s390: introduce DUMY opcode for special use.

src/s390/simulator-s390.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdarg.h>
 #include <stdlib.h>
 #include <cmath>
 
 #if V8_TARGET_ARCH_S390
 
@@ skipping 725 matching lines @@
   base::CallOnce(&once, &Simulator::EvalTableInit);
 }
 
 Simulator::EvaluateFuncType Simulator::EvalTable[] = {NULL};
 
 void Simulator::EvalTableInit() {
   for (int i = 0; i < MAX_NUM_OPCODES; i++) {
     EvalTable[i] = &Simulator::Evaluate_Unknown;
   }
 
+  EvalTable[DUMY] = &Simulator::Evaluate_DUMY;
   EvalTable[BKPT] = &Simulator::Evaluate_BKPT;
   EvalTable[SPM] = &Simulator::Evaluate_SPM;
   EvalTable[BALR] = &Simulator::Evaluate_BALR;
   EvalTable[BCTR] = &Simulator::Evaluate_BCTR;
   EvalTable[BCR] = &Simulator::Evaluate_BCR;
   EvalTable[SVC] = &Simulator::Evaluate_SVC;
   EvalTable[BSM] = &Simulator::Evaluate_BSM;
   EvalTable[BASSM] = &Simulator::Evaluate_BASSM;
   EvalTable[BASR] = &Simulator::Evaluate_BASR;
   EvalTable[MVCL] = &Simulator::Evaluate_MVCL;
@@ skipping 5295 matching lines @@
 
 #define GET_ADDRESS(index_reg, base_reg, offset)       \
   (((index_reg) == 0) ? 0 : get_register(index_reg)) + \
       (((base_reg) == 0) ? 0 : get_register(base_reg)) + offset
 
 int Simulator::Evaluate_Unknown(Instruction* instr) {
   UNREACHABLE();
   return 0;
 }
 
+EVALUATE(DUMY) {
+  DCHECK_OPCODE(DUMY);
+  // dummy instruction does nothing.
+  return 6;
+}
+
 EVALUATE(CLR) {
   DCHECK_OPCODE(CLR);
   DECODE_RR_INSTRUCTION(r1, r2);
   uint32_t r1_val = get_low_register<uint32_t>(r1);
   uint32_t r2_val = get_low_register<uint32_t>(r2);
   SetS390ConditionCode<uint32_t>(r1_val, r2_val);
   return length;
 }
 
 EVALUATE(LR) {
@@ skipping 6566 matching lines @@
   return 0;
 }
 
 #undef EVALUATE
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // USE_SIMULATOR
 #endif  // V8_TARGET_ARCH_S390