Make all pointers to TargetRegisterClass const since they are all pointers to static...

[oota-llvm.git] / lib / Transforms / Scalar / LoopIdiomRecognize.cpp

diff --git a/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
index dbf6eec331dae2101851f4e0f0dfaac4c0fc3130..ad15cbb9b436ab98d0e883eb9ea64f8defeb3dda 100644 (file)
--- a/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
+++ b/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
@@ -167,12 +167,17 @@ static void deleteDeadInstruction(Instruction *I, ScalarEvolution &SE) {
 static void deleteIfDeadInstruction(Value *V, ScalarEvolution &SE) {
   if (Instruction *I = dyn_cast<Instruction>(V))
     if (isInstructionTriviallyDead(I))
-      deleteDeadInstruction(I, SE);    
+      deleteDeadInstruction(I, SE);
 }
 
 bool LoopIdiomRecognize::runOnLoop(Loop *L, LPPassManager &LPM) {
   CurLoop = L;
 
+  // Disable loop idiom recognition if the function's name is a common idiom. 
+  StringRef Name = L->getHeader()->getParent()->getName();
+  if (Name == "memset" || Name == "memcpy")
+    return false;
+
   // The trip count of the loop must be analyzable.
   SE = &getAnalysis<ScalarEvolution>();
   if (!SE->hasLoopInvariantBackedgeTakenCount(L))
@@ -262,7 +267,7 @@ bool LoopIdiomRecognize::runOnLoopBlock(BasicBlock *BB, const SCEV *BECount,
 
 /// processLoopStore - See if this store can be promoted to a memset or memcpy.
 bool LoopIdiomRecognize::processLoopStore(StoreInst *SI, const SCEV *BECount) {
-  if (SI->isVolatile()) return false;
+  if (!SI->isSimple()) return false;
 
   Value *StoredVal = SI->getValueOperand();
   Value *StorePtr = SI->getPointerOperand();
@@ -309,7 +314,7 @@ bool LoopIdiomRecognize::processLoopStore(StoreInst *SI, const SCEV *BECount) {
     const SCEVAddRecExpr *LoadEv =
       dyn_cast<SCEVAddRecExpr>(SE->getSCEV(LI->getOperand(0)));
     if (LoadEv && LoadEv->getLoop() == CurLoop && LoadEv->isAffine() &&
-        StoreEv->getOperand(1) == LoadEv->getOperand(1) && !LI->isVolatile())
+        StoreEv->getOperand(1) == LoadEv->getOperand(1) && LI->isSimple())
       if (processLoopStoreOfLoopLoad(SI, StoreSize, StoreEv, LoadEv, BECount))
         return true;
   }
@@ -458,7 +463,7 @@ processLoopStridedStore(Value *DestPtr, unsigned StoreSize,
     SplatValue = 0;
   } else {
     // Otherwise, this isn't an idiom we can transform.  For example, we can't
-    // do anything with a 3-byte store, for example.
+    // do anything with a 3-byte store.
     return false;
   }
 
@@ -467,8 +472,8 @@ processLoopStridedStore(Value *DestPtr, unsigned StoreSize,
   // header.  This allows us to insert code for it in the preheader.
   BasicBlock *Preheader = CurLoop->getLoopPreheader();
   IRBuilder<> Builder(Preheader->getTerminator());
-  SCEVExpander Expander(*SE);
-  
+  SCEVExpander Expander(*SE, "loop-idiom");
+
   // Okay, we have a strided store "p[i]" of a splattable value.  We can turn
   // this into a memset in the loop preheader now if we want.  However, this
   // would be unsafe to do if there is anything else in the loop that may read
@@ -488,12 +493,12 @@ processLoopStridedStore(Value *DestPtr, unsigned StoreSize,
     deleteIfDeadInstruction(BasePtr, *SE);
     return false;
   }
-  
+
   // Okay, everything looks good, insert the memset.
 
   // The # stored bytes is (BECount+1)*Size.  Expand the trip count out to
   // pointer size if it isn't already.
-  const Type *IntPtr = TD->getIntPtrType(DestPtr->getContext());
+  Type *IntPtr = TD->getIntPtrType(DestPtr->getContext());
   BECount = SE->getTruncateOrZeroExtend(BECount, IntPtr);
 
   const SCEV *NumBytesS = SE->getAddExpr(BECount, SE->getConstant(IntPtr, 1),
@@ -556,8 +561,8 @@ processLoopStoreOfLoopLoad(StoreInst *SI, unsigned StoreSize,
   // header.  This allows us to insert code for it in the preheader.
   BasicBlock *Preheader = CurLoop->getLoopPreheader();
   IRBuilder<> Builder(Preheader->getTerminator());
-  SCEVExpander Expander(*SE);
-  
+  SCEVExpander Expander(*SE, "loop-idiom");
+
   // Okay, we have a strided store "p[i]" of a loaded value.  We can turn
   // this into a memcpy in the loop preheader now if we want.  However, this
   // would be unsafe to do if there is anything else in the loop that may read
@@ -568,7 +573,7 @@ processLoopStoreOfLoopLoad(StoreInst *SI, unsigned StoreSize,
     Expander.expandCodeFor(StoreEv->getStart(),
                            Builder.getInt8PtrTy(SI->getPointerAddressSpace()),
                            Preheader->getTerminator());
-  
+
   if (mayLoopAccessLocation(StoreBasePtr, AliasAnalysis::ModRef,
                             CurLoop, BECount, StoreSize,
                             getAnalysis<AliasAnalysis>(), SI)) {
@@ -593,13 +598,13 @@ processLoopStoreOfLoopLoad(StoreInst *SI, unsigned StoreSize,
     deleteIfDeadInstruction(StoreBasePtr, *SE);
     return false;
   }
-  
+
   // Okay, everything is safe, we can transform this!
-  
+
 
   // The # stored bytes is (BECount+1)*Size.  Expand the trip count out to
   // pointer size if it isn't already.
-  const Type *IntPtr = TD->getIntPtrType(SI->getContext());
+  Type *IntPtr = TD->getIntPtrType(SI->getContext());
   BECount = SE->getTruncateOrZeroExtend(BECount, IntPtr);
 
   const SCEV *NumBytesS = SE->getAddExpr(BECount, SE->getConstant(IntPtr, 1),
@@ -619,7 +624,7 @@ processLoopStoreOfLoopLoad(StoreInst *SI, unsigned StoreSize,
   DEBUG(dbgs() << "  Formed memcpy: " << *NewCall << "\n"
                << "    from load ptr=" << *LoadEv << " at: " << *LI << "\n"
                << "    from store ptr=" << *StoreEv << " at: " << *SI << "\n");
-  
+
 
   // Okay, the memset has been formed.  Zap the original store and anything that
   // feeds into it.