Fix for running with --throw_on_javascript_int_overflow: recognize pattern (a << b) & mask and test…

runtime/vm/flow_graph_builder.cc

Index: runtime/vm/flow_graph_builder.cc
===================================================================
--- runtime/vm/flow_graph_builder.cc	(revision 26025)
+++ runtime/vm/flow_graph_builder.cc	(working copy)
@@ -946,6 +946,16 @@
 }
 
 
+
+static const String& BinaryOpAndMaskName(BinaryOpNode* node) {
+  if (node->kind() == Token::kSHL) {
+    return PrivateCoreLibName(Symbols::_leftShiftWithMask32());
+  }
+  UNIMPLEMENTED();
+  return String::ZoneHandle();
+}
+
+
 // <Expression> :: BinaryOp { kind:  Token::Kind
 //                            left:  <Expression>
 //                            right: <Expression> }
@@ -953,6 +963,7 @@
   // Operators "&&" and "||" cannot be overloaded therefore do not call
   // operator.
   if ((node->kind() == Token::kAND) || (node->kind() == Token::kOR)) {
+    ASSERT(!node->has_mask32());
     // See ValueGraphVisitor::VisitBinaryOpNode.
     TestGraphVisitor for_left(owner(),
                               temp_index(),
@@ -978,18 +989,40 @@
   Append(for_right_value);
   PushArgumentInstr* push_right = PushArgument(for_right_value.value());
 
+  PushArgumentInstr* push_mask = NULL;
+  if (node->has_mask32()) {
+    Value* mask_value = Bind(new ConstantInstr(
+        Integer::ZoneHandle(Integer::New(node->mask32(), Heap::kOld))));
+    push_mask = PushArgument(mask_value);
+  }
+
+  InstanceCallInstr* call = NULL;
   ZoneGrowableArray<PushArgumentInstr*>* arguments =
-      new ZoneGrowableArray<PushArgumentInstr*>(2);
+      new ZoneGrowableArray<PushArgumentInstr*>(node->has_mask32() ? 3 : 2);
   arguments->Add(push_left);
   arguments->Add(push_right);
-  const String& name = String::ZoneHandle(Symbols::New(node->Name()));
-  InstanceCallInstr* call = new InstanceCallInstr(node->token_pos(),
-                                                  name,
-                                                  node->kind(),
-                                                  arguments,
-                                                  Object::null_array(),
-                                                  2,
-                                                  owner()->ic_data_array());
+  if (node->has_mask32()) {
+    // Call to special method 'BinaryOpAndMaskName(node)'.
+    arguments->Add(push_mask);
+    call = new InstanceCallInstr(node->token_pos(),
+                                 BinaryOpAndMaskName(node),
+                                 Token::kILLEGAL,
+                                 arguments,
+                                 Object::null_array(),
+                                 2,  // Collect data for both arguments.
+                                 owner()->ic_data_array());
+
+  } else {
+    // Regular code.
+    const String& name = String::ZoneHandle(Symbols::New(node->Name()));
+    call = new InstanceCallInstr(node->token_pos(),
+                                 name,
+                                 node->kind(),
+                                 arguments,
+                                 Object::null_array(),
+                                 2,  // Collect data for both arguments.
+                                 owner()->ic_data_array());
+  }
   ReturnDefinition(call);
 }
 
@@ -999,6 +1032,7 @@
   // Operators "&&" and "||" cannot be overloaded therefore do not call
   // operator.
   if ((node->kind() == Token::kAND) || (node->kind() == Token::kOR)) {
+    ASSERT(!node->has_mask32());
     // Implement short-circuit logic: do not evaluate right if evaluation
     // of left is sufficient.
     // AND:  left ? right === true : false;