[llvm] r293361 - MemorySSA: Fix block numbering invalidation and replacement bugs discovered by updater

[Daniel Berlin via llvm-commits]

Author: dannyb
Date: Fri Jan 27 20:22:52 2017
New Revision: 293361

URL: http://llvm.org/viewvc/llvm-project?rev=293361&view=rev
Log:
MemorySSA: Fix block numbering invalidation and replacement bugs discovered by updater

Modified:
    llvm/trunk/lib/Transforms/Utils/MemorySSA.cpp
    llvm/trunk/lib/Transforms/Utils/MemorySSAUpdater.cpp

Modified: llvm/trunk/lib/Transforms/Utils/MemorySSA.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/MemorySSA.cpp?rev=293361&r1=293360&r2=293361&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/MemorySSA.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/MemorySSA.cpp Fri Jan 27 20:22:52 2017
@@ -1597,6 +1597,7 @@ void MemorySSA::insertIntoListsForBlock(
       Defs->push_back(*NewAccess);
     }
   }
+  BlockNumberingValid.erase(BB);
 }
 
 void MemorySSA::insertIntoListsBefore(MemoryAccess *What, const BasicBlock *BB,
@@ -1624,6 +1625,7 @@ void MemorySSA::insertIntoListsBefore(Me
         Defs->insert(InsertPt->getDefsIterator(), *What);
     }
   }
+  BlockNumberingValid.erase(BB);
 }
 
 // Move What before Where in the IR.  The end result is taht What will belong to
@@ -1638,13 +1640,19 @@ void MemorySSA::moveTo(MemoryUseOrDef *W
   insertIntoListsBefore(What, BB, Where);
 }
 
+void MemorySSA::moveTo(MemoryUseOrDef *What, BasicBlock *BB,
+                       InsertionPlace Point) {
+  removeFromLists(What, false);
+  What->setBlock(BB);
+  insertIntoListsForBlock(What, BB, Point);
+}
+
 MemoryPhi *MemorySSA::createMemoryPhi(BasicBlock *BB) {
   assert(!getMemoryAccess(BB) && "MemoryPhi already exists for this BB");
   MemoryPhi *Phi = new MemoryPhi(BB->getContext(), BB, NextID++);
+  // Phi's always are placed at the front of the block.
   insertIntoListsForBlock(Phi, BB, Beginning);
   ValueToMemoryAccess[BB] = Phi;
-  // Phi's always are placed at the front of the block.
-  BlockNumberingValid.erase(BB);
   return Phi;
 }
 
@@ -1665,7 +1673,6 @@ MemoryAccess *MemorySSA::createMemoryAcc
                                                 InsertionPlace Point) {
   MemoryUseOrDef *NewAccess = createDefinedAccess(I, Definition);
   insertIntoListsForBlock(NewAccess, BB, Point);
-  BlockNumberingValid.erase(BB);
   return NewAccess;
 }
 
@@ -1675,7 +1682,6 @@ MemoryUseOrDef *MemorySSA::createMemoryA
   assert(I->getParent() == InsertPt->getBlock() &&
          "New and old access must be in the same block");
   MemoryUseOrDef *NewAccess = createDefinedAccess(I, Definition);
-  BlockNumberingValid.erase(InsertPt->getBlock());
   insertIntoListsBefore(NewAccess, InsertPt->getBlock(),
                         InsertPt->getIterator());
   return NewAccess;
@@ -1687,7 +1693,6 @@ MemoryUseOrDef *MemorySSA::createMemoryA
   assert(I->getParent() == InsertPt->getBlock() &&
          "New and old access must be in the same block");
   MemoryUseOrDef *NewAccess = createDefinedAccess(I, Definition);
-  BlockNumberingValid.erase(InsertPt->getBlock());
   insertIntoListsBefore(NewAccess, InsertPt->getBlock(),
                         ++(InsertPt->getIterator()));
   return NewAccess;

Modified: llvm/trunk/lib/Transforms/Utils/MemorySSAUpdater.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/MemorySSAUpdater.cpp?rev=293361&r1=293360&r2=293361&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/MemorySSAUpdater.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/MemorySSAUpdater.cpp Fri Jan 27 20:22:52 2017
@@ -243,13 +243,17 @@ void MemorySSAUpdater::insertDef(MemoryD
   // of that thing with us, since we are in the way of whatever was there
   // before.
   // We now define that def's memorydefs and memoryphis
-  for (auto UI = DefBefore->use_begin(), UE = DefBefore->use_end(); UI != UE;) {
-    Use &U = *UI++;
-    // Leave the uses alone
-    if (isa<MemoryUse>(U.getUser()))
-      continue;
-    U.set(MD);
+  if (DefBeforeSameBlock) {
+    for (auto UI = DefBefore->use_begin(), UE = DefBefore->use_end();
+         UI != UE;) {
+      Use &U = *UI++;
+      // Leave the uses alone
+      if (isa<MemoryUse>(U.getUser()))
+        continue;
+      U.set(MD);
+    }
   }
+
   // and that def is now our defining access.
   // We change them in this order otherwise we will appear in the use list
   // above and reset ourselves.