[RDF] Add recursion limit to getAllReachingDefsRec
For large programs this function can take significant amounts of time.
Let it abort gracefully when the program is too complex.
llvm-svn: 296662
diff --git a/llvm/lib/Target/Hexagon/HexagonOptAddrMode.cpp b/llvm/lib/Target/Hexagon/HexagonOptAddrMode.cpp
index 49d5cb3..be50288 100644
--- a/llvm/lib/Target/Hexagon/HexagonOptAddrMode.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonOptAddrMode.cpp
@@ -208,7 +208,16 @@
NodeAddr<UseNode *> UN = *I;
RegisterRef UR = UN.Addr->getRegRef(*DFG);
NodeSet Visited, Defs;
- const auto &ReachingDefs = LV->getAllReachingDefsRec(UR, UN, Visited, Defs);
+ const auto &P = LV->getAllReachingDefsRec(UR, UN, Visited, Defs);
+ if (!P.second) {
+ DEBUG({
+ dbgs() << "*** Unable to collect all reaching defs for use ***\n"
+ << PrintNode<UseNode*>(UN, *DFG) << '\n'
+ << "The program's complexity may exceed the limits.\n";
+ });
+ return false;
+ }
+ const auto &ReachingDefs = P.first;
if (ReachingDefs.size() > 1) {
DEBUG({
dbgs() << "*** Multiple Reaching Defs found!!! ***\n";