Improve instruction scheduling when calling the store buffer stub.

runtime/vm/assembler_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"  // NOLINT
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/assembler.h"
 #include "vm/longjump.h"
 #include "vm/runtime_entry.h"
@@ skipping 527 matching lines @@
 }
 
 
 void Assembler::BranchLinkPatchable(const StubEntry& stub_entry) {
   BranchLink(Code::ZoneHandle(stub_entry.code()), kPatchable);
 }
 
 
 void Assembler::BranchLinkToRuntime() {
   lw(T9, Address(THR, Thread::call_to_runtime_entry_point_offset()));
-  lw(CODE_REG, Address(THR, Thread::call_to_runtime_stub_offset()));
   jalr(T9);
+  delay_slot()->lw(CODE_REG,
+                   Address(THR, Thread::call_to_runtime_stub_offset()));
 }
 
 
 void Assembler::BranchLinkWithEquivalence(const StubEntry& stub_entry,
                                           const Object& equivalence) {
   const Code& target = Code::ZoneHandle(stub_entry.code());
   ASSERT(!in_delay_slot_);
   const int32_t offset = ObjectPool::element_offset(
       object_pool_wrapper_.FindObject(target, equivalence));
   LoadWordFromPoolOffset(CODE_REG, offset - kHeapObjectTag);
@@ skipping 134 matching lines @@
     // Preserve T0.
     addiu(SP, SP, Immediate(-2 * kWordSize));
     sw(T0, Address(SP, 1 * kWordSize));
   } else {
     addiu(SP, SP, Immediate(-1 * kWordSize));
   }
   sw(RA, Address(SP, 0 * kWordSize));
   if (object != T0) {
     mov(T0, object);
   }
-  lw(CODE_REG, Address(THR, Thread::update_store_buffer_code_offset()));
   lw(T9, Address(THR, Thread::update_store_buffer_entry_point_offset()));
   jalr(T9);
+  delay_slot()->lw(CODE_REG,
+                   Address(THR, Thread::update_store_buffer_code_offset()));
   lw(RA, Address(SP, 0 * kWordSize));
   if (value != T0) {
     // Restore T0.
     lw(T0, Address(SP, 1 * kWordSize));
     addiu(SP, SP, Immediate(2 * kWordSize));
   } else {
     addiu(SP, SP, Immediate(1 * kWordSize));
   }
   Bind(&done);
 }
@@ skipping 682 matching lines @@
   Label stop;
   b(&stop);
   Emit(reinterpret_cast<int32_t>(message));
   Bind(&stop);
   break_(Instr::kStopMessageCode);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS