Improve representation inference

src/hydrogen-instructions.cc

 // Copyright 2012 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 1280 matching lines @@
   ASSERT(block() == NULL);
 }
 
 
 void HPhi::InitRealUses(int phi_id) {
   // Initialize real uses.
   phi_id_ = phi_id;
   for (HUseIterator it(uses()); !it.Done(); it.Advance()) {
     HValue* value = it.value();
     if (!value->IsPhi()) {
-      Representation rep = value->RequiredInputRepresentation(it.index());
+      Representation rep = value->ObservedInputRepresentation(it.index());
       non_phi_uses_[rep.kind()] += value->LoopWeight();
+      if (FLAG_trace_representation) {
+        PrintF("%d %s is used by %d %s as %s\n",
+               this->id(),
+               this->Mnemonic(),
+               value->id(),
+               value->Mnemonic(),
+               rep.Mnemonic());
+      }
     }
   }
 }
 
 
 void HPhi::AddNonPhiUsesFrom(HPhi* other) {
+  if (FLAG_trace_representation) {
+    PrintF("adding to %d %s uses of %d %s: i%d d%d t%d\n",
+           this->id(),
+           this->Mnemonic(),
+           other->id(),
+           other->Mnemonic(),
+           other->non_phi_uses_[Representation::kInteger32],
+           other->non_phi_uses_[Representation::kDouble],
+           other->non_phi_uses_[Representation::kTagged]);
+  }
+
   for (int i = 0; i < Representation::kNumRepresentations; i++) {
     indirect_uses_[i] += other->non_phi_uses_[i];
   }
 }
 
 
 void HPhi::AddIndirectUsesTo(int* dest) {
   for (int i = 0; i < Representation::kNumRepresentations; i++) {
     dest[i] += indirect_uses_[i];
   }
@@ skipping 1132 matching lines @@
 
 
 void HCheckPrototypeMaps::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal