phi.java

来自「一种将c高级语言转化给VHDL的编译器」· Java 代码 · 共 122 行

/*
 *
 LA-CC 05-135 Trident 0.7.1

Copyright Notice
Copyright 2006 (c) the Regents of the University of California.

This Software was produced under a U.S. Government contract
(W-7405-ENG-36) by Los Alamos National Laboratory, which is operated
by the University of California for the U.S. Department of Energy. The
U.S. Government is licensed to use, reproduce, and distribute this
Software. Permission is granted to the public to copy and use this
Software without charge, provided that this Notice and any statement
of authorship are reproduced on all copies. Neither the Government nor
the University makes any warranty, express or implied, or assumes any
liability or responsibility for the user of this Software.


 */



package fp.flowgraph;

import java.util.*;

import fp.util.BooleanEquation;

public class Phi extends InstructionFormat {

  public static boolean conforms(Instruction i) {
    return conforms(i.operator);
  }

  public static boolean conforms(Operator op) {
    return op.format == Phi_format;
  }
  
  // handle Results
  public static Operand getResult(Instruction i) {
    return i.getOperand(0);
  }

  public static void setResult(Instruction i, Operand result) {
    i.putOperand(0, result);
  }

  // is this necessary?
  public static int indexOfResult(Instruction i) { return 0; }

  public static boolean hasResult(Instruction i) {
    return i.getOperand(0) != null;
  }


  public static LabelOperand getValLabel(Instruction i, int index) {
    return (LabelOperand)i.getOperand(2*(index+1) );
  }

  public static Operand getValOperand(Instruction i, int index) {
    return i.getOperand(2*index + 1);
  }

  public static void setVal(Instruction i, int index, Operand value, 
			    Operand label) {
    i.putOperand(2*index + 1, value);
    i.putOperand(2*(index + 1), label);
  }

  public static boolean hasVal(Instruction i, int index) {
    return i.getOperand(2*(index+1)) != null;
  }

  public static Instruction create(Operator o, Type type, Operand result,
				   LinkedList values) {
    return Phi.create(o, type, result, values, null);
  }

  public static Instruction create(Operator o, Type type, Operand result,
                                   LinkedList values, BooleanEquation eq) {
    Instruction i = new Instruction(o, type, eq);
    i.putOperand(0, result);
    if (values != null) {
      i.resizeNumberOfOperands( values.size() + 5 );
      
      int index = 0;
      
      for(ListIterator iter = values.listIterator(); iter.hasNext(); ) {
	Operand value = (Operand)iter.next();
	LabelOperand label = (LabelOperand)iter.next();
	i.putOperand(2*index + 1, value);
	i.putOperand(2*(index + 1), label);
	index++;
      }
    }
    return i;
  }

  public static void verify(Instruction i) throws IllegalOperand {
    if (!hasResult(i)) {
      throw new IllegalOperand("Phi instruction does not have a result operand.");
    }

    int index = 0;
    while (hasVal(i, index)) {
      Operand value = getValOperand(i, index);
      Operand label = getValLabel(i, index);
      if ((label==null) || (value==null)) {
	throw new IllegalOperand("Phi instruction missing operand in its value/label pairs");
      }
      if (!label.isLabel()) {
	throw new IllegalOperand("Phi instruction label operand " + label.getName() + " is not label.");
      }
      if (!value.isFirstClassOperand()) {
	throw new IllegalOperand("Phi instruction value operand " + value.getName() + " is not first class operand.");
      }
      index++;
    }
  }
											  
}