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/*
* Code formatter project
* CS 4481
*/
package submit.ast;
import submit.MIPSResult;
import submit.RegisterAllocator;
import submit.SymbolTable;
/**
*
* @author edwajohn
*/
public class If extends AbstractNode implements Statement {
private final Expression expression;
private final Statement trueStatement;
private final Statement falseStatement;
public If(Expression expression, Statement trueStatement,
Statement falseStatement) {
this.expression = expression;
this.trueStatement = trueStatement;
this.falseStatement = falseStatement;
}
@Override
public void toCminus(StringBuilder builder, String prefix) {
builder.append(prefix).append("if (");
expression.toCminus(builder, prefix);
builder.append(")\n");
if (trueStatement instanceof CompoundStatement) {
trueStatement.toCminus(builder, prefix);
} else {
trueStatement.toCminus(builder, prefix + " ");
}
if (falseStatement != null) {
builder.append(prefix).append("else\n");
// falseStatement.toCminus(builder, prefix);
if (falseStatement instanceof CompoundStatement) {
falseStatement.toCminus(builder, prefix);
} else {
falseStatement.toCminus(builder, prefix + " ");
}
}
// builder.append(prefix).append("}");
}
@Override
public MIPSResult toMIPS(StringBuilder code, StringBuilder data,
SymbolTable symbolTable,
RegisterAllocator regAllocator) {
String continueLabel = "if_" + SymbolTable.nextId();
String elseLabel = "else_" + SymbolTable.nextId();
MIPSResult expressionTruthiness =
expression.toMIPS(code, data, symbolTable, regAllocator);
code.append(String.format("bne %s $zero %s\n",
expressionTruthiness.getRegister(), elseLabel));
regAllocator.clear(expressionTruthiness.getRegister());
MIPSResult trueRes =
trueStatement.toMIPS(code, data, symbolTable, regAllocator);
regAllocator.clear(trueRes.getRegister());
code.append(String.format("j %s\n", continueLabel))
.append(String.format("%s:\n", elseLabel));
regAllocator.clear(expressionTruthiness.getRegister());
if (falseStatement != null) {
MIPSResult falseRes =
falseStatement.toMIPS(code, data, symbolTable, regAllocator);
regAllocator.clear(falseRes.getRegister());
}
code.append(String.format("%s:\n", continueLabel));
return MIPSResult.createVoidResult();
}
}
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