Only do a full verify after computing dominators.

src/hydrogen.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 404 matching lines @@
     }
   }
 
   int visited_count_;
   ZoneList<HBasicBlock*> stack_;
   BitVector reachable_;
   HBasicBlock* dont_visit_;
 };
 
 
-void HGraph::Verify() const {
+void HGraph::Verify(bool do_full_verify) const {
   for (int i = 0; i < blocks_.length(); i++) {
     HBasicBlock* block = blocks_.at(i);
 
     block->Verify();
 
     // Check that every block contains at least one node and that only the last
     // node is a control instruction.
     HInstruction* current = block->first();
     ASSERT(current != NULL && current->IsBlockEntry());
     while (current != NULL) {
@@ skipping 30 matching lines @@
         HBasicBlock* predecessor = block->predecessors()->at(k);
         ASSERT(predecessor->end()->IsGoto());
         ASSERT(predecessor->last_environment()->ast_id() == id);
       }
     }
   }
 
   // Check special property of first block to have no predecessors.
   ASSERT(blocks_.at(0)->predecessors()->is_empty());
 
-  // Check that the graph is fully connected.
-  ReachabilityAnalyzer analyzer(entry_block_, blocks_.length(), NULL);
-  ASSERT(analyzer.visited_count() == blocks_.length());
+  if (do_full_verify) {
+    // Check that the graph is fully connected.
+    ReachabilityAnalyzer analyzer(entry_block_, blocks_.length(), NULL);
+    ASSERT(analyzer.visited_count() == blocks_.length());
 
-  // Check that entry block dominator is NULL.
-  ASSERT(entry_block_->dominator() == NULL);
+    // Check that entry block dominator is NULL.
+    ASSERT(entry_block_->dominator() == NULL);
 
-  // Check dominators.
-  for (int i = 0; i < blocks_.length(); ++i) {
-    HBasicBlock* block = blocks_.at(i);
-    if (block->dominator() == NULL) {
-      // Only start block may have no dominator assigned to.
-      ASSERT(i == 0);
-    } else {
-      // Assert that block is unreachable if dominator must not be visited.
-      ReachabilityAnalyzer dominator_analyzer(entry_block_,
-                                              blocks_.length(),
-                                              block->dominator());
-      ASSERT(!dominator_analyzer.reachable()->Contains(block->block_id()));
+    // Check dominators.
+    for (int i = 0; i < blocks_.length(); ++i) {
+      HBasicBlock* block = blocks_.at(i);
+      if (block->dominator() == NULL) {
+        // Only start block may have no dominator assigned to.
+        ASSERT(i == 0);
+      } else {
+        // Assert that block is unreachable if dominator must not be visited.
+        ReachabilityAnalyzer dominator_analyzer(entry_block_,
+                                                blocks_.length(),
+                                                block->dominator());
+        ASSERT(!dominator_analyzer.reachable()->Contains(block->block_id()));
+      }
     }
   }
 }
 
 #endif
 
 
 HConstant* HGraph::GetConstant(SetOncePointer<HConstant>* pointer,
                                Object* value) {
   if (!pointer->is_set()) {
@@ skipping 1808 matching lines @@
 
     if (current_block() != NULL) {
       HReturn* instr = new(zone()) HReturn(graph()->GetConstantUndefined());
       current_block()->FinishExit(instr);
       set_current_block(NULL);
     }
   }
 
   graph()->OrderBlocks();
   graph()->AssignDominators();
+
+#ifdef DEBUG
+  // Do a full verify after building the graph and computing dominators.
+  graph()->Verify(true);
+#endif
+
   graph()->PropagateDeoptimizingMark();
   graph()->EliminateRedundantPhis();
   if (!graph()->CheckPhis()) {
     Bailout("Unsupported phi use of arguments object");
     return NULL;
   }
   if (FLAG_eliminate_dead_phis) graph()->EliminateUnreachablePhis();
   if (!graph()->CollectPhis()) {
     Bailout("Unsupported phi use of uninitialized constant");
     return NULL;
@@ skipping 4482 matching lines @@
 
   if (FLAG_trace_hydrogen) {
     if (graph_ != NULL) HTracer::Instance()->TraceHydrogen(name_, graph_);
     if (chunk_ != NULL) HTracer::Instance()->TraceLithium(name_, chunk_);
     if (allocator_ != NULL) {
       HTracer::Instance()->TraceLiveRanges(name_, allocator_);
     }
   }
 
 #ifdef DEBUG
-  if (graph_ != NULL) graph_->Verify();
+  if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal