Method IsValid

cfa/post_loop.go:100–116

IsValid reports whether the cond and exit node candidates of prim form a valid post-test loop in g. Control flow graph: cond ↘ ↓ ↖↲ ↓ exit

(g graph.Directed, dom cfg.DominatorTree)

//    ↓
//    exit
func (prim PostLoop) IsValid(g graph.Directed, dom cfg.DominatorTree) bool {
	// Dominator sanity check.
	cond, exit := prim.Cond, prim.Exit
	if !dom.Dominates(cond, exit) {
		return false
	}

	// Verify that cond has two successors (cond and exit).
	condSuccs := g.From(cond)
	if len(condSuccs) != 2 || !g.HasEdgeFromTo(cond, cond) || !g.HasEdgeFromTo(cond, exit) {
		return false
	}

	// Verify that exit has one predecessor (cond).
	exitPreds := g.To(exit)
	return len(exitPreds) == 1
}