BinaryOperand.java

/*
  BinaryOperand.java

  (c) 2008-2014 Edward Swartz

  All rights reserved. This program and the accompanying materials
  are made available under the terms of the Eclipse Public License v1.0
  which accompanies this distribution, and is available at
  http://www.eclipse.org/legal/epl-v10.html
 */
package v9t9.tools.asm.operand.hl;

import v9t9.common.asm.IInstruction;
import v9t9.common.asm.ResolveException;
import v9t9.tools.asm.IAssembler;
import v9t9.tools.asm.operand.ll.LLForwardOperand;
import v9t9.tools.asm.operand.ll.LLImmedOperand;
import v9t9.tools.asm.operand.ll.LLOperand;

/**
 * @author ejs
 *
 */
public class BinaryOperand extends BaseOperand {

	private final int type;
	private final AssemblerOperand left;
	private final AssemblerOperand right;

	public BinaryOperand(int type, AssemblerOperand left, AssemblerOperand right) {
		this.type = type;
		this.left = left;
		this.right = right;
	}

	@Override
	public String toString() {
		return left + (" " + (char)type + " " ) + right;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((left == null) ? 0 : left.hashCode());
		result = prime * result + ((right == null) ? 0 : right.hashCode());
		result = prime * result + type;
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj) {
			return true;
		}
		if (obj == null) {
			return false;
		}
		if (getClass() != obj.getClass()) {
			return false;
		}
		BinaryOperand other = (BinaryOperand) obj;
		if (left == null) {
			if (other.left != null) {
				return false;
			}
		} else if (!left.equals(other.left)) {
			return false;
		}
		if (right == null) {
			if (other.right != null) {
				return false;
			}
		} else if (!right.equals(other.right)) {
			return false;
		}
		if (type != other.type) {
			return false;
		}
		return true;
	}
	
	/* (non-Javadoc)
	 * @see v9t9.tools.asm.operand.hl.AssemblerOperand#isMemory()
	 */
	@Override
	public boolean isMemory() {
		return false;
	}
	/* (non-Javadoc)
	 * @see v9t9.tools.asm.operand.hl.AssemblerOperand#isRegister()
	 */
	@Override
	public boolean isRegister() {
		return false;
	}
	
	/* (non-Javadoc)
	 * @see v9t9.tools.asm.operand.hl.AssemblerOperand#isConst()
	 */
	@Override
	public boolean isConst() {
		return left.isConst() && right.isConst();
	}
	public LLOperand resolve(IAssembler assembler, IInstruction inst)
			throws ResolveException {
		LLOperand leftRes = left.resolve(assembler, inst);
		LLOperand rightRes = right.resolve(assembler, inst);
		if (leftRes instanceof LLForwardOperand || rightRes instanceof LLForwardOperand) {
			return new LLForwardOperand(this, leftRes.getSize() | rightRes.getSize());
		}
		if (leftRes instanceof LLImmedOperand) {
			if (rightRes instanceof LLImmedOperand) {
				int immed = doOp(inst, leftRes.getImmediate(), rightRes.getImmediate());
				return new LLImmedOperand(this, immed);
			} else {
				throw new ResolveException(rightRes, "Expected immediate");
			}
		}
		else
			throw new ResolveException(leftRes, "Expected immediate");
		
	}

	/**
	 * @param inst  
	 */
	private int doOp(IInstruction inst, int l, int r) throws ResolveException {
		switch (type) {
		case '+': return (l + r);
		case '-': return (l - r);
		case '*': return (l * r);
		case '/': if (r != 0) return (l / r); 
			else throw new ResolveException(this, "Division by zero");
		case '>': return (l > r) ? 1 : 0;
		case '<': return (l < r) ? 1 : 0;
		case '=': return (l == r) ? 1 : 0;
		case '≤': return (l <= r) ? 1 : 0;
		case '≥': return (l >= r) ? 1 : 0;
		case '«': return (l << r);
		case '»': return (l >> r);
		}
		throw new IllegalStateException("unknown operation: " + (char)type);
	}

	public int getKind() {
		return type;
	}

	public AssemblerOperand getLeft() {
		return left;
	}

	public AssemblerOperand getRight() {
		return right;
	}
	

	/* (non-Javadoc)
	 * @see v9t9.tools.asm.operand.hl.BaseOperand#replaceOperand(v9t9.tools.asm.operand.hl.AssemblerOperand, v9t9.tools.asm.operand.hl.AssemblerOperand)
	 */
	@Override
	public AssemblerOperand replaceOperand(AssemblerOperand src,
			AssemblerOperand dst) {
		if (src.equals(this))
			return dst;
		AssemblerOperand newLeft = left.replaceOperand(src, dst);
		AssemblerOperand newRight = right.replaceOperand(src, dst);
		if (newLeft != left || newRight != right) {
			return new BinaryOperand(type, newLeft, newRight);
		}
		return this;
	}
	
	/* (non-Javadoc)
	 * @see v9t9.tools.asm.operand.hl.AssemblerOperand#getChildren()
	 */
	@Override
	public AssemblerOperand[] getChildren() {
		return new AssemblerOperand[] { left, right };
	}
	
	/* (non-Javadoc)
	 * @see v9t9.tools.asm.operand.hl.AssemblerOperand#addOffset(int)
	 */
	@Override
	public AssemblerOperand addOffset(int i) {
		return new BinaryOperand('+',  this, new NumberOperand(i));
	}
}