Enables language tests for SIMMIPS.

runtime/vm/stub_code_mips.cc

 // Copyright (c) 2013, 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"
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 77 matching lines @@
   // Retval is next to 1st argument.
   __ delay_slot()->addiu(A3, A2, Immediate(kWordSize));
   __ TraceSimMsg("CallToRuntimeStub return");
 
   // Reset exit frame information in Isolate structure.
   __ sw(ZR, Address(CTX, Isolate::top_exit_frame_info_offset()));
 
   // Load Context pointer from Isolate structure into A2.
   __ lw(A2, Address(CTX, Isolate::top_context_offset()));
 
-  // Reload NULLREG.
-  __ LoadImmediate(NULLREG, reinterpret_cast<intptr_t>(Object::null()));
+  // Load null.
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
 
   // Reset Context pointer in Isolate structure.
-  __ sw(NULLREG, Address(CTX, Isolate::top_context_offset()));
+  __ sw(TMP, Address(CTX, Isolate::top_context_offset()));
 
   // Cache Context pointer into CTX while executing Dart code.
   __ mov(CTX, A2);
 
   __ mov(SP, FP);
   __ lw(RA, Address(SP, 1 * kWordSize));
   __ lw(FP, Address(SP, 0 * kWordSize));
   __ Ret();
   __ delay_slot()->addiu(SP, SP, Immediate(2 * kWordSize));
 }
@@ skipping 82 matching lines @@
   // Call native function or redirection via simulator.
   __ jalr(T5);
   __ TraceSimMsg("CallNativeCFunctionStub return");
 
   // Reset exit frame information in Isolate structure.
   __ sw(ZR, Address(CTX, Isolate::top_exit_frame_info_offset()));
 
   // Load Context pointer from Isolate structure into A2.
   __ lw(A2, Address(CTX, Isolate::top_context_offset()));
 
-  // Reload NULLREG.
-  __ LoadImmediate(NULLREG, reinterpret_cast<intptr_t>(Object::null()));
+  // Load null.
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
 
   // Reset Context pointer in Isolate structure.
-  __ sw(NULLREG, Address(CTX, Isolate::top_context_offset()));
+  __ sw(TMP, Address(CTX, Isolate::top_context_offset()));
 
   // Cache Context pointer into CTX while executing Dart code.
   __ mov(CTX, A2);
 
   __ mov(SP, FP);
   __ lw(RA, Address(SP, 1 * kWordSize));
   __ lw(FP, Address(SP, 0 * kWordSize));
   __ Ret();
   __ delay_slot()->addiu(SP, SP, Immediate(2 * kWordSize));
 }
 
 
 // Input parameters:
 //   S4: arguments descriptor array.
 void StubCode::GenerateCallStaticFunctionStub(Assembler* assembler) {
   __ TraceSimMsg("CallStaticFunctionStub");
   __ EnterStubFrame();
   // Setup space on stack for return value and preserve arguments descriptor.
 
   __ addiu(SP, SP, Immediate(-2 * kWordSize));
   __ sw(S4, Address(SP, 1 * kWordSize));
-  __ sw(NULLREG, Address(SP, 0 * kWordSize));
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(TMP, Address(SP, 0 * kWordSize));
 
   __ CallRuntime(kPatchStaticCallRuntimeEntry);
   __ TraceSimMsg("CallStaticFunctionStub return");
 
   // Get Code object result and restore arguments descriptor array.
   __ lw(T0, Address(SP, 0 * kWordSize));
   __ lw(S4, Address(SP, 1 * kWordSize));
   __ addiu(SP, SP, Immediate(2 * kWordSize));
 
   __ lw(T0, FieldAddress(T0, Code::instructions_offset()));
   __ AddImmediate(T0, Instructions::HeaderSize() - kHeapObjectTag);
 
   // Remove the stub frame as we are about to jump to the dart function.
   __ LeaveStubFrameAndReturn(T0);
 }
 
 
 // Called from a static call only when an invalid code has been entered
 // (invalid because its function was optimized or deoptimized).
 // S4: arguments descriptor array.
 void StubCode::GenerateFixCallersTargetStub(Assembler* assembler) {
   // Create a stub frame as we are pushing some objects on the stack before
   // calling into the runtime.
   __ TraceSimMsg("FixCallersTarget");
   __ EnterStubFrame();
   // Setup space on stack for return value and preserve arguments descriptor.
   __ addiu(SP, SP, Immediate(-2 * kWordSize));
   __ sw(S4, Address(SP, 1 * kWordSize));
-  __ sw(NULLREG, Address(SP, 0 * kWordSize));
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(TMP, Address(SP, 0 * kWordSize));
   __ CallRuntime(kFixCallersTargetRuntimeEntry);
   // Get Code object result and restore arguments descriptor array.
   __ lw(T0, Address(SP, 0 * kWordSize));
   __ lw(S4, Address(SP, 1 * kWordSize));
   __ addiu(SP, SP, Immediate(2 * kWordSize));
 
   // Jump to the dart function.
   __ lw(T0, FieldAddress(T0, Code::instructions_offset()));
   __ AddImmediate(T0, T0, Instructions::HeaderSize() - kHeapObjectTag);
 
