re PR ipa/63576 (ICE : in ipa_merge_profiles, at ipa-utils.c:540 during Firefox LTO/PGO build)

	PR ipa/63576
	* ipa-utils.c (ipa_merge_profiles): Merge speculative edges.

From-SVN: r219910

1 files changed, 84 insertions, 8 deletions

diff --git a/gcc/ipa-utils.c b/gcc/ipa-utils.c
index bc538c5..7612548 100644
--- a/gcc/ipa-utils.c
+++ b/gcc/ipa-utils.c
@@ -539,7 +539,7 @@ ipa_merge_profiles (struct cgraph_node *dst,
     }
   if (match)
     {
-      struct cgraph_edge *e;
+      struct cgraph_edge *e, *e2;
       basic_block srcbb, dstbb;
 
       /* TODO: merge also statement histograms.  */
@@ -562,19 +562,95 @@ ipa_merge_profiles (struct cgraph_node *dst,
       pop_cfun ();
       for (e = dst->callees; e; e = e->next_callee)
 	{
-	  gcc_assert (!e->speculative);
+	  if (e->speculative)
+	    continue;
 	  e->count = gimple_bb (e->call_stmt)->count;
 	  e->frequency = compute_call_stmt_bb_frequency
 			     (dst->decl,
 			      gimple_bb (e->call_stmt));
 	}
-      for (e = dst->indirect_calls; e; e = e->next_callee)
+      for (e = dst->indirect_calls, e2 = src->indirect_calls; e;
+	   e2 = (e2 ? e2->next_callee : NULL), e = e->next_callee)
 	{
-	  gcc_assert (!e->speculative);
-	  e->count = gimple_bb (e->call_stmt)->count;
-	  e->frequency = compute_call_stmt_bb_frequency
-			     (dst->decl,
-			      gimple_bb (e->call_stmt));
+	  gcov_type count = gimple_bb (e->call_stmt)->count;
+	  int freq = compute_call_stmt_bb_frequency
+			(dst->decl,
+			 gimple_bb (e->call_stmt));
+	  /* When call is speculative, we need to re-distribute probabilities
+	     the same way as they was.  This is not really correct because
+	     in the other copy the speculation may differ; but probably it
+	     is not really worth the effort.  */
+	  if (e->speculative)
+	    {
+	      cgraph_edge *direct, *indirect;
+	      cgraph_edge *direct2 = NULL, *indirect2 = NULL;
+	      ipa_ref *ref;
+
+	      e->speculative_call_info (direct, indirect, ref);
+	      gcc_assert (e == indirect);
+	      if (e2 && e2->speculative)
+	        e2->speculative_call_info (direct2, indirect2, ref);
+	      if (indirect->count || direct->count)
+		{
+		  /* We should mismatch earlier if there is no matching
+		     indirect edge.  */
+		  if (!e2)
+		    {
+		      if (dump_file)
+		        fprintf (dump_file,
+				 "Mismatch in merging indirect edges\n");
+		    }
+		  else if (!e2->speculative)
+		    indirect->count += e2->count;
+		  else if (e2->speculative)
+		    {
+		      if (DECL_ASSEMBLER_NAME (direct2->callee->decl)
+			  != DECL_ASSEMBLER_NAME (direct->callee->decl))
+			{
+			  if (direct2->count >= direct->count)
+			    {
+			      direct->redirect_callee (direct2->callee);
+			      indirect->count += indirect2->count
+						 + direct->count;
+			      direct->count = direct2->count;
+			    }
+			  else
+			    indirect->count += indirect2->count + direct2->count;
+			}
+		      else
+			{
+			   direct->count += direct2->count;
+			   indirect->count += indirect2->count;
+			}
+		    }
+		  int  prob = RDIV (direct->count * REG_BR_PROB_BASE ,
+				    direct->count + indirect->count);
+		  direct->frequency = RDIV (freq * prob, REG_BR_PROB_BASE);
+		  indirect->frequency = RDIV (freq * (REG_BR_PROB_BASE - prob),
+					      REG_BR_PROB_BASE);
+		}
+	      else
+		/* At the moment we should have only profile feedback based
+		   speculations when merging.  */
+		gcc_unreachable ();
+	    }
+	  else if (e2->speculative)
+	    {
+	      cgraph_edge *direct, *indirect;
+	      ipa_ref *ref;
+
+	      e2->speculative_call_info (direct, indirect, ref);
+	      e->count = count;
+	      e->frequency = freq;
+	      int prob = RDIV (direct->count * REG_BR_PROB_BASE, e->count);
+	      e->make_speculative (direct->callee, direct->count,
+				   RDIV (freq * prob, REG_BR_PROB_BASE));
+	    }
+	  else
+	    {
+	      e->count = count;
+	      e->frequency = freq;
+	    }
 	}
       src->release_body ();
       inline_update_overall_summary (dst);