vstack.push(IntItem.createConst(-val.getValue()));
vstack.push(ifac.createIConst(-val.getValue()));
    public final void visit_ineg() {        final IntItem val = vstack.popInt();        val.loadIf(eContext, ~Item.Kind.CONSTANT);        if (val.isConstant()) {            vstack.push(IntItem.createConst(-val.getValue()));        } else {            os.writeNEG(val.getRegister());            vstack.push(val);        }    }