Revert "Revert "Add Constant Hoisting Pass" (r200034)"

This reverts commit r200058 and adds the using directive for
ARMTargetTransformInfo to silence two g++ overload warnings.

llvm-svn: 200062

6 files changed, 62 insertions, 25 deletions

diff --git a/llvm/lib/CodeGen/Passes.cpp b/llvm/lib/CodeGen/Passes.cpp
index 0e8e50eca79..7a7c42bfcc6 100644
--- a/llvm/lib/CodeGen/Passes.cpp
+++ b/llvm/lib/CodeGen/Passes.cpp
@@ -70,6 +70,8 @@ static cl::opt<bool> DisableMachineSink("disable-machine-sink", cl::Hidden,
     cl::desc("Disable Machine Sinking"));
 static cl::opt<bool> DisableLSR("disable-lsr", cl::Hidden,
     cl::desc("Disable Loop Strength Reduction Pass"));
+static cl::opt<bool> DisableConstantHoisting("disable-constant-hoisting",
+    cl::Hidden, cl::desc("Disable ConstantHoisting"));
 static cl::opt<bool> DisableCGP("disable-cgp", cl::Hidden,
     cl::desc("Disable Codegen Prepare"));
 static cl::opt<bool> DisableCopyProp("disable-copyprop", cl::Hidden,
@@ -396,6 +398,10 @@ void TargetPassConfig::addIRPasses() {
 
   // Make sure that no unreachable blocks are instruction selected.
   addPass(createUnreachableBlockEliminationPass());
+
+  // Prepare expensive constants for SelectionDAG.
+  if (getOptLevel() != CodeGenOpt::None && !DisableConstantHoisting)
+    addPass(createConstantHoistingPass());
 }
 
 /// Turn exception handling constructs into something the code generators can
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 69e2ce198e0..3fa2a32e868 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3212,11 +3212,14 @@ SDValue DAGCombiner::visitOR(SDNode *N) {
   if (N1C && N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
              isa<ConstantSDNode>(N0.getOperand(1))) {
     ConstantSDNode *C1 = cast<ConstantSDNode>(N0.getOperand(1));
-    if ((C1->getAPIntValue() & N1C->getAPIntValue()) != 0)
+    if ((C1->getAPIntValue() & N1C->getAPIntValue()) != 0) {
+      SDValue COR = DAG.FoldConstantArithmetic(ISD::OR, VT, N1C, C1);
+      if (!COR.getNode())
+        return SDValue();
       return DAG.getNode(ISD::AND, SDLoc(N), VT,
                          DAG.getNode(ISD::OR, SDLoc(N0), VT,
-                                     N0.getOperand(0), N1),
-                         DAG.FoldConstantArithmetic(ISD::OR, VT, N1C, C1));
+                                     N0.getOperand(0), N1), COR);
+    }
   }
   // fold (or (setcc x), (setcc y)) -> (setcc (or x, y))
   if (isSetCCEquivalent(N0, LL, LR, CC0) && isSetCCEquivalent(N1, RL, RR, CC1)){
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index e003caeddb1..430736aa46f 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -384,9 +384,12 @@ static void AddNodeIDCustom(FoldingSetNodeID &ID, const SDNode *N) {
     llvm_unreachable("Should only be used on nodes with operands");
   default: break;  // Normal nodes don't need extra info.
   case ISD::TargetConstant:
-  case ISD::Constant:
-    ID.AddPointer(cast<ConstantSDNode>(N)->getConstantIntValue());
+  case ISD::Constant: {
+    const ConstantSDNode *C = cast<ConstantSDNode>(N);
+    ID.AddPointer(C->getConstantIntValue());
+    ID.AddBoolean(C->isOpaque());
     break;
+  }
   case ISD::TargetConstantFP:
   case ISD::ConstantFP: {
     ID.AddPointer(cast<ConstantFPSDNode>(N)->getConstantFPValue());
@@ -971,19 +974,21 @@ SDValue SelectionDAG::getNOT(SDLoc DL, SDValue Val, EVT VT) {
   return getNode(ISD::XOR, DL, VT, Val, NegOne);
 }
 
