On Mon, Oct 28, 2013 at 9:49 PM, Xinliang David Li <davi...@google.com> wrote:
>> Is it sufficient to check if the final caller is defined in primary module?
>
> This might not be sufficient because the final caller may come from
> comdat of aux-modules (not defined in the primary module).
>
>>
>> Note that in some cases, doing profile update 'speculatively' (without
>> your fix) can be more precise (assuming the inlining gets materialized
>> in a different compilation), but in general it might be better to be
>> conservative in profile update (as in your patch) -- the downside is
>> you may end up with less aggressive size optimization.
>
> This is actually no speculatively update profile, but double update.
>
> E.g. comdat_foo()-->bar() with count 100
>
> and comdat_foo() has been defined in 2 aux-modules. Then there will be
> two edges from comdat_foo()-->bar(), each of which has the count 100.
> But bar()'s entry count is only 100 (assume comdat_foo is the only
> caller). Then if we update bar() twice when inline these two edges,
> the second update will be wrong.
>
> Dehao
>
>>
>> David
>>
>> On Mon, Oct 28, 2013 at 3:51 PM, Dehao Chen <de...@google.com> wrote:
>>> This patch changes to no update callee count if caller count is not a
>>> resolved node (in LIPO mode) during AutoFDO compilation. This is
>>> because AutoFDO will have the same edge counts for all unresolved
>>> nodes. Original update method will lead to multi-update of the callee.
>>>
>>> Bootstrapped and testing on going.
>>>
>>> OK for google-4_8 if test is OK?
>>>
>>> Thanks,
>>> Dehao
>>>
>>> Index: gcc/ipa-inline-transform.c
>>> ===================================================================
>>> --- gcc/ipa-inline-transform.c (revision 204131)
>>> +++ gcc/ipa-inline-transform.c (working copy)
>>> @@ -169,6 +169,15 @@ clone_inlined_nodes (struct cgraph_edge *e, bool d
>>> else
>>> {
>>> struct cgraph_node *n;
>>> + if (flag_auto_profile && L_IPO_COMP_MODE
>>> + && cgraph_pre_profiling_inlining_done)
>>> + {
>>> + struct cgraph_node *caller = e->caller;
>>> + if (caller->global.inlined_to)
>>> + caller = caller->global.inlined_to;
>>> + if (cgraph_lipo_get_resolved_node (caller->symbol.decl) != caller)
>>> + update_original = false;
>>> + }
>>> n = cgraph_clone_node (e->callee, e->callee->symbol.decl,
>>> e->count, e->frequency,
>>> update_original, vNULL, true);
