commit 328a635eb4ed2c1d3cf0224f8be2057c38e2993b
author Daniel Berlin <dberlin@dberlin.org> Tue May 30 06:42:29 2017
committer Daniel Berlin <dberlin@dberlin.org> Tue May 30 06:42:29 2017
tree 35af6c52d297d34065bc5e17547562b6d7112185
parent 38012725da648efd91e6a6cdace34f0a798084a7

NewGVN: Fix PR33194, memory corruption by putting temporary instructions in tables sometimes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304194 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/NewGVN.cpp

diff --git a/lib/Transforms/Scalar/NewGVN.cpp b/lib/Transforms/Scalar/NewGVN.cpp
index 67abc31..39ed209 100644
--- a/lib/Transforms/Scalar/NewGVN.cpp
+++ b/lib/Transforms/Scalar/NewGVN.cpp
@@ -956,8 +956,12 @@
   if (CC && CC->getDefiningExpr()) {
     // If we simplified to something else, we need to communicate
     // that we're users of the value we simplified to.
-    if (I != V)
-      addAdditionalUsers(V, I);
+    if (I != V) {
+      // Don't add temporary instructions to the user lists.
+      if (!AllTempInstructions.count(I))
+        addAdditionalUsers(V, I);
+    }
+
     if (I)
       DEBUG(dbgs() << "Simplified " << *I << " to "
                    << " expression " << *CC->getDefiningExpr() << "\n");
@@ -2502,9 +2506,8 @@
         // Clone the instruction, create an expression from it, and see if we
         // have a leader.
         Instruction *ValueOp = I->clone();
-        auto Iter = TempToMemory.end();
         if (MemAccess)
-          Iter = TempToMemory.insert({ValueOp, MemAccess}).first;
+          TempToMemory.insert({ValueOp, MemAccess});
 
         for (auto &Op : ValueOp->operands()) {
           Op = Op->DoPHITranslation(PHIBlock, PredBB);
@@ -2523,7 +2526,7 @@
         AllTempInstructions.erase(ValueOp);
         ValueOp->deleteValue();
         if (MemAccess)
-          TempToMemory.erase(Iter);
+          TempToMemory.erase(ValueOp);
         if (!E)
           return nullptr;
         FoundVal = findPhiOfOpsLeader(E, PredBB);