   // Remove the stub frame.
   __ LeaveStubFrameAndReturn(T0);
 }
 
 
 // Input parameters:
 //   A1: Smi-tagged argument count, may be zero.
 //   FP[kParamEndSlotFromFp + 1]: Last argument.
 static void PushArgumentsArray(Assembler* assembler) {
   __ TraceSimMsg("PushArgumentsArray");
   // Allocate array to store arguments of caller.
-  __ mov(A0, NULLREG);
+  __ LoadImmediate(A0, reinterpret_cast<intptr_t>(Object::null()));
   // A0: Null element type for raw Array.
   // A1: Smi-tagged argument count, may be zero.
   __ BranchLink(&StubCode::AllocateArrayLabel());
   __ TraceSimMsg("PushArgumentsArray return");
   // V0: newly allocated array.
   // A1: Smi-tagged argument count, may be zero (was preserved by the stub).
   __ Push(V0);  // Array is in V0 and on top of stack.
   __ sll(T1, A1, 1);
   __ addu(T1, FP, T1);
   __ AddImmediate(T1, kParamEndSlotFromFp * kWordSize);
@@ skipping 29 matching lines @@
   __ lw(A1, FieldAddress(S4, ArgumentsDescriptor::count_offset()));
   __ sll(TMP1, A1, 1);  // A1 is Smi.
   __ addu(TMP1, FP, TMP1);
   __ lw(T1, Address(TMP1, kParamEndSlotFromFp * kWordSize));
 
   // Push space for the return value.
   // Push the receiver.
   // Push TMP1 data object.
   // Push arguments descriptor array.
   __ addiu(SP, SP, Immediate(-4 * kWordSize));
-  __ sw(NULLREG, Address(SP, 3 * kWordSize));
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(TMP, Address(SP, 3 * kWordSize));
   __ sw(T1, Address(SP, 2 * kWordSize));
   __ sw(S5, Address(SP, 1 * kWordSize));
   __ sw(S4, Address(SP, 0 * kWordSize));
 
   // A1: Smi-tagged arguments array length.
   PushArgumentsArray(assembler);
   __ TraceSimMsg("InstanceFunctionLookupStub return");
 
   __ CallRuntime(kInstanceFunctionLookupRuntimeEntry);
 
@@ skipping 148 matching lines @@
   GenerateDeoptimizationSequence(assembler, true);  // Preserve V0.
 }
 
 
 void StubCode::GenerateDeoptimizeStub(Assembler* assembler) {
   GenerateDeoptimizationSequence(assembler, false);  // Don't preserve V0.
 }
 
 
 void StubCode::GenerateMegamorphicMissStub(Assembler* assembler) {
-  __ Unimplemented("MegamorphicMiss stub");
-  return;
+  __ EnterStubFrame();
+
+  // Load the receiver.
+  __ lw(T2, FieldAddress(S4, ArgumentsDescriptor::count_offset()));
+  __ sll(T2, T2, 1);  // T2 is a Smi.
+  __ addu(TMP, FP, T2);
+  __ lw(T6, Address(TMP, kParamEndSlotFromFp * kWordSize));
+
+  // Preserve IC data and arguments descriptor.
+  __ addiu(SP, SP, Immediate(-6 * kWordSize));
+  __ sw(S5, Address(SP, 5 * kWordSize));
+  __ sw(S4, Address(SP, 4 * kWordSize));
+
+  // Push space for the return value.
+  // Push the receiver.
+  // Push IC data object.
+  // Push arguments descriptor array.
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(TMP, Address(SP, 3 * kWordSize));
+  __ sw(T6, Address(SP, 2 * kWordSize));
+  __ sw(S5, Address(SP, 1 * kWordSize));
+  __ sw(S4, Address(SP, 0 * kWordSize));
+
+  __ CallRuntime(kMegamorphicCacheMissHandlerRuntimeEntry);
+
+  __ lw(T0, Address(SP, 3 * kWordSize));  // Get result.
+  __ lw(S4, Address(SP, 4 * kWordSize));  // Restore argument descriptor.
+  __ lw(S5, Address(SP, 5 * kWordSize));  // Restore IC data.
+  __ addiu(SP, SP, Immediate(6 * kWordSize));
+
+  __ LeaveStubFrame();
+
+  Label nonnull;
+  __ BranchNotEqual(T0, reinterpret_cast<int32_t>(Object::null()), &nonnull);
+  __ Branch(&StubCode::InstanceFunctionLookupLabel());
+  __ Bind(&nonnull);
+  __ AddImmediate(T0, Instructions::HeaderSize() - kHeapObjectTag);
+  __ jr(T0);
 }
 
 
 // Called for inline allocation of arrays.
 // Input parameters:
 //   RA: return address.
 //   A1: Array length as Smi.
 //   A0: array element type (either NULL or an instantiated type).
 // NOTE: A1 cannot be clobbered here as the caller relies on it being saved.
 // The newly allocated object is returned in V0.
@@ skipping 84 matching lines @@
     __ sw(T3, FieldAddress(V0, Array::tags_offset()));
 
     // Initialize all array elements to raw_null.
     // V0: new object start as a tagged pointer.
     // T2: new object end address.
     // A1: Array length as Smi.
     __ AddImmediate(T3, V0, Array::data_offset() - kHeapObjectTag);
     // T3: iterator which initially points to the start of the variable
     // data area to be initialized.
 
+    __ LoadImmediate(T7, reinterpret_cast<intptr_t>(Object::null()));
     Label loop, loop_exit;
     __ BranchUnsignedGreaterEqual(T3, T2, &loop_exit);
     __ Bind(&loop);
     __ addiu(T3, T3, Immediate(kWordSize));
     __ bne(T3, T2, &loop);
-    __ delay_slot()->sw(NULLREG, Address(T3, -kWordSize));
+    __ delay_slot()->sw(T7, Address(T3, -kWordSize));
     __ Bind(&loop_exit);
 
     // Done allocating and initializing the array.
     // V0: new object.
     // A1: Array length as Smi (preserved for the caller.)
     __ Ret();
   }
 
