What is interesting is to study what Calvin himself taught about the passages that express God's desire for all to be saved. It just seems so very different than what we see from some Calvinists:
"...he demonstrates that God has at heart the salvation of all, because he invites all to the acknowledgment of his truth. This belongs to that kind of argument in which the cause is proved from the effect; for, if
“the gospel is the power of God for salvation to every one that believeth,” (Romans 1:16,) it is certain that all those to whom the gospel is addressed are invited to the hope of eternal life...God wishes that the gospel should be proclaimed to all without exception. Now the preaching of the gospel gives life; and hence he justly concludes that God invites all equally to partake salvation."
"So wonderful is his love towards mankind, that he would have them all to be saved, and is of his own self prepared to bestow salvation on the lost. But the order is to be noticed, that God is ready to receive all to repentance, so that none may perish; for in these words the way and manner of obtaining salvation is pointed out. Every one of us, therefore, who is desirous of salvation, must learn to enter in by this way.
But it may be asked, If God wishes none to perish, why is it that so many do perish? To this my answer is, that no mention is here made of the hidden purpose of God, according to which the reprobate are doomed to their own ruin, but only of his will as made known to us in the gospel. For God there stretches forth his hand without a difference to all, but lays hold only of those, to lead them to himself, whom he has chosen before the foundation of the world." -John Calvin