// Reachability handling.
void updateReachableEdge(BasicBlock *, BasicBlock *);
void processOutgoingEdges(TerminatorInst *, BasicBlock *);
- bool isOnlyReachableViaThisEdge(const BasicBlockEdge &) const;
Value *findConditionEquivalence(Value *) const;
// Elimination.
return E;
}
-// There is an edge from 'Src' to 'Dst'. Return true if every path from
-// the entry block to 'Dst' passes via this edge. In particular 'Dst'
-// must not be reachable via another edge from 'Src'.
-bool NewGVN::isOnlyReachableViaThisEdge(const BasicBlockEdge &E) const {
-
- // While in theory it is interesting to consider the case in which Dst has
- // more than one predecessor, because Dst might be part of a loop which is
- // only reachable from Src, in practice it is pointless since at the time
- // GVN runs all such loops have preheaders, which means that Dst will have
- // been changed to have only one predecessor, namely Src.
- const BasicBlock *Pred = E.getEnd()->getSinglePredecessor();
- const BasicBlock *Src = E.getStart();
- assert((!Pred || Pred == Src) && "No edge between these basic blocks!");
- (void)Src;
- return Pred != nullptr;
-}
-
void NewGVN::markUsersTouched(Value *V) {
// Now mark the users as touched.
for (auto *User : V->users()) {