MIPS: Allow the deoptimizer translation to track de-materialized objects.

Port r15087 (63e1626)

Original commit message:
This allows the deoptimizer to materialize objects (e.g. the arguments
object) while deopting without having a consective stack area holding
the object values. The LEnvironment explicitly tracks locations for
these values and preserves them in the translation.

TEST=mjsunit/compiler/inline-arguments
BUG=

Review URL: https://codereview.chromium.org/16846002
Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15097 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-codegen-mips.cc

@@ -561,27 +561,15 @@ MemOperand LCodeGen::ToHighMemOperand(LOperand* op) const {
 
 
 void LCodeGen::WriteTranslation(LEnvironment* environment,
-                                Translation* translation,
-                                int* pushed_arguments_index,
-                                int* pushed_arguments_count) {
+                                Translation* translation) {
   if (environment == NULL) return;
 
   // The translation includes one command per value in the environment.
-  int translation_size = environment->values()->length();
+  int translation_size = environment->translation_size();
   // The output frame height does not include the parameters.
   int height = translation_size - environment->parameter_count();
 
-  // Function parameters are arguments to the outermost environment. The
-  // arguments index points to the first element of a sequence of tagged
-  // values on the stack that represent the arguments. This needs to be
-  // kept in sync with the LArgumentsElements implementation.
-  *pushed_arguments_index = -environment->parameter_count();
-  *pushed_arguments_count = environment->parameter_count();
-
-  WriteTranslation(environment->outer(),
-                   translation,
-                   pushed_arguments_index,
-                   pushed_arguments_count);
+  WriteTranslation(environment->outer(), translation);
   bool has_closure_id = !info()->closure().is_null() &&
       !info()->closure().is_identical_to(environment->closure());
   int closure_id = has_closure_id
@@ -613,23 +601,6 @@ void LCodeGen::WriteTranslation(LEnvironment* environment,
       break;
   }
 
-  // Inlined frames which push their arguments cause the index to be
-  // bumped and another stack area to be used for materialization,
-  // otherwise actual argument values are unknown for inlined frames.
-  bool arguments_known = true;
-  int arguments_index = *pushed_arguments_index;
-  int arguments_count = *pushed_arguments_count;
-  if (environment->entry() != NULL) {
-    arguments_known = environment->entry()->arguments_pushed();
-    arguments_index = arguments_index < 0
-        ? GetStackSlotCount() : arguments_index + arguments_count;
-    arguments_count = environment->entry()->arguments_count() + 1;
-    if (environment->entry()->arguments_pushed()) {
-      *pushed_arguments_index = arguments_index;
-      *pushed_arguments_count = arguments_count;
-    }
-  }
-
   for (int i = 0; i < translation_size; ++i) {
     LOperand* value = environment->values()->at(i);
     // spilled_registers_ and spilled_double_registers_ are either
@@ -641,10 +612,7 @@ void LCodeGen::WriteTranslation(LEnvironment* environment,
         AddToTranslation(translation,
                          environment->spilled_registers()[value->index()],
                          environment->HasTaggedValueAt(i),
-                         environment->HasUint32ValueAt(i),
-                         arguments_known,
-                         arguments_index,
-                         arguments_count);
+                         environment->HasUint32ValueAt(i));
       } else if (
           value->IsDoubleRegister() &&
           environment->spilled_double_registers()[value->index()] != NULL) {
@@ -653,20 +621,36 @@ void LCodeGen::WriteTranslation(LEnvironment* environment,
             translation,
             environment->spilled_double_registers()[value->index()],
             false,
-            false,
-            arguments_known,
-            arguments_index,
-            arguments_count);
+            false);
+      }
+    }
+
+    // TODO(mstarzinger): Introduce marker operands to indicate that this value
+    // is not present and must be reconstructed from the deoptimizer. Currently
+    // this is only used for the arguments object.
+    if (value == NULL) {
+      int arguments_count = environment->values()->length() - translation_size;
+      translation->BeginArgumentsObject(arguments_count);
+      for (int i = 0; i < arguments_count; ++i) {
+        LOperand* value = environment->values()->at(translation_size + i);
+        ASSERT(environment->spilled_registers() == NULL ||
+               !value->IsRegister() ||
+               environment->spilled_registers()[value->index()] == NULL);
+        ASSERT(environment->spilled_registers() == NULL ||
+               !value->IsDoubleRegister() ||
+               environment->spilled_double_registers()[value->index()] == NULL);
+        AddToTranslation(translation,
+                         value,
+                         environment->HasTaggedValueAt(translation_size + i),
+                         environment->HasUint32ValueAt(translation_size + i));
       }
+      continue;
     }
 
     AddToTranslation(translation,
                      value,
                      environment->HasTaggedValueAt(i),
-                     environment->HasUint32ValueAt(i),
-                     arguments_known,
-                     arguments_index,
-                     arguments_count);
+                     environment->HasUint32ValueAt(i));
   }
 }
 
