Use a reserved stack local variable to store the Code object so that it can be looked up easily whe…

vm/flow_graph_compiler_x64.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "lib/error.h"
@@ skipping 646 matching lines @@
 }
 
 
 void FlowGraphCompiler::VisitNativeCall(NativeCallComp* comp) {
   // Push the result place holder initialized to NULL.
   __ PushObject(Object::ZoneHandle());
   // Pass a pointer to the first argument in RAX.
   if (!comp->has_optional_parameters()) {
     __ leaq(RAX, Address(RBP, (1 + comp->argument_count()) * kWordSize));
   } else {
-    __ leaq(RAX, Address(RBP, -1 * kWordSize));
+    __ leaq(RAX,
+            Address(RBP, ParsedFunction::kFirstLocalSlotIndex * kWordSize));
   }
   __ movq(RBX, Immediate(reinterpret_cast<uword>(comp->native_c_function())));
   __ movq(R10, Immediate(comp->argument_count()));
   GenerateCall(comp->token_index(),
                comp->try_index(),
                &StubCode::CallNativeCFunctionLabel(),
                PcDescriptors::kOther);
   __ popq(RAX);
 }
 
@@ skipping 449 matching lines @@
 }
 
 
 // Restore stack and initialize the two exception variables:
 // exception and stack trace variables.
 void FlowGraphCompiler::VisitCatchEntry(CatchEntryComp* comp) {
   // Restore RSP from RBP as we are coming from a throw and the code for
   // popping arguments has not been run.
   const intptr_t locals_space_size = StackSize() * kWordSize;
   ASSERT(locals_space_size >= 0);
-  if (locals_space_size == 0) {
-    __ movq(RSP, RBP);
-  } else {
-    __ leaq(RSP, Address(RBP, -locals_space_size));
-  }
+  intptr_t offset_size = -locals_space_size + kLocalsOffsetFromFP;
+  __ leaq(RSP, Address(RBP, offset_size));
 
   ASSERT(!comp->exception_var().is_captured());
   ASSERT(!comp->stacktrace_var().is_captured());
   __ movq(Address(RBP, comp->exception_var().index() * kWordSize),
           kExceptionObjectReg);
   __ movq(Address(RBP, comp->stacktrace_var().index() * kWordSize),
           kStackTraceObjectReg);
 }
 
 
@@ skipping 148 matching lines @@
   }
 }
 
 
 // Coped from CodeGenerator::CopyParameters (CodeGenerator will be deprecated).
 void FlowGraphCompiler::CopyParameters() {
   const Function& function = parsed_function_.function();
   LocalScope* scope = parsed_function_.node_sequence()->scope();
   const int num_fixed_params = function.num_fixed_parameters();
   const int num_opt_params = function.num_optional_parameters();
-  ASSERT(parsed_function_.first_parameter_index() == -1);
+  ASSERT(parsed_function_.first_parameter_index() ==
+         ParsedFunction::kFirstLocalSlotIndex);
   // Copy positional arguments.
   // Check that no fewer than num_fixed_params positional arguments are passed
   // in and that no more than num_params arguments are passed in.
-  // Passed argument i at fp[1 + argc - i] copied to fp[-1 - i].
+  // Passed argument i at fp[1 + argc - i]
+  // copied to fp[ParsedFunction::kFirstLocalSlotIndex - i].
   const int num_params = num_fixed_params + num_opt_params;
 
