[SCCP] Fix non-deterministic uselists of return values (DenseMap -> MapVector)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364482 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/SCCP.cpp

@@ -20,6 +20,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/PointerIntPair.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallPtrSet.h"
@@ -209,11 +210,11 @@ class SCCPSolver : public InstVisitor<SCCPSolver> {
   /// TrackedRetVals - If we are tracking arguments into and the return
   /// value out of a function, it will have an entry in this map, indicating
   /// what the known return value for the function is.
-  DenseMap<Function *, LatticeVal> TrackedRetVals;
+  MapVector<Function *, LatticeVal> TrackedRetVals;
 
   /// TrackedMultipleRetVals - Same as TrackedRetVals, but used for functions
   /// that return multiple values.
-  DenseMap<std::pair<Function *, unsigned>, LatticeVal> TrackedMultipleRetVals;
+  MapVector<std::pair<Function *, unsigned>, LatticeVal> TrackedMultipleRetVals;
 
   /// MRVFunctionsTracked - Each function in TrackedMultipleRetVals is
   /// represented here for efficient lookup.
@@ -371,7 +372,7 @@ public:
   }
 
   /// getTrackedRetVals - Get the inferred return value map.
-  const DenseMap<Function*, LatticeVal> &getTrackedRetVals() {
+  const MapVector<Function*, LatticeVal> &getTrackedRetVals() {
     return TrackedRetVals;
   }
 
@@ -837,7 +838,7 @@ void SCCPSolver::visitReturnInst(ReturnInst &I) {
 
   // If we are tracking the return value of this function, merge it in.
   if (!TrackedRetVals.empty() && !ResultOp->getType()->isStructTy()) {
-    DenseMap<Function*, LatticeVal>::iterator TFRVI =
+    MapVector<Function*, LatticeVal>::iterator TFRVI =
       TrackedRetVals.find(F);
     if (TFRVI != TrackedRetVals.end()) {
       mergeInValue(TFRVI->second, F, getValueState(ResultOp));
@@ -1351,7 +1352,7 @@ CallOverdefined:
       mergeInValue(getStructValueState(I, i), I,
                    TrackedMultipleRetVals[std::make_pair(F, i)]);
   } else {
-    DenseMap<Function*, LatticeVal>::iterator TFRVI = TrackedRetVals.find(F);
+    MapVector<Function*, LatticeVal>::iterator TFRVI = TrackedRetVals.find(F);
     if (TFRVI == TrackedRetVals.end())
       goto CallOverdefined;  // Not tracking this callee.
 
@@ -2158,7 +2159,7 @@ bool llvm::runIPSCCP(
   // whether other functions are optimizable.
   SmallVector<ReturnInst*, 8> ReturnsToZap;
 
-  const DenseMap<Function*, LatticeVal> &RV = Solver.getTrackedRetVals();
+  const MapVector<Function*, LatticeVal> &RV = Solver.getTrackedRetVals();
   for (const auto &I : RV) {
     Function *F = I.first;
     if (I.second.isOverdefined() || F->getReturnType()->isVoidTy())