[runtime] Turn ArgumentAccessStub into FastNewSloppyArgumentsStub.

src/mips/code-stubs-mips.cc

Index: src/mips/code-stubs-mips.cc
diff --git a/src/mips/code-stubs-mips.cc b/src/mips/code-stubs-mips.cc
index 0c3a7d6fde22f63bd254e4e7ea6577f97b84b002..cc1ff0f4824c3714554f8a90adf87ec0671c0149 100644
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -1591,236 +1591,6 @@ void FunctionPrototypeStub::Generate(MacroAssembler* masm) {
 }
 
 
-void ArgumentsAccessStub::GenerateNewSloppySlow(MacroAssembler* masm) {
-  // a1 : function
-  // a2 : number of parameters (tagged)
-  // a3 : parameters pointer
-
-  DCHECK(a1.is(ArgumentsAccessNewDescriptor::function()));
-  DCHECK(a2.is(ArgumentsAccessNewDescriptor::parameter_count()));
-  DCHECK(a3.is(ArgumentsAccessNewDescriptor::parameter_pointer()));
-
-  // Check if the calling frame is an arguments adaptor frame.
-  Label runtime;
-  __ lw(t0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
-  __ lw(a0, MemOperand(t0, StandardFrameConstants::kContextOffset));
-  __ Branch(&runtime, ne, a0,
-            Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
-
-  // Patch the arguments.length and the parameters pointer in the current frame.
-  __ lw(a2, MemOperand(t0, ArgumentsAdaptorFrameConstants::kLengthOffset));
-  __ Lsa(t0, t0, a2, 1);
-  __ addiu(a3, t0, StandardFrameConstants::kCallerSPOffset);
-
-  __ bind(&runtime);
-  __ Push(a1, a3, a2);
-  __ TailCallRuntime(Runtime::kNewSloppyArguments);
-}
-
-
-void ArgumentsAccessStub::GenerateNewSloppyFast(MacroAssembler* masm) {
-  // a1 : function
-  // a2 : number of parameters (tagged)
-  // a3 : parameters pointer
-  // Registers used over whole function:
-  //  t1 : arguments count (tagged)
-  //  t2 : mapped parameter count (tagged)
-
-  DCHECK(a1.is(ArgumentsAccessNewDescriptor::function()));
-  DCHECK(a2.is(ArgumentsAccessNewDescriptor::parameter_count()));
-  DCHECK(a3.is(ArgumentsAccessNewDescriptor::parameter_pointer()));
-
-  // Check if the calling frame is an arguments adaptor frame.
-  Label adaptor_frame, try_allocate, runtime;
-  __ lw(t0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
-  __ lw(a0, MemOperand(t0, StandardFrameConstants::kContextOffset));
-  __ Branch(&adaptor_frame, eq, a0,
-            Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
-
-  // No adaptor, parameter count = argument count.
-  __ mov(t1, a2);
-  __ Branch(USE_DELAY_SLOT, &try_allocate);
-  __ mov(t2, a2);  // In delay slot.
-
-  // We have an adaptor frame. Patch the parameters pointer.
-  __ bind(&adaptor_frame);
-  __ lw(t1, MemOperand(t0, ArgumentsAdaptorFrameConstants::kLengthOffset));
-  __ Lsa(t0, t0, t1, 1);
-  __ Addu(a3, t0, Operand(StandardFrameConstants::kCallerSPOffset));
-
-  // t1 = argument count (tagged)
-  // t2 = parameter count (tagged)
-  // Compute the mapped parameter count = min(t2, t1) in t2.
-  __ mov(t2, a2);
-  __ Branch(&try_allocate, le, t2, Operand(t1));
-  __ mov(t2, t1);
-
-  __ bind(&try_allocate);
-
-  // 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;
-  // If there are no mapped parameters, we do not need the parameter_map.
-  Label param_map_size;
-  DCHECK_EQ(static_cast<Smi*>(0), Smi::FromInt(0));
-  __ Branch(USE_DELAY_SLOT, &param_map_size, eq, t2, Operand(zero_reg));
-  __ mov(t5, zero_reg);  // In delay slot: param map size = 0 when t2 == 0.
-  __ sll(t5, t2, 1);
-  __ addiu(t5, t5, kParameterMapHeaderSize);
-  __ bind(&param_map_size);
-
-  // 2. Backing store.
-  __ Lsa(t5, t5, t1, 1);
-  __ Addu(t5, t5, Operand(FixedArray::kHeaderSize));
-
-  // 3. Arguments object.
-  __ Addu(t5, t5, Operand(JSSloppyArgumentsObject::kSize));
-
-  // Do the allocation of all three objects in one go.
-  __ Allocate(t5, v0, t5, t0, &runtime, TAG_OBJECT);
-
-  // v0 = address of new object(s) (tagged)
-  // a2 = argument count (smi-tagged)
-  // Get the arguments boilerplate from the current native context into t0.
-  const int kNormalOffset =
-      Context::SlotOffset(Context::SLOPPY_ARGUMENTS_MAP_INDEX);
-  const int kAliasedOffset =
-      Context::SlotOffset(Context::FAST_ALIASED_ARGUMENTS_MAP_INDEX);
-
-  __ lw(t0, NativeContextMemOperand());
-  Label skip2_ne, skip2_eq;
-  __ Branch(&skip2_ne, ne, t2, Operand(zero_reg));
-  __ lw(t0, MemOperand(t0, kNormalOffset));
-  __ bind(&skip2_ne);
-
-  __ Branch(&skip2_eq, eq, t2, Operand(zero_reg));
-  __ lw(t0, MemOperand(t0, kAliasedOffset));
-  __ bind(&skip2_eq);
-
-  // v0 = address of new object (tagged)
-  // a2 = argument count (smi-tagged)
-  // t0 = address of arguments map (tagged)
-  // t2 = mapped parameter count (tagged)
-  __ sw(t0, FieldMemOperand(v0, JSObject::kMapOffset));
-  __ LoadRoot(t5, Heap::kEmptyFixedArrayRootIndex);
-  __ sw(t5, FieldMemOperand(v0, JSObject::kPropertiesOffset));
-  __ sw(t5, FieldMemOperand(v0, JSObject::kElementsOffset));
-
-  // Set up the callee in-object property.
-  __ AssertNotSmi(a1);
-  __ sw(a1, FieldMemOperand(v0, JSSloppyArgumentsObject::kCalleeOffset));
-
-  // Use the length (smi tagged) and set that as an in-object property too.
-  __ AssertSmi(t1);
-  __ sw(t1, FieldMemOperand(v0, JSSloppyArgumentsObject::kLengthOffset));
-
-  // Set up the elements pointer in the allocated arguments object.
-  // If we allocated a parameter map, t0 will point there, otherwise
-  // it will point to the backing store.
-  __ Addu(t0, v0, Operand(JSSloppyArgumentsObject::kSize));
-  __ sw(t0, FieldMemOperand(v0, JSObject::kElementsOffset));
-
-  // v0 = address of new object (tagged)
-  // a2 = argument count (tagged)
-  // t0 = address of parameter map or backing store (tagged)
-  // t2 = mapped parameter count (tagged)
-  // Initialize parameter map. If there are no mapped arguments, we're done.
-  Label skip_parameter_map;
-  Label skip3;
-  __ Branch(&skip3, ne, t2, Operand(Smi::FromInt(0)));
-  // Move backing store address to a1, because it is
-  // expected there when filling in the unmapped arguments.
-  __ mov(a1, t0);
-  __ bind(&skip3);
-
-  __ Branch(&skip_parameter_map, eq, t2, Operand(Smi::FromInt(0)));
-
-  __ LoadRoot(t1, Heap::kSloppyArgumentsElementsMapRootIndex);
-  __ sw(t1, FieldMemOperand(t0, FixedArray::kMapOffset));
-  __ Addu(t1, t2, Operand(Smi::FromInt(2)));
-  __ sw(t1, FieldMemOperand(t0, FixedArray::kLengthOffset));
-  __ sw(cp, FieldMemOperand(t0, FixedArray::kHeaderSize + 0 * kPointerSize));
-  __ Lsa(t1, t0, t2, 1);
-  __ Addu(t1, t1, Operand(kParameterMapHeaderSize));
-  __ sw(t1, FieldMemOperand(t0, FixedArray::kHeaderSize + 1 * kPointerSize));
-
-  // 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.
