SimdItem.h

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// -*- tab-width: 2; indent-tabs-mode: nil; coding: utf-8-with-signature -*-
//-----------------------------------------------------------------------------
// Copyright 2000-2026 CEA (www.cea.fr) IFPEN (www.ifpenergiesnouvelles.com)
// See the top-level COPYRIGHT file for details.
// SPDX-License-Identifier: Apache-2.0
//-----------------------------------------------------------------------------
/*---------------------------------------------------------------------------*/
/* SimdItem.h                                                  (C) 2000-2025 */
/*                                                                           */
/* Types of entities and entity enumerators for vectorization.               */
/*---------------------------------------------------------------------------*/
#ifndef ARCANE_CORE_SIMDITEM_H
#define ARCANE_CORE_SIMDITEM_H
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
#include "arcane/utils/Simd.h"
 
// The ARCANE_SIMD_BENCH macro is only defined for the Simd
// Simd (in contribs/Simd) bench and prevents including entity management.
 
#ifndef ARCANE_SIMD_BENCH
#include "arcane/core/ItemEnumerator.h"
#endif
 
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/*!
 * \file SimdItem.h
 *
 * This file contains the type declarations for managing
 * vectorization with mesh entities (Item).
 */
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
namespace Arcane
{
 
template <typename ItemType>
class SimdItemEnumeratorT;
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
/*!
 * TODO:
 * - Create a version of SimdItem by vector size (2, 4, 8).
 * - Use a mask if possible.
 * - aligned SimdItemBase
 * - create a version of the SimdItemBase constructor without (nb_valid)
 * for the case where the vector is full.
 */
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
/*!
 * \ingroup ArcaneSimd
 * \brief Class managing a SIMD vector of entities.
 *
 * This class stores \a N mesh entities, where \a N depends
 * on the size of the SIMD registers and equals SimdInfo::Int32IndexSize.
 *
 * This class is not used directly. SimdItem or
 * SimdItemT must be used.
 */
class ARCANE_CORE_EXPORT SimdItemBase
{
 protected:
 
  typedef ItemInternal* ItemInternalPtr;
 
 public:
 
  typedef SimdInfo::SimdInt32IndexType SimdIndexType;
 
 public:
 
  /*!
   * \brief Constructs an instance.
   * \warning \a ids must have the required alignment for a SimdIndexType.
   */
  ARCANE_DEPRECATED_REASON("Y2022: Use another constructor")
  SimdItemBase(const ItemInternalPtr* items, const SimdIndexType* ids)
  : m_simd_local_ids(*ids)
  , m_shared_info(ItemInternalCompatibility::_getSharedInfo(items, 1))
  {}
 
 protected:
 
  SimdItemBase(ItemSharedInfo* shared_info, const SimdIndexType* ids)
  : m_simd_local_ids(*ids)
  , m_shared_info(shared_info)
  {}
 
 public:
 
  //! Internal part (for internal use only)
  ARCANE_DEPRECATED_REASON("Y2022: Use method SimdItem::item() instead")
  ItemInternal* item(Integer si) const { return m_shared_info->m_items_internal[localId(si)]; }
 
  ARCANE_DEPRECATED_REASON("Y2022: Use method SimdItem::operator[]() instead")
  ItemInternal* operator[](Integer si) const { return m_shared_info->m_items_internal[localId(si)]; }
 
  //! List of local IDs of the instance entities
  const SimdIndexType& ARCANE_RESTRICT simdLocalIds() const { return m_simd_local_ids; }
 
  //! List of local IDs of the instance entities
  const Int32* ARCANE_RESTRICT localIds() const { return (const Int32*)&m_simd_local_ids; }
 
  //! Local ID of the entity at index \a index.
  Int32 localId(Int32 index) const { return m_simd_local_ids[index]; }
 
 protected:
 
  SimdIndexType m_simd_local_ids;
  ItemSharedInfo* m_shared_info = ItemSharedInfo::nullInstance();
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
class SimdItemDirectBase
{
 protected:
 
  typedef ItemInternal* ItemInternalPtr;
 
 public:
 
  ARCANE_DEPRECATED_REASON("Y2022: Use another constructor")
  SimdItemDirectBase(const ItemInternalPtr* items, Int32 base_local_id, Integer nb_valid)
  : m_base_local_id(base_local_id)
  , m_nb_valid(nb_valid)
  , m_shared_info(ItemInternalCompatibility::_getSharedInfo(items, nb_valid))
  {}
 
 protected:
 
  SimdItemDirectBase(ItemSharedInfo* shared_info, Int32 base_local_id, Integer nb_valid)
  : m_base_local_id(base_local_id)
  , m_nb_valid(nb_valid)
  , m_shared_info(shared_info)
  {}
 
  // TEMPORARY to avoid deprecated
  SimdItemDirectBase(Int32 base_local_id, Integer nb_valid, const ItemInternalPtr* items)
  : m_base_local_id(base_local_id)
  , m_nb_valid(nb_valid)
  , m_shared_info(ItemInternalCompatibility::_getSharedInfo(items, nb_valid))
  {}
 
 public:
 
  //! Number of valid entities in the instance.
  inline Integer nbValid() const { return m_nb_valid; }
 
  //! List of local IDs of the instance entities
  inline Int32 baseLocalId() const { return m_base_local_id; }
 
 protected:
 
  Int32 m_base_local_id;
  Integer m_nb_valid;
  ItemSharedInfo* m_shared_info = ItemSharedInfo::nullInstance();
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
/*!
 * \brief Vector index with indirection for an entity type.
 * TODO: store the indices in a vector register to be able
 * to perform the gather quickly. For this, create the equivalent of AVXSimdReal
 * for Int32.
 */
template <typename ItemType>
class SimdItemIndexT
{
 public:
 
  typedef SimdInfo::SimdInt32IndexType SimdIndexType;
 
 public:
 
  SimdItemIndexT(const SimdIndexType& ARCANE_RESTRICT local_ids)
  : m_local_ids(local_ids)
  {}
  SimdItemIndexT(const SimdIndexType* ARCANE_RESTRICT local_ids)
  : m_local_ids(*local_ids)
  {}
 
 public:
 
  //! List of local IDs of the instance entities
  const SimdIndexType& ARCANE_RESTRICT simdLocalIds() const { return m_local_ids; }
 
 private:
 
  const SimdIndexType& ARCANE_RESTRICT m_local_ids;
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
/*!
 * \brief Vector index without indirection for an entity type
 */
template <typename ItemType>
class SimdItemDirectIndexT
{
 public:
 
  SimdItemDirectIndexT(Int32 base_local_id)
  : m_base_local_id(base_local_id)
  {}
 
 public:
 
  inline Int32 baseLocalId() const { return m_base_local_id; }
 
 private:
 
  Int32 m_base_local_id;
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
/*!
 * \ingroup ArcaneSimd
 * \brief Manages a vector of \a Item entities.
 */
class SimdItem
: public SimdItemBase
{
 public:
 
  ARCANE_DEPRECATED_REASON("Y2022: Use another constructor")
  SimdItem(const ItemInternalPtr* items, const SimdInfo::SimdInt32IndexType* ids)
  : SimdItemBase(ItemInternalCompatibility::_getSharedInfo(items, 1), ids)
  {}
 
 protected:
 
  SimdItem(ItemSharedInfo* shared_info, const SimdInfo::SimdInt32IndexType* ids)
  : SimdItemBase(shared_info, ids)
  {}
 
 public:
 
  //! inline \a si-th entity of the instance
  inline Item item(Int32 si) const { return Item(localId(si), m_shared_info); }
 
  //! inline \a si-th entity of the instance
  inline Item operator[](Int32 si) const { return Item(localId(si), m_shared_info); }
};
 
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/*!
 * \ingroup ArcaneSimd
 * \brief Manages a vector of \a ItemType entities.
 */
template <typename ItemType>
class SimdItemT
: public SimdItem
{
  friend class SimdItemEnumeratorT<ItemType>;
 
 protected:
 
  typedef ItemInternal* ItemInternalPtr;
 
 public:
 
#if 0
  ARCANE_DEPRECATED_REASON("Y2022: Use another constructor")
  SimdItemT(const ItemInternalPtr* items,const SimdInfo::SimdInt32IndexType* ids)
  : SimdItem(items,ids) { }
#endif
 
 private:
 
  SimdItemT(ItemSharedInfo* shared_info, const SimdInfo::SimdInt32IndexType* ids)
  : SimdItem(shared_info, ids)
  {}
 
 public:
 
  //! Returns the \a si-th entity of the instance
  ItemType item(Integer si) const
  {
    return ItemType(localId(si), m_shared_info);
  }
 
  //! Returns the \a si-th entity of the instance
  ItemType operator[](Integer si) const
  {
    return ItemType(localId(si), m_shared_info);
  }
 
  operator SimdItemIndexT<ItemType>()
  {
    return SimdItemIndexT<ItemType>(this->simdLocalIds());
  }
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
/*!
 * \ingroup ArcaneSimd
 * \brief Manages a vector of \a ItemType entities.
 */
template <typename ItemType>
class SimdItemDirectT
: public SimdItemDirectBase
{
  friend class SimdItemEnumeratorT<ItemType>;
 
 protected:
 
  typedef ItemInternal* ItemInternalPtr;
 
 public:
 
  ARCANE_DEPRECATED_REASON("Y2022: Use another constructor")
  SimdItemDirectT(const ItemInternalPtr* items, Int32 base_local_id, Integer nb_valid)
  : SimdItemDirectBase(base_local_id, nb_valid, items)
  {}
 
 private:
 
  SimdItemDirectT(ItemSharedInfo* shared_info, Int32 base_local_id, Integer nb_valid)
  : SimdItemDirectBase(shared_info, base_local_id, nb_valid)
  {}
 
 public:
 
  operator SimdItemDirectIndexT<ItemType>()
  {
    return SimdItemDirectIndexT<ItemType>(this->m_base_local_id);
  }
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
/*!
 * \internal
 * \ingroup ArcaneSimd
 * \brief Object allowing positioning of values in a SIMD vector.
 */
template <typename DataType>
class SimdSetter
{
  typedef typename SimdTypeTraits<DataType>::SimdType SimdType;
 
 public:
 
  SimdSetter(DataType* ARCANE_RESTRICT _data,
             const SimdInfo::SimdInt32IndexType& ARCANE_RESTRICT _indexes)
  : idx(_indexes)
  , m_data(_data)
  {
  }
 
 public:
 
  void operator=(const SimdType& vr)
  {
    vr.set(m_data, idx);
  }
  void operator=(const DataType& v)
  {
    SimdType vr(v);
    vr.set(m_data, idx);
  }
 
 private:
 
  const SimdInfo::SimdInt32IndexType& ARCANE_RESTRICT idx;
  DataType* ARCANE_RESTRICT m_data;
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
/*!
 * \ingroup ArcaneSimd
 * \brief Object allowing positioning of values in a SIMD vector.
 */
template <typename DataType>
class SimdDirectSetter
{
  typedef typename SimdTypeTraits<DataType>::SimdType SimdType;
 
 public:
 
  SimdDirectSetter(DataType* ARCANE_RESTRICT _data)
  : m_data(_data)
  {}
 
 public:
 
  void operator=(const SimdType& vr)
  {
    vr.set(m_data);
  }
 
 private:
 
  DataType* ARCANE_RESTRICT m_data;
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
/*---------------------------------------------------------------------------*/
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/*!
 * \ingroup ArcaneSimd
 * \brief Base class for enumerators over vectorial entities (SimdItem).
 */
class ARCANE_CORE_EXPORT SimdItemEnumeratorBase
: public SimdEnumeratorBase
{
 protected:
 
  typedef ItemInternal* ItemInternalPtr;
 
 public:
 
  typedef SimdInfo::SimdInt32IndexType SimdIndexType;
 
 public:
 
  // TODO: Handle m_local_id_offset for this class
 
  // TODO: By end of 2024, make certain constructors internal to Arcane and deprecate others.
  // Do the same for derived classes
 
  SimdItemEnumeratorBase() = default;
 
  // TODO: Make internal to Arcane
  SimdItemEnumeratorBase(const ItemInternalVectorView& view)
  : SimdEnumeratorBase(view.localIds())
  , m_shared_info(view.m_shared_info)
  {}
  // TODO: Make internal to Arcane
  SimdItemEnumeratorBase(const ItemEnumerator& rhs)
  : SimdEnumeratorBase(rhs.m_view.m_local_ids, rhs.count())
  , m_shared_info(rhs.m_item.m_shared_info)
  {}
 
  // TODO: deprecate
  SimdItemEnumeratorBase(const ItemInternalPtr* items, const Int32* local_ids, Integer n)
  : SimdEnumeratorBase(local_ids, n)
  , m_shared_info(ItemInternalCompatibility::_getSharedInfo(items, n))
  {}
  // TODO: deprecate
  SimdItemEnumeratorBase(const ItemInternalArrayView& items, const Int32ConstArrayView& local_ids)
  : SimdEnumeratorBase(local_ids)
  , m_shared_info(ItemInternalCompatibility::_getSharedInfo(items.data(), local_ids.size()))
  {}
 
 public:
 
  // TODO: deprecate
  //! List of entities
  const ItemInternalPtr* unguardedItems() const { return m_shared_info->m_items_internal.data(); }
 
 protected:
 
  ItemSharedInfo* m_shared_info = ItemSharedInfo::nullInstance();
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
/*!
 * \ingroup ArcaneSimd
 * \brief Enumerator over a list of entities.
 */
template <typename ItemType>
class SimdItemEnumeratorT
: public SimdItemEnumeratorBase
{
 protected:
 
  typedef ItemInternal* ItemInternalPtr;
 
 public:
 
  typedef SimdItemT<ItemType> SimdItemType;
 
  SimdItemEnumeratorT()
  : SimdItemEnumeratorBase()
  {}
  SimdItemEnumeratorT(const ItemEnumerator& rhs)
  : SimdItemEnumeratorBase(rhs)
  {}
  SimdItemEnumeratorT(const ItemEnumeratorT<ItemType>& rhs)
  : SimdItemEnumeratorBase(rhs)
  {}
  SimdItemEnumeratorT(const ItemVectorViewT<ItemType>& rhs)
  : SimdItemEnumeratorBase(rhs)
  {}
 
  // TODO: deprecate
  SimdItemEnumeratorT(const ItemInternalPtr* items, const Int32* local_ids, Integer n)
  : SimdItemEnumeratorBase(items, local_ids, n)
  {}
  // TODO: deprecate
  SimdItemEnumeratorT(const ItemInternalArrayView& items, const Int32ConstArrayView& local_ids)
  : SimdItemEnumeratorBase(items, local_ids)
  {}
 
 public:
 
  SimdItemType operator*() const
  {
    return SimdItemType(m_shared_info, _currentSimdIndex());
  }
 
  SimdItemDirectT<ItemType> direct() const
  {
    return SimdItemDirectT<ItemType>(m_shared_info, m_index, nbValid());
  }
 
  operator SimdItemIndexT<ItemType>()
  {
    return SimdItemIndexT<ItemType>(_currentSimdIndex());
  }
 
