[PGO][PGSO] DAG.shouldOptForSize part.

[hjyamauchi]

Summary

(Split of off D67120)

SelectionDAG::shouldOptForSize changes for profile guided size optimization.

[davidxl]

Looks good to me. Added Sanjay and Simon for review.

[MaskRay]

llvm/lib/Target/X86/X86ISelLowering.cpp

30

clang-format the header order.

[hjyamauchi]

Address comment.

[hjyamauchi]

Rebase.

[spatel]

I don't know about the overall changes planned, but this seems fine.
One question though: what about targets other than x86? Don't we need to update them in any places they are using 'getMachineFunction().hasOptSize()' as we are for x86?

[hjyamauchi]

Cover non-x86 targets (which happens to affect AArch64 files only). PTAL.

[spatel]

In D70095#1746161, @yamauchi wrote:

Cover non-x86 targets (which happens to affect AArch64 files only). PTAL.

WebAssembly too?

class WebAssemblyDAGToDAGISel final : public SelectionDAGISel {
...
  bool ForCodeSize;
...
  ForCodeSize = MF.getFunction().hasOptSize();

[spatel]

llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp

402 ↗

(On Diff #229358)

If this was the only use of the "ForCodeSize" class variable, then it should be removed now?

[hjyamauchi]

Address comment.

[hjyamauchi]

llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp

402 ↗

(On Diff #229358)

True, done.

[RKSimon]

Does WebAssembly still need updating ?

llvm/include/llvm/CodeGen/SelectionDAG.h

241

initialize with = nullptr

[hjyamauchi]

Address comments.

[hjyamauchi]

In D70095#1754675, @RKSimon wrote:

Does WebAssembly still need updating ?

I somehow missed the WebAssembly comment. Thanks for reminding.

I think we can remove WebAssemblyDAGToDAGISel::ForCodeSize and the hasOptSize call.
Three reasons:
(1) ForCodeSize is not used,
(2) We can't call DAG.shouldOptForSize there because DAG isn't initialized at that point (if we want to query this at a block granularity, it wouldn't make sense to call it there to begin with.)
(3) Removing it would minimize confusions, I think, in case we want to implement size optimizations here for WebAssembly in the future (in which case, we could follow the other targets code and use DAG.shouldOptForSize.)
Of course, we could alternatively leave it as is, and no update needed.

[spatel]

In D70095#1755505, @yamauchi wrote:

In D70095#1754675, @RKSimon wrote:

Does WebAssembly still need updating ?

I somehow missed the WebAssembly comment. Thanks for reminding.

I think we can remove WebAssemblyDAGToDAGISel::ForCodeSize and the hasOptSize call.
Three reasons:
(1) ForCodeSize is not used,
(2) We can't call DAG.shouldOptForSize there because DAG isn't initialized at that point (if we want to query this at a block granularity, it wouldn't make sense to call it there to begin with.)
(3) Removing it would minimize confusions, I think, in case we want to implement size optimizations here for WebAssembly in the future (in which case, we could follow the other targets code and use DAG.shouldOptForSize.)

LGTM.
I agree that removing unused code is good, but I've never looked at WebAssembly before, so let's see if anyone else has comments (wait a day to commit).

[RKSimon]

LGTM - as @spatel suggested either wait a day or split off the WebAssembly diff (it appears to be completely independent + superfluous) into a separate patch for review and then you can commit this immediately.

[hjyamauchi]

Thanks, I'll try the option of splitting out the WebAssembly change.

[hjyamauchi]

Split the WebAssembly change.

[hjyamauchi]

WebAssembly change: https://reviews.llvm.org/D70567

[hjyamauchi]

Rebased.

llvm/include/llvm/CodeGen/SelectionDAG.h

 #include <tuple>
 #include <utility>
 #include <vector>
 
 namespace llvm {
 
 class AAResults;
 class BlockAddress;
+class BlockFrequencyInfo;
 class Constant;
 class ConstantFP;
 class ConstantInt;
 class DataLayout;
 struct fltSemantics;
 class GlobalValue;
 struct KnownBits;
 class LegacyDivergenceAnalysis;
 class LLVMContext;
 class MachineBasicBlock;
 class MachineConstantPoolValue;
 class MCSymbol;
 class OptimizationRemarkEmitter;
+class ProfileSummaryInfo;
 class SDDbgValue;
 class SDDbgLabel;
 class SelectionDAG;
 class SelectionDAGTargetInfo;
 class TargetLibraryInfo;
 class TargetLowering;
 class TargetMachine;
 class TargetSubtargetInfo;
class SelectionDAG {
 
