Simplify Hydrogen code stubs with variable argument count

src/deoptimizer.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1568 matching lines @@
       (output_frame_size - output_frame_offset) + kPointerSize;
   output_frame->SetFrameSlot(output_frame_offset, value);
   if (trace_scope_ != NULL) {
     PrintF(trace_scope_->file(),
            "    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
            V8PRIxPTR " ; args*\n",
            top_address + output_frame_offset, output_frame_offset, value);
   }
 
   // Copy the register parameters to the failure frame.
+  int arguments_length_offset = -1;
   for (int i = 0; i < descriptor->register_param_count_; ++i) {
     output_frame_offset -= kPointerSize;
     DoTranslateCommand(iterator, 0, output_frame_offset);
+
+    if (!arg_count_known && descriptor->IsParameterCountRegister(i)) {
+      arguments_length_offset = output_frame_offset;
+    }
   }
 
+  ASSERT(0 == output_frame_offset);
+
   if (!arg_count_known) {
-    DoTranslateCommand(iterator, 0, length_frame_offset,
-                       TRANSLATED_VALUE_IS_NATIVE);
-    caller_arg_count = output_frame->GetFrameSlot(length_frame_offset);
+    ASSERT(arguments_length_offset >= 0);
+    // We know it's a smi because 1) the code stub guarantees the stack
+    // parameter count is in smi range, and 2) the DoTranslateCommand in the
+    // parameter loop above translated that to a tagged value.
+    Smi* smi_caller_arg_count = reinterpret_cast<Smi*>(
+        output_frame->GetFrameSlot(arguments_length_offset));
+    caller_arg_count = smi_caller_arg_count->value();
+    output_frame->SetFrameSlot(length_frame_offset, caller_arg_count);
+    if (trace_scope_ != NULL) {
+      PrintF(trace_scope_->file(),
+             "    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
+             V8PRIxPTR " ; args.length\n",
+             top_address + length_frame_offset, length_frame_offset,
+             caller_arg_count);
+    }
     value = frame_ptr + StandardFrameConstants::kCallerSPOffset +
         (caller_arg_count - 1) * kPointerSize;
     output_frame->SetFrameSlot(args_arguments_offset, value);
     if (trace_scope_ != NULL) {
       PrintF(trace_scope_->file(),
              "    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
              V8PRIxPTR " ; args.arguments\n",
-             top_address + args_arguments_offset, args_arguments_offset, value);
+             top_address + args_arguments_offset, args_arguments_offset,
+             value);
     }
   }
 
-  ASSERT(0 == output_frame_offset);
-
   // Copy the double registers from the input into the output frame.
   CopyDoubleRegisters(output_frame);
 
   // Fill registers containing handler and number of parameters.
   SetPlatformCompiledStubRegisters(output_frame, descriptor);
 
   // Compute this frame's PC, state, and continuation.
   Code* trampoline = NULL;
   StubFunctionMode function_mode = descriptor->function_mode_;
   StubFailureTrampolineStub(function_mode).FindCodeInCache(&trampoline,
@@ skipping 246 matching lines @@
                index);
       }
 
       info->SetExpression(index, *num);
     }
   }
 }
 #endif
 
 
-static const char* TraceValueType(bool is_smi, bool is_native = false) {
-  if (is_native) {
-    return "native";
-  } else if (is_smi) {
+static const char* TraceValueType(bool is_smi) {
+  if (is_smi) {
     return "smi";
   }
 
   return "heap number";
 }
 
 
 void Deoptimizer::DoTranslateObject(TranslationIterator* iterator,
                                     int object_index,
                                     int field_index) {
@@ skipping 248 matching lines @@
       for (int i = 0; i < length; i++) {
         DoTranslateObject(iterator, object_index, i);
       }
       return;
     }
   }
 }
 
 
 void Deoptimizer::DoTranslateCommand(TranslationIterator* iterator,
-    int frame_index,
-    unsigned output_offset,
-    DeoptimizerTranslatedValueType value_type) {
+                                     int frame_index,
+                                     unsigned output_offset) {
   disasm::NameConverter converter;
   // A GC-safe temporary placeholder that we can put in the output frame.
   const intptr_t kPlaceholder = reinterpret_cast<intptr_t>(Smi::FromInt(0));
-  bool is_native = value_type == TRANSLATED_VALUE_IS_NATIVE;
 
