Sad to say, but that is an example of what can go very wrong. It is not actually warp by definition, but rather, collapse.
The end grain irregularities show a pretty big problem. Even if the wood inside did not seperate (collapse technically) it is highly stressed due to the enlarged edges and the skinny middle reach.
If it is long dry it is probably history from a blank perspective. If not too old you could plane it straight and true on all 4 sides and cut the ends off clean and straight. Monitor it for warping at that point because some of the stresses will have been relieved and the wood will likely move a lot.
If it is not a pretty special piece of wood I would not consider building a stock with it. However, the demands on a two-piece are vastly easier to meet than a one-piece.
art
