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36 #ifndef GMX_NBNXM_PAIRLIST_H
37 #define GMX_NBNXM_PAIRLIST_H
41 #include "gromacs/gpu_utils/hostallocator.h"
42 #include "gromacs/math/vectypes.h"
43 #include "gromacs/mdtypes/nblist.h"
44 #include "gromacs/utility/basedefinitions.h"
45 #include "gromacs/utility/defaultinitializationallocator.h"
46 #include "gromacs/utility/enumerationhelpers.h"
47 #include "gromacs/utility/real.h"
49 // This file with constants is separate from this file to be able
50 // to include it during OpenCL jitting without including config.h
51 #include "constants.h"
53 #include "pairlistparams.h"
55 struct NbnxnPairlistCpuWork;
56 struct NbnxnPairlistGpuWork;
59 /* Convenience type for vector with aligned memory */
61 using AlignedVector = std::vector < T, gmx::AlignedAllocator < T>>;
63 /* Convenience type for vector that avoids initialization at resize() */
65 using FastVector = std::vector < T, gmx::DefaultInitializationAllocator < T>>;
67 /* A buffer data structure of 64 bytes
68 * to be placed at the beginning and end of structs
69 * to avoid cache invalidation of the real contents
70 * of the struct by writes to neighboring memory.
74 } gmx_cache_protect_t;
76 /* This is the actual cluster-pair list j-entry.
77 * cj is the j-cluster.
78 * The interaction bits in excl are indexed i-major, j-minor.
79 * The cj entries are sorted such that ones with exclusions come first.
80 * This means that once a full mask (=NBNXN_INTERACTION_MASK_ALL)
81 * is found, all subsequent j-entries in the i-entry also have full masks.
85 int cj; /* The j-cluster */
86 unsigned int excl; /* The exclusion (interaction) bits */
89 /* In nbnxn_ci_t the integer shift contains the shift in the lower 7 bits.
90 * The upper bits contain information for non-bonded kernel optimization.
91 * Simply calculating LJ and Coulomb for all pairs in a cluster pair is fine.
92 * But three flags can be used to skip interactions, currently only for subc=0
93 * !(shift & NBNXN_CI_DO_LJ(subc)) => we can skip LJ for all pairs
94 * shift & NBNXN_CI_HALF_LJ(subc) => we can skip LJ for the second half of i
95 * !(shift & NBNXN_CI_DO_COUL(subc)) => we can skip Coulomb for all pairs
97 #define NBNXN_CI_SHIFT 127
98 #define NBNXN_CI_DO_LJ(subc) (1<<(7+3*(subc)))
99 #define NBNXN_CI_HALF_LJ(subc) (1<<(8+3*(subc)))
100 #define NBNXN_CI_DO_COUL(subc) (1<<(9+3*(subc)))
102 /* Cluster-pair Interaction masks
103 * Bit i*j-cluster-size + j tells if atom i and j interact.
105 // TODO: Rename according to convention when moving into Nbnxn namespace
106 /* All interaction mask is the same for all kernels */
107 constexpr unsigned int NBNXN_INTERACTION_MASK_ALL = 0xffffffffU;
108 /* 4x4 kernel diagonal mask */
109 constexpr unsigned int NBNXN_INTERACTION_MASK_DIAG = 0x08ceU;
110 /* 4x2 kernel diagonal masks */
111 constexpr unsigned int NBNXN_INTERACTION_MASK_DIAG_J2_0 = 0x0002U;
112 constexpr unsigned int NBNXN_INTERACTION_MASK_DIAG_J2_1 = 0x002fU;
113 /* 4x8 kernel diagonal masks */
114 constexpr unsigned int NBNXN_INTERACTION_MASK_DIAG_J8_0 = 0xf0f8fcfeU;
115 constexpr unsigned int NBNXN_INTERACTION_MASK_DIAG_J8_1 = 0x0080c0e0U;
117 /* Simple pair-list i-unit */
120 int ci; /* i-cluster */
121 int shift; /* Shift vector index plus possible flags, see above */
122 int cj_ind_start; /* Start index into cj */
123 int cj_ind_end; /* End index into cj */
126 /* Grouped pair-list i-unit */
128 /* Returns the number of j-cluster groups in this entry */
129 int numJClusterGroups() const
131 return cj4_ind_end - cj4_ind_start;
134 int sci; /* i-super-cluster */
135 int shift; /* Shift vector index plus possible flags */
136 int cj4_ind_start; /* Start index into cj4 */
137 int cj4_ind_end; /* End index into cj4 */
140 /* Interaction data for a j-group for one warp */
143 // The i-cluster interactions mask for 1 warp
144 unsigned int imask = 0U;
145 // Index into the exclusion array for 1 warp, default index 0 which means no exclusions
150 int cj[c_nbnxnGpuJgroupSize]; /* The 4 j-clusters */
151 nbnxn_im_ei_t imei[c_nbnxnGpuClusterpairSplit]; /* The i-cluster mask data for 2 warps */
154 /* Struct for storing the atom-pair interaction bits for a cluster pair in a GPU pairlist */
157 /* Constructor, sets no exclusions, so all atom pairs interacting */
160 for (unsigned int &pairEntry : pair)
162 pairEntry = NBNXN_INTERACTION_MASK_ALL;
166 /* Topology exclusion interaction bits per warp */
167 unsigned int pair[c_nbnxnGpuExclSize];
170 /* Cluster pairlist type for use on CPUs */
171 struct NbnxnPairlistCpu
175 gmx_cache_protect_t cp0;
177 int na_ci; /* The number of atoms per i-cluster */
178 int na_cj; /* The number of atoms per j-cluster */
179 real rlist; /* The radius for constructing the list */
180 FastVector<nbnxn_ci_t> ci; /* The i-cluster list */
181 FastVector<nbnxn_ci_t> ciOuter; /* The outer, unpruned i-cluster list */
183 FastVector<nbnxn_cj_t> cj; /* The j-cluster list, size ncj */
184 FastVector<nbnxn_cj_t> cjOuter; /* The outer, unpruned j-cluster list */
185 int ncjInUse; /* The number of j-clusters that are used by ci entries in this list, will be <= cj.size() */
187 int nci_tot; /* The total number of i clusters */
189 /* Working data storage for list construction */
190 std::unique_ptr<NbnxnPairlistCpuWork> work;
192 gmx_cache_protect_t cp1;
195 /* Cluster pairlist type, with extra hierarchies, for on the GPU
197 * NOTE: for better performance when combining lists over threads,
198 * all vectors should use default initialization. But when
199 * changing this, excl should be intialized when adding entries.
201 struct NbnxnPairlistGpu
205 * \param[in] pinningPolicy Sets the pinning policy for all buffers used on the GPU
207 NbnxnPairlistGpu(gmx::PinningPolicy pinningPolicy);
209 gmx_cache_protect_t cp0;
211 int na_ci; /* The number of atoms per i-cluster */
212 int na_cj; /* The number of atoms per j-cluster */
213 int na_sc; /* The number of atoms per super cluster */
214 real rlist; /* The radius for constructing the list */
215 // The i-super-cluster list, indexes into cj4;
216 gmx::HostVector<nbnxn_sci_t> sci;
217 // The list of 4*j-cluster groups
218 gmx::HostVector<nbnxn_cj4_t> cj4;
219 // Atom interaction bits (non-exclusions)
220 gmx::HostVector<nbnxn_excl_t> excl;
221 // The total number of i-clusters
224 /* Working data storage for list construction */
225 std::unique_ptr<NbnxnPairlistGpuWork> work;
227 gmx_cache_protect_t cp1;
230 //! Initializes a free-energy pair-list
231 void nbnxn_init_pairlist_fep(t_nblist *nl);