   // Unable to allocate the array using the fast inline code, just call
   // into the runtime.
   __ Bind(&slow_case);
   // Create a stub frame as we are pushing some objects on the stack before
   // calling into the runtime.
   __ EnterStubFrame();
   // Setup space on stack for return value.
   // Push array length as Smi and element type.
   __ addiu(SP, SP, Immediate(-3 * kWordSize));
-  __ sw(NULLREG, Address(SP, 2 * kWordSize));
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(TMP, Address(SP, 2 * kWordSize));
   __ sw(A1, Address(SP, 1 * kWordSize));
-  __ sw(T3, Address(SP, 0 * kWordSize));
+  __ sw(A0, Address(SP, 0 * kWordSize));
   __ CallRuntime(kAllocateArrayRuntimeEntry);
   __ TraceSimMsg("AllocateArrayStub return");
   // Pop arguments; result is popped in IP.
-  __ lw(TMP1, Address(SP, 2 * kWordSize));
+  __ lw(V0, Address(SP, 2 * kWordSize));
   __ lw(A1, Address(SP, 1 * kWordSize));
-  __ lw(T3, Address(SP, 0 * kWordSize));
+  __ lw(A0, Address(SP, 0 * kWordSize));
   __ addiu(SP, SP, Immediate(3 * kWordSize));
-  __ mov(V0, TMP1);
 
   __ LeaveStubFrameAndReturn();
 }
 
 
 // Input parameters:
 //   RA: return address.
 //   SP: address of last argument.
 //   S4: Arguments descriptor array.
 // Return: V0.
 // Note: The closure object is the first argument to the function being
 //       called, the stub accesses the closure from this location directly
 //       when trying to resolve the call.
 void StubCode::GenerateCallClosureFunctionStub(Assembler* assembler) {
   // Load num_args.
   __ TraceSimMsg("GenerateCallClosureFunctionStub");
   __ lw(T0, FieldAddress(S4, ArgumentsDescriptor::count_offset()));
   __ LoadImmediate(TMP1, Smi::RawValue(1));
   __ subu(T0, T0, TMP1);
 
   // Load closure object in T1.
   __ sll(T1, T0, 1);  // T0 (num_args - 1) is a Smi.
   __ addu(T1, SP, T1);
   __ lw(T1, Address(T1));
 
   // Verify that T1 is a closure by checking its class.
   Label not_closure;
 
+  __ LoadImmediate(T7, reinterpret_cast<intptr_t>(Object::null()));
+
   // See if it is not a closure, but null object.
-  __ beq(T1, NULLREG, &not_closure);
+  __ beq(T1, T7, &not_closure);
 
   __ andi(CMPRES, T1, Immediate(kSmiTagMask));
   __ beq(CMPRES, ZR, &not_closure);  // Not a closure, but a smi.
 
   // Verify that the class of the object is a closure class by checking that
   // class.signature_function() is not null.
   __ LoadClass(T0, T1);
   __ lw(T0, FieldAddress(T0, Class::signature_function_offset()));
 
   // See if actual class is not a closure class.
-  __ beq(T0, NULLREG, &not_closure);
+  __ beq(T0, T7, &not_closure);
 
   // T0 is just the signature function. Load the actual closure function.
   __ lw(T2, FieldAddress(T1, Closure::function_offset()));
 
   // Load closure context in CTX; note that CTX has already been preserved.
   __ lw(CTX, FieldAddress(T1, Closure::context_offset()));
 
   Label function_compiled;
   // Load closure function code in T0.
   __ lw(T0, FieldAddress(T2, Function::code_offset()));
-  __ bne(T0, NULLREG, &function_compiled);
+  __ bne(T0, T7, &function_compiled);
 
   // Create a stub frame as we are pushing some objects on the stack before
   // calling into the runtime.
   __ EnterStubFrame();
 
   // Preserve arguments descriptor array and read-only function object argument.
   __ addiu(SP, SP, Immediate(-2 * kWordSize));
   __ sw(S4, Address(SP, 1 * kWordSize));
   __ sw(T2, Address(SP, 0 * kWordSize));
   __ CallRuntime(kCompileFunctionRuntimeEntry);
@@ skipping 21 matching lines @@
   // returning here.
   // If no call method exists, throw a NoSuchMethodError.
   // T1: non-closure object.
   // S4: arguments descriptor array.
 
   // Create a stub frame as we are pushing some objects on the stack before
   // calling into the runtime.
   __ EnterStubFrame();
 
   // Setup space on stack for result from error reporting.
-  __ addiu(SP, SP, Immediate(2 * kWordSize));
+  __ addiu(SP, SP, Immediate(-2 * kWordSize));
   // Arguments descriptor and raw null.
-  __ sw(NULLREG, Address(SP, 1 * kWordSize));
+  __ sw(T7, Address(SP, 1 * kWordSize));
   __ sw(S4, Address(SP, 0 * kWordSize));
 
   // Load smi-tagged arguments array length, including the non-closure.
   __ lw(A1, FieldAddress(S4, ArgumentsDescriptor::count_offset()));
   PushArgumentsArray(assembler);
 
   // Stack:
   // TOS + 0: Argument array.
   // TOS + 1: Arguments descriptor array.
   // TOS + 2: Place for result from the call.
@@ skipping 71 matching lines @@
   // Load arguments descriptor array into S4, which is passed to Dart code.
   __ lw(S4, Address(A1, VMHandles::kOffsetOfRawPtrInHandle));
 
   // Load number of arguments into S5.
   __ lw(T1, FieldAddress(S4, ArgumentsDescriptor::count_offset()));
   __ SmiUntag(T1);
 
   // Compute address of 'arguments array' data area into A2.
   __ lw(A2, Address(A2, VMHandles::kOffsetOfRawPtrInHandle));
 
-  // Load the null Object into NULLREG for easy comparisons.
-  __ LoadImmediate(NULLREG, reinterpret_cast<intptr_t>(Object::null()));
-
   // Set up arguments for the Dart call.
   Label push_arguments;
   Label done_push_arguments;
   __ beq(T1, ZR, &done_push_arguments);  // check if there are arguments.
   __ delay_slot()->addiu(A2, A2,
                          Immediate(Array::data_offset() - kHeapObjectTag));
   __ mov(A1, ZR);
   __ Bind(&push_arguments);
   __ lw(A3, Address(A2));
   __ Push(A3);
@@ skipping 112 matching lines @@
     __ sw(T1, FieldAddress(V0, Context::num_variables_offset()));
 
