[llvm-commits] [poolalloc] r159498 - in /poolalloc/trunk: include/dsa/DSNode.h lib/DSA/DataStructure.cpp lib/DSA/Local.cpp

[Will Dietz]

Author: wdietz2
Date: Sat Jun 30 18:04:50 2012
New Revision: 159498

URL: http://llvm.org/viewvc/llvm-project?rev=159498&view=rev
Log:
Refactor OOB Offset folding and use in BU as well.

Takes the check that was touched up in r159480, and re-use it elsewhere
so we also fold (instead of assert failing) when cloning results in trying
to point to an offset beyond a node's size.

Fixes BU on 483.xalancbmk.

Modified:
    poolalloc/trunk/include/dsa/DSNode.h
    poolalloc/trunk/lib/DSA/DataStructure.cpp
    poolalloc/trunk/lib/DSA/Local.cpp

Modified: poolalloc/trunk/include/dsa/DSNode.h
URL: http://llvm.org/viewvc/llvm-project/poolalloc/trunk/include/dsa/DSNode.h?rev=159498&r1=159497&r2=159498&view=diff
==============================================================================
--- poolalloc/trunk/include/dsa/DSNode.h (original)
+++ poolalloc/trunk/include/dsa/DSNode.h Sat Jun 30 18:04:50 2012
@@ -441,6 +441,10 @@
   ///
   void markReachableNodes(llvm::DenseSet<const DSNode*> &ReachableNodes) const;
 
+
+  /// checkOffsetFoldIfNeeded - Fold DSNode if the specified offset is
+  /// larger than its size, and the node isn't an array or forwarding.
+  void checkOffsetFoldIfNeeded(int Offset);
 private:
   friend class DSNodeHandle;
 

Modified: poolalloc/trunk/lib/DSA/DataStructure.cpp
URL: http://llvm.org/viewvc/llvm-project/poolalloc/trunk/lib/DSA/DataStructure.cpp?rev=159498&r1=159497&r2=159498&view=diff
==============================================================================
--- poolalloc/trunk/lib/DSA/DataStructure.cpp (original)
+++ poolalloc/trunk/lib/DSA/DataStructure.cpp Sat Jun 30 18:04:50 2012
@@ -39,6 +39,7 @@
 #define COLLAPSE_ARRAYS_AGGRESSIVELY 0
 namespace {
   STATISTIC (NumFolds, "Number of nodes completely folded");
+  STATISTIC (NumFoldsOOBOffset, "Number of OOB offsets that caused node folding");
   STATISTIC (NumNodeAllocated  , "Number of nodes allocated");
 }
 
@@ -722,6 +723,25 @@
   }
 }
 
+void DSNode::checkOffsetFoldIfNeeded(int Offset) {
+  if (!isNodeCompletelyFolded() &&
+      (Size != 0 || Offset != 0) &&
+      !isForwarding()) {
+    if ((Offset >= (int)Size) || Offset < 0) {
+      // Accessing offsets out of node size range
+      // This is seen in the "magic" struct in named (from bind), where the
+      // fourth field is an array of length 0, presumably used to create struct
+      // instances of different sizes
+      // More generally this happens whenever code indexes past the end
+      // of a struct type.  We don't model this, so fold!
+
+      // Collapse the node since its size is now variable
+      foldNodeCompletely();
+
+      ++NumFoldsOOBOffset;
+    }
+  }
+}
 //===----------------------------------------------------------------------===//
 // ReachabilityCloner Implementation
 //===----------------------------------------------------------------------===//
@@ -733,7 +753,12 @@
   DSNodeHandle &NH = NodeMap[SN];
   if (!NH.isNull()) { // Node already mapped?
     DSNode *NHN = NH.getNode();
-    return DSNodeHandle(NHN, NH.getOffset() + SrcNH.getOffset());
+    unsigned NewOffset = NH.getOffset() + SrcNH.getOffset();
+    if (NHN) {
+      NHN->checkOffsetFoldIfNeeded(NewOffset);
+      NHN = NH.getNode();
+    }
+    return DSNodeHandle(NHN, NewOffset);
   }
 
   // If SrcNH has globals and the destination graph has one of the same globals,
@@ -749,7 +774,12 @@
         merge(GI->second, Src->getNodeForValue(GV));
         assert(!NH.isNull() && "Didn't merge node!");
         DSNode *NHN = NH.getNode();
-        return DSNodeHandle(NHN, NH.getOffset()+SrcNH.getOffset());
+        unsigned NewOffset = NH.getOffset() + SrcNH.getOffset();
+        if (NHN) {
+          NHN->checkOffsetFoldIfNeeded(NewOffset);
+          NHN = NH.getNode();
+        }
+        return DSNodeHandle(NHN, NewOffset);
       }
     }
   }
@@ -797,7 +827,13 @@
   }
   NH.getNode()->mergeGlobals(*SN);
 
-  return DSNodeHandle(NH.getNode(), NH.getOffset()+SrcNH.getOffset());
+  DSNode* NHN = NH.getNode();
+  unsigned NewOffset = NH.getOffset() + SrcNH.getOffset();
+  if (NHN) {
+    NHN->checkOffsetFoldIfNeeded(NewOffset);
+    NHN = NH.getNode();
+  }
+  return DSNodeHandle(NHN, NewOffset);
 }
 
 void ReachabilityCloner::merge(const DSNodeHandle &NH,

Modified: poolalloc/trunk/lib/DSA/Local.cpp
URL: http://llvm.org/viewvc/llvm-project/poolalloc/trunk/lib/DSA/Local.cpp?rev=159498&r1=159497&r2=159498&view=diff
==============================================================================
--- poolalloc/trunk/lib/DSA/Local.cpp (original)
+++ poolalloc/trunk/lib/DSA/Local.cpp Sat Jun 30 18:04:50 2012
@@ -804,23 +804,9 @@
 
   // Check the offset
   DSNode *N = Value.getNode();
-  Offset = Value.getOffset();
-  if (N &&
-      !N->isNodeCompletelyFolded() &&
-      (N->getSize() != 0 || Offset != 0) &&
-      !N->isForwarding()) {
-    if ((Offset >= (int)N->getSize()) || Offset < 0) {
-      // Accessing offsets out of node size range
-      // This is seen in the "magic" struct in named (from bind), where the
-      // fourth field is an array of length 0, presumably used to create struct
-      // instances of different sizes
+  if (N) N->checkOffsetFoldIfNeeded(Value.getOffset());
 
-      // Collapse the node since its size is now variable
-      N->foldNodeCompletely();
-    }
-  }
-
-  // Value is now the pointer we want to GEP to be...  
+  // Value is now the pointer we want to GEP to be...
   setDestTo(GEP, Value);
 }