   LegacyDivergenceAnalysis * DA = nullptr;
   FunctionLoweringInfo * FLI = nullptr;
 
   /// The function-level optimization remark emitter.  Used to emit remarks
   /// whenever manipulating the DAG.
   OptimizationRemarkEmitter *ORE;
 
+  ProfileSummaryInfo *PSI;
+  BlockFrequencyInfo *BFI;
+
   /// The starting token.
   SDNode EntryNode;
 
   /// The root of the entire DAG.
   SDValue Root;
 
   /// A linked list of nodes in the current DAG.
   ilist<SDNode> AllNodes;
public:
   explicit SelectionDAG(const TargetMachine &TM, CodeGenOpt::Level);
   SelectionDAG(const SelectionDAG &) = delete;
   SelectionDAG &operator=(const SelectionDAG &) = delete;
   ~SelectionDAG();
 
   /// Prepare this SelectionDAG to process code in the given MachineFunction.
   void init(MachineFunction &NewMF, OptimizationRemarkEmitter &NewORE,
             Pass *PassPtr, const TargetLibraryInfo *LibraryInfo,
-            LegacyDivergenceAnalysis * Divergence);
+            LegacyDivergenceAnalysis * Divergence,
+            ProfileSummaryInfo *PSIin, BlockFrequencyInfo *BFIin);
 
   void setFunctionLoweringInfo(FunctionLoweringInfo * FuncInfo) {
     FLI = FuncInfo;
   }
 
   /// Clear state and free memory necessary to make this
   /// SelectionDAG ready to process a new block.
   void clear();
 
   MachineFunction &getMachineFunction() const { return *MF; }
   const Pass *getPass() const { return SDAGISelPass; }
 
   const DataLayout &getDataLayout() const { return MF->getDataLayout(); }
   const TargetMachine &getTarget() const { return TM; }
   const TargetSubtargetInfo &getSubtarget() const { return MF->getSubtarget(); }
   const TargetLowering &getTargetLoweringInfo() const { return *TLI; }
   const TargetLibraryInfo &getLibInfo() const { return *LibInfo; }
   const SelectionDAGTargetInfo &getSelectionDAGInfo() const { return *TSI; }
   const LegacyDivergenceAnalysis *getDivergenceAnalysis() const { return DA; }
   LLVMContext *getContext() const {return Context; }
   OptimizationRemarkEmitter &getORE() const { return *ORE; }
+  ProfileSummaryInfo *getPSI() const { return PSI; }
+  BlockFrequencyInfo *getBFI() const { return BFI; }
 
   /// Pop up a GraphViz/gv window with the DAG rendered using 'dot'.
   void viewGraph(const std::string &Title);
   void viewGraph();
 
 #ifndef NDEBUG
   std::map<const SDNode *, std::string> NodeGraphAttrs;
 #endif
public:
   /// Return the HeapAllocSite type associated with the SDNode, if it exists.
   MDNode *getHeapAllocSite(const SDNode *Node) {
     auto It = SDCallSiteDbgInfo.find(Node);
     if (It == SDCallSiteDbgInfo.end())
       return nullptr;
     return It->second.HeapAllocSite;
   }
 
+  bool shouldOptForSize() const;
+
 private:
   void InsertNode(SDNode *N);
   bool RemoveNodeFromCSEMaps(SDNode *N);
   void AddModifiedNodeToCSEMaps(SDNode *N);
   SDNode *FindModifiedNodeSlot(SDNode *N, SDValue Op, void *&InsertPos);
   SDNode *FindModifiedNodeSlot(SDNode *N, SDValue Op1, SDValue Op2,
                                void *&InsertPos);
   SDNode *FindModifiedNodeSlot(SDNode *N, ArrayRef<SDValue> Ops,

llvm/include/llvm/CodeGen/SelectionDAGISel.h

 class TargetLowering;
 class TargetLibraryInfo;
 class FunctionLoweringInfo;
 class ScheduleHazardRecognizer;
 class SwiftErrorValueTracking;
 class GCFunctionInfo;
 class ScheduleDAGSDNodes;
 class LoadInst;
+class ProfileSummaryInfo;
+class BlockFrequencyInfo;
 
 /// SelectionDAGISel - This is the common base class used for SelectionDAG-based
 /// pattern-matching instruction selectors.
 class SelectionDAGISel : public MachineFunctionPass {
 public:
   TargetMachine &TM;
   const TargetLibraryInfo *LibInfo;
   FunctionLoweringInfo *FuncInfo;
protected:
   virtual StringRef getPatternForIndex(unsigned index) {
     llvm_unreachable("Tblgen should generate the implementation of this!");
   }
 
   /// getIncludePathForIndex - get the td source location of pattern instantiation
   virtual StringRef getIncludePathForIndex(unsigned index) {
     llvm_unreachable("Tblgen should generate the implementation of this!");
   }
+
+  bool shouldOptForSize(const MachineFunction *MF) const {
+    return CurDAG->shouldOptForSize();
+  }
+
 public:
   // Calls to these predicates are generated by tblgen.
   bool CheckAndMask(SDValue LHS, ConstantSDNode *RHS,
                     int64_t DesiredMaskS) const;
   bool CheckOrMask(SDValue LHS, ConstantSDNode *RHS,
                     int64_t DesiredMaskS) const;
 
 

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

class DAGCombiner {
 
     /// Call the node-specific routine that folds each particular type of node.
     SDValue visit(SDNode *N);
 
   public:
     DAGCombiner(SelectionDAG &D, AliasAnalysis *AA, CodeGenOpt::Level OL)
         : DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
           OptLevel(OL), AA(AA) {
-      ForCodeSize = DAG.getMachineFunction().getFunction().hasOptSize();
+      ForCodeSize = DAG.shouldOptForSize();
 
       MaximumLegalStoreInBits = 0;
       for (MVT VT : MVT::all_valuetypes())
         if (EVT(VT).isSimple() && VT != MVT::Other &&
             TLI.isTypeLegal(EVT(VT)) &&
             VT.getSizeInBits() >= MaximumLegalStoreInBits)
           MaximumLegalStoreInBits = VT.getSizeInBits();
     }
if ((!Flags.hasNoSignedZeros() && ExponentIs025) || !Flags.hasNoInfs() ||
       return SDValue();
 
     // Don't double the number of libcalls. We are trying to inline fast code.
     if (!DAG.getTargetLoweringInfo().isOperationLegalOrCustom(ISD::FSQRT, VT))
       return SDValue();
 
     // Assume that libcalls are the smallest code.
     // TODO: This restriction should probably be lifted for vectors.
-    if (DAG.getMachineFunction().getFunction().hasOptSize())
+    if (ForCodeSize)
       return SDValue();
 
     // pow(X, 0.25) --> sqrt(sqrt(X))
     SDLoc DL(N);
     SDValue Sqrt = DAG.getNode(ISD::FSQRT, DL, VT, N->getOperand(0), Flags);
     SDValue SqrtSqrt = DAG.getNode(ISD::FSQRT, DL, VT, Sqrt, Flags);
     if (ExponentIs025)
       return SqrtSqrt;

llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/None.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/ADT/Twine.h"
+#include "llvm/Analysis/BlockFrequencyInfo.h"
+#include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/CodeGen/ISDOpcodes.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/RuntimeLibcalls.h"

 #include "llvm/Support/KnownBits.h"
 #include "llvm/Support/MachineValueType.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/Mutex.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"
+#include "llvm/Transforms/Utils/SizeOpts.h"
 #include <algorithm>
 #include <cassert>
 #include <cstdint>
 #include <cstdlib>
 #include <limits>
 #include <set>
 #include <string>
 #include <utility>
: TM(tm), OptLevel(OL),
       Root(getEntryNode()) {
   InsertNode(&EntryNode);
   DbgInfo = new SDDbgInfo();
 }
 
 void SelectionDAG::init(MachineFunction &NewMF,
                         OptimizationRemarkEmitter &NewORE,
                         Pass *PassPtr, const TargetLibraryInfo *LibraryInfo,
-                        LegacyDivergenceAnalysis * Divergence) {
+                        LegacyDivergenceAnalysis * Divergence,
+                        ProfileSummaryInfo *PSIin,
+                        BlockFrequencyInfo *BFIin) {
   MF = &NewMF;
   SDAGISelPass = PassPtr;
   ORE = &NewORE;
   TLI = getSubtarget().getTargetLowering();
   TSI = getSubtarget().getSelectionDAGInfo();
   LibInfo = LibraryInfo;
   Context = &MF->getFunction().getContext();
   DA = Divergence;
+  PSI = PSIin;
+  BFI = BFIin;
 }
 
 SelectionDAG::~SelectionDAG() {
   assert(!UpdateListeners && "Dangling registered DAGUpdateListeners");
   allnodes_clear();
   OperandRecycler.clear(OperandAllocator);
   delete DbgInfo;
 }
 
+bool SelectionDAG::shouldOptForSize() const {
+  return MF->getFunction().hasOptSize() ||
+      llvm::shouldOptimizeForSize(FLI->MBB->getBasicBlock(), PSI, BFI);
+}
+
 void SelectionDAG::allnodes_clear() {
   assert(&*AllNodes.begin() == &EntryNode);
   AllNodes.remove(AllNodes.begin());
   while (!AllNodes.empty())
     DeallocateNode(&AllNodes.front());
 #ifndef NDEBUG
   NextPersistentId = 0;
 #endif

 
 SDValue SelectionDAG::getConstantPool(const Constant *C, EVT VT,
                                       unsigned Alignment, int Offset,
                                       bool isTarget,
                                       unsigned TargetFlags) {
   assert((TargetFlags == 0 || isTarget) &&
          "Cannot set target flags on target-independent globals");
   if (Alignment == 0)
-    Alignment = MF->getFunction().hasOptSize()
+    Alignment = shouldOptForSize()
                     ? getDataLayout().getABITypeAlignment(C->getType())
                     : getDataLayout().getPrefTypeAlignment(C->getType());
   unsigned Opc = isTarget ? ISD::TargetConstantPool : ISD::ConstantPool;
   FoldingSetNodeID ID;
   AddNodeIDNode(ID, Opc, getVTList(VT), None);
   ID.AddInteger(Alignment);
   ID.AddInteger(Offset);
   ID.AddPointer(C);
static bool isMemSrcFromConstant(SDValue Src, ConstantDataArraySlice &Slice) {
   }
   if (!G)
     return false;
 
   return getConstantDataArrayInfo(G->getGlobal(), Slice, 8,
                                   SrcDelta + G->getOffset());
 }
 
-static bool shouldLowerMemFuncForSize(const MachineFunction &MF) {
+static bool shouldLowerMemFuncForSize(const MachineFunction &MF,
+                                      SelectionDAG &DAG) {
   // On Darwin, -Os means optimize for size without hurting performance, so
   // only really optimize for size when -Oz (MinSize) is used.
   if (MF.getTarget().getTargetTriple().isOSDarwin())
     return MF.getFunction().hasMinSize();
-  return MF.getFunction().hasOptSize();
+  return DAG.shouldOptForSize();
 }
 
 static void chainLoadsAndStoresForMemcpy(SelectionDAG &DAG, const SDLoc &dl,
                           SmallVector<SDValue, 32> &OutChains, unsigned From,
                           unsigned To, SmallVector<SDValue, 16> &OutLoadChains,
                           SmallVector<SDValue, 16> &OutStoreChains) {
   assert(OutLoadChains.size() && "Missing loads in memcpy inlining");
   assert(OutStoreChains.size() && "Missing stores in memcpy inlining");
static SDValue getMemcpyLoadsAndStores(SelectionDAG &DAG, const SDLoc &dl,
   // rather than maybe a humongous number of loads and stores.
   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   const DataLayout &DL = DAG.getDataLayout();
   LLVMContext &C = *DAG.getContext();
   std::vector<EVT> MemOps;
   bool DstAlignCanChange = false;
   MachineFunction &MF = DAG.getMachineFunction();
   MachineFrameInfo &MFI = MF.getFrameInfo();
-  bool OptSize = shouldLowerMemFuncForSize(MF);
+  bool OptSize = shouldLowerMemFuncForSize(MF, DAG);
   FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Dst);
   if (FI && !MFI.isFixedObjectIndex(FI->getIndex()))
     DstAlignCanChange = true;
   unsigned SrcAlign = DAG.InferPtrAlignment(Src);
   if (Alignment > SrcAlign)
     SrcAlign = Alignment;
   ConstantDataArraySlice Slice;
   bool CopyFromConstant = isMemSrcFromConstant(Src, Slice);
static SDValue getMemmoveLoadsAndStores(SelectionDAG &DAG, const SDLoc &dl,
   // below a certain threshold.
   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   const DataLayout &DL = DAG.getDataLayout();
   LLVMContext &C = *DAG.getContext();
   std::vector<EVT> MemOps;
   bool DstAlignCanChange = false;
   MachineFunction &MF = DAG.getMachineFunction();
   MachineFrameInfo &MFI = MF.getFrameInfo();
-  bool OptSize = shouldLowerMemFuncForSize(MF);
+  bool OptSize = shouldLowerMemFuncForSize(MF, DAG);
   FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Dst);
   if (FI && !MFI.isFixedObjectIndex(FI->getIndex()))
     DstAlignCanChange = true;
   unsigned SrcAlign = DAG.InferPtrAlignment(Src);
   if (Align > SrcAlign)
     SrcAlign = Align;
   unsigned Limit = AlwaysInline ? ~0U : TLI.getMaxStoresPerMemmove(OptSize);
   // FIXME: `AllowOverlap` should really be `!isVol` but there is a bug in
static SDValue getMemsetStores(SelectionDAG &DAG, const SDLoc &dl,
 
   // Expand memset to a series of load/store ops if the size operand
   // falls below a certain threshold.
   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   std::vector<EVT> MemOps;
   bool DstAlignCanChange = false;
   MachineFunction &MF = DAG.getMachineFunction();
   MachineFrameInfo &MFI = MF.getFrameInfo();
-  bool OptSize = shouldLowerMemFuncForSize(MF);
+  bool OptSize = shouldLowerMemFuncForSize(MF, DAG);
   FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Dst);
   if (FI && !MFI.isFixedObjectIndex(FI->getIndex()))
     DstAlignCanChange = true;
   bool IsZeroVal =
     isa<ConstantSDNode>(Src) && cast<ConstantSDNode>(Src)->isNullValue();
   if (!TLI.findOptimalMemOpLowering(
           MemOps, TLI.getMaxStoresPerMemset(OptSize), Size,
           (DstAlignCanChange ? 0 : Align), 0, /*IsMemset=*/true,

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/BranchProbabilityInfo.h"
+#include "llvm/Analysis/BlockFrequencyInfo.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/EHPersonalities.h"
 #include "llvm/Analysis/Loads.h"
 #include "llvm/Analysis/MemoryLocation.h"
+#include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/Analysis/VectorUtils.h"
 #include "llvm/CodeGen/Analysis.h"
 #include "llvm/CodeGen/FunctionLoweringInfo.h"
 #include "llvm/CodeGen/GCMetadata.h"
 #include "llvm/CodeGen/ISDOpcodes.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS)) {
     // Get the exponent as a positive value.
     unsigned Val = RHSC->getSExtValue();
     if ((int)Val < 0) Val = -Val;
 
     // powi(x, 0) -> 1.0
     if (Val == 0)
       return DAG.getConstantFP(1.0, DL, LHS.getValueType());
 
-    const Function &F = DAG.getMachineFunction().getFunction();
-    if (!F.hasOptSize() ||
+    bool OptForSize = DAG.shouldOptForSize();
+    if (!OptForSize ||
         // If optimizing for size, don't insert too many multiplies.
         // This inserts up to 5 multiplies.
         countPopulation(Val) + Log2_32(Val) < 7) {
       // We use the simple binary decomposition method to generate the multiply
       // sequence.  There are more optimal ways to do this (for example,
       // powi(x,15) generates one more multiply than it should), but this has
       // the benefit of being both really simple and much better than a libcall.
       SDValue Res;  // Logically starts equal to 1.0
if (Clusters.empty()) {
     SwitchMBB->addSuccessor(DefaultMBB);
     if (DefaultMBB != NextBlock(SwitchMBB)) {
       DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(), MVT::Other,
                               getControlRoot(), DAG.getBasicBlock(DefaultMBB)));
     }
     return;
   }
 
-  SL->findJumpTables(Clusters, &SI, DefaultMBB, nullptr, nullptr);
+  SL->findJumpTables(Clusters, &SI, DefaultMBB, DAG.getPSI(), DAG.getBFI());
   SL->findBitTestClusters(Clusters, &SI);
 
   LLVM_DEBUG({
     dbgs() << "Case clusters: ";
     for (const CaseCluster &C : Clusters) {
       if (C.Kind == CC_JumpTable)
         dbgs() << "JT:";
       if (C.Kind == CC_BitTests)

llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
   auto *LIWP = getAnalysisIfAvailable<LoopInfoWrapperPass>();
   LoopInfo *LI = LIWP ? &LIWP->getLoopInfo() : nullptr;
 
   LLVM_DEBUG(dbgs() << "\n\n\n=== " << Fn.getName() << "\n");
 
   SplitCriticalSideEffectEdges(const_cast<Function &>(Fn), DT, LI);
 
   CurDAG->init(*MF, *ORE, this, LibInfo,
-   getAnalysisIfAvailable<LegacyDivergenceAnalysis>());
+               getAnalysisIfAvailable<LegacyDivergenceAnalysis>(),
+               nullptr, nullptr);
   FuncInfo->set(Fn, *MF, CurDAG);
   SwiftError->setFunction(*MF);
 
   // Now get the optional analyzes if we want to.
   // This is based on the possibly changed OptLevel (after optnone is taken
   // into account).  That's unfortunate but OK because it just means we won't
   // ask for passes that have been required anyway.
 

llvm/lib/Target/X86/X86FastISel.cpp

private:
   const MachineInstrBuilder &addFullAddress(const MachineInstrBuilder &MIB,
                                             X86AddressMode &AM);
 
   unsigned fastEmitInst_rrrr(unsigned MachineInstOpcode,
                              const TargetRegisterClass *RC, unsigned Op0,
                              bool Op0IsKill, unsigned Op1, bool Op1IsKill,
                              unsigned Op2, bool Op2IsKill, unsigned Op3,
                              bool Op3IsKill);
+
+  bool shouldOptForSize(const MachineFunction *MF) const {
+    // TODO: Implement PGSO.
+    return MF->getFunction().hasOptSize();
+  }
 };
 
 } // end anonymous namespace.
 
 static std::pair<unsigned, bool>
 getX86SSEConditionCode(CmpInst::Predicate Predicate) {
   unsigned CC;
   bool NeedSwap = false;

llvm/lib/Target/X86/X86ISelDAGToDAG.cpp

private:
     // that can be kept in a register.
     //
     bool shouldAvoidImmediateInstFormsForSize(SDNode *N) const {
       uint32_t UseCount = 0;
 
       // Do not want to hoist if we're not optimizing for size.
       // TODO: We'd like to remove this restriction.
       // See the comment in X86InstrInfo.td for more info.
-      if (!OptForSize)
+      if (!CurDAG->shouldOptForSize())
         return false;
 
       // Walk all the users of the immediate.
       for (SDNode::use_iterator UI = N->use_begin(),
            UE = N->use_end(); (UI != UE) && (UseCount < 2); ++UI) {
 
         SDNode *User = *UI;
 
if (IsNegate) {
       const SDValue Ops[] = {Base, Scale, Index, Disp, Segment, InputChain};
       Result = CurDAG->getMachineNode(NewOpc, SDLoc(Node), MVT::i32,
                                       MVT::Other, Ops);
       break;
     }
    LLVM_FALLTHROUGH;
   case X86ISD::ADD:
     // Try to match inc/dec.
-    if (!Subtarget->slowIncDec() || OptForSize) {
+    if (!Subtarget->slowIncDec() || CurDAG->shouldOptForSize()) {
       bool IsOne = isOneConstant(StoredVal.getOperand(1));
       bool IsNegOne = isAllOnesConstant(StoredVal.getOperand(1));
       // ADD/SUB with 1/-1 and carry flag isn't used can use inc/dec.
       if ((IsOne || IsNegOne) && hasNoCarryFlagUses(StoredVal.getValue(1))) {
         unsigned NewOpc = 
           ((Opc == X86ISD::ADD) == IsOne)
               ? SelectOpcode(X86::INC64m, X86::INC32m, X86::INC16m, X86::INC8m)
               : SelectOpcode(X86::DEC64m, X86::DEC32m, X86::DEC16m, X86::DEC8m);

llvm/lib/Target/X86/X86ISelLowering.cpp

 #include "X86MachineFunctionInfo.h"
 #include "X86TargetMachine.h"
 #include "X86TargetObjectFile.h"
 #include "llvm/ADT/SmallBitVector.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/Analysis/BlockFrequencyInfo.h"
 #include "llvm/Analysis/EHPersonalities.h"
+#include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/CodeGen/IntrinsicLowering.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineJumpTableInfo.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/TargetLowering.h"
static SDValue lowerBuildVectorAsBroadcast(BuildVectorSDNode *BVOp,
   unsigned ScalarSize = Ld.getValueSizeInBits();
   bool IsGE256 = (VT.getSizeInBits() >= 256);
 
   // When optimizing for size, generate up to 5 extra bytes for a broadcast
   // instruction to save 8 or more bytes of constant pool data.
   // TODO: If multiple splats are generated to load the same constant,
   // it may be detrimental to overall size. There needs to be a way to detect
   // that condition to know if this is truly a size win.
-  bool OptForSize = DAG.getMachineFunction().getFunction().hasOptSize();
+  bool OptForSize = DAG.shouldOptForSize();
 
   // Handle broadcasting a single constant scalar from the constant pool
   // into a vector.
   // On Sandybridge (no AVX2), it is still better to load a constant vector
   // from the constant pool and not to broadcast it from a scalar.
   // But override that restriction when optimizing for size.
   // TODO: Check if splatting is recommended for other AVX-capable CPUs.
   if (ConstSplatVal && (Subtarget.hasAVX2() || OptForSize)) {
static SDValue lowerShuffleAsBlend(const SDLoc &DL, MVT VT, SDValue V1,
   }
   case MVT::v16f32:
   case MVT::v8f64:
   case MVT::v8i64:
   case MVT::v16i32:
   case MVT::v32i16:
   case MVT::v64i8: {
     // Attempt to lower to a bitmask if we can. Only if not optimizing for size.
-    bool OptForSize = DAG.getMachineFunction().getFunction().hasOptSize();
+    bool OptForSize = DAG.shouldOptForSize();
     if (!OptForSize) {
       if (SDValue Masked = lowerShuffleAsBitMask(DL, VT, V1, V2, Mask, Zeroable,
                                                  Subtarget, DAG))
         return Masked;
     }
 
     // Otherwise load an immediate into a GPR, cast to k-register, and use a
     // masked move.
if (VT.isVector()) {
     return DAG.getNode(IsFSHR ? X86ISD::VSHRDV : X86ISD::VSHLDV, DL, VT,
                        Op0, Op1, Amt);
   }
 
   assert((VT == MVT::i16 || VT == MVT::i32 || VT == MVT::i64) &&
          "Unexpected funnel shift type!");
 
   // Expand slow SHLD/SHRD cases if we are not optimizing for size.
-  bool OptForSize = DAG.getMachineFunction().getFunction().hasOptSize();
+  bool OptForSize = DAG.shouldOptForSize();
   if (!OptForSize && Subtarget.isSHLDSlow())
     return SDValue();
 
   if (IsFSHR)
     std::swap(Op0, Op1);
 
   // i16 needs to modulo the shift amount, but i32/i64 have implicit modulo.
   if (VT == MVT::i16)
SDValue X86TargetLowering::BuildFILD(SDValue Op, EVT SrcVT, SDValue Chain,
   return Result;
 }
 
 /// Horizontal vector math instructions may be slower than normal math with
 /// shuffles. Limit horizontal op codegen based on size/speed trade-offs, uarch
 /// implementation, and likely shuffle complexity of the alternate sequence.
 static bool shouldUseHorizontalOp(bool IsSingleSource, SelectionDAG &DAG,
                                   const X86Subtarget &Subtarget) {
-  bool IsOptimizingSize = DAG.getMachineFunction().getFunction().hasOptSize();
+  bool IsOptimizingSize = DAG.shouldOptForSize();
   bool HasFastHOps = Subtarget.hasFastHorizontalOps();
   return !IsSingleSource || IsOptimizingSize || HasFastHOps;
 }
 
 /// 64-bit unsigned integer to double expansion.
 static SDValue LowerUINT_TO_FP_i64(SDValue Op, SelectionDAG &DAG,
                                    const X86Subtarget &Subtarget) {
   // This algorithm is not obvious. Here it is what we're trying to output:
if (Op0.getOpcode() == ISD::SHL) {
     SDValue AndLHS = Op0;
 
     if (AndRHSVal == 1 && AndLHS.getOpcode() == ISD::SRL) {
       Src = AndLHS.getOperand(0);
       BitNo = AndLHS.getOperand(1);
     } else {
       // Use BT if the immediate can't be encoded in a TEST instruction or we
       // are optimizing for size and the immedaite won't fit in a byte.
-      bool OptForSize = DAG.getMachineFunction().getFunction().hasOptSize();
+      bool OptForSize = DAG.shouldOptForSize();
       if ((!isUInt<32>(AndRHSVal) || (OptForSize && !isUInt<8>(AndRHSVal))) &&
           isPowerOf2_64(AndRHSVal)) {
         Src = AndLHS;
         BitNo = DAG.getConstant(Log2_64_Ceil(AndRHSVal), dl,
                                 Src.getValueType());
       }
     }
   }
static SDValue combineOrShiftToFunnelShift(SDNode *N, SelectionDAG &DAG,
   EVT VT = N->getValueType(0);
   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
 
   if (!TLI.isOperationLegalOrCustom(ISD::FSHL, VT) ||
       !TLI.isOperationLegalOrCustom(ISD::FSHR, VT))
     return SDValue();
 
   // fold (or (x << c) | (y >> (64 - c))) ==> (shld64 x, y, c)
-  bool OptForSize = DAG.getMachineFunction().getFunction().hasOptSize();
+  bool OptForSize = DAG.shouldOptForSize();
   unsigned Bits = VT.getScalarSizeInBits();
 
   // SHLD/SHRD instructions have lower register pressure, but on some
   // platforms they have higher latency than the equivalent
   // series of shifts/or that would otherwise be generated.
   // Don't fold (or (x << c) | (y >> (64 - c))) if SHLD/SHRD instructions
   // have higher latencies and we are not optimizing for size.
   if (!OptForSize && Subtarget.isSHLDSlow())

llvm/lib/Target/X86/X86InstrInfo.td

 def NearData     : Predicate<"TM.getCodeModel() == CodeModel::Small ||"
                              "TM.getCodeModel() == CodeModel::Kernel">;
 def IsNotPIC     : Predicate<"!TM.isPositionIndependent()">;
 
 // We could compute these on a per-module basis but doing so requires accessing
 // the Function object through the <Target>Subtarget and objections were raised
 // to that (see post-commit review comments for r301750).
 let RecomputePerFunction = 1 in {
-  def OptForSize   : Predicate<"MF->getFunction().hasOptSize()">;
+  def OptForSize   : Predicate<"shouldOptForSize(MF)">;
   def OptForMinSize : Predicate<"MF->getFunction().hasMinSize()">;
-  def OptForSpeed  : Predicate<"!MF->getFunction().hasOptSize()">;
+  def OptForSpeed  : Predicate<"!shouldOptForSize(MF)">;
   def UseIncDec : Predicate<"!Subtarget->slowIncDec() || "
-                            "MF->getFunction().hasOptSize()">;
-  def NoSSE41_Or_OptForSize : Predicate<"MF->getFunction().hasOptSize() || "
+                            "shouldOptForSize(MF)">;
+  def NoSSE41_Or_OptForSize : Predicate<"shouldOptForSize(MF) || "
                                         "!Subtarget->hasSSE41()">;
 }
 
 def CallImmAddr  : Predicate<"Subtarget->isLegalToCallImmediateAddr()">;
 def FavorMemIndirectCall  : Predicate<"!Subtarget->slowTwoMemOps()">;
 def HasFastMem32 : Predicate<"!Subtarget->isUnalignedMem32Slow()">;
 def HasFastLZCNT : Predicate<"Subtarget->hasFastLZCNT()">;
 def HasFastSHLDRotate : Predicate<"Subtarget->hasFastSHLDRotate()">;

llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp

void SetUp() override {
 
     MF = std::make_unique<MachineFunction>(*F, *TM, *TM->getSubtargetImpl(*F), 0,
                                       MMI);
 
     DAG = std::make_unique<SelectionDAG>(*TM, CodeGenOpt::None);
     if (!DAG)
       report_fatal_error("DAG?");
     OptimizationRemarkEmitter ORE(F);
-    DAG->init(*MF, ORE, nullptr, nullptr, nullptr);
+    DAG->init(*MF, ORE, nullptr, nullptr, nullptr, nullptr, nullptr);
   }
 
   LLVMContext Context;
   std::unique_ptr<LLVMTargetMachine> TM;
   std::unique_ptr<Module> M;
   Function *F;
   std::unique_ptr<MachineFunction> MF;
   std::unique_ptr<SelectionDAG> DAG;

llvm/utils/TableGen/GlobalISelEmitter.cpp

std::copy_if(SubtargetFeatures.begin(), SubtargetFeatures.end(),
                std::inserter(FunctionFeatures, FunctionFeatures.end()),
                [](const SubtargetFeatureInfoMap::value_type &X) {
                  return X.second.mustRecomputePerFunction();
                });
 
   SubtargetFeatureInfo::emitComputeAvailableFeatures(
       Target.getName(), "InstructionSelector", "computeAvailableModuleFeatures",
       ModuleFeatures, OS);
+
+  if (Target.getName() == "X86") {
+    // TODO: Implement PGSO.
+    OS << "static bool shouldOptForSize(const MachineFunction *MF) {\n";
+    OS << "    return MF->getFunction().hasOptSize();\n";
+    OS << "}\n\n";
+  }
+
   SubtargetFeatureInfo::emitComputeAvailableFeatures(
       Target.getName(), "InstructionSelector",
       "computeAvailableFunctionFeatures", FunctionFeatures, OS,
       "const MachineFunction *MF");
 
   // Emit a table containing the LLT objects needed by the matcher and an enum
   // for the matcher to reference them with.
   std::vector<LLTCodeGen> TypeObjects;