-SDValue SelectionDAG::getConstant(uint64_t Val, EVT VT, bool isT) {
+SDValue SelectionDAG::getConstant(uint64_t Val, EVT VT, bool isT, bool isO) {
   EVT EltVT = VT.getScalarType();
   assert((EltVT.getSizeInBits() >= 64 ||
          (uint64_t)((int64_t)Val >> EltVT.getSizeInBits()) + 1 < 2) &&
          "getConstant with a uint64_t value that doesn't fit in the type!");
-  return getConstant(APInt(EltVT.getSizeInBits(), Val), VT, isT);
+  return getConstant(APInt(EltVT.getSizeInBits(), Val), VT, isT, isO);
 }
 
-SDValue SelectionDAG::getConstant(const APInt &Val, EVT VT, bool isT) {
-  return getConstant(*ConstantInt::get(*Context, Val), VT, isT);
+SDValue SelectionDAG::getConstant(const APInt &Val, EVT VT, bool isT, bool isO)
+{
+  return getConstant(*ConstantInt::get(*Context, Val), VT, isT, isO);
 }
 
-SDValue SelectionDAG::getConstant(const ConstantInt &Val, EVT VT, bool isT) {
+SDValue SelectionDAG::getConstant(const ConstantInt &Val, EVT VT, bool isT,
+                                  bool isO) {
   assert(VT.isInteger() && "Cannot create FP integer constant!");
 
   EVT EltVT = VT.getScalarType();
@@ -1025,7 +1030,7 @@ SDValue SelectionDAG::getConstant(const ConstantInt &Val, EVT VT, bool isT) {
     for (unsigned i = 0; i < ViaVecNumElts / VT.getVectorNumElements(); ++i) {
       EltParts.push_back(getConstant(NewVal.lshr(i * ViaEltSizeInBits)
                                            .trunc(ViaEltSizeInBits),
-                                     ViaEltVT, isT));
+                                     ViaEltVT, isT, isO));
     }
 
     // EltParts is currently in little endian order. If we actually want
@@ -1056,6 +1061,7 @@ SDValue SelectionDAG::getConstant(const ConstantInt &Val, EVT VT, bool isT) {
   FoldingSetNodeID ID;
   AddNodeIDNode(ID, Opc, getVTList(EltVT), 0, 0);
   ID.AddPointer(Elt);
+  ID.AddBoolean(isO);
   void *IP = 0;
   SDNode *N = NULL;
   if ((N = CSEMap.FindNodeOrInsertPos(ID, IP)))
@@ -1063,7 +1069,7 @@ SDValue SelectionDAG::getConstant(const ConstantInt &Val, EVT VT, bool isT) {
       return SDValue(N, 0);
 
   if (!N) {
-    N = new (NodeAllocator) ConstantSDNode(isT, Elt, EltVT);
+    N = new (NodeAllocator) ConstantSDNode(isT, isO, Elt, EltVT);
     CSEMap.InsertNode(N, IP);
     AllNodes.push_back(N);
   }
@@ -2789,10 +2795,13 @@ SDValue SelectionDAG::FoldConstantArithmetic(unsigned Opcode, EVT VT,
 
   ConstantSDNode *Scalar1 = dyn_cast<ConstantSDNode>(Cst1);
   ConstantSDNode *Scalar2 = dyn_cast<ConstantSDNode>(Cst2);
-  if (Scalar1 && Scalar2) {
+  if (Scalar1 && Scalar2 && (Scalar1->isOpaque() || Scalar2->isOpaque()))
+    return SDValue();
+
+  if (Scalar1 && Scalar2)
     // Scalar instruction.
     Inputs.push_back(std::make_pair(Scalar1, Scalar2));
-  } else {
+  else {
     // For vectors extract each constant element into Inputs so we can constant
     // fold them individually.
     BuildVectorSDNode *BV1 = dyn_cast<BuildVectorSDNode>(Cst1);
@@ -2808,6 +2817,9 @@ SDValue SelectionDAG::FoldConstantArithmetic(unsigned Opcode, EVT VT,
       if (!V1 || !V2) // Not a constant, bail.
         return SDValue();
 
+      if (V1->isOpaque() || V2->isOpaque())
+        return SDValue();
+
       // Avoid BUILD_VECTOR nodes that perform implicit truncation.
       // FIXME: This is valid and could be handled by truncating the APInts.
       if (V1->getValueType(0) != SVT || V2->getValueType(0) != SVT)
@@ -3561,10 +3573,11 @@ static SDValue getMemsetStringVal(EVT VT, SDLoc dl, SelectionDAG &DAG,
       Val |= (uint64_t)(unsigned char)Str[i] << (NumVTBytes-i-1)*8;
   }
 
-  // If the "cost" of materializing the integer immediate is 1 or free, then
-  // it is cost effective to turn the load into the immediate.
+  // If the "cost" of materializing the integer immediate is less than the cost
+  // of a load, then it is cost effective to turn the load into the immediate.
   const TargetTransformInfo *TTI = DAG.getTargetTransformInfo();
-  if (TTI->getIntImmCost(Val, VT.getTypeForEVT(*DAG.getContext())) < 2)
+  if (TTI->getIntImmCost(Val, VT.getTypeForEVT(*DAG.getContext())) <
+      TargetTransformInfo::TCC_Load)
     return DAG.getConstant(Val, VT);
   return SDValue(0, 0);
 }
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 6c8e2f83a4f..a561c5190ac 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -2945,6 +2945,9 @@ void SelectionDAGBuilder::visitBitCast(const User &I) {
   if (DestVT != N.getValueType())
     setValue(&I, DAG.getNode(ISD::BITCAST, getCurSDLoc(),
                              DestVT, N)); // convert types.
+  else if(ConstantSDNode *C = dyn_cast<ConstantSDNode>(N))
+    setValue(&I, DAG.getConstant(C->getAPIntValue(), C->getValueType(0),
+                                 /*isTarget=*/false, /*isOpaque*/true));
   else
     setValue(&I, N);            // noop cast.
 }
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp
index 79377f74247..6f980884bea 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp
@@ -81,7 +81,10 @@ std::string SDNode::getOperationName(const SelectionDAG *G) const {
   case ISD::VALUETYPE:                  return "ValueType";
   case ISD::Register:                   return "Register";
   case ISD::RegisterMask:               return "RegisterMask";
-  case ISD::Constant:                   return "Constant";
+  case ISD::Constant:
+    if (cast<ConstantSDNode>(this)->isOpaque())
+      return "OpaqueConstant";
+    return "Constant";
   case ISD::ConstantFP:                 return "ConstantFP";
   case ISD::GlobalAddress:              return "GlobalAddress";
   case ISD::GlobalTLSAddress:           return "GlobalTLSAddress";
@@ -111,7 +114,10 @@ std::string SDNode::getOperationName(const SelectionDAG *G) const {
   }
 
   case ISD::BUILD_VECTOR:               return "BUILD_VECTOR";
-  case ISD::TargetConstant:             return "TargetConstant";
+  case ISD::TargetConstant:
+    if (cast<ConstantSDNode>(this)->isOpaque())
+      return "OpaqueTargetConstant";
+    return "TargetConstant";
   case ISD::TargetConstantFP:           return "TargetConstantFP";
   case ISD::TargetGlobalAddress:        return "TargetGlobalAddress";
   case ISD::TargetGlobalTLSAddress:     return "TargetGlobalTLSAddress";
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index fa5f9b4c942..6052a486408 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1470,17 +1470,23 @@ TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
     if (Cond == ISD::SETGE || Cond == ISD::SETUGE) {
       if (C1 == MinVal) return DAG.getConstant(1, VT);   // X >= MIN --> true
       // X >= C0 --> X > (C0-1)
-      return DAG.getSetCC(dl, VT, N0,
-                          DAG.getConstant(C1-1, N1.getValueType()),
-                          (Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT);
+      APInt C = C1-1;
+      if (!N1C->isOpaque() || (N1C->isOpaque() && C.getBitWidth() <= 64 &&
+                               isLegalICmpImmediate(C.getSExtValue())))
+        return DAG.getSetCC(dl, VT, N0,
+                            DAG.getConstant(C, N1.getValueType()),
+                            (Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT);
     }
 
     if (Cond == ISD::SETLE || Cond == ISD::SETULE) {
       if (C1 == MaxVal) return DAG.getConstant(1, VT);   // X <= MAX --> true
       // X <= C0 --> X < (C0+1)
-      return DAG.getSetCC(dl, VT, N0,
-                          DAG.getConstant(C1+1, N1.getValueType()),
-                          (Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT);
+      APInt C = C1+1;
+      if (!N1C->isOpaque() || (N1C->isOpaque() && C.getBitWidth() <= 64 &&
+                               isLegalICmpImmediate(C.getSExtValue())))
+        return DAG.getSetCC(dl, VT, N0,
+                            DAG.getConstant(C, N1.getValueType()),
+                            (Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT);
     }
 
     if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal)