--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/lib/CodeGen/CGLoopInfo.h	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,288 @@
+//===---- CGLoopInfo.h - LLVM CodeGen for loop metadata -*- 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 is the internal state used for llvm translation for loop statement
+// metadata.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_LIB_CODEGEN_CGLOOPINFO_H
+#define LLVM_CLANG_LIB_CODEGEN_CGLOOPINFO_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/IR/DebugLoc.h"
+#include "llvm/IR/Value.h"
+#include "llvm/Support/Compiler.h"
+
+namespace llvm {
+class BasicBlock;
+class Instruction;
+class MDNode;
+} // end namespace llvm
+
+namespace clang {
+class Attr;
+class ASTContext;
+namespace CodeGen {
+
+/// Attributes that may be specified on loops.
+struct LoopAttributes {
+  explicit LoopAttributes(bool IsParallel = false);
+  void clear();
+
+  /// Generate llvm.loop.parallel metadata for loads and stores.
+  bool IsParallel;
+
+  /// State of loop vectorization or unrolling.
+  enum LVEnableState { Unspecified, Enable, Disable, Full };
+
+  /// Value for llvm.loop.vectorize.enable metadata.
+  LVEnableState VectorizeEnable;
+
+  /// Value for llvm.loop.unroll.* metadata (enable, disable, or full).
+  LVEnableState UnrollEnable;
+
+  /// Value for llvm.loop.unroll_and_jam.* metadata (enable, disable, or full).
+  LVEnableState UnrollAndJamEnable;
+
+  /// Value for llvm.loop.vectorize.predicate metadata
+  LVEnableState VectorizePredicateEnable;
+
+  /// Value for llvm.loop.vectorize.width metadata.
+  unsigned VectorizeWidth;
+
+  /// Value for llvm.loop.interleave.count metadata.
+  unsigned InterleaveCount;
+
+  /// llvm.unroll.
+  unsigned UnrollCount;
+
+  /// llvm.unroll.
+  unsigned UnrollAndJamCount;
+
+  /// Value for llvm.loop.distribute.enable metadata.
+  LVEnableState DistributeEnable;
+
+  /// Value for llvm.loop.pipeline.disable metadata.
+  bool PipelineDisabled;
+
+  /// Value for llvm.loop.pipeline.iicount metadata.
+  unsigned PipelineInitiationInterval;
+};
+
+/// Information used when generating a structured loop.
+class LoopInfo {
+public:
+  /// Construct a new LoopInfo for the loop with entry Header.
+  LoopInfo(llvm::BasicBlock *Header, const LoopAttributes &Attrs,
+           const llvm::DebugLoc &StartLoc, const llvm::DebugLoc &EndLoc,
+           LoopInfo *Parent);
+
+  /// Get the loop id metadata for this loop.
+  llvm::MDNode *getLoopID() const { return TempLoopID.get(); }
+
+  /// Get the header block of this loop.
+  llvm::BasicBlock *getHeader() const { return Header; }
+
+  /// Get the set of attributes active for this loop.
+  const LoopAttributes &getAttributes() const { return Attrs; }
+
+  /// Return this loop's access group or nullptr if it does not have one.
+  llvm::MDNode *getAccessGroup() const { return AccGroup; }
+
+  /// Create the loop's metadata. Must be called after its nested loops have
+  /// been processed.
+  void finish();
+
+private:
+  /// Loop ID metadata.
+  llvm::TempMDTuple TempLoopID;
+  /// Header block of this loop.
+  llvm::BasicBlock *Header;
+  /// The attributes for this loop.
+  LoopAttributes Attrs;
+  /// The access group for memory accesses parallel to this loop.
+  llvm::MDNode *AccGroup = nullptr;
+  /// Start location of this loop.
+  llvm::DebugLoc StartLoc;
+  /// End location of this loop.
+  llvm::DebugLoc EndLoc;
+  /// The next outer loop, or nullptr if this is the outermost loop.
+  LoopInfo *Parent;
+  /// If this loop has unroll-and-jam metadata, this can be set by the inner
+  /// loop's LoopInfo to set the llvm.loop.unroll_and_jam.followup_inner
+  /// metadata.
+  llvm::MDNode *UnrollAndJamInnerFollowup = nullptr;
+
+  /// Create a LoopID without any transformations.
+  llvm::MDNode *
+  createLoopPropertiesMetadata(llvm::ArrayRef<llvm::Metadata *> LoopProperties);
+
+  /// Create a LoopID for transformations.
+  ///
+  /// The methods call each other in case multiple transformations are applied
+  /// to a loop. The transformation first to be applied will use LoopID of the
+  /// next transformation in its followup attribute.
+  ///
+  /// @param Attrs             The loop's transformations.
+  /// @param LoopProperties    Non-transformation properties such as debug
+  ///                          location, parallel accesses and disabled
+  ///                          transformations. These are added to the returned
+  ///                          LoopID.
+  /// @param HasUserTransforms [out] Set to true if the returned MDNode encodes
+  ///                          at least one transformation.
+  ///
+  /// @return A LoopID (metadata node) that can be used for the llvm.loop
+  ///         annotation or followup-attribute.
+  /// @{
+  llvm::MDNode *
+  createPipeliningMetadata(const LoopAttributes &Attrs,
+                           llvm::ArrayRef<llvm::Metadata *> LoopProperties,
+                           bool &HasUserTransforms);
+  llvm::MDNode *
+  createPartialUnrollMetadata(const LoopAttributes &Attrs,
+                              llvm::ArrayRef<llvm::Metadata *> LoopProperties,
+                              bool &HasUserTransforms);
+  llvm::MDNode *
+  createUnrollAndJamMetadata(const LoopAttributes &Attrs,
+                             llvm::ArrayRef<llvm::Metadata *> LoopProperties,
+                             bool &HasUserTransforms);
+  llvm::MDNode *
+  createLoopVectorizeMetadata(const LoopAttributes &Attrs,
+                              llvm::ArrayRef<llvm::Metadata *> LoopProperties,
+                              bool &HasUserTransforms);
+  llvm::MDNode *
+  createLoopDistributeMetadata(const LoopAttributes &Attrs,
+                               llvm::ArrayRef<llvm::Metadata *> LoopProperties,
+                               bool &HasUserTransforms);
+  llvm::MDNode *
+  createFullUnrollMetadata(const LoopAttributes &Attrs,
+                           llvm::ArrayRef<llvm::Metadata *> LoopProperties,
+                           bool &HasUserTransforms);
+  /// @}
+
+  /// Create a LoopID for this loop, including transformation-unspecific
+  /// metadata such as debug location.
+  ///
+  /// @param Attrs             This loop's attributes and transformations.
+  /// @param LoopProperties    Additional non-transformation properties to add
+  ///                          to the LoopID, such as transformation-specific
+  ///                          metadata that are not covered by @p Attrs.
+  /// @param HasUserTransforms [out] Set to true if the returned MDNode encodes
+  ///                          at least one transformation.
+  ///
+  /// @return A LoopID (metadata node) that can be used for the llvm.loop
+  ///         annotation.
+  llvm::MDNode *createMetadata(const LoopAttributes &Attrs,
+                               llvm::ArrayRef<llvm::Metadata *> LoopProperties,
+                               bool &HasUserTransforms);
+};
+
+/// A stack of loop information corresponding to loop nesting levels.
+/// This stack can be used to prepare attributes which are applied when a loop
+/// is emitted.
+class LoopInfoStack {
+  LoopInfoStack(const LoopInfoStack &) = delete;
+  void operator=(const LoopInfoStack &) = delete;
+
+public:
+  LoopInfoStack() {}
+
+  /// Begin a new structured loop. The set of staged attributes will be
+  /// applied to the loop and then cleared.
