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

1 files changed, 158 insertions, 0 deletions

diff --git a/clang-r353983/include/llvm/Analysis/PhiValues.h b/clang-r353983/include/llvm/Analysis/PhiValues.h
new file mode 100644
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+++ b/clang-r353983/include/llvm/Analysis/PhiValues.h
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+//===- PhiValues.h - Phi Value Analysis -------------------------*- 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 the PhiValues class, and associated passes, which can be
+// used to find the underlying values of the phis in a function, i.e. the
+// non-phi values that can be found by traversing the phi graph.
+//
+// This information is computed lazily and cached. If new phis are added to the
+// function they are handled correctly, but if an existing phi has its operands
+// modified PhiValues has to be notified by calling invalidateValue.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_PHIVALUES_H
+#define LLVM_ANALYSIS_PHIVALUES_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/IR/ValueHandle.h"
+#include "llvm/Pass.h"
+
+namespace llvm {
+
+class Use;
+class Value;
+class PHINode;
+class Function;
+
+/// Class for calculating and caching the underlying values of phis in a
+/// function.
+///
+/// Initially the PhiValues is empty, and gets incrementally populated whenever
+/// it is queried.
+class PhiValues {
+public:
+  using ValueSet = SmallPtrSet<Value *, 4>;
+
+  /// Construct an empty PhiValues.
+  PhiValues(const Function &F) : F(F) {}
+
+  /// Get the underlying values of a phi.
+  ///
+  /// This returns the cached value if PN has previously been processed,
+  /// otherwise it processes it first.
+  const ValueSet &getValuesForPhi(const PHINode *PN);
+
+  /// Notify PhiValues that the cached information using V is no longer valid
+  ///
+  /// Whenever a phi has its operands modified the cached values for that phi
+  /// (and the phis that use that phi) become invalid. A user of PhiValues has
+  /// to notify it of this by calling invalidateValue on either the operand or
+  /// the phi, which will then clear the relevant cached information.
+  void invalidateValue(const Value *V);
+
+  /// Free the memory used by this class.
+  void releaseMemory();
+
+  /// Print out the values currently in the cache.
+  void print(raw_ostream &OS) const;
+
+  /// Handle invalidation events in the new pass manager.
+  bool invalidate(Function &, const PreservedAnalyses &,
+                  FunctionAnalysisManager::Invalidator &);
+
+private:
+  using PhiSet = SmallPtrSet<const PHINode *, 4>;
+  using ConstValueSet = SmallPtrSet<const Value *, 4>;
+
+  /// The next depth number to be used by processPhi.
+  unsigned int NextDepthNumber = 1;
+
+  /// Depth numbers of phis. Phis with the same depth number are part of the
+  /// same strongly connected component.
+  DenseMap<const PHINode *, unsigned int> DepthMap;
+
+  /// Non-phi values reachable from each component.
+  DenseMap<unsigned int, ValueSet> NonPhiReachableMap;
+
+  /// All values reachable from each component.
+  DenseMap<unsigned int, ConstValueSet> ReachableMap;
+
+  /// A CallbackVH to notify PhiValues when a value is deleted or replaced, so
+  /// that the cached information for that value can be cleared to avoid
+  /// dangling pointers to invalid values.
+  class PhiValuesCallbackVH final : public CallbackVH {
+    PhiValues *PV;
+    void deleted() override;
+    void allUsesReplacedWith(Value *New) override;
+
+  public:
+    PhiValuesCallbackVH(Value *V, PhiValues *PV = nullptr)
+        : CallbackVH(V), PV(PV) {}
+  };
+
+  /// A set of callbacks to the values that processPhi has seen.
+  DenseSet<PhiValuesCallbackVH, DenseMapInfo<Value *>> TrackedValues;
+
+  /// The function that the PhiValues is for.
+  const Function &F;
+
+  /// Process a phi so that its entries in the depth and reachable maps are
+  /// fully populated.
+  void processPhi(const PHINode *PN, SmallVector<const PHINode *, 8> &Stack);
+};
+
+/// The analysis pass which yields a PhiValues
+///
+/// The analysis does nothing by itself, and just returns an empty PhiValues
+/// which will get filled in as it's used.
+class PhiValuesAnalysis : public AnalysisInfoMixin<PhiValuesAnalysis> {
+  friend AnalysisInfoMixin<PhiValuesAnalysis>;
+  static AnalysisKey Key;
+
+public:
+  using Result = PhiValues;
+  PhiValues run(Function &F, FunctionAnalysisManager &);
+};
+
+/// A pass for printing the PhiValues for a function.
+///
+/// This pass doesn't print whatever information the PhiValues happens to hold,
+/// but instead first uses the PhiValues to analyze all the phis in the function
+/// so the complete information is printed.
+class PhiValuesPrinterPass : public PassInfoMixin<PhiValuesPrinterPass> {
+  raw_ostream &OS;
+
+public:
+  explicit PhiValuesPrinterPass(raw_ostream &OS) : OS(OS) {}
+  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+};
+
+/// Wrapper pass for the legacy pass manager
+class PhiValuesWrapperPass : public FunctionPass {
+  std::unique_ptr<PhiValues> Result;
+
+public:
+  static char ID;
+  PhiValuesWrapperPass();
+
+  PhiValues &getResult() { return *Result; }
+  const PhiValues &getResult() const { return *Result; }
+
+  bool runOnFunction(Function &F) override;
+  void releaseMemory() override;
+  void getAnalysisUsage(AnalysisUsage &AU) const override;
+};
+
+} // namespace llvm
+
+#endif