-  Label parameters_loop, parameters_test;
-  __ mov(t1, t2);
-  __ Addu(t5, a2, Operand(Smi::FromInt(Context::MIN_CONTEXT_SLOTS)));
-  __ Subu(t5, t5, Operand(t2));
-  __ LoadRoot(t3, Heap::kTheHoleValueRootIndex);
-  __ Lsa(a1, t0, t1, 1);
-  __ Addu(a1, a1, Operand(kParameterMapHeaderSize));
-
-  // a1 = address of backing store (tagged)
-  // t0 = address of parameter map (tagged)
-  // a0 = temporary scratch (a.o., for address calculation)
-  // t1 = loop variable (tagged)
-  // t3 = the hole value
-  __ jmp(&parameters_test);
-
-  __ bind(&parameters_loop);
-  __ Subu(t1, t1, Operand(Smi::FromInt(1)));
-  __ sll(a0, t1, 1);
-  __ Addu(a0, a0, Operand(kParameterMapHeaderSize - kHeapObjectTag));
-  __ Addu(t6, t0, a0);
-  __ sw(t5, MemOperand(t6));
-  __ Subu(a0, a0, Operand(kParameterMapHeaderSize - FixedArray::kHeaderSize));
-  __ Addu(t6, a1, a0);
-  __ sw(t3, MemOperand(t6));
-  __ Addu(t5, t5, Operand(Smi::FromInt(1)));
-  __ bind(&parameters_test);
-  __ Branch(&parameters_loop, ne, t1, Operand(Smi::FromInt(0)));
-
-  // t1 = argument count (tagged).
-  __ lw(t1, FieldMemOperand(v0, JSSloppyArgumentsObject::kLengthOffset));
-
-  __ bind(&skip_parameter_map);
-  // v0 = address of new object (tagged)
-  // a1 = address of backing store (tagged)
-  // t1 = argument count (tagged)
-  // t2 = mapped parameter count (tagged)
-  // t5 = scratch
-  // Copy arguments header and remaining slots (if there are any).
-  __ LoadRoot(t5, Heap::kFixedArrayMapRootIndex);
-  __ sw(t5, FieldMemOperand(a1, FixedArray::kMapOffset));
-  __ sw(t1, FieldMemOperand(a1, FixedArray::kLengthOffset));
-
-  Label arguments_loop, arguments_test;
-  __ sll(t6, t2, 1);
-  __ Subu(a3, a3, Operand(t6));
-  __ jmp(&arguments_test);
-
-  __ bind(&arguments_loop);
-  __ Subu(a3, a3, Operand(kPointerSize));
-  __ lw(t0, MemOperand(a3, 0));
-  __ Lsa(t5, a1, t2, 1);
-  __ sw(t0, FieldMemOperand(t5, FixedArray::kHeaderSize));
-  __ Addu(t2, t2, Operand(Smi::FromInt(1)));
-
-  __ bind(&arguments_test);
-  __ Branch(&arguments_loop, lt, t2, Operand(t1));
-
-  // Return.
-  __ Ret();
-
-  // Do the runtime call to allocate the arguments object.
-  // t1 = argument count (tagged)
-  __ bind(&runtime);
-  __ Push(a1, a3, t1);
-  __ TailCallRuntime(Runtime::kNewSloppyArguments);
-}
-
-
 void LoadIndexedInterceptorStub::Generate(MacroAssembler* masm) {
   // Return address is in ra.
   Label slow;
@@ -5141,6 +4911,220 @@ void FastNewRestParameterStub::Generate(MacroAssembler* masm) {
 }
 
 
+void FastNewSloppyArgumentsStub::Generate(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- a1 : function
+  //  -- cp : context
+  //  -- fp : frame pointer
+  //  -- ra : return address
+  // -----------------------------------
+  __ AssertFunction(a1);
+
+  // TODO(bmeurer): Cleanup to match the FastNewStrictArgumentsStub.
+  __ lw(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
+  __ lw(a2,
+        FieldMemOperand(a2, SharedFunctionInfo::kFormalParameterCountOffset));
+  __ Lsa(a3, fp, a2, kPointerSizeLog2 - 1);
+  __ Addu(a3, a3, Operand(StandardFrameConstants::kCallerSPOffset));
+
+  // a1 : function
+  // a2 : number of parameters (tagged)
+  // a3 : parameters pointer
+  // Registers used over whole function:
+  //  t1 : arguments count (tagged)
+  //  t2 : mapped parameter count (tagged)
+
+  // Check if the calling frame is an arguments adaptor frame.
+  Label adaptor_frame, try_allocate, runtime;
+  __ lw(t0, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ lw(a0, MemOperand(t0, StandardFrameConstants::kContextOffset));
+  __ Branch(&adaptor_frame, eq, a0,
+            Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+
+  // No adaptor, parameter count = argument count.