+  void push(llvm::BasicBlock *Header, const llvm::DebugLoc &StartLoc,
+            const llvm::DebugLoc &EndLoc);
+
+  /// Begin a new structured loop. Stage attributes from the Attrs list.
+  /// The staged attributes are applied to the loop and then cleared.
+  void push(llvm::BasicBlock *Header, clang::ASTContext &Ctx,
+            llvm::ArrayRef<const Attr *> Attrs, const llvm::DebugLoc &StartLoc,
+            const llvm::DebugLoc &EndLoc);
+
+  /// End the current loop.
+  void pop();
+
+  /// Return the top loop id metadata.
+  llvm::MDNode *getCurLoopID() const { return getInfo().getLoopID(); }
+
+  /// Return true if the top loop is parallel.
+  bool getCurLoopParallel() const {
+    return hasInfo() ? getInfo().getAttributes().IsParallel : false;
+  }
+
+  /// Function called by the CodeGenFunction when an instruction is
+  /// created.
+  void InsertHelper(llvm::Instruction *I) const;
+
+  /// Set the next pushed loop as parallel.
+  void setParallel(bool Enable = true) { StagedAttrs.IsParallel = Enable; }
+
+  /// Set the next pushed loop 'vectorize.enable'
+  void setVectorizeEnable(bool Enable = true) {
+    StagedAttrs.VectorizeEnable =
+        Enable ? LoopAttributes::Enable : LoopAttributes::Disable;
+  }
+
+  /// Set the next pushed loop as a distribution candidate.
+  void setDistributeState(bool Enable = true) {
+    StagedAttrs.DistributeEnable =
+        Enable ? LoopAttributes::Enable : LoopAttributes::Disable;
+  }
+
+  /// Set the next pushed loop unroll state.
+  void setUnrollState(const LoopAttributes::LVEnableState &State) {
+    StagedAttrs.UnrollEnable = State;
+  }
+
+  /// Set the next pushed vectorize predicate state.
+  void setVectorizePredicateState(const LoopAttributes::LVEnableState &State) {
+    StagedAttrs.VectorizePredicateEnable = State;
+  }
+
+  /// Set the next pushed loop unroll_and_jam state.
+  void setUnrollAndJamState(const LoopAttributes::LVEnableState &State) {
+    StagedAttrs.UnrollAndJamEnable = State;
+  }
+
+  /// Set the vectorize width for the next loop pushed.
+  void setVectorizeWidth(unsigned W) { StagedAttrs.VectorizeWidth = W; }
+
+  /// Set the interleave count for the next loop pushed.
+  void setInterleaveCount(unsigned C) { StagedAttrs.InterleaveCount = C; }
+
+  /// Set the unroll count for the next loop pushed.
+  void setUnrollCount(unsigned C) { StagedAttrs.UnrollCount = C; }
+
+  /// \brief Set the unroll count for the next loop pushed.
+  void setUnrollAndJamCount(unsigned C) { StagedAttrs.UnrollAndJamCount = C; }
+
+  /// Set the pipeline disabled state.
+  void setPipelineDisabled(bool S) { StagedAttrs.PipelineDisabled = S; }
+
+  /// Set the pipeline initiation interval.
+  void setPipelineInitiationInterval(unsigned C) {
+    StagedAttrs.PipelineInitiationInterval = C;
+  }
+
+private:
+  /// Returns true if there is LoopInfo on the stack.
+  bool hasInfo() const { return !Active.empty(); }
+  /// Return the LoopInfo for the current loop. HasInfo should be called
+  /// first to ensure LoopInfo is present.
+  const LoopInfo &getInfo() const { return *Active.back(); }
+  /// The set of attributes that will be applied to the next pushed loop.
+  LoopAttributes StagedAttrs;
+  /// Stack of active loops.
+  llvm::SmallVector<std::unique_ptr<LoopInfo>, 4> Active;
+};
+
+} // end namespace CodeGen
+} // end namespace clang
+
+#endif