Remove dead code from InvokeDartCode stub.

runtime/vm/stub_code_arm.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_ARM)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/cpu.h"
@@ skipping 767 matching lines @@
 //   LR : points to return address.
 //   R0 : entrypoint of the Dart function to call.
 //   R1 : arguments descriptor array.
 //   R2 : arguments array.
 //   R3 : new context containing the current isolate pointer.
 void StubCode::GenerateInvokeDartCodeStub(Assembler* assembler) {
   // Save frame pointer coming in.
   __ EnterFrame((1 << FP) | (1 << LR), 0);
 
   // Save new context and C++ ABI callee-saved registers.
-  const intptr_t kNewContextOffsetFromFp =
-      -(1 + kAbiPreservedCpuRegCount) * kWordSize;
   __ PushList((1 << R3) | kAbiPreservedCpuRegs);
 
   const DRegister firstd = EvenDRegisterOf(kAbiFirstPreservedFpuReg);
   if (TargetCPUFeatures::vfp_supported()) {
     ASSERT(2 * kAbiPreservedFpuRegCount < 16);
     // Save FPU registers. 2 D registers per Q register.
     __ vstmd(DB_W, SP, firstd, 2 * kAbiPreservedFpuRegCount);
   } else {
     __ sub(SP, SP, Operand(kAbiPreservedFpuRegCount * kFpuRegisterSize));
   }
@@ skipping 64 matching lines @@
   __ Push(R3);
   __ AddImmediate(R2, kWordSize);
   __ AddImmediate(R1, 1);
   __ cmp(R1, Operand(R5));
   __ b(&push_arguments, LT);
   __ Bind(&done_push_arguments);
 
   // Call the Dart code entrypoint.
   __ blx(R0);  // R4 is the arguments descriptor array.
 
-  // Read the saved new Context pointer.
-  __ ldr(CTX, Address(FP, kNewContextOffsetFromFp));
-  __ ldr(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 saved Context pointer into the Isolate structure.
   // Uses R4 as a temporary register for this.
   // Restore the saved top exit frame info back into the Isolate structure.
   // Uses R5 as a temporary register for this.
   __ PopList((1 << R4) | (1 << R5));
   __ StoreToOffset(kWord, R4, CTX, Isolate::top_context_offset());
   __ StoreToOffset(kWord, R5, CTX, Isolate::top_exit_frame_info_offset());
 
@@ skipping 1149 matching lines @@
   const Register right = R0;
   __ ldr(left, Address(SP, 1 * kWordSize));
   __ ldr(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM