Node * peel_do_loop (doNode *);

// Loop peeling transformation for Do:
//
// do stmt while (expr);
// =>
// stmt; if (expr) { do stmt while (expr); }
//
// Returns a node that is the result of the above transformation.

Node * LoopPeelingChanger::peel_do_loop (doNode *p) {

        // We'll return a new block containing both the stmt and the If:
        //      { }

        blockNode *newblock = new blockNode (NULL, NULL);

        // Insert a copy of the Do loop body:
        //      { stmt; }

        newblock->stmts().push_back (
                (stmtNode *) clone_changer::clone(p->body()));

        // Make a copy of the entire Do loop:
        //      do stmt while (expr);

        doNode *newdo = new doNode (
                (stmtNode *) clone_changer::clone(p->body()),
                (exprNode *) clone_changer::clone(p->cond()));

        // Prepend an If to execute the Do if the first iteration hasn't 
        // changed the Do condition:
        //      if (expr) do stmt while (expr);

        ifNode *newif = new ifNode (
                (exprNode *) clone_changer::clone(p->cond()), NULL, newdo);

        // Now put everything together in the first block:
        //      { stmt; if (expr) do stmt while (expr); }

        newblock->stmts().push_back ((stmtNode *) newif);
        return newblock;
}