Add a stub for allocating parameter maps.

src/ia32/code-stubs-ia32.cc

Index: src/ia32/code-stubs-ia32.cc
===================================================================
--- src/ia32/code-stubs-ia32.cc	(revision 7540)
+++ src/ia32/code-stubs-ia32.cc	(working copy)
@@ -3655,18 +3655,261 @@
 }
 
 
-void ArgumentsAccessStub::GenerateNewObject(MacroAssembler* masm) {
+void ArgumentsAccessStub::GenerateNewNonStrictSlow(MacroAssembler* masm) {
   // esp[0] : return address
   // esp[4] : number of parameters
   // esp[8] : receiver displacement
   // esp[12] : function
 
-  // The displacement is used for skipping the return address and the
-  // frame pointer on the stack. It is the offset of the last
-  // parameter (if any) relative to the frame pointer.
-  static const int kDisplacement = 2 * kPointerSize;
+  // Check if the calling frame is an arguments adaptor frame.
+  NearLabel runtime;
+  __ mov(edx, Operand(ebp, StandardFrameConstants::kCallerFPOffset));
+  __ mov(ecx, Operand(edx, StandardFrameConstants::kContextOffset));
+  __ cmp(Operand(ecx), Immediate(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+  __ j(not_equal, &runtime);
 
+  // Patch the arguments.length and the parameters pointer.
+  __ mov(ecx, Operand(edx, ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ mov(Operand(esp, 1 * kPointerSize), ecx);
+  __ lea(edx, Operand(edx, ecx, times_2,
+		      StandardFrameConstants::kCallerSPOffset));
+  __ mov(Operand(esp, 2 * kPointerSize), edx);
+
+  // Try the new space allocation. Start out with computing the size of
+  // the arguments object and the elements array.
+  __ bind(&runtime);
+  __ TailCallRuntime(Runtime::kNewArgumentsFast, 3, 1);
+}
+
+
+void ArgumentsAccessStub::GenerateNewNonStrictFast(MacroAssembler* masm) {
+  // esp[0] : return address
+  // esp[4] : number of parameters (tagged)
+  // esp[8] : receiver displacement
+  // esp[12] : function
+
+  // ebx = parameter count (tagged)
+  __ mov(ebx, Operand(esp, 1 * kPointerSize));
+
   // Check if the calling frame is an arguments adaptor frame.
+  // TODO(rossberg): Factor out some of the bits that are shared with the other
+  // Generate* functions.
+  Label runtime;
+  NearLabel adaptor_frame, try_allocate;
+  __ mov(edx, Operand(ebp, StandardFrameConstants::kCallerFPOffset));
+  __ mov(ecx, Operand(edx, StandardFrameConstants::kContextOffset));
+  __ cmp(Operand(ecx), Immediate(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+  __ j(equal, &adaptor_frame);
+
+  // No adaptor, parameter count = argument count.
+  __ mov(ecx, ebx);
+  __ jmp(&try_allocate);
+
+  // We have an adaptor frame. Patch the parameters pointer.
+  __ bind(&adaptor_frame);
+  __ mov(ecx, Operand(edx, ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ lea(edx, Operand(edx, ecx, times_2,
+		      StandardFrameConstants::kCallerSPOffset));
+  __ mov(Operand(esp, 2 * kPointerSize), edx);
+
+  // ebx = parameter count (tagged)
+  // ecx = argument count (tagged)
+  // esp[4] = parameter count (tagged)
+  // esp[8] = address of receiver argument
+  // Compute the mapped parameter count = min(ebx, ecx) in ebx.
+  __ cmp(ebx, Operand(ecx));
+  __ j(less_equal, &try_allocate);
+  __ mov(ebx, ecx);
+
+  __ bind(&try_allocate);
+
+  // Save mapped parameter count.
+  __ push(ebx);
+
+  // Compute the sizes of backing store, parameter map, and arguments object.
+  // 1. Parameter map, has 2 extra words containing context and backing store.
+  const int kParameterMapHeaderSize =
+      FixedArray::kHeaderSize + 2 * kPointerSize;
+  NearLabel no_parameter_map;
+  __ test(ebx, Operand(ebx));
+  __ j(zero, &no_parameter_map);
+  __ lea(ebx, Operand(ebx, times_2, kParameterMapHeaderSize));
+  __ bind(&no_parameter_map);
+
+  // 2. Backing store.
+  __ lea(ebx, Operand(ebx, ecx, times_2, FixedArray::kHeaderSize));
+
+  // 3. Arguments object.
+  __ add(Operand(ebx), Immediate(Heap::kArgumentsObjectSize));
+
+  // Do the allocation of all three objects in one go.
+  __ AllocateInNewSpace(ebx, eax, edx, edi, &runtime, TAG_OBJECT);
+
+  // eax = address of new object(s) (tagged)
+  // ecx = argument count (tagged)
+  // esp[0] = mapped parameter count (tagged)
+  // esp[8] = parameter count (tagged)
+  // esp[12] = address of receiver argument
+  // Get the arguments boilerplate from the current (global) context into edi.
+  NearLabel has_mapped_parameters, copy;
+  __ mov(edi, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX)));
+  __ mov(edi, FieldOperand(edi, GlobalObject::kGlobalContextOffset));
+  __ mov(ebx, Operand(esp, 0 * kPointerSize));
+  __ test(ebx, Operand(ebx));
+  __ j(not_zero, &has_mapped_parameters);
+  __ mov(edi, Operand(edi,
+         Context::SlotOffset(Context::ARGUMENTS_BOILERPLATE_INDEX)));
+  __ jmp(&copy);
+
+  __ bind(&has_mapped_parameters);
+  __ mov(edi, Operand(edi,
+            Context::SlotOffset(Context::ALIASED_ARGUMENTS_BOILERPLATE_INDEX)));
+  __ bind(&copy);
+
+  // eax = address of new object (tagged)
+  // ebx = mapped parameter count (tagged)
+  // ecx = argument count (tagged)
+  // edi = address of boilerplate object (tagged)
+  // esp[0] = mapped parameter count (tagged)
+  // esp[8] = parameter count (tagged)
+  // esp[12] = address of receiver argument
+  // Copy the JS object part.
+  for (int i = 0; i < JSObject::kHeaderSize; i += kPointerSize) {
+    __ mov(edx, FieldOperand(edi, i));
+    __ mov(FieldOperand(eax, i), edx);
+  }
+
+  // Setup the callee in-object property.
+  STATIC_ASSERT(Heap::kArgumentsCalleeIndex == 1);
+  __ mov(edx, Operand(esp, 4 * kPointerSize));
+  __ mov(FieldOperand(eax, JSObject::kHeaderSize +
+                      Heap::kArgumentsCalleeIndex * kPointerSize),
+         edx);
+
+  // Use the length (smi tagged) and set that as an in-object property too.
+  STATIC_ASSERT(Heap::kArgumentsLengthIndex == 0);
+  __ mov(FieldOperand(eax, JSObject::kHeaderSize +
+                      Heap::kArgumentsLengthIndex * kPointerSize),
+         ecx);
+
+  // Setup the elements pointer in the allocated arguments object.
+  // If we allocated a parameter map, edi will point there, otherwise to the
+  // backing store.
+  __ lea(edi, Operand(eax, Heap::kArgumentsObjectSize));
+  __ mov(FieldOperand(eax, JSObject::kElementsOffset), edi);
+
