PR bootstrap/50709 (bootstrap miscompare)
Tue Oct 25 16:47:00 GMT 2011
On Thu, Oct 20, 2011 at 5:23 AM, Jan Hubicka <firstname.lastname@example.org> wrote:
>> @@ -1392,16 +1393,20 @@ inline_small_functions (void)
>> if (!edge->inline_failed)
>> - /* Be sure that caches are maintained consistent. */
>> #ifdef ENABLE_CHECKING
>> + /* Be sure that caches are maintained conservatively consistent.
>> + This means that cached badness is allways smaller or equal
>> + to the real badness. */
>> + cached_badness = edge_badness (edge, false);
>> reset_edge_growth_cache (edge);
>> reset_node_growth_cache (edge->callee);
>> /* When updating the edge costs, we only decrease badness in the keys.
>> Increases of badness are handled lazilly; when we see key with out
>> of date value on it, we re-insert it now. */
>> current_badness = edge_badness (edge, false);
>> + gcc_assert (cached_badness == -1 || cached_badness <= current_badness);
> This new check actually cathes a bug that is in tree since introduction of new
> ipa-inline-analysis code. The inliner assume that when it produce a new inline
> copy, the overall growth estimates for all callees can only degrade. This is
> not quite true: when a new knowledge is propagated, the callees might actually
> become cheaper and reduce the growth.
> This patch takes the easy but expensive way to plug the problem by forcing
> updating of all keys in the queue. It increases LTO compile time of Mozilla to
> 10 minutes, so I will need to develop better sollution. (the trick saving
> recomputation was originally introduced to reduce copmile time particularly on
> this testcase) Just I should not keep tree ICEing on many C++ sources until I
> am done.
> Bootstrapped/regtested x86_64-linux, comitted.
> Index: ChangeLog
> --- ChangeLog (revision 180247)
> +++ ChangeLog (working copy)
> @@ -1,5 +1,10 @@
> 2011-10-19 Jan Hubicka <email@example.com>
> + * ipa-inline.c (inline_small_functions): Always update all calles after
> + inlining.
> +2011-10-19 Jan Hubicka <firstname.lastname@example.org>
> PR bootstrap/50709
> * ipa-inline.c (inline_small_functions): Fix checking code to not make
> effect on fibheap stability.
Those changes may have caused:
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