   Translation::Opcode opcode =
       static_cast<Translation::Opcode>(iterator->Next());
 
   switch (opcode) {
     case Translation::BEGIN:
     case Translation::JS_FRAME:
     case Translation::ARGUMENTS_ADAPTOR_FRAME:
     case Translation::CONSTRUCT_STUB_FRAME:
     case Translation::GETTER_STUB_FRAME:
@@ skipping 17 matching lines @@
             trace_scope_->file());
         PrintF(trace_scope_->file(), "\n");
       }
       output_[frame_index]->SetFrameSlot(output_offset, input_value);
       return;
     }
 
     case Translation::INT32_REGISTER: {
       int input_reg = iterator->Next();
       intptr_t value = input_->GetRegister(input_reg);
-      bool is_smi = (value_type == TRANSLATED_VALUE_IS_TAGGED) &&
-          Smi::IsValid(value);
+      bool is_smi = Smi::IsValid(value);
       if (trace_scope_ != NULL) {
         PrintF(
             trace_scope_->file(),
             "    0x%08" V8PRIxPTR ": [top + %d] <- %" V8PRIdPTR " ; %s (%s)\n",
             output_[frame_index]->GetTop() + output_offset,
             output_offset,
             value,
             converter.NameOfCPURegister(input_reg),
-            TraceValueType(is_smi, is_native));
+            TraceValueType(is_smi));
       }
       if (is_smi) {
         intptr_t tagged_value =
             reinterpret_cast<intptr_t>(Smi::FromInt(static_cast<int>(value)));
         output_[frame_index]->SetFrameSlot(output_offset, tagged_value);
-      } else if (value_type == TRANSLATED_VALUE_IS_NATIVE) {
-        output_[frame_index]->SetFrameSlot(output_offset, value);
       } else {
         // We save the untagged value on the side and store a GC-safe
         // temporary placeholder in the frame.
-        ASSERT(value_type == TRANSLATED_VALUE_IS_TAGGED);
         AddDoubleValue(output_[frame_index]->GetTop() + output_offset,
                        static_cast<double>(static_cast<int32_t>(value)));
         output_[frame_index]->SetFrameSlot(output_offset, kPlaceholder);
       }
       return;
     }
 
     case Translation::UINT32_REGISTER: {
       int input_reg = iterator->Next();
       uintptr_t value = static_cast<uintptr_t>(input_->GetRegister(input_reg));
-      bool is_smi = (value_type == TRANSLATED_VALUE_IS_TAGGED) &&
-          (value <= static_cast<uintptr_t>(Smi::kMaxValue));
+      bool is_smi = value <= static_cast<uintptr_t>(Smi::kMaxValue);
       if (trace_scope_ != NULL) {
         PrintF(
             trace_scope_->file(),
             "    0x%08" V8PRIxPTR ": [top + %d] <- %" V8PRIuPTR
             " ; uint %s (%s)\n",
             output_[frame_index]->GetTop() + output_offset,
             output_offset,
             value,
             converter.NameOfCPURegister(input_reg),
-            TraceValueType(is_smi, is_native));
+            TraceValueType(is_smi));
       }
       if (is_smi) {
         intptr_t tagged_value =
             reinterpret_cast<intptr_t>(Smi::FromInt(static_cast<int>(value)));
         output_[frame_index]->SetFrameSlot(output_offset, tagged_value);
-      } else if (value_type == TRANSLATED_VALUE_IS_NATIVE) {
-        output_[frame_index]->SetFrameSlot(output_offset, value);
       } else {
         // We save the untagged value on the side and store a GC-safe
         // temporary placeholder in the frame.
-        ASSERT(value_type == TRANSLATED_VALUE_IS_TAGGED);
         AddDoubleValue(output_[frame_index]->GetTop() + output_offset,
                        static_cast<double>(static_cast<uint32_t>(value)));
         output_[frame_index]->SetFrameSlot(output_offset, kPlaceholder);
       }
       return;
     }
 
     case Translation::DOUBLE_REGISTER: {
       int input_reg = iterator->Next();
       double value = input_->GetDoubleRegister(input_reg);
@@ skipping 30 matching lines @@
         PrintF(trace_scope_->file(), "\n");
       }
       output_[frame_index]->SetFrameSlot(output_offset, input_value);
       return;
     }
 