     // Setup isolate field.
     // Load Isolate pointer from Context structure into R2.
     // V0: new object.
     // T1: number of context variables.
     __ lw(T2, FieldAddress(CTX, Context::isolate_offset()));
     // T2: isolate, not an object.
     __ sw(T2, FieldAddress(V0, Context::isolate_offset()));
 
+    __ LoadImmediate(T7, reinterpret_cast<intptr_t>(Object::null()));
+
     // Initialize the context variables.
     // V0: new object.
     // T1: number of context variables.
     Label loop, loop_exit;
     __ blez(T1, &loop_exit);
     // Setup the parent field.
-    __ delay_slot()->sw(NULLREG, FieldAddress(V0, Context::parent_offset()));
+    __ delay_slot()->sw(T7, FieldAddress(V0, Context::parent_offset()));
     __ AddImmediate(T3, V0, Context::variable_offset(0) - kHeapObjectTag);
     __ sll(T1, T1, 2);
     __ Bind(&loop);
     __ addiu(T1, T1, Immediate(-kWordSize));
     __ addu(TMP1, T3, T1);
     __ bgtz(T1, &loop);
-    __ delay_slot()->sw(NULLREG, Address(TMP1));
+    __ delay_slot()->sw(T7, Address(TMP1));
     __ Bind(&loop_exit);
 
     // Done allocating and initializing the context.
     // V0: new object.
     __ Ret();
 
     __ Bind(&slow_case);
   }
   // Create a stub frame as we are pushing some objects on the stack before
   // calling into the runtime.
   __ EnterStubFrame();
   // Setup space on stack for return value.
   __ SmiTag(T1);
   __ addiu(SP, SP, Immediate(-2 * kWordSize));
-  __ sw(NULLREG, Address(SP, 1 * kWordSize));
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(TMP, Address(SP, 1 * kWordSize));  // Store null.
   __ sw(T1, Address(SP, 0 * kWordSize));
   __ CallRuntime(kAllocateContextRuntimeEntry);  // Allocate context.
   __ lw(V0, Address(SP, 1 * kWordSize));  // Get the new context.
   __ addiu(SP, SP, Immediate(2 * kWordSize));  // Pop argument and return.
 
   // V0: new object
   // Restore the frame pointer.
   __ LeaveStubFrameAndReturn();
 }
 
@@ skipping 163 matching lines @@
     // T3: next object start.
     // T1: new object type arguments (if is_cls_parameterized).
     // Set the tags.
     uword tags = 0;
     tags = RawObject::SizeTag::update(instance_size, tags);
     ASSERT(cls.id() != kIllegalCid);
     tags = RawObject::ClassIdTag::update(cls.id(), tags);
     __ LoadImmediate(T0, tags);
     __ sw(T0, Address(T2, Instance::tags_offset()));
 
+    __ LoadImmediate(T7, reinterpret_cast<intptr_t>(Object::null()));
+
     // Initialize the remaining words of the object.
     // T2: new object start.
     // T3: next object start.
     // T1: new object type arguments (if is_cls_parameterized).
     // First try inlining the initialization without a loop.
     if (instance_size < (kInlineInstanceSize * kWordSize)) {
       // Check if the object contains any non-header fields.
       // Small objects are initialized using a consecutive set of writes.
       for (intptr_t current_offset = sizeof(RawObject);
            current_offset < instance_size;
            current_offset += kWordSize) {
-        __ sw(NULLREG, Address(T2, current_offset));
+        __ sw(T7, Address(T2, current_offset));
       }
     } else {
       __ addiu(T4, T2, Immediate(sizeof(RawObject)));
       // Loop until the whole object is initialized.
       // T2: new object.
       // T3: next object start.
       // T4: next word to be initialized.
       // T1: new object type arguments (if is_cls_parameterized).
       Label loop, loop_exit;
       __ BranchUnsignedGreaterEqual(T4, T3, &loop_exit);
       __ Bind(&loop);
       __ addiu(T4, T4, Immediate(kWordSize));
       __ bne(T4, T3, &loop);
-      __ delay_slot()->sw(NULLREG, Address(T4, -kWordSize));
+      __ delay_slot()->sw(T7, Address(T4, -kWordSize));
       __ Bind(&loop_exit);
     }
     if (is_cls_parameterized) {
       // R1: new object type arguments.
       // Set the type arguments in the new object.
       __ sw(T1, Address(T2, cls.type_arguments_field_offset()));
     }
     // Done allocating and initializing the instance.
     // T2: new object still missing its heap tag.
     __ Ret();
     __ delay_slot()->addiu(V0, T2, Immediate(kHeapObjectTag));
 
     __ Bind(&slow_case);
   }
   if (is_cls_parameterized) {
     __ lw(T1, Address(SP, 1 * kWordSize));
     __ lw(T0, Address(SP, 0 * kWordSize));
   }
   // Create a stub frame as we are pushing some objects on the stack before
   // calling into the runtime.
   __ EnterStubFrame(true);  // Uses pool pointer to pass cls to runtime.
   __ LoadObject(TMP1, cls);
 
   __ addiu(SP, SP, Immediate(-4 * kWordSize));
   // Space on stack for return value.
-  __ sw(NULLREG, Address(SP, 3 * kWordSize));
+  __ LoadImmediate(T7, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(T7, Address(SP, 3 * kWordSize));
   __ sw(TMP1, Address(SP, 2 * kWordSize));  // Class of object to be allocated.
 
