Use the correct oracle in TestContext::BuildBranch.

When inlining is being done, it is crucial to use the correct type feedback
oracle with a given type feedback ID. To ensure this, TestContext now carries an
oracle which is associated with the context's condition, and these are both used
together in TestContext::BuildBranch.

Note that in VisitReturnStatement and TryInline we are currently lucky that the
oracles don't go out of sync in an observable way, but this will change when we
inline setters. Therefore, there is no separate test case...

Review URL: https://chromiumcodereview.appspot.com/10834247

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12284 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen.cc

@@ -2769,10 +2769,13 @@ FunctionState::FunctionState(HGraphBuilder* owner,
       HBasicBlock* if_false = owner->graph()->CreateBasicBlock();
       if_true->MarkAsInlineReturnTarget();
       if_false->MarkAsInlineReturnTarget();
-      Expression* cond = TestContext::cast(owner->ast_context())->condition();
+      TestContext* outer_test_context = TestContext::cast(owner->ast_context());
+      Expression* cond = outer_test_context->condition();
+      TypeFeedbackOracle* outer_oracle = outer_test_context->oracle();
       // The AstContext constructor pushed on the context stack.  This newed
       // instance is the reason that AstContext can't be BASE_EMBEDDED.
-      test_context_ = new TestContext(owner, cond, if_true, if_false);
+      test_context_ =
+          new TestContext(owner, cond, outer_oracle, if_true, if_false);
     } else {
       function_return_ = owner->graph()->CreateBasicBlock();
       function_return()->MarkAsInlineReturnTarget();
@@ -2939,7 +2942,7 @@ void TestContext::BuildBranch(HValue* value) {
   HBasicBlock* empty_true = builder->graph()->CreateBasicBlock();
   HBasicBlock* empty_false = builder->graph()->CreateBasicBlock();
   TypeFeedbackId test_id = condition()->test_id();
-  ToBooleanStub::Types expected(builder->oracle()->ToBooleanTypes(test_id));
+  ToBooleanStub::Types expected(oracle()->ToBooleanTypes(test_id));
   HBranch* test = new(zone()) HBranch(value, empty_true, empty_false, expected);
   builder->current_block()->Finish(test);
 
@@ -2997,7 +3000,7 @@ void HGraphBuilder::VisitForTypeOf(Expression* expr) {
 void HGraphBuilder::VisitForControl(Expression* expr,
                                     HBasicBlock* true_block,
                                     HBasicBlock* false_block) {
-  TestContext for_test(this, expr, true_block, false_block);
+  TestContext for_test(this, expr, oracle(), true_block, false_block);
   Visit(expr);
 }
 

src/hydrogen.h

@@ -671,10 +671,12 @@ class TestContext: public AstContext {
  public:
   TestContext(HGraphBuilder* owner,
               Expression* condition,
+              TypeFeedbackOracle* oracle,
               HBasicBlock* if_true,
               HBasicBlock* if_false)
       : AstContext(owner, Expression::kTest),
         condition_(condition),
+        oracle_(oracle),
         if_true_(if_true),
         if_false_(if_false) {
   }
@@ -689,6 +691,7 @@ class TestContext: public AstContext {
   }
 
   Expression* condition() const { return condition_; }
+  TypeFeedbackOracle* oracle() const { return oracle_; }
   HBasicBlock* if_true() const { return if_true_; }
   HBasicBlock* if_false() const { return if_false_; }
 
@@ -698,6 +701,7 @@ class TestContext: public AstContext {
   void BuildBranch(HValue* value);
 
   Expression* condition_;
+  TypeFeedbackOracle* oracle_;
   HBasicBlock* if_true_;
   HBasicBlock* if_false_;
 };