+  // eax = address of new object (tagged)
+  // ebx = mapped parameter count (tagged)
+  // ecx = argument count (tagged)
+  // edi = address of parameter map or backing store (tagged)
+  // esp[0] = mapped parameter count (tagged)
+  // esp[8] = parameter count (tagged)
+  // esp[12] = address of receiver argument
+  // Free a register.
+  __ push(eax);
+
+  // Initialize parameter map. If there are no mapped arguments, we're done.
+  Label skip_parameter_map;
+  __ test(ebx, Operand(ebx));
+  __ j(zero, &skip_parameter_map);
+
+  __ mov(FieldOperand(edi, FixedArray::kMapOffset),
+         Immediate(FACTORY->non_strict_arguments_elements_map()));
+  __ lea(eax, Operand(ebx, reinterpret_cast<intptr_t>(Smi::FromInt(2))));
+  __ mov(FieldOperand(edi, FixedArray::kLengthOffset), eax);
+  __ mov(FieldOperand(edi, FixedArray::kHeaderSize + 0 * kPointerSize), esi);
+  __ lea(eax, Operand(edi, ebx, times_2, kParameterMapHeaderSize));
+  __ mov(FieldOperand(edi, FixedArray::kHeaderSize + 1 * kPointerSize), eax);
+
+  // Copy the parameter slots and the holes in the arguments.
+  // We need to fill in mapped_parameter_count slots. They index the context,
+  // where parameters are stored in reverse order, at
+  //   MIN_CONTEXT_SLOTS .. MIN_CONTEXT_SLOTS+parameter_count-1
+  // The mapped parameter thus need to get indices
+  //   MIN_CONTEXT_SLOTS+parameter_count-1 ..
+  //       MIN_CONTEXT_SLOTS+parameter_count-mapped_parameter_count
+  // We loop from right to left.
+  NearLabel parameters_loop, parameters_test;
+  __ push(ecx);
+  __ mov(eax, Operand(esp, 2 * kPointerSize));
+  __ mov(ebx, Immediate(Smi::FromInt(Context::MIN_CONTEXT_SLOTS)));
+  __ add(ebx, Operand(esp, 4 * kPointerSize));
+  __ sub(ebx, Operand(eax));
+  __ mov(ecx, FACTORY->the_hole_value());
+  __ mov(edx, edi);
+  __ lea(edi, Operand(edi, eax, times_2, kParameterMapHeaderSize));
+  // eax = loop variable (tagged)
+  // ebx = mapping index (tagged)
+  // ecx = the hole value
+  // edx = address of parameter map (tagged)
+  // edi = address of backing store (tagged)
+  // esp[0] = argument count (tagged)
+  // esp[4] = address of new object (tagged)
+  // esp[8] = mapped parameter count (tagged)
+  // esp[16] = parameter count (tagged)
+  // esp[20] = address of receiver argument
+  __ jmp(&parameters_test);
+
+  __ bind(&parameters_loop);
+  __ sub(Operand(eax), Immediate(Smi::FromInt(1)));
+  __ mov(FieldOperand(edx, eax, times_2, kParameterMapHeaderSize), ebx);
+  __ mov(FieldOperand(edi, eax, times_2, FixedArray::kHeaderSize), ecx);
+  __ add(Operand(ebx), Immediate(Smi::FromInt(1)));
+  __ bind(&parameters_test);
+  __ test(eax, Operand(eax));
+  __ j(not_zero, &parameters_loop);
+  __ pop(ecx);
+
+  __ bind(&skip_parameter_map);
+
+  // ecx = argument count (tagged)
+  // edi = address of backing store (tagged)
+  // esp[0] = address of new object (tagged)
+  // esp[4] = mapped parameter count (tagged)
+  // esp[12] = parameter count (tagged)
+  // esp[16] = address of receiver argument
+  // Copy arguments header and remaining slots (if there are any).
+  __ mov(FieldOperand(edi, FixedArray::kMapOffset),
+         Immediate(FACTORY->fixed_array_map()));
+  __ mov(FieldOperand(edi, FixedArray::kLengthOffset), ecx);
+
+  NearLabel arguments_loop, arguments_test;
+  __ mov(ebx, Operand(esp, 1 * kPointerSize));
+  __ mov(edx, Operand(esp, 4 * kPointerSize));
+  __ sub(Operand(edx), ebx);  // Is there a smarter way to do negative scaling?
+  __ sub(Operand(edx), ebx);
+  __ jmp(&arguments_test);
+  __ bind(&arguments_loop);
+  __ sub(Operand(edx), Immediate(kPointerSize));
+  __ mov(eax, Operand(edx, 0));
+  __ mov(FieldOperand(edi, ebx, times_2, FixedArray::kHeaderSize), eax);
+  __ add(Operand(ebx), Immediate(Smi::FromInt(1)));
+  __ bind(&arguments_test);
+  __ cmp(ebx, Operand(ecx));
+  __ j(less, &arguments_loop);
+
+  // Restore.
+  __ pop(eax);  // Address of arguments object.
+  __ pop(ebx);  // Parameter count.
+
+  // Return and remove the on-stack parameters.
+  __ ret(3 * kPointerSize);
+
+  // Do the runtime call to allocate the arguments object.
+  __ bind(&runtime);
+  __ pop(eax);  // Remove saved parameter count.
+  __ mov(Operand(esp, 1 * kPointerSize), ecx);  // Patch argument count.
+  __ TailCallRuntime(Runtime::kNewStrictArgumentsFast, 3, 1);
+}
+
+
+void ArgumentsAccessStub::GenerateNewStrict(MacroAssembler* masm) {
+  // esp[0] : return address
+  // esp[4] : number of parameters
+  // esp[8] : receiver displacement
+  // esp[12] : function
+
+  // Check if the calling frame is an arguments adaptor frame.
   Label adaptor_frame, try_allocate, runtime;
   __ mov(edx, Operand(ebp, StandardFrameConstants::kCallerFPOffset));
   __ mov(ecx, Operand(edx, StandardFrameConstants::kContextOffset));
@@ -3681,90 +3924,79 @@
   __ bind(&adaptor_frame);
   __ mov(ecx, Operand(edx, ArgumentsAdaptorFrameConstants::kLengthOffset));
   __ mov(Operand(esp, 1 * kPointerSize), ecx);
-  __ lea(edx, Operand(edx, ecx, times_2, kDisplacement));
+  __ lea(edx, Operand(edx, ecx, times_2,
+		      StandardFrameConstants::kCallerSPOffset));
   __ mov(Operand(esp, 2 * kPointerSize), edx);
 
