コード例 #1
0
 /**
  * Perform scalar replacement actions for a Def of a heap variable. NOTE: Even loads can def a
  * heap variable.
  *
  * @param UseRepSet stores the uses(loads) that have been eliminated
  * @param registers mapping from valueNumber -> temporary register
  */
 static void replaceDefs(IR ir, UseRecordSet UseRepSet, HashMap<UseRecord, Register> registers) {
   SSADictionary ssa = ir.HIRInfo.dictionary;
   for (Enumeration<Instruction> e = ir.forwardInstrEnumerator(); e.hasMoreElements(); ) {
     Instruction s = e.nextElement();
     if (!GetField.conforms(s)
         && !GetStatic.conforms(s)
         && !PutField.conforms(s)
         && !PutStatic.conforms(s)
         && !ALoad.conforms(s)
         && !AStore.conforms(s)) {
       continue;
     }
     if (!ssa.defsHeapVariable(s)) {
       continue;
     }
     // this instruction is a DEF of heap variable H.
     // Check if UseRepSet needs the scalar assigned by this def
     HeapOperand<?>[] H = ssa.getHeapDefs(s);
     if (H.length != 1) {
       throw new OptimizingCompilerException(
           "LoadElimination: encountered a store with more than one def? " + s);
     }
     int valueNumber = -1;
     Object index = null;
     if (AStore.conforms(s)) {
       Object address = AStore.getArray(s);
       index = AStore.getIndex(s);
       valueNumber = ir.HIRInfo.valueNumbers.getValueNumber(address);
     } else if (GetField.conforms(s)) {
       Object address = GetField.getRef(s);
       valueNumber = ir.HIRInfo.valueNumbers.getValueNumber(address);
     } else if (PutField.conforms(s)) {
       Object address = PutField.getRef(s);
       valueNumber = ir.HIRInfo.valueNumbers.getValueNumber(address);
     } else if (GetStatic.conforms(s)) {
       valueNumber = 0;
     } else if (PutStatic.conforms(s)) {
       valueNumber = 0;
     } else if (ALoad.conforms(s)) {
       Object address = ALoad.getArray(s);
       valueNumber = ir.HIRInfo.valueNumbers.getValueNumber(address);
       index = ALoad.getIndex(s);
     }
     if (index == null) {
       // Load/Store
       if (UseRepSet.containsMatchingUse(H[0].getHeapVariable(), valueNumber)) {
         Operand value = null;
         if (PutField.conforms(s)) {
           value = PutField.getValue(s);
         } else if (PutStatic.conforms(s)) {
           value = PutStatic.getValue(s);
         } else if (GetField.conforms(s) || GetStatic.conforms(s)) {
           value = ResultCarrier.getResult(s);
         }
         TypeReference type = value.getType();
         Register r =
             findOrCreateRegister(H[0].getHeapType(), valueNumber, registers, ir.regpool, type);
         appendMove(r, value, s);
       }
     } else {
       // ALoad / AStore
       int v1 = valueNumber;
       int v2 = ir.HIRInfo.valueNumbers.getValueNumber(index);
       if (UseRepSet.containsMatchingUse(H[0].getHeapVariable(), v1, v2)) {
         Operand value = null;
         if (AStore.conforms(s)) {
           value = AStore.getValue(s);
         } else if (ALoad.conforms(s)) {
           value = ALoad.getResult(s);
         }
         TypeReference type = value.getType();
         Register r =
             findOrCreateRegister(H[0].getHeapType(), v1, v2, registers, ir.regpool, type);
         appendMove(r, value, s);
       }
     }
   }
 }
コード例 #2
0
 /**
  * Update the value graph to account for a given PUTFIELD instruction.
  *
  * <p><b>PRECONDITION:</b> <code> PutField.conforms(s); </code> Make sure we have value graph
  * nodes for a constant value
  *
  * @param s the instruction in question
  */
 private void processPutField(Instruction s) {
   Operand value = PutField.getValue(s);
   if (value.isConstant()) {
     findOrCreateVertex((ConstantOperand) value);
   }
 }