Remove dead code from InvokeDartCode stub.

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 852 matching lines @@
 //   A3 : new context containing the current isolate pointer.
 void StubCode::GenerateInvokeDartCodeStub(Assembler* assembler) {
   // Save frame pointer coming in.
   __ TraceSimMsg("InvokeDartCodeStub");
   __ EnterFrame();
 
   // Save new context and C++ ABI callee-saved registers.
 
   // The new context, saved vm tag, the top exit frame, and the old context.
   const intptr_t kPreservedContextSlots = 4;
-  const intptr_t kNewContextOffsetFromFp =
-      -(1 + kAbiPreservedCpuRegCount + kAbiPreservedFpuRegCount) * kWordSize;
   const intptr_t kPreservedRegSpace =
       kWordSize * (kAbiPreservedCpuRegCount + kAbiPreservedFpuRegCount +
                    kPreservedContextSlots);
 
   __ addiu(SP, SP, Immediate(-kPreservedRegSpace));
   for (int i = S0; i <= S7; i++) {
     Register r = static_cast<Register>(i);
     const intptr_t slot = i - S0 + kPreservedContextSlots;
     __ sw(r, Address(SP, slot * kWordSize));
   }
@@ skipping 81 matching lines @@
   __ delay_slot()->addiu(A2, A2, Immediate(kWordSize));
 
   __ Bind(&done_push_arguments);
 
   // Call the Dart code entrypoint.
   // We are calling into Dart code, here, so there is no need to call through
   // T9 to match the ABI.
   __ jalr(A0);  // S4 is the arguments descriptor array.
   __ TraceSimMsg("InvokeDartCodeStub return");
 
-  // Read the saved new Context pointer.
-  __ lw(CTX, Address(FP, kNewContextOffsetFromFp));
-  __ lw(CTX, Address(CTX, VMHandles::kOffsetOfRawPtrInHandle));
-
   // Get rid of arguments pushed on the stack.
   __ AddImmediate(SP, FP, kSavedContextSlotFromEntryFp * kWordSize);
 
-  // Load Isolate pointer into CTX. Drop Context.
+  // Load Isolate pointer into CTX.
   __ LoadIsolate(CTX);
 
   // Restore the current VMTag from the stack.
   __ lw(T1, Address(SP, 2 * kWordSize));
   __ sw(T1, Address(CTX, Isolate::vm_tag_offset()));
 
   // Restore the saved Context pointer into the Isolate structure.
   // Uses T1 as a temporary register for this.
   // Restore the saved top exit frame info back into the Isolate structure.
   // Uses T0 as a temporary register for this.
@@ skipping 1263 matching lines @@
   const Register right = T0;
   __ lw(left, Address(SP, 1 * kWordSize));
   __ lw(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp1, temp2);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS