[MemorySSA] Use SetVector to avoid nondeterminism.

Summary:
Use a SetVector for DeadBlockSet.
Resolves PR42574.

Reviewers: george.burgess.iv, uabelho, dblaikie

Subscribers: jlebar, Prazek, mgrang, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64601

llvm-svn: 365970

5 files changed, 9 insertions, 8 deletions

diff --git a/llvm/lib/Analysis/MemorySSAUpdater.cpp b/llvm/lib/Analysis/MemorySSAUpdater.cpp
index 19559a62eb9..4c1feee7fd9 100644
--- a/llvm/lib/Analysis/MemorySSAUpdater.cpp
+++ b/llvm/lib/Analysis/MemorySSAUpdater.cpp
@@ -1247,7 +1247,7 @@ void MemorySSAUpdater::removeMemoryAccess(MemoryAccess *MA, bool OptimizePhis) {
 }
 
 void MemorySSAUpdater::removeBlocks(
-    const SmallPtrSetImpl<BasicBlock *> &DeadBlocks) {
+    const SmallSetVector<BasicBlock *, 8> &DeadBlocks) {
   // First delete all uses of BB in MemoryPhis.
   for (BasicBlock *BB : DeadBlocks) {
     Instruction *TI = BB->getTerminator();
diff --git a/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp b/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
index c650abb412d..046f4c8af49 100644
--- a/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
@@ -428,8 +428,8 @@ private:
   /// relevant updates to DT and LI.
   void deleteDeadLoopBlocks() {
     if (MSSAU) {
-      SmallPtrSet<BasicBlock *, 8> DeadLoopBlocksSet(DeadLoopBlocks.begin(),
-                                                     DeadLoopBlocks.end());
+      SmallSetVector<BasicBlock *, 8> DeadLoopBlocksSet(DeadLoopBlocks.begin(),
+                                                        DeadLoopBlocks.end());
       MSSAU->removeBlocks(DeadLoopBlocksSet);
     }
 
diff --git a/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp b/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
index 97153292238..aeac6f548b3 100644
--- a/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
+++ b/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
@@ -1463,8 +1463,8 @@ deleteDeadClonedBlocks(Loop &L, ArrayRef<BasicBlock *> ExitBlocks,
 
   // Remove all MemorySSA in the dead blocks
   if (MSSAU) {
-    SmallPtrSet<BasicBlock *, 16> DeadBlockSet(DeadBlocks.begin(),
-                                               DeadBlocks.end());
+    SmallSetVector<BasicBlock *, 8> DeadBlockSet(DeadBlocks.begin(),
+                                                 DeadBlocks.end());
     MSSAU->removeBlocks(DeadBlockSet);
   }
 
@@ -1482,7 +1482,7 @@ static void deleteDeadBlocksFromLoop(Loop &L,
                                      MemorySSAUpdater *MSSAU) {
   // Find all the dead blocks tied to this loop, and remove them from their
   // successors.
-  SmallPtrSet<BasicBlock *, 16> DeadBlockSet;
+  SmallSetVector<BasicBlock *, 8> DeadBlockSet;
 
   // Start with loop/exit blocks and get a transitive closure of reachable dead
   // blocks.
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 91d33cb0f20..39b6b889f91 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -2238,7 +2238,7 @@ bool llvm::removeUnreachableBlocks(Function &F, LazyValueInfo *LVI,
   assert(Reachable.size() < F.size());
   NumRemoved += F.size()-Reachable.size();
 
-  SmallPtrSet<BasicBlock *, 16> DeadBlockSet;
+  SmallSetVector<BasicBlock *, 8> DeadBlockSet;
   for (Function::iterator I = ++F.begin(), E = F.end(); I != E; ++I) {
     auto *BB = &*I;
     if (Reachable.count(BB))
diff --git a/llvm/lib/Transforms/Utils/LoopSimplify.cpp b/llvm/lib/Transforms/Utils/LoopSimplify.cpp
index 5ec12aafff0..7e6da02d570 100644
--- a/llvm/lib/Transforms/Utils/LoopSimplify.cpp
+++ b/llvm/lib/Transforms/Utils/LoopSimplify.cpp
@@ -681,7 +681,8 @@ ReprocessLoop:
       }
       DT->eraseNode(ExitingBlock);
       if (MSSAU) {
-        SmallPtrSet<BasicBlock *, 1> ExitBlockSet{ExitingBlock};
+        SmallSetVector<BasicBlock *, 8> ExitBlockSet;
+        ExitBlockSet.insert(ExitingBlock);
         MSSAU->removeBlocks(ExitBlockSet);
       }