Hi,
I found the problem. It was pretty obvious - we compute sum of times twice.
Once when computing statement sizes and second time by summing the summaries.
because sreal is not distributive, it leads to different results.
I have comitted the following patch. Incrementally I will drop the
code duplication.
Bootstrapped/regtested x86_64-linux
Honza
--- trunk/gcc/ipa-inline-analysis.c 2017/05/07 19:41:09 247728
+++ trunk/gcc/ipa-inline-analysis.c 2017/05/07 22:21:05 247729
@@ -3119,12 +3120,13 @@
info->size = info->self_size;
info->stack_frame_offset = 0;
info->estimated_stack_size = info->estimated_self_stack_size;
- if (flag_checking)
- {
- inline_update_overall_summary (node);
- gcc_assert (!(info->time - info->self_time).to_int ()
- && info->size == info->self_size);
- }
+
+ /* Code above should compute exactly the same result as
+ inline_update_overall_summary but because computation happens in
+ different order the roundoff errors result in slight changes. */
+ inline_update_overall_summary (node);
+ gcc_assert (!(info->time - info->self_time).to_int ()
+ && info->size == info->self_size);
}
