LoopAttributes.h

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//===--- LoopAttributes.h - Shared loop hint state ---------------*- 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 holds the state of the attributes and hints that may be specified
// on a loop, and the logic to determine it from the loop's statement
// attributes and the command line options. Both classic CodeGen and CIR
// CodeGen use it, and each translates the state into its own representation.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_CLANG_CODEGENUTILS_LOOPATTRIBUTES_H
#define LLVM_CLANG_CODEGENUTILS_LOOPATTRIBUTES_H
 
#include "llvm/ADT/ArrayRef.h"
 
namespace clang {
class ASTContext;
class Attr;
class CodeGenOptions;
} // namespace clang
 
namespace clang::CodeGenUtils {
 
/// 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.vectorize.scalable.enable
  LVEnableState VectorizeScalable;
 
  /// 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.licm.disable metadata.
  bool LICMDisabled;
 
  /// Value for llvm.loop.pipeline.iicount metadata.
  unsigned PipelineInitiationInterval;
 
  /// Value for 'llvm.loop.align' metadata.
  unsigned CodeAlign;
 
  /// Value for whether the loop is required to make progress.
  bool MustProgress;
};
 
/// Update \p Attrs with the loop hints in \p StmtAttrs (`#pragma clang loop`,
/// `#pragma unroll`, `[[clang::code_align]]`, the OpenCL and HLSL spellings),
/// the command line options that adjust every loop (-falign-loops and
/// -fno-unroll-loops), and whether the loop must make progress.
void updateLoopAttributes(LoopAttributes &Attrs, ASTContext &Ctx,
                          const CodeGenOptions &CGOpts,
                          llvm::ArrayRef<const Attr *> StmtAttrs,
                          bool MustProgress);
 
} // namespace clang::CodeGenUtils
 
#endif // LLVM_CLANG_CODEGENUTILS_LOOPATTRIBUTES_H