[llvm-commits] [llvm] r40746 - in /llvm/trunk/lib: Analysis/MemoryDependenceAnalysis.cpp Transforms/Scalar/GVN.cpp

[Owen Anderson]

Author: resistor
Date: Thu Aug  2 12:56:05 2007
New Revision: 40746

URL: http://llvm.org/viewvc/llvm-project?rev=40746&view=rev
Log:
Fix a bug that was causing several miscompilations on SPEC.

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

Modified: llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp
URL: 
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp?rev=40746&r1=40745&r2=40746&view=diff

==============================================================================
--- llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/MemoryDependenceAnalysis.cpp Thu Aug  2 12:56:05 
2007
@@ -111,19 +111,31 @@
   while (!stack.empty()) {
     BasicBlock* BB = stack.back();
     
-    visited.insert(BB);
-    
-    if (resp.count(BB)) {
+    if (visited.count(BB)) {
       stack.pop_back();
       continue;
     }
     
     if (BB != block) {
+      visited.insert(BB);
+      
       Instruction* localDep = getDependency(query, 0, BB);
       if (localDep != NonLocal) {
         resp.insert(std::make_pair(BB, localDep));
+        stack.pop_back();
+        
         continue;
       }
+    } else if (BB == block && stack.size() > 1) {
+      visited.insert(BB);
+      
+      Instruction* localDep = getDependency(query, 0, BB);
+      if (localDep != query)
+        resp.insert(std::make_pair(BB, localDep));
+      
+      stack.pop_back();
+      
+      continue;
     }
     
     bool predOnStack = false;

Modified: llvm/trunk/lib/Transforms/Scalar/GVN.cpp
URL: 
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/GVN.cpp?rev=40746&r1=40745&r2=40746&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/GVN.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/GVN.cpp Thu Aug  2 12:56:05 2007
@@ -658,7 +658,8 @@
                             SmallVector<Instruction*, 4>& toErase);
     bool processNonLocalLoad(LoadInst* L, SmallVector<Instruction*, 4>& 
toErase);
     Value *GetValueForBlock(BasicBlock *BB, LoadInst* orig,
-                                  DenseMap<BasicBlock*, Value*> &Phis);
+                            DenseMap<BasicBlock*, Value*> &Phis,
+                            bool top_level = false);
     void dump(DenseMap<BasicBlock*, Value*>& d);
   };
   
@@ -715,11 +716,12 @@
 /// GetValueForBlock - Get the value to use within the specified basic block.
 /// available values are in Phis.
 Value *GVN::GetValueForBlock(BasicBlock *BB, LoadInst* orig,
-                               DenseMap<BasicBlock*, Value*> &Phis) { 
+                               DenseMap<BasicBlock*, Value*> &Phis,
+                               bool top_level) { 
                                  
   // If we have already computed this value, return the previously computed 
val.
   Value *&V = Phis[BB];
-  if (V) return V;
+  if (V && ! top_level) return V;
   
   BasicBlock* singlePred = BB->getSinglePredecessor();
   if (singlePred)
@@ -799,7 +801,7 @@
     }
   
   SmallPtrSet<BasicBlock*, 4> visited;
-  Value* v = GetValueForBlock(L->getParent(), L, repl);
+  Value* v = GetValueForBlock(L->getParent(), L, repl, true);
   
   MD.removeInstruction(L);
   L->replaceAllUsesWith(v);


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