   // Try the new space allocation. Start out with computing the size of
   // the arguments object and the elements array.
   NearLabel add_arguments_object;
   __ bind(&try_allocate);
-  if (type_ == NEW_NON_STRICT) {
-    __ TailCallRuntime(Runtime::kNewArgumentsFast, 3, 1);
-  } else {
-    __ test(ecx, Operand(ecx));
-    __ j(zero, &add_arguments_object);
-    __ lea(ecx, Operand(ecx, times_2, FixedArray::kHeaderSize));
-    __ bind(&add_arguments_object);
-    __ add(Operand(ecx), Immediate(GetArgumentsObjectSize()));
+  __ test(ecx, Operand(ecx));
+  __ j(zero, &add_arguments_object);
+  __ lea(ecx, Operand(ecx, times_2, FixedArray::kHeaderSize));
+  __ bind(&add_arguments_object);
+  __ add(Operand(ecx), Immediate(Heap::kArgumentsObjectSizeStrict));
 
-    // Do the allocation of both objects in one go.
-    __ AllocateInNewSpace(ecx, eax, edx, ebx, &runtime, TAG_OBJECT);
+  // Do the allocation of both objects in one go.
+  __ AllocateInNewSpace(ecx, eax, edx, ebx, &runtime, TAG_OBJECT);
 
-    // Get the arguments boilerplate from the current (global) context.
-    __ mov(edi, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX)));
-    __ mov(edi, FieldOperand(edi, GlobalObject::kGlobalContextOffset));
-    __ mov(edi, Operand(edi,
-                        Context::SlotOffset(GetArgumentsBoilerplateIndex())));
+  // Get the arguments boilerplate from the current (global) context.
+  __ mov(edi, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX)));
+  __ mov(edi, FieldOperand(edi, GlobalObject::kGlobalContextOffset));
+  const int offset =
+      Context::SlotOffset(Context::STRICT_MODE_ARGUMENTS_BOILERPLATE_INDEX);
+  __ mov(edi, Operand(edi, offset));
 
-    // Copy the JS object part.
-    for (int i = 0; i < JSObject::kHeaderSize; i += kPointerSize) {
-      __ mov(ebx, FieldOperand(edi, i));
-      __ mov(FieldOperand(eax, i), ebx);
-    }
+  // Copy the JS object part.
+  for (int i = 0; i < JSObject::kHeaderSize; i += kPointerSize) {
+    __ mov(ebx, FieldOperand(edi, i));
+    __ mov(FieldOperand(eax, i), ebx);
+  }
 
