[llvm-commits] [llvm] r159667 - in /llvm/trunk: include/llvm/Analysis/MemoryBuiltins.h lib/Analysis/MemoryBuiltins.cpp

[Nuno Lopes]

Author: nlopes
Date: Tue Jul  3 12:13:25 2012
New Revision: 159667

URL: http://llvm.org/viewvc/llvm-project?rev=159667&view=rev
Log:
fold PHI nodes in SizeOffsetEvaluator whenever possible.
Unfortunately this change requires the cache map to hold WeakVHs instead

Modified:
    llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h
    llvm/trunk/lib/Analysis/MemoryBuiltins.cpp

Modified: llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h?rev=159667&r1=159666&r2=159667&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h (original)
+++ llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h Tue Jul  3 12:13:25 2012
@@ -22,6 +22,7 @@
 #include "llvm/Support/DataTypes.h"
 #include "llvm/Support/InstVisitor.h"
 #include "llvm/Support/TargetFolder.h"
+#include "llvm/Support/ValueHandle.h"
 
 namespace llvm {
 class CallInst;
@@ -195,7 +196,8 @@
   : public InstVisitor<ObjectSizeOffsetEvaluator, SizeOffsetEvalType> {
 
   typedef IRBuilder<true, TargetFolder> BuilderTy;
-  typedef DenseMap<const Value*, SizeOffsetEvalType> CacheMapTy;
+  typedef std::pair<WeakVH, WeakVH> WeakEvalType;
+  typedef DenseMap<const Value*, WeakEvalType> CacheMapTy;
   typedef SmallPtrSet<const Value*, 8> PtrSetTy;
 
   const TargetData *TD;
@@ -216,19 +218,19 @@
   ObjectSizeOffsetEvaluator(const TargetData *TD, LLVMContext &Context);
   SizeOffsetEvalType compute(Value *V);
 
-  bool knownSize(SizeOffsetEvalType &SizeOffset) {
+  bool knownSize(SizeOffsetEvalType SizeOffset) {
     return SizeOffset.first;
   }
 
-  bool knownOffset(SizeOffsetEvalType &SizeOffset) {
+  bool knownOffset(SizeOffsetEvalType SizeOffset) {
     return SizeOffset.second;
   }
 
-  bool anyKnown(SizeOffsetEvalType &SizeOffset) {
+  bool anyKnown(SizeOffsetEvalType SizeOffset) {
     return knownSize(SizeOffset) || knownOffset(SizeOffset);
   }
 
-  bool bothKnown(SizeOffsetEvalType &SizeOffset) {
+  bool bothKnown(SizeOffsetEvalType SizeOffset) {
     return knownSize(SizeOffset) && knownOffset(SizeOffset);
   }
 

Modified: llvm/trunk/lib/Analysis/MemoryBuiltins.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/MemoryBuiltins.cpp?rev=159667&r1=159666&r2=159667&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/MemoryBuiltins.cpp (original)
+++ llvm/trunk/lib/Analysis/MemoryBuiltins.cpp Tue Jul  3 12:13:25 2012
@@ -682,7 +682,19 @@
     SizePHI->addIncoming(EdgeData.first, PHI.getIncomingBlock(i));
     OffsetPHI->addIncoming(EdgeData.second, PHI.getIncomingBlock(i));
   }
-  return std::make_pair(SizePHI, OffsetPHI);
+
+  Value *Size = SizePHI, *Offset = OffsetPHI, *Tmp;
+  if ((Tmp = SizePHI->hasConstantValue())) {
+    Size = Tmp;
+    SizePHI->replaceAllUsesWith(Size);
+    SizePHI->eraseFromParent();
+  }
+  if ((Tmp = OffsetPHI->hasConstantValue())) {
+    Offset = Tmp;
+    OffsetPHI->replaceAllUsesWith(Offset);
+    OffsetPHI->eraseFromParent();
+  }
+  return std::make_pair(Size, Offset);
 }
 
 SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitSelectInst(SelectInst &I) {