Start using the overwrite mode from the full codegens to generate...

src/arm/codegen-arm.cc

Index: src/arm/codegen-arm.cc
===================================================================
--- src/arm/codegen-arm.cc	(revision 5338)
+++ src/arm/codegen-arm.cc	(working copy)
@@ -3550,9 +3550,7 @@
 
     // Perform the binary operation.
     Literal* literal = node->value()->AsLiteral();
-    bool overwrite_value =
-        (node->value()->AsBinaryOperation() != NULL &&
-         node->value()->AsBinaryOperation()->ResultOverwriteAllowed());
+    bool overwrite_value = node->value()->ResultOverwriteAllowed();
     if (literal != NULL && literal->handle()->IsSmi()) {
       SmiOperation(node->binary_op(),
                    literal->handle(),
@@ -3650,9 +3648,7 @@
 
     // Perform the binary operation.
     Literal* literal = node->value()->AsLiteral();
-    bool overwrite_value =
-        (node->value()->AsBinaryOperation() != NULL &&
-         node->value()->AsBinaryOperation()->ResultOverwriteAllowed());
+    bool overwrite_value = node->value()->ResultOverwriteAllowed();
     if (literal != NULL && literal->handle()->IsSmi()) {
       SmiOperation(node->binary_op(),
                    literal->handle(),
@@ -3766,9 +3762,7 @@
 
     // Perform the binary operation.
     Literal* literal = node->value()->AsLiteral();
-    bool overwrite_value =
-        (node->value()->AsBinaryOperation() != NULL &&
-         node->value()->AsBinaryOperation()->ResultOverwriteAllowed());
+    bool overwrite_value = node->value()->ResultOverwriteAllowed();
     if (literal != NULL && literal->handle()->IsSmi()) {
       SmiOperation(node->binary_op(),
                    literal->handle(),
@@ -5755,9 +5749,7 @@
     frame_->EmitPush(r0);  // r0 has result
 
   } else {
-    bool can_overwrite =
-        (node->expression()->AsBinaryOperation() != NULL &&
-         node->expression()->AsBinaryOperation()->ResultOverwriteAllowed());
+    bool can_overwrite = node->expression()->ResultOverwriteAllowed();
     UnaryOverwriteMode overwrite =
         can_overwrite ? UNARY_OVERWRITE : UNARY_NO_OVERWRITE;
 
@@ -6081,12 +6073,8 @@
     Literal* rliteral = node->right()->AsLiteral();
     // NOTE: The code below assumes that the slow cases (calls to runtime)
     // never return a constant/immutable object.
-    bool overwrite_left =
-        (node->left()->AsBinaryOperation() != NULL &&
-         node->left()->AsBinaryOperation()->ResultOverwriteAllowed());
-    bool overwrite_right =
-        (node->right()->AsBinaryOperation() != NULL &&
-         node->right()->AsBinaryOperation()->ResultOverwriteAllowed());
+    bool overwrite_left = node->left()->ResultOverwriteAllowed();
+    bool overwrite_right = node->right()->ResultOverwriteAllowed();
 
     if (rliteral != NULL && rliteral->handle()->IsSmi()) {
       VirtualFrame::RegisterAllocationScope scope(this);