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38 * \brief Declares the grid and bounding box objects
40 * \author Berk Hess <hess@kth.se>
42 * \ingroup module_nbnxm
45 #ifndef GMX_NBNXM_GRID_H
46 #define GMX_NBNXM_GRID_H
51 #include "gromacs/math/vectypes.h"
52 #include "gromacs/simd/simd.h"
53 #include "gromacs/utility/alignedallocator.h"
56 struct gmx_domdec_zones_t;
61 /* Pair search box lower and upper corner in x,y,z.
62 * Store this in 4 iso 3 reals, which is useful with 4-wide SIMD.
63 * To avoid complicating the code we also use 4 without 4-wide SIMD.
66 /* Pair search box lower and upper bound in z only. */
68 /* Pair search box lower and upper corner x,y,z indices, entry 3 is unused */
76 /* Bounding box for a nbnxn atom cluster */
78 float lower[NNBSBB_C];
79 float upper[NNBSBB_C];
85 /* Bounding box calculations are (currently) always in single precision, so
86 * we only need to check for single precision support here.
87 * This uses less (cache-)memory and SIMD is faster, at least on x86.
89 #if GMX_SIMD4_HAVE_FLOAT
90 # define NBNXN_SEARCH_BB_SIMD4 1
91 /* Memory alignment in bytes as required by SIMD aligned loads/stores */
92 # define NBNXN_SEARCH_BB_MEM_ALIGN (GMX_SIMD4_WIDTH*sizeof(float))
94 # define NBNXN_SEARCH_BB_SIMD4 0
95 /* No alignment required, but set it so we can call the same routines */
96 # define NBNXN_SEARCH_BB_MEM_ALIGN 32
100 #if NBNXN_SEARCH_BB_SIMD4
101 /* Always use 4-wide SIMD for bounding box calculations */
104 /* Single precision BBs + coordinates, we can also load coordinates with SIMD */
105 # define NBNXN_SEARCH_SIMD4_FLOAT_X_BB 1
107 # define NBNXN_SEARCH_SIMD4_FLOAT_X_BB 0
110 /* The packed bounding box coordinate stride is always set to 4.
111 * With AVX we could use 8, but that turns out not to be faster.
113 # define STRIDE_PBB GMX_SIMD4_WIDTH
114 # define STRIDE_PBB_2LOG 2
116 /* Store bounding boxes corners as quadruplets: xxxxyyyyzzzz */
117 # define NBNXN_BBXXXX 1
118 /* Size of bounding box corners quadruplet */
119 # define NNBSBB_XXXX (NNBSBB_D*DIM*STRIDE_PBB)
121 #else /* NBNXN_SEARCH_BB_SIMD4 */
123 # define NBNXN_SEARCH_SIMD4_FLOAT_X_BB 0
124 # define NBNXN_BBXXXX 0
126 #endif /* NBNXN_SEARCH_BB_SIMD4 */
131 /* A pair-search grid struct for one domain decomposition zone
133 * Note that when atom groups, instead of individual atoms, are assigned
134 * to grid cells, individual atoms can be geometrically outside the cell
135 * and grid that they have been assigned to (as determined by the center
136 * or geometry of the atom group they belong to).
140 rvec c0; /* The lower corner of the (local) grid */
141 rvec c1; /* The upper corner of the (local) grid */
142 rvec size; /* c1 - c0 */
143 real atom_density; /* The atom number density for the local grid */
144 real maxAtomGroupRadius; /* The maximum distance an atom can be outside
145 * of a cell and outside of the grid
148 gmx_bool bSimple; /* Is this grid simple or super/sub */
149 int na_c; /* Number of atoms per cluster */
150 int na_cj; /* Number of atoms for list j-clusters */
151 int na_sc; /* Number of atoms per super-cluster */
152 int na_c_2log; /* 2log of na_c */
154 int numCells[DIM - 1]; /* Number of cells along x/y */
155 int nc; /* Total number of cells */
157 real cellSize[DIM - 1]; /* size of a cell */
158 real invCellSize[DIM - 1]; /* 1/cellSize */
160 int cell0; /* Index in nbs->cell corresponding to cell 0 */
163 std::vector<int> cxy_na; /* The number of atoms for each column in x,y */
164 std::vector<int> cxy_ind; /* Grid (super)cell index, offset from cell0 */
166 std::vector<int> nsubc; /* The number of sub cells for each super cell */
169 std::vector<float> bbcz; /* Bounding boxes in z for the cells */
170 std::vector < nbnxn_bb_t, gmx::AlignedAllocator < nbnxn_bb_t>> bb; /* 3D bounding boxes for the sub cells */
171 std::vector < nbnxn_bb_t, gmx::AlignedAllocator < nbnxn_bb_t>> bbjStorage; /* 3D j-bounding boxes for the case where
172 * the i- and j-cluster sizes are different */
173 gmx::ArrayRef<nbnxn_bb_t> bbj; /* 3D j-bounding boxes */
174 std::vector < float, gmx::AlignedAllocator < float>> pbb; /* 3D b. boxes in xxxx format per super cell */
176 /* Bit-flag information */
177 std::vector<int> flags; /* Flags for properties of clusters in each cell */
178 std::vector<unsigned int> fep; /* FEP signal bits for atoms in each cluster */
181 int nsubc_tot; /* Total number of subcell, used for printing */