   if (is_cls_parameterized) {
     // Push type arguments of object to be allocated and of instantiator.
     __ sw(T1, Address(SP, 1 * kWordSize));
     __ sw(T0, Address(SP, 0 * kWordSize));
   } else {
     // Push null type arguments and kNoInstantiator.
     __ LoadImmediate(T1, Smi::RawValue(StubCode::kNoInstantiator));
-    __ sw(NULLREG, Address(SP, 1 * kWordSize));
+    __ sw(T7, Address(SP, 1 * kWordSize));
     __ sw(T1, Address(SP, 0 * kWordSize));
   }
   __ CallRuntime(kAllocateObjectRuntimeEntry);  // Allocate object.
   __ TraceSimMsg("AllocationStubForClass return");
   // Pop result (newly allocated object).
   __ lw(V0, Address(SP, 3 * kWordSize));
   __ addiu(SP, SP, Immediate(4 * kWordSize));  // Pop arguments.
   // V0: new object
   // Restore the frame pointer and return.
   __ LeaveStubFrameAndReturn(RA, true);
@@ skipping 10 matching lines @@
   ASSERT(func.IsClosureFunction());
   const bool is_implicit_static_closure =
       func.IsImplicitStaticClosureFunction();
   const bool is_implicit_instance_closure =
       func.IsImplicitInstanceClosureFunction();
   const Class& cls = Class::ZoneHandle(func.signature_class());
   const bool has_type_arguments = cls.HasTypeArguments();
 
   __ TraceSimMsg("AllocationStubForClosure");
   __ EnterStubFrame(true);  // Uses pool pointer to refer to function.
-  const intptr_t kTypeArgumentsFPOffset = 4 * kWordSize;
-  const intptr_t kReceiverFPOffset = 5 * kWordSize;
+  const intptr_t kTypeArgumentsFPOffset = 3 * kWordSize;
+  const intptr_t kReceiverFPOffset = 4 * kWordSize;
   const intptr_t closure_size = Closure::InstanceSize();
   const intptr_t context_size = Context::InstanceSize(1);  // Captured receiver.
   if (FLAG_inline_alloc &&
       Heap::IsAllocatableInNewSpace(closure_size + context_size)) {
     Label slow_case;
     Heap* heap = Isolate::Current()->heap();
     __ LoadImmediate(T5, heap->TopAddress());
     __ lw(T2, Address(T5));
     __ AddImmediate(T3, T2, closure_size);
     if (is_implicit_instance_closure) {
@@ skipping 51 matching lines @@
 
       // Set number of variables field to 1 (for captured receiver).
       __ LoadImmediate(T0, 1);
       __ sw(T0, Address(T4, Context::num_variables_offset()));
 
       // Set isolate field to isolate of current context.
       __ lw(T0, FieldAddress(CTX, Context::isolate_offset()));
       __ sw(T0, Address(T4, Context::isolate_offset()));
 
       // Set the parent to null.
-      __ sw(NULLREG, Address(T4, Context::parent_offset()));
+      __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
+      __ sw(TMP, Address(T4, Context::parent_offset()));
 
       // Initialize the context variable to the receiver.
       __ lw(T0, Address(FP, kReceiverFPOffset));
       __ sw(T0, Address(T4, Context::variable_offset(0)));
 
       // Set the newly allocated context in the newly allocated closure.
       __ AddImmediate(T1, T4, kHeapObjectTag);
       __ sw(T1, Address(T2, Closure::context_offset()));
     } else {
       __ sw(CTX, Address(T2, Closure::context_offset()));
@@ skipping 12 matching lines @@
     __ Bind(&slow_case);
   }
 
   // If it's an implicit static closure we need 2 stack slots. Otherwise,
   // If it's an implicit instance closure we need 4 stack slots, o/w only 3.
   int num_slots = 2;
   if (!is_implicit_static_closure) {
     num_slots = is_implicit_instance_closure ? 4 : 3;
   }
   __ addiu(SP, SP, Immediate(-num_slots * kWordSize));
+  // Setup space on stack for return value.
+  __ LoadImmediate(T7, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(T7, Address(SP, (num_slots - 1) * kWordSize));
   __ LoadObject(TMP1, func);
-  // Setup space on stack for return value.
-  __ sw(NULLREG, Address(SP, (num_slots - 1) * kWordSize));
   __ sw(TMP1, Address(SP, (num_slots - 2) * kWordSize));
   if (is_implicit_static_closure) {
     __ CallRuntime(kAllocateImplicitStaticClosureRuntimeEntry);
     __ TraceSimMsg("AllocationStubForClosure return");
   } else {
+    __ mov(T2, T7);
     if (is_implicit_instance_closure) {
       __ lw(T1, Address(FP, kReceiverFPOffset));
       __ sw(T1, Address(SP, (num_slots - 3) * kWordSize));  // Receiver.
-      __ sw(NULLREG, Address(SP, (num_slots - 4) * kWordSize));  // Push null.
     }
     if (has_type_arguments) {
-      __ lw(V0, Address(FP, kTypeArgumentsFPOffset));
-      // Push type arguments of closure.
-      __ sw(V0, Address(SP, (num_slots - 3) * kWordSize));
+      __ lw(T2, Address(FP, kTypeArgumentsFPOffset));
     }
+    __ sw(T2, Address(SP, 0 * kWordSize));
 
     if (is_implicit_instance_closure) {
       __ CallRuntime(kAllocateImplicitInstanceClosureRuntimeEntry);
       __ TraceSimMsg("AllocationStubForClosure return");
     } else {
       ASSERT(func.IsNonImplicitClosureFunction());
       __ CallRuntime(kAllocateClosureRuntimeEntry);
       __ TraceSimMsg("AllocationStubForClosure return");
     }
   }
   __ lw(V0, Address(SP, (num_slots - 1) * kWordSize));  // Pop function object.
   __ addiu(SP, SP, Immediate(num_slots * kWordSize));
 
   // V0: new object
   // Restore the frame pointer.
   __ LeaveStubFrameAndReturn(RA, true);
 }
 
 
+// The target function was not found, so invoke method
+// "dynamic noSuchMethod(Invocation invocation)".
+//  S5: inline cache data object.
+//  S4: arguments descriptor array.
 void StubCode::GenerateCallNoSuchMethodFunctionStub(Assembler* assembler) {
-  __ Unimplemented("CallNoSuchMethodFunction stub");
+  __ EnterStubFrame();
+
+  // Load the receiver.
+  __ lw(A1, FieldAddress(S4, ArgumentsDescriptor::count_offset()));
+  __ sll(TMP, A1, 1);  // A1 is a Smi.
+  __ addu(TMP, FP, TMP);
+  __ lw(T6, Address(TMP, kParamEndSlotFromFp * kWordSize));
+
+  // Push space for the return value.
+  // Push the receiver.
+  // Push IC data object.
+  // Push arguments descriptor array.
+  __ addiu(SP, SP, Immediate(-4 * kWordSize));
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(TMP, Address(SP, 3 * kWordSize));
+  __ sw(T6, Address(SP, 2 * kWordSize));
+  __ sw(S5, Address(SP, 1 * kWordSize));
+  __ sw(S4, Address(SP, 0 * kWordSize));
+
+  // A1: Smi-tagged arguments array length.
+  PushArgumentsArray(assembler);
+
+  __ CallRuntime(kInvokeNoSuchMethodFunctionRuntimeEntry);
+
+  __ lw(V0, Address(SP, 4 * kWordSize));  // Get result into V0.
+  __ LeaveStubFrameAndReturn();
 }
 
 
 //  T0: function object.
 //  S5: inline cache data object.
 //  S4: arguments descriptor array.
 void StubCode::GenerateOptimizedUsageCounterIncrement(Assembler* assembler) {
   __ TraceSimMsg("OptimizedUsageCounterIncrement");
   Register ic_reg = S5;
   Register func_reg = T0;
@@ skipping 156 matching lines @@
   // T1: address of receiver.
   // Create a stub frame as we are pushing some objects on the stack before
   // calling into the runtime.
   __ EnterStubFrame();
   // Preserve IC data object and arguments descriptor array and
   // setup space on stack for result (target code object).
   int num_slots = num_args + 5;
   __ addiu(SP, SP, Immediate(-num_slots * kWordSize));
   __ sw(S5, Address(SP, (num_slots - 1) * kWordSize));
   __ sw(S4, Address(SP, (num_slots - 2) * kWordSize));
-  __ sw(NULLREG, Address(SP, (num_slots - 3) * kWordSize));
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(TMP, Address(SP, (num_slots - 3) * kWordSize));
   // Push call arguments.
   for (intptr_t i = 0; i < num_args; i++) {
     __ lw(TMP1, Address(T1, -i * kWordSize));
     __ sw(TMP1, Address(SP, (num_slots - i - 4) * kWordSize));
   }
   // Pass IC data object and arguments descriptor array.
   __ sw(S5, Address(SP, (num_slots - num_args - 4) * kWordSize));
   __ sw(S4, Address(SP, (num_slots - num_args - 5) * kWordSize));
 
   if (num_args == 1) {
     __ CallRuntime(kInlineCacheMissHandlerOneArgRuntimeEntry);
   } else if (num_args == 2) {
     __ CallRuntime(kInlineCacheMissHandlerTwoArgsRuntimeEntry);
   } else if (num_args == 3) {
     __ CallRuntime(kInlineCacheMissHandlerThreeArgsRuntimeEntry);
   } else {
     UNIMPLEMENTED();
   }
   __ TraceSimMsg("NArgsCheckInlineCacheStub return");
   // Pop returned code object into T3 (null if not found).
   // Restore arguments descriptor array and IC data array.
   __ lw(T3, Address(SP, (num_slots - 3) * kWordSize));
   __ lw(S4, Address(SP, (num_slots - 2) * kWordSize));
   __ lw(S5, Address(SP, (num_slots - 1) * kWordSize));
   // Remove the call arguments pushed earlier, including the IC data object
   // and the arguments descriptor array.
   __ addiu(SP, SP, Immediate(num_slots * kWordSize));
   __ LeaveStubFrame();
   Label call_target_function;
-  __ bne(T3, NULLREG, &call_target_function);
+  __ BranchNotEqual(T3, reinterpret_cast<int32_t>(Object::null()),
+                    &call_target_function);
 
   // NoSuchMethod or closure.
   // Mark IC call that it may be a closure call that does not collect
   // type feedback.
   __ LoadImmediate(TMP1, 1);
   __ Branch(&StubCode::InstanceFunctionLookupLabel());
   __ delay_slot()->sb(TMP1, FieldAddress(S5, ICData::is_closure_call_offset()));
 
   __ Bind(&found);
   // T0: Pointer to an IC data check group.
@@ skipping 101 matching lines @@
 //  RA: return address (Dart code).
 //  S4: Arguments descriptor array.
 void StubCode::GenerateBreakpointStaticStub(Assembler* assembler) {
   __ TraceSimMsg("BreakpointStaticStub");
   // Create a stub frame as we are pushing some objects on the stack before
   // calling into the runtime.
   __ EnterStubFrame();
   // Preserve arguments descriptor and make room for result.
   __ addiu(SP, SP, Immediate(-2 * kWordSize));
   __ sw(S4, Address(SP, 1 * kWordSize));
-  __ sw(NULLREG, Address(SP, 0 * kWordSize));
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(TMP, Address(SP, 0 * kWordSize));
   __ CallRuntime(kBreakpointStaticHandlerRuntimeEntry);
   // Pop code object result and restore arguments descriptor.
   __ lw(T0, Address(SP, 0 * kWordSize));
   __ lw(S4, Address(SP, 1 * kWordSize));
   __ addiu(SP, SP, Immediate(2 * kWordSize));
   __ LeaveStubFrame();
 
   // Now call the static function. The breakpoint handler function
   // ensures that the call target is compiled.
   __ lw(T0, FieldAddress(T0, Code::instructions_offset()));
@@ skipping 79 matching lines @@
   }
   __ LoadClassId(T0, A0);
   // A0: instance.
   // A1: instantiator type arguments or NULL.
   // A2: SubtypeTestCache.
   // T0: instance class id.
   // T1: instance type arguments (null if none), used only if n > 1.
   __ lw(T2, FieldAddress(A2, SubtypeTestCache::cache_offset()));
   __ AddImmediate(T2, Array::data_offset() - kHeapObjectTag);
 
+  __ LoadImmediate(T7, reinterpret_cast<intptr_t>(Object::null()));
+
   Label loop, found, not_found, next_iteration;
   // T0: instance class id.
   // T1: instance type arguments.
   // T2: Entry start.
+  // T7: null.
   __ SmiTag(T0);
   __ Bind(&loop);
   __ lw(T3, Address(T2, kWordSize * SubtypeTestCache::kInstanceClassId));
-  __ beq(T3, NULLREG, &not_found);
+  __ beq(T3, T7, &not_found);
 
   if (n == 1) {
     __ beq(T3, T0, &found);
   } else {
     __ bne(T3, T0, &next_iteration);
     __ lw(T3,
           Address(T2, kWordSize * SubtypeTestCache::kInstanceTypeArguments));
     if (n == 2) {
       __ beq(T3, T1, &found);
     } else {
       __ bne(T3, T1, &next_iteration);
       __ lw(T3, Address(T2, kWordSize *
                         SubtypeTestCache::kInstantiatorTypeArguments));
       __ beq(T3, A1, &found);
     }
   }
   __ Bind(&next_iteration);
   __ b(&loop);
   __ delay_slot()->addiu(T2, T2,
       Immediate(kWordSize * SubtypeTestCache::kTestEntryLength));
   // Fall through to not found.
   __ Bind(&not_found);
   __ Ret();
-  __ delay_slot()->mov(V0, NULLREG);
+  __ delay_slot()->mov(V0, T7);
 
   __ Bind(&found);
   __ Ret();
   __ delay_slot()->lw(V0,
                       Address(T2, kWordSize * SubtypeTestCache::kTestResult));
 }
 
 
 // Used to check class and type arguments. Arguments passed in registers:
 // RA: return address.
@@ skipping 58 matching lines @@
 // Implements equality operator when one of the arguments is null
 // (identity check) and updates ICData if necessary.
 // RA: return address.
 // A1: left argument.
 // A0: right argument.
 // T0: ICData.
 // V0: result.
 // TODO(srdjan): Move to VM stubs once Boolean objects become VM objects.
 void StubCode::GenerateEqualityWithNullArgStub(Assembler* assembler) {
   __ TraceSimMsg("EqualityWithNullArgStub");
+  __ Comment("EqualityWithNullArgStub");
   __ EnterStubFrame();
   static const intptr_t kNumArgsTested = 2;
 #if defined(DEBUG)
   { Label ok;
     __ lw(TMP1, FieldAddress(T0, ICData::num_args_tested_offset()));
     __ BranchEqual(TMP1, kNumArgsTested, &ok);
     __ Stop("Incorrect ICData for equality");
     __ Bind(&ok);
   }
 #endif  // DEBUG
@@ skipping 81 matching lines @@
 
 // Calls to the runtime to optimize the given function.
 // T0: function to be reoptimized.
 // S4: argument descriptor (preserved).
 void StubCode::GenerateOptimizeFunctionStub(Assembler* assembler) {
   __ TraceSimMsg("OptimizeFunctionStub");
   __ EnterStubFrame();
   __ addiu(SP, SP, Immediate(-3 * kWordSize));
   __ sw(S4, Address(SP, 2 * kWordSize));
   // Setup space on stack for return value.
-  __ sw(NULLREG, Address(SP, 1 * kWordSize));
+  __ LoadImmediate(TMP, reinterpret_cast<intptr_t>(Object::null()));
+  __ sw(TMP, Address(SP, 1 * kWordSize));
   __ sw(T0, Address(SP, 0 * kWordSize));
   __ CallRuntime(kOptimizeInvokedFunctionRuntimeEntry);
   __ TraceSimMsg("OptimizeFunctionStub return");
   __ lw(T0, Address(SP, 1 * kWordSize));  // Get Code object
   __ lw(S4, Address(SP, 2 * kWordSize));  // Restore argument descriptor.
   __ addiu(SP, SP, Immediate(3 * kWordSize));  // Discard argument.
 
   __ lw(T0, FieldAddress(T0, Code::instructions_offset()));
   __ AddImmediate(T0, Instructions::HeaderSize() - kHeapObjectTag);
   __ LeaveStubFrameAndReturn(T0);
@@ skipping 10 matching lines @@
 // Does identical check (object references are equal or not equal) with special
 // checks for boxed numbers.
 // RA: return address.
 // SP + 4: left operand.
 // SP + 0: right operand.
 // Return: CMPRES is zero if equal, non-zero otherwise.
 // Note: A Mint cannot contain a value that would fit in Smi, a Bigint
 // cannot contain a value that fits in Mint or Smi.
 void StubCode::GenerateIdenticalWithNumberCheckStub(Assembler* assembler) {
   __ TraceSimMsg("IdenticalWithNumberCheckStub");
-  const Register ret = CMPRES;
+  __ Comment("IdenticalWithNumberCheckStub");
   const Register temp1 = T2;
   const Register temp2 = T3;
   const Register left = T1;
   const Register right = T0;
   // Preserve left, right.
-  __ addiu(SP, SP, Immediate(-2 * kWordSize));
-  __ sw(T1, Address(SP, 1 * kWordSize));
-  __ sw(T0, Address(SP, 0 * kWordSize));
+  __ addiu(SP, SP, Immediate(-4 * kWordSize));
+  __ sw(temp1, Address(SP, 3 * kWordSize));
+  __ sw(temp2, Address(SP, 2 * kWordSize));
+  __ sw(left, Address(SP, 1 * kWordSize));
+  __ sw(right, Address(SP, 0 * kWordSize));
   // TOS + 3: left argument.
   // TOS + 2: right argument.
   // TOS + 1: saved left
   // TOS + 0: saved right
-  __ lw(left, Address(SP, 3 * kWordSize));
-  __ lw(right, Address(SP, 2 * kWordSize));
+  __ lw(left, Address(SP, 5 * kWordSize));
+  __ lw(right, Address(SP, 4 * kWordSize));
   Label reference_compare, done, check_mint, check_bigint;
   // If any of the arguments is Smi do reference compare.
   __ andi(temp1, left, Immediate(kSmiTagMask));
   __ beq(temp1, ZR, &reference_compare);
   __ andi(temp1, right, Immediate(kSmiTagMask));
   __ beq(temp1, ZR, &reference_compare);
 
   // Value compare for two doubles.
   __ LoadImmediate(temp1, kDoubleCid);
   __ LoadClassId(temp2, left);
   __ bne(temp1, temp2, &check_mint);
   __ LoadClassId(temp2, right);
-  __ subu(ret, temp1, temp2);
-  __ bne(ret, ZR, &done);
+  __ subu(CMPRES, temp1, temp2);
+  __ bne(CMPRES, ZR, &done);
 
   // Double values bitwise compare.
   __ lw(temp1, FieldAddress(left, Double::value_offset() + 0 * kWordSize));
-  __ lw(temp1, FieldAddress(right, Double::value_offset() + 0 * kWordSize));
-  __ subu(ret, temp1, temp2);
-  __ bne(ret, ZR, &done);
+  __ lw(temp2, FieldAddress(right, Double::value_offset() + 0 * kWordSize));
+  __ subu(CMPRES, temp1, temp2);
+  __ bne(CMPRES, ZR, &done);
   __ lw(temp1, FieldAddress(left, Double::value_offset() + 1 * kWordSize));
   __ lw(temp2, FieldAddress(right, Double::value_offset() + 1 * kWordSize));
   __ b(&done);
-  __ delay_slot()->subu(ret, temp1, temp2);
+  __ delay_slot()->subu(CMPRES, temp1, temp2);
 
   __ Bind(&check_mint);
   __ LoadImmediate(temp1, kMintCid);
   __ LoadClassId(temp2, left);
   __ bne(temp1, temp2, &check_bigint);
   __ LoadClassId(temp2, right);
-  __ subu(ret, temp1, temp2);
-  __ bne(ret, ZR, &done);
+  __ subu(CMPRES, temp1, temp2);
+  __ bne(CMPRES, ZR, &done);
 
   __ lw(temp1, FieldAddress(left, Mint::value_offset() + 0 * kWordSize));
   __ lw(temp2, FieldAddress(right, Mint::value_offset() + 0 * kWordSize));
-  __ subu(ret, temp1, temp2);
-  __ bne(ret, ZR, &done);
+  __ subu(CMPRES, temp1, temp2);
+  __ bne(CMPRES, ZR, &done);
   __ lw(temp1, FieldAddress(left, Mint::value_offset() + 1 * kWordSize));
   __ lw(temp2, FieldAddress(right, Mint::value_offset() + 1 * kWordSize));
   __ b(&done);
-  __ delay_slot()->subu(ret, temp1, temp2);
+  __ delay_slot()->subu(CMPRES, temp1, temp2);
 
   __ Bind(&check_bigint);
   __ LoadImmediate(temp1, kBigintCid);
   __ LoadClassId(temp2, left);
   __ bne(temp1, temp2, &reference_compare);
   __ LoadClassId(temp2, right);
-  __ subu(ret, temp1, temp2);
-  __ bne(ret, ZR, &done);
+  __ subu(CMPRES, temp1, temp2);
+  __ bne(CMPRES, ZR, &done);
 
-  __ EnterStubFrame(0);
+  __ EnterStubFrame();
   __ ReserveAlignedFrameSpace(2 * kWordSize);
-  __ sw(T1, Address(SP, 1 * kWordSize));
-  __ sw(T0, Address(SP, 0 * kWordSize));
+  __ sw(left, Address(SP, 1 * kWordSize));
+  __ sw(right, Address(SP, 0 * kWordSize));
+  __ mov(A0, left);
+  __ mov(A1, right);
   __ CallRuntime(kBigintCompareRuntimeEntry);
   __ TraceSimMsg("IdenticalWithNumberCheckStub return");
   // Result in V0, 0 means equal.
   __ LeaveStubFrame();
   __ b(&done);
   __ delay_slot()->mov(CMPRES, V0);
 
   __ Bind(&reference_compare);
-  __ subu(ret, left, right);
+  __ subu(CMPRES, left, right);
   __ Bind(&done);
   // A branch or test after this comparison will check CMPRES == TMP1.
   __ mov(TMP1, ZR);
-  __ lw(T0, Address(SP, 0 * kWordSize));
-  __ lw(T1, Address(SP, 1 * kWordSize));
+  __ lw(right, Address(SP, 0 * kWordSize));
+  __ lw(left, Address(SP, 1 * kWordSize));
+  __ lw(temp2, Address(SP, 2 * kWordSize));
+  __ lw(temp1, Address(SP, 3 * kWordSize));
   __ Ret();
-  __ delay_slot()->addiu(SP, SP, Immediate(2 * kWordSize));
+  __ delay_slot()->addiu(SP, SP, Immediate(4 * kWordSize));
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS