[llvm-commits] [llvm] r48660 - /llvm/trunk/lib/Transforms/Scalar/GVN.cpp

[Chris Lattner]

Author: lattner
Date: Fri Mar 21 16:33:23 2008
New Revision: 48660

URL: http://llvm.org/viewvc/llvm-project?rev=48660&view=rev
Log:
make gvn marginally faster by reallocating the lastSeenLoad map for
each basic block.

Modified:
    llvm/trunk/lib/Transforms/Scalar/GVN.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/GVN.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/GVN.cpp?rev=48660&r1=48659&r2=48660&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/GVN.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/GVN.cpp Fri Mar 21 16:33:23 2008
@@ -1287,15 +1287,16 @@
   DominatorTree &DT = getAnalysis<DominatorTree>();   
   
   SmallVector<Instruction*, 4> toErase;
-  
+  DenseMap<Value*, LoadInst*> lastSeenLoad;
+
   // Top-down walk of the dominator tree
   for (df_iterator<DomTreeNode*> DI = df_begin(DT.getRootNode()),
          E = df_end(DT.getRootNode()); DI != E; ++DI) {
     
     // Get the set to update for this block
     ValueNumberedSet& currAvail = availableOut[DI->getBlock()];     
-    DenseMap<Value*, LoadInst*> lastSeenLoad;
-    
+    lastSeenLoad.clear();
+
     BasicBlock* BB = DI->getBlock();
   
     // A block inherits AVAIL_OUT from its dominator