[PATCH, PR 54394] Compute loops when generating inline summaries

[Martin Jambor]

Hi,

the patch below fixes PR 54394.  The problem is that since revision
190346 we depend on bb->loop_father being non-NULL to get loop_depth.
However, with loops not computed, the loop_father is NULL, loop_depth
is thus considered zero and call graph edges out of such BB can be
considered much cooler, leading to inlining regressions.

This patch fixes that by recomputing loops whenever optimizing, not
only for loop bounds hints.  We might put the computation elsewhere or
do it only under more restrictive circumstances, but I believe that
after rev. 190346 we have to do it.  In particular, I am not sure
whether we had (semi)correct loop_depths when doing early inlining or
not, this patch re-calculates it for early inliner too.

Bootstrapped and tested on x86_64-linux, fixes fatigue run-time on
an x86_64-linux and i686-linux for me.  What do you think?

Thanks,

Martin


2012-08-29  Martin Jambor  <mjam...@suse.cz>

        PR middle-end/54394
        * ipa-inline-analysis.c (estimate_function_body_sizes): Compute
        dominance info and loops whenever optimizing.


Index: src/gcc/ipa-inline-analysis.c
===================================================================
--- src.orig/gcc/ipa-inline-analysis.c
+++ src/gcc/ipa-inline-analysis.c
@@ -2102,6 +2102,11 @@ estimate_function_body_sizes (struct cgr
   info->conds = 0;
   info->entry = 0;
 
+  if (optimize)
+    {
+      calculate_dominance_info (CDI_DOMINATORS);
+      loop_optimizer_init (LOOPS_NORMAL | LOOPS_HAVE_RECORDED_EXITS);
+    }
 
   if (dump_file)
     fprintf (dump_file, "\nAnalyzing function body size: %s\n",
@@ -2270,9 +2275,6 @@ estimate_function_body_sizes (struct cgr
       loop_iterator li;
       predicate loop_iterations = true_predicate ();
 
-      calculate_dominance_info (CDI_DOMINATORS);
-      loop_optimizer_init (LOOPS_NORMAL
-                          | LOOPS_HAVE_RECORDED_EXITS);
       if (dump_file && (dump_flags & TDF_DETAILS))
        flow_loops_dump (dump_file, NULL, 0);
       scev_initialize ();
@@ -2305,12 +2307,15 @@ estimate_function_body_sizes (struct cgr
           *inline_summary (node)->loop_iterations = loop_iterations;
        }
       scev_finalize ();
-      loop_optimizer_finalize ();
-      free_dominance_info (CDI_DOMINATORS);
     }
   inline_summary (node)->self_time = time;
   inline_summary (node)->self_size = size;
   VEC_free (predicate_t, heap, nonconstant_names);
+  if (optimize)
+    {
+      loop_optimizer_finalize ();
+      free_dominance_info (CDI_DOMINATORS);
+    }
   if (dump_file)
     {
       fprintf (dump_file, "\n");