Merge "Update prebuilt Clang to r353983." into p9.0HEADp9.0-backupp9.0

1 files changed, 466 insertions, 0 deletions

diff --git a/clang-r353983/include/llvm/Analysis/AliasSetTracker.h b/clang-r353983/include/llvm/Analysis/AliasSetTracker.h
new file mode 100644
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+++ b/clang-r353983/include/llvm/Analysis/AliasSetTracker.h
@@ -0,0 +1,466 @@
+//===- llvm/Analysis/AliasSetTracker.h - Build Alias Sets -------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines two classes: AliasSetTracker and AliasSet. These interfaces
+// are used to classify a collection of pointer references into a maximal number
+// of disjoint sets. Each AliasSet object constructed by the AliasSetTracker
+// object refers to memory disjoint from the other sets.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_ALIASSETTRACKER_H
+#define LLVM_ANALYSIS_ALIASSETTRACKER_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseMapInfo.h"
+#include "llvm/ADT/ilist.h"
+#include "llvm/ADT/ilist_node.h"
+#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/IR/ValueHandle.h"
+#include "llvm/Support/Casting.h"
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <iterator>
+#include <vector>
+
+namespace llvm {
+
+class AliasSetTracker;
+class BasicBlock;
+class LoadInst;
+class Loop;
+class MemorySSA;
+class AnyMemSetInst;
+class AnyMemTransferInst;
+class raw_ostream;
+class StoreInst;
+class VAArgInst;
+class Value;
+
+class AliasSet : public ilist_node<AliasSet> {
+  friend class AliasSetTracker;
+
+  class PointerRec {
+    Value *Val;  // The pointer this record corresponds to.
+    PointerRec **PrevInList = nullptr;
+    PointerRec *NextInList = nullptr;
+    AliasSet *AS = nullptr;
+    LocationSize Size = LocationSize::mapEmpty();
+    AAMDNodes AAInfo;
+
+    // Whether the size for this record has been set at all. This makes no
+    // guarantees about the size being known.
+    bool isSizeSet() const { return Size != LocationSize::mapEmpty(); }
+
+  public:
+    PointerRec(Value *V)
+      : Val(V), AAInfo(DenseMapInfo<AAMDNodes>::getEmptyKey()) {}
+
+    Value *getValue() const { return Val; }
+
+    PointerRec *getNext() const { return NextInList; }
+    bool hasAliasSet() const { return AS != nullptr; }
+
+    PointerRec** setPrevInList(PointerRec **PIL) {
+      PrevInList = PIL;
+      return &NextInList;
+    }
+
+    bool updateSizeAndAAInfo(LocationSize NewSize, const AAMDNodes &NewAAInfo) {
+      bool SizeChanged = false;
+      if (NewSize != Size) {
+        LocationSize OldSize = Size;
+        Size = isSizeSet() ? Size.unionWith(NewSize) : NewSize;
+        SizeChanged = OldSize != Size;
+      }
+
+      if (AAInfo == DenseMapInfo<AAMDNodes>::getEmptyKey())
+        // We don't have a AAInfo yet. Set it to NewAAInfo.
+        AAInfo = NewAAInfo;
+      else {
+        AAMDNodes Intersection(AAInfo.intersect(NewAAInfo));
+        if (!Intersection) {
+          // NewAAInfo conflicts with AAInfo.
+          AAInfo = DenseMapInfo<AAMDNodes>::getTombstoneKey();
+          return SizeChanged;
+        }
+        AAInfo = Intersection;
+      }
+      return SizeChanged;
+    }
+
+    LocationSize getSize() const {
+      assert(isSizeSet() && "Getting an unset size!");
+      return Size;
+    }
+
+    /// Return the AAInfo, or null if there is no information or conflicting
+    /// information.
+    AAMDNodes getAAInfo() const {
+      // If we have missing or conflicting AAInfo, return null.
+      if (AAInfo == DenseMapInfo<AAMDNodes>::getEmptyKey() ||
+          AAInfo == DenseMapInfo<AAMDNodes>::getTombstoneKey())
+        return AAMDNodes();
+      return AAInfo;
+    }
+
+    AliasSet *getAliasSet(AliasSetTracker &AST) {
+      assert(AS && "No AliasSet yet!");
+      if (AS->Forward) {
+        AliasSet *OldAS = AS;
+        AS = OldAS->getForwardedTarget(AST);
+        AS->addRef();
+        OldAS->dropRef(AST);
+      }
+      return AS;
+    }
+
+    void setAliasSet(AliasSet *as) {
+      assert(!AS && "Already have an alias set!");
+      AS = as;
+    }
+
+    void eraseFromList() {
+      if (NextInList) NextInList->PrevInList = PrevInList;
+      *PrevInList = NextInList;
+      if (AS->PtrListEnd == &NextInList) {
+        AS->PtrListEnd = PrevInList;
+        assert(*AS->PtrListEnd == nullptr && "List not terminated right!");
+      }
+      delete this;
+    }
+  };
+
+  // Doubly linked list of nodes.
+  PointerRec *PtrList = nullptr;
+  PointerRec **PtrListEnd;
+  // Forwarding pointer.
+  AliasSet *Forward = nullptr;
+
+  /// All instructions without a specific address in this alias set.
+  /// In rare cases this vector can have a null'ed out WeakVH
+  /// instances (can happen if some other loop pass deletes an
+  /// instruction in this list).
+  std::vector<WeakVH> UnknownInsts;
+
+  /// Number of nodes pointing to this AliasSet plus the number of AliasSets
+  /// forwarding to it.
+  unsigned RefCount : 27;
+
+  // Signifies that this set should be considered to alias any pointer.
+  // Use when the tracker holding this set is saturated.
+  unsigned AliasAny : 1;
+
+  /// The kinds of access this alias set models.
+  ///
+  /// We keep track of whether this alias set merely refers to the locations of
+  /// memory (and not any particular access), whether it modifies or references
+  /// the memory, or whether it does both. The lattice goes from "NoAccess" to
+  /// either RefAccess or ModAccess, then to ModRefAccess as necessary.
+  enum AccessLattice {
+    NoAccess = 0,
+    RefAccess = 1,
+    ModAccess = 2,
+    ModRefAccess = RefAccess | ModAccess
+  };
+  unsigned Access : 2;
+
+  /// The kind of alias relationship between pointers of the set.
+  ///
+  /// These represent conservatively correct alias results between any members
+  /// of the set. We represent these independently of the values of alias
+  /// results in order to pack it into a single bit. Lattice goes from
+  /// MustAlias to MayAlias.
+  enum AliasLattice {
+    SetMustAlias = 0, SetMayAlias = 1
+  };
+  unsigned Alias : 1;
+
+  unsigned SetSize = 0;
+
+  void addRef() { ++RefCount; }
+
+  void dropRef(AliasSetTracker &AST) {
+    assert(RefCount >= 1 && "Invalid reference count detected!");
+    if (--RefCount == 0)
+      removeFromTracker(AST);
+  }
+
+  Instruction *getUnknownInst(unsigned i) const {
+    assert(i < UnknownInsts.size());
+    return cast_or_null<Instruction>(UnknownInsts[i]);
+  }
+
+public:
+  AliasSet(const AliasSet &) = delete;
+  AliasSet &operator=(const AliasSet &) = delete;
+
+  /// Accessors...
+  bool isRef() const { return Access & RefAccess; }
+  bool isMod() const { return Access & ModAccess; }
+  bool isMustAlias() const { return Alias == SetMustAlias; }
+  bool isMayAlias()  const { return Alias == SetMayAlias; }
+
+  /// Return true if this alias set should be ignored as part of the
+  /// AliasSetTracker object.
+  bool isForwardingAliasSet() const { return Forward; }
+
+  /// Merge the specified alias set into this alias set.
+  void mergeSetIn(AliasSet &AS, AliasSetTracker &AST);
+
+  // Alias Set iteration - Allow access to all of the pointers which are part of
+  // this alias set.
+  class iterator;
+  iterator begin() const { return iterator(PtrList); }
+  iterator end()   const { return iterator(); }
+  bool empty() const { return PtrList == nullptr; }
+
+  // Unfortunately, ilist::size() is linear, so we have to add code to keep
+  // track of the list's exact size.
+  unsigned size() { return SetSize; }
+
+  /// If this alias set is known to contain a single instruction and *only* a
+  /// single unique instruction, return it.  Otherwise, return nullptr.
+  Instruction* getUniqueInstruction();
+
+  void print(raw_ostream &OS) const;
+  void dump() const;
+
+  /// Define an iterator for alias sets... this is just a forward iterator.
+  class iterator : public std::iterator<std::forward_iterator_tag,
+                                        PointerRec, ptrdiff_t> {
+    PointerRec *CurNode;
+
+  public:
+    explicit iterator(PointerRec *CN = nullptr) : CurNode(CN) {}
+
+    bool operator==(const iterator& x) const {
+      return CurNode == x.CurNode;
+    }
+    bool operator!=(const iterator& x) const { return !operator==(x); }
+
+    value_type &operator*() const {
+      assert(CurNode && "Dereferencing AliasSet.end()!");
+      return *CurNode;
+    }
+    value_type *operator->() const { return &operator*(); }
+
+    Value *getPointer() const { return CurNode->getValue(); }
+    LocationSize getSize() const { return CurNode->getSize(); }
+    AAMDNodes getAAInfo() const { return CurNode->getAAInfo(); }
+
+    iterator& operator++() {                // Preincrement
+      assert(CurNode && "Advancing past AliasSet.end()!");
+      CurNode = CurNode->getNext();
+      return *this;
+    }
+    iterator operator++(int) { // Postincrement
+      iterator tmp = *this; ++*this; return tmp;
+    }
+  };
+
+private:
+  // Can only be created by AliasSetTracker.
+  AliasSet()
+      : PtrListEnd(&PtrList), RefCount(0),  AliasAny(false), Access(NoAccess),
+        Alias(SetMustAlias) {}
+
+  PointerRec *getSomePointer() const {
+    return PtrList;
+  }
+
+  /// Return the real alias set this represents. If this has been merged with
+  /// another set and is forwarding, return the ultimate destination set. This
+  /// also implements the union-find collapsing as well.
+  AliasSet *getForwardedTarget(AliasSetTracker &AST) {
+    if (!Forward) return this;
+
+    AliasSet *Dest = Forward->getForwardedTarget(AST);
+    if (Dest != Forward) {
+      Dest->addRef();
+      Forward->dropRef(AST);
+      Forward = Dest;
+    }
+    return Dest;
+  }
+
+  void removeFromTracker(AliasSetTracker &AST);
+
+  void addPointer(AliasSetTracker &AST, PointerRec &Entry, LocationSize Size,
+                  const AAMDNodes &AAInfo, bool KnownMustAlias = false,
+                  bool SkipSizeUpdate = false);
+  void addUnknownInst(Instruction *I, AliasAnalysis &AA);
+
+  void removeUnknownInst(AliasSetTracker &AST, Instruction *I) {
+    bool WasEmpty = UnknownInsts.empty();
+    for (size_t i = 0, e = UnknownInsts.size(); i != e; ++i)
+      if (UnknownInsts[i] == I) {
+        UnknownInsts[i] = UnknownInsts.back();
+        UnknownInsts.pop_back();
+        --i; --e;  // Revisit the moved entry.
+      }
+    if (!WasEmpty && UnknownInsts.empty())
+      dropRef(AST);
+  }
+
+public:
+  /// If the specified pointer "may" (or must) alias one of the members in the
+  /// set return the appropriate AliasResult. Otherwise return NoAlias.
+  AliasResult aliasesPointer(const Value *Ptr, LocationSize Size,
+                             const AAMDNodes &AAInfo, AliasAnalysis &AA) const;
+  bool aliasesUnknownInst(const Instruction *Inst, AliasAnalysis &AA) const;
+};
+
+inline raw_ostream& operator<<(raw_ostream &OS, const AliasSet &AS) {
+  AS.print(OS);
+  return OS;
+}
+
+class AliasSetTracker {
+  /// A CallbackVH to arrange for AliasSetTracker to be notified whenever a
+  /// Value is deleted.
+  class ASTCallbackVH final : public CallbackVH {
+    AliasSetTracker *AST;
+
+    void deleted() override;
+    void allUsesReplacedWith(Value *) override;
+
+  public:
+    ASTCallbackVH(Value *V, AliasSetTracker *AST = nullptr);
+
+    ASTCallbackVH &operator=(Value *V);
+  };
+  /// Traits to tell DenseMap that tell us how to compare and hash the value
+  /// handle.
+  struct ASTCallbackVHDenseMapInfo : public DenseMapInfo<Value *> {};
+
+  AliasAnalysis &AA;
+  MemorySSA *MSSA;
+  Loop *L;
+  ilist<AliasSet> AliasSets;
+
+  using PointerMapType = DenseMap<ASTCallbackVH, AliasSet::PointerRec *,
+                                  ASTCallbackVHDenseMapInfo>;
+
+  // Map from pointers to their node
+  PointerMapType PointerMap;
+
+public:
+  /// Create an empty collection of AliasSets, and use the specified alias
+  /// analysis object to disambiguate load and store addresses.
+  explicit AliasSetTracker(AliasAnalysis &aa) : AA(aa) {}
+  explicit AliasSetTracker(AliasAnalysis &aa, MemorySSA *mssa, Loop *l)
+      : AA(aa), MSSA(mssa), L(l) {}
+  ~AliasSetTracker() { clear(); }
+
+  /// These methods are used to add different types of instructions to the alias
+  /// sets. Adding a new instruction can result in one of three actions
+  /// happening:
+  ///
+  ///   1. If the instruction doesn't alias any other sets, create a new set.
+  ///   2. If the instruction aliases exactly one set, add it to the set
+  ///   3. If the instruction aliases multiple sets, merge the sets, and add
+  ///      the instruction to the result.
+  ///
+  /// These methods return true if inserting the instruction resulted in the
+  /// addition of a new alias set (i.e., the pointer did not alias anything).
+  ///
+  void add(Value *Ptr, LocationSize Size, const AAMDNodes &AAInfo); // Add a loc
+  void add(LoadInst *LI);
+  void add(StoreInst *SI);
+  void add(VAArgInst *VAAI);
+  void add(AnyMemSetInst *MSI);
+  void add(AnyMemTransferInst *MTI);
+  void add(Instruction *I);       // Dispatch to one of the other add methods...
+  void add(BasicBlock &BB);       // Add all instructions in basic block
+  void add(const AliasSetTracker &AST); // Add alias relations from another AST
+  void addUnknown(Instruction *I);
+  void addAllInstructionsInLoopUsingMSSA();
+
+  void clear();
+
+  /// Return the alias sets that are active.
+  const ilist<AliasSet> &getAliasSets() const { return AliasSets; }
+
+  /// Return the alias set which contains the specified memory location.  If
+  /// the memory location aliases two or more existing alias sets, will have
+  /// the effect of merging those alias sets before the single resulting alias
+  /// set is returned.
+  AliasSet &getAliasSetFor(const MemoryLocation &MemLoc);
+
+  /// Return the underlying alias analysis object used by this tracker.
+  AliasAnalysis &getAliasAnalysis() const { return AA; }
+
+  /// This method is used to remove a pointer value from the AliasSetTracker
+  /// entirely. It should be used when an instruction is deleted from the
+  /// program to update the AST. If you don't use this, you would have dangling
+  /// pointers to deleted instructions.
+  void deleteValue(Value *PtrVal);
+
+  /// This method should be used whenever a preexisting value in the program is
+  /// copied or cloned, introducing a new value.  Note that it is ok for clients
+  /// that use this method to introduce the same value multiple times: if the
+  /// tracker already knows about a value, it will ignore the request.
+  void copyValue(Value *From, Value *To);
+
+  using iterator = ilist<AliasSet>::iterator;
+  using const_iterator = ilist<AliasSet>::const_iterator;
+
+  const_iterator begin() const { return AliasSets.begin(); }
+  const_iterator end()   const { return AliasSets.end(); }
+
+  iterator begin() { return AliasSets.begin(); }
+  iterator end()   { return AliasSets.end(); }
+
+  void print(raw_ostream &OS) const;
+  void dump() const;
+
+private:
+  friend class AliasSet;
+
+  // The total number of pointers contained in all "may" alias sets.
+  unsigned TotalMayAliasSetSize = 0;
+
+  // A non-null value signifies this AST is saturated. A saturated AST lumps
+  // all pointers into a single "May" set.
+  AliasSet *AliasAnyAS = nullptr;
+
+  void removeAliasSet(AliasSet *AS);
+
+  /// Just like operator[] on the map, except that it creates an entry for the
+  /// pointer if it doesn't already exist.
+  AliasSet::PointerRec &getEntryFor(Value *V) {
+    AliasSet::PointerRec *&Entry = PointerMap[ASTCallbackVH(V, this)];
+    if (!Entry)
+      Entry = new AliasSet::PointerRec(V);
+    return *Entry;
+  }
+
+  AliasSet &addPointer(MemoryLocation Loc, AliasSet::AccessLattice E);
+  AliasSet *mergeAliasSetsForPointer(const Value *Ptr, LocationSize Size,
+                                     const AAMDNodes &AAInfo,
+                                     bool &MustAliasAll);
+
+  /// Merge all alias sets into a single set that is considered to alias any
+  /// pointer.
+  AliasSet &mergeAllAliasSets();
+
+  AliasSet *findAliasSetForUnknownInst(Instruction *Inst);
+};
+
+inline raw_ostream& operator<<(raw_ostream &OS, const AliasSetTracker &AST) {
+  AST.print(OS);
+  return OS;
+}
+
+} // end namespace llvm
+
+#endif // LLVM_ANALYSIS_ALIASSETTRACKER_H