lib/CodeGen/CGLoopInfo.h - clang - Git at Google

 //===---- 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
	//===---- 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