[MemorySSA] Verify Phi incoming blocks are block predecessors.

[asbirlea]

Summary

Make the MemorySSA verify also check that all Phi incoming blocks are block predecessors.

[george.burgess.iv]

LGTM after a nit is fixed; thanks!

lib/Analysis/MemorySSA.cpp

1751 ↗

(On Diff #151971)

nit: I think you can drop the llvm:: and just spell this find(.

[asbirlea]

Fix nit.

[asbirlea]

Thank you for the review!

llvm/trunk/lib/Analysis/MemorySSA.cpp

 /// appropriate def's use list
 void MemorySSA::verifyDefUses(Function &F) const {
   for (BasicBlock &B : F) {
     // Phi nodes are attached to basic blocks
     if (MemoryPhi *Phi = getMemoryAccess(&B)) {
       assert(Phi->getNumOperands() == static_cast<unsigned>(std::distance(
                                           pred_begin(&B), pred_end(&B))) &&
              "Incomplete MemoryPhi Node");
-      for (unsigned I = 0, E = Phi->getNumIncomingValues(); I != E; ++I)
+      for (unsigned I = 0, E = Phi->getNumIncomingValues(); I != E; ++I) {
         verifyUseInDefs(Phi->getIncomingValue(I), Phi);
+        assert(find(predecessors(&B), Phi->getIncomingBlock(I)) !=
+                   pred_end(&B) &&
+               "Incoming phi block not a block predecessor");
+      }
     }
 
     for (Instruction &I : B) {
       if (MemoryUseOrDef *MA = getMemoryAccess(&I)) {
         verifyUseInDefs(MA->getDefiningAccess(), MA);
       }
     }
   }