     case Translation::INT32_STACK_SLOT: {
       int input_slot_index = iterator->Next();
       unsigned input_offset = input_->GetOffsetFromSlotIndex(input_slot_index);
       intptr_t value = input_->GetFrameSlot(input_offset);
-      bool is_smi = (value_type == TRANSLATED_VALUE_IS_TAGGED) &&
-          Smi::IsValid(value);
+      bool is_smi = Smi::IsValid(value);
       if (trace_scope_ != NULL) {
         PrintF(trace_scope_->file(),
                "    0x%08" V8PRIxPTR ": ",
                output_[frame_index]->GetTop() + output_offset);
         PrintF(trace_scope_->file(),
                "[top + %d] <- %" V8PRIdPTR " ; [sp + %d] (%s)\n",
                output_offset,
                value,
                input_offset,
-               TraceValueType(is_smi, is_native));
+               TraceValueType(is_smi));
       }
       if (is_smi) {
         intptr_t tagged_value =
             reinterpret_cast<intptr_t>(Smi::FromInt(static_cast<int>(value)));
         output_[frame_index]->SetFrameSlot(output_offset, tagged_value);
-      } else if (value_type == TRANSLATED_VALUE_IS_NATIVE) {
-        output_[frame_index]->SetFrameSlot(output_offset, value);
       } else {
         // We save the untagged value on the side and store a GC-safe
         // temporary placeholder in the frame.
-        ASSERT(value_type == TRANSLATED_VALUE_IS_TAGGED);
         AddDoubleValue(output_[frame_index]->GetTop() + output_offset,
                        static_cast<double>(static_cast<int32_t>(value)));
         output_[frame_index]->SetFrameSlot(output_offset, kPlaceholder);
       }
       return;
     }
 
     case Translation::UINT32_STACK_SLOT: {
       int input_slot_index = iterator->Next();
       unsigned input_offset = input_->GetOffsetFromSlotIndex(input_slot_index);
       uintptr_t value =
           static_cast<uintptr_t>(input_->GetFrameSlot(input_offset));
-      bool is_smi = (value_type == TRANSLATED_VALUE_IS_TAGGED) &&
-          (value <= static_cast<uintptr_t>(Smi::kMaxValue));
+      bool is_smi = value <= static_cast<uintptr_t>(Smi::kMaxValue);
       if (trace_scope_ != NULL) {
         PrintF(trace_scope_->file(),
                "    0x%08" V8PRIxPTR ": ",
                output_[frame_index]->GetTop() + output_offset);
         PrintF(trace_scope_->file(),
                "[top + %d] <- %" V8PRIuPTR " ; [sp + %d] (uint32 %s)\n",
                output_offset,
                value,
                input_offset,
-               TraceValueType(is_smi, is_native));
+               TraceValueType(is_smi));
       }
       if (is_smi) {
         intptr_t tagged_value =
             reinterpret_cast<intptr_t>(Smi::FromInt(static_cast<int>(value)));
         output_[frame_index]->SetFrameSlot(output_offset, tagged_value);
-      } else if (value_type == TRANSLATED_VALUE_IS_NATIVE) {
-        output_[frame_index]->SetFrameSlot(output_offset, value);
       } else {
         // We save the untagged value on the side and store a GC-safe
         // temporary placeholder in the frame.
-        ASSERT(value_type == TRANSLATED_VALUE_IS_TAGGED);
         AddDoubleValue(output_[frame_index]->GetTop() + output_offset,
                        static_cast<double>(static_cast<uint32_t>(value)));
         output_[frame_index]->SetFrameSlot(output_offset, kPlaceholder);
       }
       return;
     }
 
     case Translation::DOUBLE_STACK_SLOT: {
       int input_slot_index = iterator->Next();
       unsigned input_offset = input_->GetOffsetFromSlotIndex(input_slot_index);
@@ skipping 682 matching lines @@
 
 void DeoptimizedFrameInfo::Iterate(ObjectVisitor* v) {
   v->VisitPointer(BitCast<Object**>(&function_));
   v->VisitPointers(parameters_, parameters_ + parameters_count_);
   v->VisitPointers(expression_stack_, expression_stack_ + expression_count_);
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal