Revert "Lazy deopt without code patching."

runtime/vm/instructions_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"  // Needed here to get TARGET_ARCH_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/constants_mips.h"
 #include "vm/cpu.h"
 #include "vm/instructions.h"
@@ skipping 199 matching lines @@
       object_pool_.RawValueAt(native_function_pool_index_));
 }
 
 
 void NativeCallPattern::set_native_function(NativeFunction func) const {
   object_pool_.SetRawValueAt(native_function_pool_index_,
       reinterpret_cast<uword>(func));
 }
 
 
+void CallPattern::InsertDeoptCallAt(uword pc, uword target_address) {
+  Instr* lui = Instr::At(pc + (0 * Instr::kInstrSize));
+  Instr* ori = Instr::At(pc + (1 * Instr::kInstrSize));
+  Instr* jr = Instr::At(pc + (2 * Instr::kInstrSize));
+  Instr* nop = Instr::At(pc + (3 * Instr::kInstrSize));
+  uint16_t target_lo = target_address & 0xffff;
+  uint16_t target_hi = target_address >> 16;
+
+  lui->SetImmInstrBits(LUI, ZR, T9, target_hi);
+  ori->SetImmInstrBits(ORI, T9, T9, target_lo);
+  jr->SetSpecialInstrBits(JALR, T9, ZR, RA);
+  nop->SetInstructionBits(Instr::kNopInstruction);
+
+  ASSERT(kDeoptCallLengthInBytes == 4 * Instr::kInstrSize);
+  CPU::FlushICache(pc, kDeoptCallLengthInBytes);
+}
+
+
 SwitchableCallPattern::SwitchableCallPattern(uword pc, const Code& code)
     : object_pool_(ObjectPool::Handle(code.GetObjectPool())),
       data_pool_index_(-1),
       target_pool_index_(-1) {
   ASSERT(code.ContainsInstructionAt(pc));
   // Last instruction: jalr t9.
   ASSERT(*(reinterpret_cast<uword*>(pc) - 1) == 0);  // Delay slot.
   ASSERT(*(reinterpret_cast<uword*>(pc) - 2) == 0x0320f809);
 
   Register reg;
@@ skipping 40 matching lines @@
 bool ReturnPattern::IsValid() const {
   Instr* jr = Instr::At(pc_);
   return (jr->OpcodeField() == SPECIAL) &&
          (jr->FunctionField() == JR) &&
          (jr->RsField() == RA);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS