llvm/lib/Transforms/Vectorize/VPlanAnalysis.h

//===- VPlanAnalysis.h - Various Analyses working on VPlan ------*- 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
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_TRANSFORMS_VECTORIZE_VPLANANALYSIS_H
#define LLVM_TRANSFORMS_VECTORIZE_VPLANANALYSIS_H

#include "VPlan.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Type.h"

namespace llvm {

class VPRecipeBase;
class VPlan;
class TargetTransformInfo;
class InstructionCost;

struct VPCostContext;

// Collect a VPlan's ephemeral recipes (those used only by an assume).
void collectEphemeralRecipesForVPlan(VPlan &Plan,
                                     DenseSet<VPRecipeBase *> &EphRecipes);

/// A struct that represents some properties of the register usage
/// of a loop.
struct VPRegisterUsage {
  /// Holds the number of loop invariant values that are used in the loop.
  /// The key is ClassID of target-provided register class.
  SmallMapVector<unsigned, unsigned, 4> LoopInvariantRegs;
  /// Holds the maximum number of concurrent live intervals in the loop.
  /// The key is ClassID of target-provided register class.
  SmallMapVector<unsigned, unsigned, 4> MaxLocalUsers;

  /// Calculate the estimated cost of any spills due to using more registers
  /// than the number available for the target. If non-zero, OverrideMaxNumRegs
  /// is used in place of the target's number of registers.
  InstructionCost spillCost(const TargetTransformInfo &TTI,
                            TargetTransformInfo::TargetCostKind CostKind,
                            unsigned OverrideMaxNumRegs = 0) const;
};

/// Estimate the register usage for \p Plan and vectorization factors in \p VFs
/// by calculating the highest number of values that are live at a single
/// location as a rough estimate. Returns the register usage for each VF in \p
/// VFs.
SmallVector<VPRegisterUsage, 8> calculateRegisterUsageForPlan(
    VPlan &Plan, ArrayRef<ElementCount> VFs, const TargetTransformInfo &TTI,
    const SmallPtrSetImpl<const Value *> &ValuesToIgnore);

} // end namespace llvm

#endif // LLVM_TRANSFORMS_VECTORIZE_VPLANANALYSIS_H