#ifndef ARCANE_SIMD_BENCH
  inline ItemEnumeratorT<ItemType> enumerator() const
  {
    return ItemEnumeratorT<ItemType>(m_shared_info, Int32ConstArrayView(nbValid(), m_local_ids + m_index));
  }
#endif
 
 protected:
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
#ifndef ARCANE_SIMD_BENCH
/*!
 * \ingroup ArcaneSimd
 * \brief SIMD vector of \a Node.
 */
typedef SimdItemT<Node> SimdNode;
/*!
 * \ingroup ArcaneSimd
 * \brief SIMD vector of \a Edge.
 */
typedef SimdItemT<Edge> SimdEdge;
/*!
 * \ingroup ArcaneSimd
 * \brief SIMD vector of \a Face.
 */
typedef SimdItemT<Face> SimdFace;
/*!
 * \ingroup ArcaneSimd
 * \brief SIMD vector of \a Cell.
 */
typedef SimdItemT<Cell> SimdCell;
/*!
 * \ingroup ArcaneSimd
 * \brief SIMD vector of \a Particle.
 */
typedef SimdItemT<Particle> SimdParticle;
#else
/*!
 * \ingroup ArcaneSimd
 * \brief SIMD vector of \a Cell.
 */
typedef SimdItemT<Cell> SimdCell;
#endif
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
template <typename ItemType>
class SimdItemEnumeratorContainerTraits
{
 public:
 
  static SimdItemEnumeratorT<ItemType> getSimdEnumerator(const ItemGroupT<ItemType>& g)
  {
    return g._simdEnumerator();
  }
  // Create an iterator from an ItemVectorView. This view must have padding
  // equal to the vector size.
  static SimdItemEnumeratorT<ItemType> getSimdEnumerator(const ItemVectorViewT<ItemType>& g)
  {
    return g.enumerator();
  }
 
  // For compatibility with existing code
  // If we are here, it means that the type 'T' is not an Arcane type.
  // This call should eventually be forbidden (e.g., by end of 2025)
  template <typename T>
  static SimdItemEnumeratorT<ItemType> getSimdEnumerator(const T& g)
  {
    return g.enumerator();
  }
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
#define ENUMERATE_SIMD_(type, iname, view) \
  for (A_TRACE_ITEM_ENUMERATOR(SimdItemEnumeratorT<type>) iname(::Arcane::SimdItemEnumeratorContainerTraits<type>::getSimdEnumerator(view) A_TRACE_ENUMERATOR_WHERE); iname.hasNext(); ++iname)
 
// TODO: To be removed. Use ENUMERATE_SIMD_ instead
#define ENUMERATE_SIMD_GENERIC(type, iname, view) \
  ENUMERATE_SIMD_(type, iname, view)
 
/*!
 * \ingroup ArcaneSimd
 * \brief SIMD enumerator over a group or list of nodes.
 */
#define ENUMERATE_SIMD_NODE(name, group) ENUMERATE_SIMD_(::Arcane::Node, name, group)
 
/*!
 * \ingroup ArcaneSimd
 * \brief SIMD enumerator over a group or list of edges.
 */
#define ENUMERATE_SIMD_EDGE(name, group) ENUMERATE_SIMD_(::Arcane::Edge, name, group)
 
/*!
 * \ingroup ArcaneSimd
 * \brief SIMD enumerator over a group or list of faces.
 */
#define ENUMERATE_SIMD_FACE(name, group) ENUMERATE_SIMD_(::Arcane::Face, name, group)
 
/*!
 * \ingroup ArcaneSimd
 * \brief SIMD enumerator over a group or list of cells.
 */
#define ENUMERATE_SIMD_CELL(name, group) ENUMERATE_SIMD_(::Arcane::Cell, name, group)
 
/*!
 * \ingroup ArcaneSimd
 * \brief SIMD enumerator over a group or list of particles.
 */
#define ENUMERATE_SIMD_PARTICLE(name, group) ENUMERATE_SIMD_(::Arcane::Particle, name, group)
 
/*---------------------------------------------------------------------------*/
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} // End namespace Arcane
 
/*---------------------------------------------------------------------------*/
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#endif