Simplify and improve optimization of is-tests in the precompiler.

runtime/vm/constant_propagator.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/constant_propagator.h"
 
 #include "vm/bit_vector.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
 #include "vm/flow_graph_range_analysis.h"
@@ skipping 1496 matching lines @@
           // Remove uses from branch and all the empty blocks that
           // are now unreachable.
           branch->UnuseAllInputs();
           for (BitVector::Iterator it(empty_blocks); !it.Done(); it.Advance()) {
             BlockEntryInstr* empty_block = graph_->preorder()[it.Current()];
             empty_block->ClearAllInstructions();
           }
 
           changed = true;
 
-          if (FLAG_trace_constant_propagation) {
-            OS::Print("Eliminated branch in B%" Pd " common target B%" Pd "\n",
+          if (FLAG_trace_constant_propagation &&
+              FlowGraphPrinter::ShouldPrint(graph_->function())) {
+            THR_Print("Eliminated branch in B%" Pd " common target B%" Pd "\n",
                       block->block_id(), join->block_id());
           }
         }
       }
     }
   }
 
   if (changed) {
     graph_->DiscoverBlocks();
     // TODO(fschneider): Update dominator tree in place instead of recomputing.
     GrowableArray<BitVector*> dominance_frontier;
     graph_->ComputeDominators(&dominance_frontier);
   }
 }
 
 
 void ConstantPropagator::Transform() {
-  if (FLAG_trace_constant_propagation) {
+  if (FLAG_trace_constant_propagation &&
+      FlowGraphPrinter::ShouldPrint(graph_->function())) {
     FlowGraphPrinter::PrintGraph("Before CP", graph_);
   }
 
   // We will recompute dominators, block ordering, block ids, block last
   // instructions, previous pointers, predecessors, etc. after eliminating
   // unreachable code.  We do not maintain those properties during the
   // transformation.
   for (BlockIterator b = graph_->reverse_postorder_iterator();
        !b.Done();
        b.Advance()) {
     BlockEntryInstr* block = b.Current();
     if (!reachable_->Contains(block->preorder_number())) {
-      if (FLAG_trace_constant_propagation) {
-        OS::Print("Unreachable B%" Pd "\n", block->block_id());
+      if (FLAG_trace_constant_propagation &&
+          FlowGraphPrinter::ShouldPrint(graph_->function())) {
+        THR_Print("Unreachable B%" Pd "\n", block->block_id());
       }
       // Remove all uses in unreachable blocks.
       block->ClearAllInstructions();
       continue;
     }
 
     JoinEntryInstr* join = block->AsJoinEntry();
     if (join != NULL) {
       // Remove phi inputs corresponding to unreachable predecessor blocks.
       // Predecessors will be recomputed (in block id order) after removing
@@ skipping 50 matching lines @@
       // effects.  Do this for smis only to avoid having to copy other
       // objects into the heap's old generation.
       if ((defn != NULL) &&
           IsConstant(defn->constant_value()) &&
           (defn->constant_value().IsSmi() || defn->constant_value().IsOld()) &&
           !defn->IsConstant() &&
           !defn->IsPushArgument() &&
           !defn->IsStoreIndexed() &&
           !defn->IsStoreInstanceField() &&
           !defn->IsStoreStaticField()) {
-        if (FLAG_trace_constant_propagation) {
-          OS::Print("Constant v%" Pd " = %s\n",
+        if (FLAG_trace_constant_propagation &&
+            FlowGraphPrinter::ShouldPrint(graph_->function())) {
+          THR_Print("Constant v%" Pd " = %s\n",
                     defn->ssa_temp_index(),
                     defn->constant_value().ToCString());
         }
         ConstantInstr* constant = graph_->GetConstant(defn->constant_value());
         defn->ReplaceUsesWith(constant);
         i.RemoveCurrentFromGraph();
       }
     }
 
     // Replace branches where one target is unreachable with jumps.
@@ skipping 41 matching lines @@
         branch->UnuseAllInputs();
       }
     }
   }
 
   graph_->DiscoverBlocks();
   graph_->MergeBlocks();
   GrowableArray<BitVector*> dominance_frontier;
   graph_->ComputeDominators(&dominance_frontier);
 
-  if (FLAG_trace_constant_propagation) {
+  if (FLAG_trace_constant_propagation &&
+      FlowGraphPrinter::ShouldPrint(graph_->function())) {
     FlowGraphPrinter::PrintGraph("After CP", graph_);
   }
 }
 
 }  // namespace dart