+  __ mov(t1, a2);
+  __ Branch(USE_DELAY_SLOT, &try_allocate);
+  __ mov(t2, a2);  // In delay slot.
+
+  // We have an adaptor frame. Patch the parameters pointer.
+  __ bind(&adaptor_frame);
+  __ lw(t1, MemOperand(t0, ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ Lsa(t0, t0, t1, 1);
+  __ Addu(a3, t0, Operand(StandardFrameConstants::kCallerSPOffset));
+
+  // t1 = argument count (tagged)
+  // t2 = parameter count (tagged)
+  // Compute the mapped parameter count = min(t2, t1) in t2.
+  __ mov(t2, a2);
+  __ Branch(&try_allocate, le, t2, Operand(t1));
+  __ mov(t2, t1);
+
+  __ bind(&try_allocate);
+
+  // 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;
+  // If there are no mapped parameters, we do not need the parameter_map.
+  Label param_map_size;
+  DCHECK_EQ(static_cast<Smi*>(0), Smi::FromInt(0));
+  __ Branch(USE_DELAY_SLOT, &param_map_size, eq, t2, Operand(zero_reg));
+  __ mov(t5, zero_reg);  // In delay slot: param map size = 0 when t2 == 0.
+  __ sll(t5, t2, 1);
+  __ addiu(t5, t5, kParameterMapHeaderSize);
+  __ bind(&param_map_size);
+
+  // 2. Backing store.
+  __ Lsa(t5, t5, t1, 1);
+  __ Addu(t5, t5, Operand(FixedArray::kHeaderSize));
+
+  // 3. Arguments object.
+  __ Addu(t5, t5, Operand(JSSloppyArgumentsObject::kSize));
+
+  // Do the allocation of all three objects in one go.
+  __ Allocate(t5, v0, t5, t0, &runtime, TAG_OBJECT);
+
+  // v0 = address of new object(s) (tagged)
+  // a2 = argument count (smi-tagged)
+  // Get the arguments boilerplate from the current native context into t0.
+  const int kNormalOffset =
+      Context::SlotOffset(Context::SLOPPY_ARGUMENTS_MAP_INDEX);
+  const int kAliasedOffset =
+      Context::SlotOffset(Context::FAST_ALIASED_ARGUMENTS_MAP_INDEX);
+
+  __ lw(t0, NativeContextMemOperand());
+  Label skip2_ne, skip2_eq;
+  __ Branch(&skip2_ne, ne, t2, Operand(zero_reg));
+  __ lw(t0, MemOperand(t0, kNormalOffset));
+  __ bind(&skip2_ne);
+
+  __ Branch(&skip2_eq, eq, t2, Operand(zero_reg));
+  __ lw(t0, MemOperand(t0, kAliasedOffset));
+  __ bind(&skip2_eq);
+
+  // v0 = address of new object (tagged)
+  // a2 = argument count (smi-tagged)
+  // t0 = address of arguments map (tagged)
+  // t2 = mapped parameter count (tagged)
+  __ sw(t0, FieldMemOperand(v0, JSObject::kMapOffset));
+  __ LoadRoot(t5, Heap::kEmptyFixedArrayRootIndex);
+  __ sw(t5, FieldMemOperand(v0, JSObject::kPropertiesOffset));
+  __ sw(t5, FieldMemOperand(v0, JSObject::kElementsOffset));
+
+  // Set up the callee in-object property.
+  __ AssertNotSmi(a1);
+  __ sw(a1, FieldMemOperand(v0, JSSloppyArgumentsObject::kCalleeOffset));
+
+  // Use the length (smi tagged) and set that as an in-object property too.
+  __ AssertSmi(t1);
+  __ sw(t1, FieldMemOperand(v0, JSSloppyArgumentsObject::kLengthOffset));
+
+  // Set up the elements pointer in the allocated arguments object.
+  // If we allocated a parameter map, t0 will point there, otherwise
+  // it will point to the backing store.
+  __ Addu(t0, v0, Operand(JSSloppyArgumentsObject::kSize));
+  __ sw(t0, FieldMemOperand(v0, JSObject::kElementsOffset));
+
+  // v0 = address of new object (tagged)
+  // a2 = argument count (tagged)
+  // t0 = address of parameter map or backing store (tagged)
+  // t2 = mapped parameter count (tagged)
+  // Initialize parameter map. If there are no mapped arguments, we're done.