@@ -674,17 +658,8 @@ void LCodeGen::WriteTranslation(LEnvironment* environment,
 void LCodeGen::AddToTranslation(Translation* translation,
                                 LOperand* op,
                                 bool is_tagged,
-                                bool is_uint32,
-                                bool arguments_known,
-                                int arguments_index,
-                                int arguments_count) {
-  if (op == NULL) {
-    // TODO(twuerthinger): Introduce marker operands to indicate that this value
-    // is not present and must be reconstructed from the deoptimizer. Currently
-    // this is only used for the arguments object.
-    translation->StoreArgumentsObject(
-        arguments_known, arguments_index, arguments_count);
-  } else if (op->IsStackSlot()) {
+                                bool is_uint32) {
+  if (op->IsStackSlot()) {
     if (is_tagged) {
       translation->StoreStackSlot(op->index());
     } else if (is_uint32) {
@@ -779,8 +754,6 @@ void LCodeGen::RegisterEnvironmentForDeoptimization(LEnvironment* environment,
 
     int frame_count = 0;
     int jsframe_count = 0;
-    int args_index = 0;
-    int args_count = 0;
     for (LEnvironment* e = environment; e != NULL; e = e->outer()) {
       ++frame_count;
       if (e->frame_type() == JS_FUNCTION) {
@@ -788,7 +761,7 @@ void LCodeGen::RegisterEnvironmentForDeoptimization(LEnvironment* environment,
       }
     }
     Translation translation(&translations_, frame_count, jsframe_count, zone());
-    WriteTranslation(environment, &translation, &args_index, &args_count);
+    WriteTranslation(environment, &translation);
     int deoptimization_index = deoptimizations_.length();
     int pc_offset = masm()->pc_offset();
     environment->Register(deoptimization_index,

src/mips/lithium-codegen-mips.h

@@ -169,10 +169,7 @@ class LCodeGen BASE_EMBEDDED {
                                  int additional_offset);
 
   // Emit frame translation commands for an environment.
-  void WriteTranslation(LEnvironment* environment,
-                        Translation* translation,
-                        int* arguments_index,
-                        int* arguments_count);
+  void WriteTranslation(LEnvironment* environment, Translation* translation);
 
   // Declare methods that deal with the individual node types.
 #define DECLARE_DO(type) void Do##type(L##type* node);
@@ -295,10 +292,7 @@ class LCodeGen BASE_EMBEDDED {
   void AddToTranslation(Translation* translation,
                         LOperand* op,
                         bool is_tagged,
-                        bool is_uint32,
-                        bool arguments_known,
-                        int arguments_index,
-                        int arguments_count);
+                        bool is_uint32);
   void RegisterDependentCodeForEmbeddedMaps(Handle<Code> code);
   void PopulateDeoptimizationData(Handle<Code> code);
   int DefineDeoptimizationLiteral(Handle<Object> literal);

src/mips/lithium-mips.cc

@@ -933,7 +933,7 @@ LEnvironment* LChunkBuilder::CreateEnvironment(
   BailoutId ast_id = hydrogen_env->ast_id();
   ASSERT(!ast_id.IsNone() ||
          hydrogen_env->frame_type() != JS_FUNCTION);
-  int value_count = hydrogen_env->length();
+  int value_count = hydrogen_env->length() - hydrogen_env->specials_count();
   LEnvironment* result = new(zone()) LEnvironment(
       hydrogen_env->closure(),
       hydrogen_env->frame_type(),
@@ -944,13 +944,15 @@ LEnvironment* LChunkBuilder::CreateEnvironment(
       outer,
       hydrogen_env->entry(),
       zone());
+  bool needs_arguments_object_materialization = false;
   int argument_index = *argument_index_accumulator;
-  for (int i = 0; i < value_count; ++i) {
+  for (int i = 0; i < hydrogen_env->length(); ++i) {
     if (hydrogen_env->is_special_index(i)) continue;
 
     HValue* value = hydrogen_env->values()->at(i);
     LOperand* op = NULL;
     if (value->IsArgumentsObject()) {
+      needs_arguments_object_materialization = true;
       op = NULL;
     } else if (value->IsPushArgument()) {
       op = new(zone()) LArgument(argument_index++);
@@ -962,6 +964,22 @@ LEnvironment* LChunkBuilder::CreateEnvironment(
                      value->CheckFlag(HInstruction::kUint32));
   }
 
+  if (needs_arguments_object_materialization) {
+    HArgumentsObject* arguments = hydrogen_env->entry() == NULL
+        ? graph()->GetArgumentsObject()
+        : hydrogen_env->entry()->arguments_object();
+    ASSERT(arguments->IsLinked());
+    for (int i = 1; i < arguments->arguments_count(); ++i) {
+      HValue* value = arguments->arguments_values()->at(i);
+      ASSERT(!value->IsArgumentsObject() && !value->IsPushArgument());
+      ASSERT(HInstruction::cast(value)->IsLinked());
+      LOperand* op = UseAny(value);
+      result->AddValue(op,
+                       value->representation(),
+                       value->CheckFlag(HInstruction::kUint32));
+    }
+  }
+
   if (hydrogen_env->frame_type() == JS_FUNCTION) {
     *argument_index_accumulator = argument_index;
   }