   // Total number of args is the first Smi in args descriptor array (R10).
   __ movq(RBX, FieldAddress(R10, Array::data_offset()));
   // Check that num_args <= num_params.
   Label wrong_num_arguments;
   __ cmpq(RBX, Immediate(Smi::RawValue(num_params)));
   __ j(GREATER, &wrong_num_arguments);
   // Number of positional args is the second Smi in descriptor array (R10).
   __ movq(RCX, FieldAddress(R10, Array::data_offset() + (1 * kWordSize)));
   // Check that num_pos_args >= num_fixed_params.
   __ cmpq(RCX, Immediate(Smi::RawValue(num_fixed_params)));
   __ j(LESS, &wrong_num_arguments);
   // Since RBX and RCX are Smi, use TIMES_4 instead of TIMES_8.
   // Let RBX point to the last passed positional argument, i.e. to
   // fp[1 + num_args - (num_pos_args - 1)].
   __ subq(RBX, RCX);
   __ leaq(RBX, Address(RBP, RBX, TIMES_4, 2 * kWordSize));
   // Let RDI point to the last copied positional argument, i.e. to
-  // fp[-1 - (num_pos_args - 1)].
+  // fp[ParsedFunction::kFirstLocalSlotIndex - (num_pos_args - 1)].
   __ SmiUntag(RCX);
   __ movq(RAX, RCX);
   __ negq(RAX);
-  __ leaq(RDI, Address(RBP, RAX, TIMES_8, 0));
+  const int index = ParsedFunction::kFirstLocalSlotIndex + 1;
+  // -num_pos_args is in RAX.
+  // (ParsedFunction::kFirstLocalSlotIndex + 1) is in index.
+  __ leaq(RDI, Address(RBP, RAX, TIMES_8, (index * kWordSize)));
   Label loop, loop_condition;
   __ jmp(&loop_condition, Assembler::kNearJump);
   // We do not use the final allocation index of the variable here, i.e.
   // scope->VariableAt(i)->index(), because captured variables still need
   // to be copied to the context that is not yet allocated.
   const Address argument_addr(RBX, RCX, TIMES_8, 0);
   const Address copy_addr(RDI, RCX, TIMES_8, 0);
   __ Bind(&loop);
   __ movq(RAX, argument_addr);
   __ movq(copy_addr, RAX);
@@ skipping 51 matching lines @@
     Address argument_addr(RBX, RAX, TIMES_4, 0);  // RAX is a negative Smi.
     __ movq(RAX, argument_addr);
     __ jmp(&assign_optional_parameter, Assembler::kNearJump);
     __ Bind(&load_default_value);
     // Load RAX with default argument at pos.
     const Object& value = Object::ZoneHandle(
         parsed_function_.default_parameter_values().At(
             param_pos - num_fixed_params));
     __ LoadObject(RAX, value);
     __ Bind(&assign_optional_parameter);
-    // Assign RAX to fp[-1 - param_pos].
+    // Assign RAX to fp[ParsedFunction::kFirstLocalSlotIndex - param_pos].
     // We do not use the final allocation index of the variable here, i.e.
     // scope->VariableAt(i)->index(), because captured variables still need
     // to be copied to the context that is not yet allocated.
-    const Address param_addr(RBP, (-1 - param_pos) * kWordSize);
+    const Address param_addr(
+        RBP, (ParsedFunction::kFirstLocalSlotIndex - param_pos) * kWordSize);
     __ movq(param_addr, RAX);
     __ Bind(&next_parameter);
   }
   delete[] opt_param;
   delete[] opt_param_position;
   // Check that RDI now points to the null terminator in the array descriptor.
   const Immediate raw_null =
       Immediate(reinterpret_cast<intptr_t>(Object::null()));
   Label all_arguments_processed;
   __ cmpq(Address(RDI, 0), raw_null);
@@ skipping 13 matching lines @@
                         kClosureArgumentMismatchRuntimeEntry);
   } else {
     // Invoke noSuchMethod function.
     const int kNumArgsChecked = 1;
     ICData& ic_data = ICData::ZoneHandle();
     ic_data = ICData::New(parsed_function_.function(),
                           String::Handle(function.name()),
                           AstNode::kNoId,
                           kNumArgsChecked);
     __ LoadObject(RBX, ic_data);
+    // RBP - 8 : PC marker, allows easy identification of RawInstruction obj.
     // RBP : points to previous frame pointer.
     // RBP + 8 : points to return address.
     // RBP + 16 : address of last argument (arg n-1).
     // RSP + 16 + 8*(n-1) : address of first argument (arg 0).
     // RBX : ic-data.
     // R10 : arguments descriptor array.
     __ call(&StubCode::CallNoSuchMethodFunctionLabel());
   }
 
   if (FLAG_trace_functions) {
@@ skipping 113 matching lines @@
     __ int3();
     __ jmp(&StubCode::FixCallersTargetLabel());
     return;
   }
   // Specialized version of entry code from CodeGenerator::GenerateEntryCode.
   const Function& function = parsed_function_.function();
 
   const int parameter_count = function.num_fixed_parameters();
   const int num_copied_params = parsed_function_.copied_parameter_count();
   const int local_count = parsed_function_.stack_local_count();
-  __ EnterFrame(StackSize() * kWordSize);
+  AssemblerMacros::EnterDartFrame(assembler_, (StackSize() * kWordSize));
 
   // We check the number of passed arguments when we have to copy them due to
   // the presence of optional named parameters.
   // No such checking code is generated if only fixed parameters are declared,
   // unless we are debug mode or unless we are compiling a closure.
   if (num_copied_params == 0) {
 #ifdef DEBUG
     const bool check_arguments = true;
 #else
     const bool check_arguments = function.IsClosureFunction();
@@ skipping 122 matching lines @@
   ASSERT(exception_handlers_list_ != NULL);
   const ExceptionHandlers& handlers = ExceptionHandlers::Handle(
       exception_handlers_list_->FinalizeExceptionHandlers(code.EntryPoint()));
   code.set_exception_handlers(handlers);
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64