Implement lowering of JSStoreContext to machine operators.

R=titzer@chromium.org

Review URL: https://codereview.chromium.org/420073004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22783 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler/js-generic-lowering.cc

@@ -388,9 +388,19 @@ Node* JSGenericLowering::LowerJSLoadContext(Node* node) {
 
 Node* JSGenericLowering::LowerJSStoreContext(Node* node) {
   ContextAccess access = OpParameter<ContextAccess>(node);
-  PatchInsertInput(node, 1, SmiConstant(access.depth()));
-  PatchInsertInput(node, 2, SmiConstant(access.index()));
-  ReplaceWithRuntimeCall(node, Runtime::kStoreContextRelative, 4);
+  // TODO(mstarzinger): Use simplified operators instead of machine operators
+  // here so that load/store optimization can be applied afterwards.
+  for (int i = 0; i < access.depth(); ++i) {
+    node->ReplaceInput(
+        0, graph()->NewNode(
+               machine()->Load(kMachineTagged),
+               NodeProperties::GetValueInput(node, 0),
+               Int32Constant(Context::SlotOffset(Context::PREVIOUS_INDEX)),
+               NodeProperties::GetEffectInput(node)));
+  }
+  node->ReplaceInput(2, NodeProperties::GetValueInput(node, 1));
+  node->ReplaceInput(1, Int32Constant(Context::SlotOffset(access.index())));
+  PatchOperator(node, machine()->Store(kMachineTagged, kFullWriteBarrier));
   return node;
 }
 

src/runtime.cc

@@ -9408,22 +9408,6 @@ RUNTIME_FUNCTION(Runtime_StoreLookupSlot) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_StoreContextRelative) {
-  SealHandleScope shs(isolate);
-  ASSERT(args.length() == 4);
-  CONVERT_ARG_CHECKED(Context, context, 0);
-  CONVERT_SMI_ARG_CHECKED(depth, 1);
-  CONVERT_SMI_ARG_CHECKED(index, 2);
-  CONVERT_ARG_CHECKED(Object, value, 3);
-  while (depth-- > 0) {
-    context = context->previous();
-    ASSERT(context->IsContext());
-  }
-  context->set(index, value);
-  return isolate->heap()->undefined_value();
-}
-
-
 RUNTIME_FUNCTION(Runtime_Throw) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);

src/runtime.h

@@ -481,7 +481,6 @@ namespace internal {
   F(LoadLookupSlot, 2, 2)                                            \
   F(LoadLookupSlotNoReferenceError, 2, 2)                            \
   F(StoreLookupSlot, 4, 1)                                           \
-  F(StoreContextRelative, 4, 1) /* TODO(turbofan): Only temporary */ \
                                                                      \
   /* Declarations and initialization */                              \
   F(DeclareGlobals, 3, 1)                                            \

tools/generate-runtime-tests.py

@@ -47,9 +47,9 @@ EXPAND_MACROS = [
 # that the parser doesn't bit-rot. Change the values as needed when you add,
 # remove or change runtime functions, but make sure we don't lose our ability
 # to parse them!
-EXPECTED_FUNCTION_COUNT = 426
+EXPECTED_FUNCTION_COUNT = 425
 EXPECTED_FUZZABLE_COUNT = 338
-EXPECTED_CCTEST_COUNT = 10
+EXPECTED_CCTEST_COUNT = 9
 EXPECTED_UNKNOWN_COUNT = 4
 EXPECTED_BUILTINS_COUNT = 816