-    if (type_ == NEW_NON_STRICT) {
-      // Setup the callee in-object property.
-      STATIC_ASSERT(Heap::kArgumentsCalleeIndex == 1);
-      __ mov(ebx, Operand(esp, 3 * kPointerSize));
-      __ mov(FieldOperand(eax, JSObject::kHeaderSize +
-                          Heap::kArgumentsCalleeIndex * kPointerSize),
-             ebx);
-    }
+  // Get the length (smi tagged) and set that as an in-object property too.
+  STATIC_ASSERT(Heap::kArgumentsLengthIndex == 0);
+  __ mov(ecx, Operand(esp, 1 * kPointerSize));
+  __ mov(FieldOperand(eax, JSObject::kHeaderSize +
+                      Heap::kArgumentsLengthIndex * kPointerSize),
+         ecx);
 
-    // Get the length (smi tagged) and set that as an in-object property too.
-    STATIC_ASSERT(Heap::kArgumentsLengthIndex == 0);
-    __ mov(ecx, Operand(esp, 1 * kPointerSize));
-    __ mov(FieldOperand(eax, JSObject::kHeaderSize +
-                        Heap::kArgumentsLengthIndex * kPointerSize),
-           ecx);
+  // If there are no actual arguments, we're done.
+  Label done;
+  __ test(ecx, Operand(ecx));
+  __ j(zero, &done);
 
-    // If there are no actual arguments, we're done.
-    Label done;
-    __ test(ecx, Operand(ecx));
-    __ j(zero, &done);
+  // Get the parameters pointer from the stack.
+  __ mov(edx, Operand(esp, 2 * kPointerSize));
 
-    // Get the parameters pointer from the stack.
-    __ mov(edx, Operand(esp, 2 * kPointerSize));
+  // Setup the elements pointer in the allocated arguments object and
+  // initialize the header in the elements fixed array.
+  __ lea(edi, Operand(eax, Heap::kArgumentsObjectSizeStrict));
+  __ mov(FieldOperand(eax, JSObject::kElementsOffset), edi);
+  __ mov(FieldOperand(edi, FixedArray::kMapOffset),
+         Immediate(FACTORY->fixed_array_map()));
 
-    // Setup the elements pointer in the allocated arguments object and
-    // initialize the header in the elements fixed array.
-    __ lea(edi, Operand(eax, GetArgumentsObjectSize()));
-    __ mov(FieldOperand(eax, JSObject::kElementsOffset), edi);
-    __ mov(FieldOperand(edi, FixedArray::kMapOffset),
-           Immediate(FACTORY->fixed_array_map()));
+  __ mov(FieldOperand(edi, FixedArray::kLengthOffset), ecx);
+  // Untag the length for the loop below.
+  __ SmiUntag(ecx);
 
-    __ mov(FieldOperand(edi, FixedArray::kLengthOffset), ecx);
-    // Untag the length for the loop below.
-    __ SmiUntag(ecx);
+  // Copy the fixed array slots.
+  NearLabel loop;
+  __ bind(&loop);
+  __ mov(ebx, Operand(edx, -1 * kPointerSize));  // Skip receiver.
+  __ mov(FieldOperand(edi, FixedArray::kHeaderSize), ebx);
+  __ add(Operand(edi), Immediate(kPointerSize));
+  __ sub(Operand(edx), Immediate(kPointerSize));
+  __ dec(ecx);
+  __ j(not_zero, &loop);
 
-    // Copy the fixed array slots.
-    NearLabel loop;
-    __ bind(&loop);
-    __ mov(ebx, Operand(edx, -1 * kPointerSize));  // Skip receiver.
-    __ mov(FieldOperand(edi, FixedArray::kHeaderSize), ebx);
-    __ add(Operand(edi), Immediate(kPointerSize));
-    __ sub(Operand(edx), Immediate(kPointerSize));
-    __ dec(ecx);
-    __ j(not_zero, &loop);
+  // Return and remove the on-stack parameters.
+  __ bind(&done);
+  __ ret(3 * kPointerSize);
 
-    // Return and remove the on-stack parameters.
-    __ bind(&done);
-    __ ret(3 * kPointerSize);
-
-    // Do the runtime call to allocate the arguments object.
-    __ bind(&runtime);
-    __ TailCallRuntime(Runtime::kNewStrictArgumentsFast, 3, 1);
-  }
+  // Do the runtime call to allocate the arguments object.
+  __ bind(&runtime);
+  __ TailCallRuntime(Runtime::kNewStrictArgumentsFast, 3, 1);
 }