+  Label skip_parameter_map;
+  Label skip3;
+  __ Branch(&skip3, ne, t2, Operand(Smi::FromInt(0)));
+  // Move backing store address to a1, because it is
+  // expected there when filling in the unmapped arguments.
+  __ mov(a1, t0);
+  __ bind(&skip3);
+
+  __ Branch(&skip_parameter_map, eq, t2, Operand(Smi::FromInt(0)));
+
+  __ LoadRoot(t1, Heap::kSloppyArgumentsElementsMapRootIndex);
+  __ sw(t1, FieldMemOperand(t0, FixedArray::kMapOffset));
+  __ Addu(t1, t2, Operand(Smi::FromInt(2)));
+  __ sw(t1, FieldMemOperand(t0, FixedArray::kLengthOffset));
+  __ sw(cp, FieldMemOperand(t0, FixedArray::kHeaderSize + 0 * kPointerSize));
+  __ Lsa(t1, t0, t2, 1);
+  __ Addu(t1, t1, Operand(kParameterMapHeaderSize));
+  __ sw(t1, FieldMemOperand(t0, FixedArray::kHeaderSize + 1 * kPointerSize));
+
+  // 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.
+  Label parameters_loop, parameters_test;
+  __ mov(t1, t2);
+  __ Addu(t5, a2, Operand(Smi::FromInt(Context::MIN_CONTEXT_SLOTS)));
+  __ Subu(t5, t5, Operand(t2));
+  __ LoadRoot(t3, Heap::kTheHoleValueRootIndex);
+  __ Lsa(a1, t0, t1, 1);
+  __ Addu(a1, a1, Operand(kParameterMapHeaderSize));
+
+  // a1 = address of backing store (tagged)
+  // t0 = address of parameter map (tagged)
+  // a0 = temporary scratch (a.o., for address calculation)
+  // t1 = loop variable (tagged)
+  // t3 = the hole value
+  __ jmp(&parameters_test);
+
+  __ bind(&parameters_loop);
+  __ Subu(t1, t1, Operand(Smi::FromInt(1)));
+  __ sll(a0, t1, 1);
+  __ Addu(a0, a0, Operand(kParameterMapHeaderSize - kHeapObjectTag));
+  __ Addu(t6, t0, a0);
+  __ sw(t5, MemOperand(t6));
+  __ Subu(a0, a0, Operand(kParameterMapHeaderSize - FixedArray::kHeaderSize));
+  __ Addu(t6, a1, a0);
+  __ sw(t3, MemOperand(t6));
+  __ Addu(t5, t5, Operand(Smi::FromInt(1)));
+  __ bind(&parameters_test);
+  __ Branch(&parameters_loop, ne, t1, Operand(Smi::FromInt(0)));
+
+  // t1 = argument count (tagged).
+  __ lw(t1, FieldMemOperand(v0, JSSloppyArgumentsObject::kLengthOffset));
+
+  __ bind(&skip_parameter_map);
+  // v0 = address of new object (tagged)
+  // a1 = address of backing store (tagged)
+  // t1 = argument count (tagged)
+  // t2 = mapped parameter count (tagged)
+  // t5 = scratch
+  // Copy arguments header and remaining slots (if there are any).
+  __ LoadRoot(t5, Heap::kFixedArrayMapRootIndex);
+  __ sw(t5, FieldMemOperand(a1, FixedArray::kMapOffset));
+  __ sw(t1, FieldMemOperand(a1, FixedArray::kLengthOffset));
+
+  Label arguments_loop, arguments_test;
+  __ sll(t6, t2, 1);
+  __ Subu(a3, a3, Operand(t6));
+  __ jmp(&arguments_test);
+
+  __ bind(&arguments_loop);
+  __ Subu(a3, a3, Operand(kPointerSize));
+  __ lw(t0, MemOperand(a3, 0));
+  __ Lsa(t5, a1, t2, 1);
+  __ sw(t0, FieldMemOperand(t5, FixedArray::kHeaderSize));
+  __ Addu(t2, t2, Operand(Smi::FromInt(1)));
+
+  __ bind(&arguments_test);
+  __ Branch(&arguments_loop, lt, t2, Operand(t1));
+
+  // Return.
+  __ Ret();
+
+  // Do the runtime call to allocate the arguments object.
+  // t1 = argument count (tagged)
+  __ bind(&runtime);
+  __ Push(a1, a3, t1);
+  __ TailCallRuntime(Runtime::kNewSloppyArguments);
+}
+
+
 void FastNewStrictArgumentsStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- a1 : function