Examples with Variable com.facebook.presto.bytecode.Variable used on opensource projects

Example 16 with Variable

use of com.facebook.presto.bytecode.Variable in project presto by prestodb.

the class JoinProbeCompiler method generateGetPosition.

private static void generateGetPosition(ClassDefinition classDefinition, FieldDefinition positionField) {
    // dummy implementation for now
    // compiled class is used only in usecase case when result of this method is ignored.
    MethodDefinition method = classDefinition.declareMethod(a(PUBLIC), "getPosition", type(int.class));
    Variable thisVariable = method.getThis();
    method.getBody().append(thisVariable.getField(positionField)).retInt();
}

Example 17 with Variable

use of com.facebook.presto.bytecode.Variable in project presto by prestodb.

the class JoinProbeCompiler method generateAdvanceNextPosition.

private static void generateAdvanceNextPosition(ClassDefinition classDefinition, FieldDefinition positionField, FieldDefinition positionCountField) {
    MethodDefinition method = classDefinition.declareMethod(a(PUBLIC), "advanceNextPosition", type(boolean.class));
    Variable thisVariable = method.getThis();
    method.getBody().comment("this.position = this.position + 1;").append(thisVariable).append(thisVariable).getField(positionField).push(1).intAdd().putField(positionField);
    LabelNode lessThan = new LabelNode("lessThan");
    LabelNode end = new LabelNode("end");
    method.getBody().comment("return position < positionCount;").append(thisVariable).getField(positionField).append(thisVariable).getField(positionCountField).append(JumpInstruction.jumpIfIntLessThan(lessThan)).push(false).gotoLabel(end).visitLabel(lessThan).push(true).visitLabel(end).retBoolean();
}

Example 18 with Variable

use of com.facebook.presto.bytecode.Variable in project presto by prestodb.

the class AndCodeGenerator method generateExpression.

@Override
public BytecodeNode generateExpression(Signature signature, BytecodeGeneratorContext generator, Type returnType, List<RowExpression> arguments) {
    Preconditions.checkArgument(arguments.size() == 2);
    Variable wasNull = generator.wasNull();
    BytecodeBlock block = new BytecodeBlock().comment("AND").setDescription("AND");
    BytecodeNode left = generator.generate(arguments.get(0));
    BytecodeNode right = generator.generate(arguments.get(1));
    block.append(left);
    IfStatement ifLeftIsNull = new IfStatement("if left wasNull...").condition(wasNull);
    LabelNode end = new LabelNode("end");
    ifLeftIsNull.ifTrue().comment("clear the null flag, pop left value off stack, and push left null flag on the stack (true)").append(wasNull.set(constantFalse())).pop(// discard left value
    arguments.get(0).getType().getJavaType()).push(true);
    LabelNode leftIsTrue = new LabelNode("leftIsTrue");
    ifLeftIsNull.ifFalse().comment("if left is false, push false, and goto end").ifTrueGoto(leftIsTrue).push(false).gotoLabel(end).comment("left was true; push left null flag on the stack (false)").visitLabel(leftIsTrue).push(false);
    block.append(ifLeftIsNull);
    // At this point we know the left expression was either NULL or TRUE.  The stack contains a single boolean
    // value for this expression which indicates if the left value was NULL.
    // eval right!
    block.append(right);
    IfStatement ifRightIsNull = new IfStatement("if right wasNull...");
    ifRightIsNull.condition().append(wasNull);
    // this leaves a single boolean on the stack which is ignored since the value in NULL
    ifRightIsNull.ifTrue().comment("right was null, pop the right value off the stack; wasNull flag remains set to TRUE").pop(arguments.get(1).getType().getJavaType());
    LabelNode rightIsTrue = new LabelNode("rightIsTrue");
    ifRightIsNull.ifFalse().comment("if right is false, pop left null flag off stack, push false and goto end").ifTrueGoto(rightIsTrue).pop(boolean.class).push(false).gotoLabel(end).comment("right was true; store left null flag (on stack) in wasNull variable, and push true").visitLabel(rightIsTrue).putVariable(wasNull).push(true);
    block.append(ifRightIsNull).visitLabel(end);
    return block;
}

Example 19 with Variable

use of com.facebook.presto.bytecode.Variable in project presto by prestodb.

the class BytecodeUtils method handleNullValue.

public static BytecodeNode handleNullValue(Scope scope, LabelNode label, Class<?> returnType, List<Class<?>> stackArgsToPop, boolean clearNullFlag) {
    Variable wasNull = scope.getVariable("wasNull");
    BytecodeBlock nullCheck = new BytecodeBlock().setDescription("ifWasNullGoto").append(wasNull);
    String clearComment = null;
    if (clearNullFlag) {
        nullCheck.append(wasNull.set(constantFalse()));
        clearComment = "clear wasNull";
    }
    BytecodeBlock isNull = new BytecodeBlock();
    for (Class<?> parameterType : stackArgsToPop) {
        isNull.pop(parameterType);
    }
    isNull.pushJavaDefault(returnType);
    String loadDefaultComment = null;
    if (returnType != void.class) {
        loadDefaultComment = format("loadJavaDefault(%s)", returnType.getName());
    }
    isNull.gotoLabel(label);
    String popComment = null;
    if (!stackArgsToPop.isEmpty()) {
        popComment = format("pop(%s)", Joiner.on(", ").join(stackArgsToPop));
    }
    return new IfStatement("if wasNull then %s", Joiner.on(", ").skipNulls().join(clearComment, popComment, loadDefaultComment, "goto " + label.getLabel())).condition(nullCheck).ifTrue(isNull);
}

Example 20 with Variable

use of com.facebook.presto.bytecode.Variable in project presto by prestodb.

the class CoalesceCodeGenerator method generateExpression.

@Override
public BytecodeNode generateExpression(Signature signature, BytecodeGeneratorContext generatorContext, Type returnType, List<RowExpression> arguments) {
    List<BytecodeNode> operands = new ArrayList<>();
    for (RowExpression expression : arguments) {
        operands.add(generatorContext.generate(expression));
    }
    Variable wasNull = generatorContext.wasNull();
    BytecodeNode nullValue = new BytecodeBlock().append(wasNull.set(constantTrue())).pushJavaDefault(returnType.getJavaType());
    // reverse list because current if statement builder doesn't support if/else so we need to build the if statements bottom up
    for (BytecodeNode operand : Lists.reverse(operands)) {
        IfStatement ifStatement = new IfStatement();
        ifStatement.condition().append(operand).append(wasNull);
        // if value was null, pop the null value, clear the null flag, and process the next operand
        ifStatement.ifTrue().pop(returnType.getJavaType()).append(wasNull.set(constantFalse())).append(nullValue);
        nullValue = ifStatement;
    }
    return nullValue;
}