Add target hook for whether it is profitable to reduce load widths

[oota-llvm.git] / lib / Target / R600 / AMDGPUPromoteAlloca.cpp

diff --git a/lib/Target/R600/AMDGPUPromoteAlloca.cpp b/lib/Target/R600/AMDGPUPromoteAlloca.cpp
index 620925a62b135e75bd46479da0b067c050f72da5..b81fef47d55a3241a407c49adc100a4af06aa255 100644 (file)
--- a/lib/Target/R600/AMDGPUPromoteAlloca.cpp
+++ b/lib/Target/R600/AMDGPUPromoteAlloca.cpp
@@ -105,14 +105,16 @@ static VectorType *arrayTypeToVecType(const Type *ArrayTy) {
                          ArrayTy->getArrayNumElements());
 }
 
-static Value* calculateVectorIndex(Value *Ptr,
-                                  std::map<GetElementPtrInst*, Value*> GEPIdx) {
+static Value *
+calculateVectorIndex(Value *Ptr,
+                     const std::map<GetElementPtrInst *, Value *> &GEPIdx) {
   if (isa<AllocaInst>(Ptr))
     return Constant::getNullValue(Type::getInt32Ty(Ptr->getContext()));
 
   GetElementPtrInst *GEP = cast<GetElementPtrInst>(Ptr);
 
-  return GEPIdx[GEP];
+  auto I = GEPIdx.find(GEP);
+  return I == GEPIdx.end() ? nullptr : I->second;
 }
 
 static Value* GEPToVectorIndex(GetElementPtrInst *GEP) {
@@ -232,7 +234,8 @@ static bool tryPromoteAllocaToVector(AllocaInst *Alloca) {
   return true;
 }
 
-static void collectUsesWithPtrTypes(Value *Val, std::vector<Value*> &WorkList) {
+static bool collectUsesWithPtrTypes(Value *Val, std::vector<Value*> &WorkList) {
+  bool Success = true;
   for (User *User : Val->users()) {
     if(std::find(WorkList.begin(), WorkList.end(), User) != WorkList.end())
       continue;
@@ -240,11 +243,20 @@ static void collectUsesWithPtrTypes(Value *Val, std::vector<Value*> &WorkList) {
       WorkList.push_back(User);
       continue;
     }
+
+    // FIXME: Correctly handle ptrtoint instructions.
+    Instruction *UseInst = dyn_cast<Instruction>(User);
+    if (UseInst && UseInst->getOpcode() == Instruction::PtrToInt)
+      return false;
+
     if (!User->getType()->isPointerTy())
       continue;
+
     WorkList.push_back(User);
-    collectUsesWithPtrTypes(User, WorkList);
+
+    Success &= collectUsesWithPtrTypes(User, WorkList);
   }
+  return Success;
 }
 
 void AMDGPUPromoteAlloca::visitAlloca(AllocaInst &I) {
@@ -272,6 +284,13 @@ void AMDGPUPromoteAlloca::visitAlloca(AllocaInst &I) {
     return;
   }
 
+  std::vector<Value*> WorkList;
+
+  if (!collectUsesWithPtrTypes(&I, WorkList)) {
+    DEBUG(dbgs() << " Do not know how to convert all uses\n");
+    return;
+  }
+
   DEBUG(dbgs() << "Promoting alloca to local memory\n");
   LocalMemAvailable -= AllocaSize;
 
@@ -318,10 +337,6 @@ void AMDGPUPromoteAlloca::visitAlloca(AllocaInst &I) {
   I.replaceAllUsesWith(Offset);
   I.eraseFromParent();
 
-  std::vector<Value*> WorkList;
-
-  collectUsesWithPtrTypes(Offset, WorkList);
-
   for (std::vector<Value*>::iterator i = WorkList.begin(),
                                      e = WorkList.end(); i != e; ++i) {
     Value *V = *i;
@@ -329,6 +344,13 @@ void AMDGPUPromoteAlloca::visitAlloca(AllocaInst &I) {
     if (!Call) {
       Type *EltTy = V->getType()->getPointerElementType();
       PointerType *NewTy = PointerType::get(EltTy, AMDGPUAS::LOCAL_ADDRESS);
+
+      // The operand's value should be corrected on its own.
+      if (isa<AddrSpaceCastInst>(V))
+        continue;
+
+      // FIXME: It doesn't really make sense to try to do this for all
+      // instructions.
       V->mutateType(NewTy);
       continue;
     }