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39 #ifndef _nbnxn_consts_h
40 #define _nbnxn_consts_h
47 /* The number of pair-search sub-cells per super-cell, used for GPU */
48 #define GPU_NSUBCELL_Z 2
49 #define GPU_NSUBCELL_Y 2
50 #define GPU_NSUBCELL_X 2
51 #define GPU_NSUBCELL (GPU_NSUBCELL_Z*GPU_NSUBCELL_Y*GPU_NSUBCELL_X)
52 /* In the non-bonded GPU kernel we operate on cluster-pairs, not cells.
53 * The number of cluster in a super-cluster matches the number of sub-cells
54 * in a pair-search cell, so we introduce a new name for the same value.
56 #define NBNXN_GPU_NCLUSTER_PER_SUPERCLUSTER GPU_NSUBCELL
58 /* With CPU kernels the i-cluster size is always 4 atoms.
59 * With x86 SIMD the j-cluster size can be 2, 4 or 8, otherwise 4.
61 #define NBNXN_CPU_CLUSTER_I_SIZE 4
63 #define NBNXN_CPU_CLUSTER_I_SIZE_2LOG 2
65 /* With GPU kernels the cluster size is 8 atoms */
66 #define NBNXN_GPU_CLUSTER_SIZE 8
68 /* With GPU kernels we group cluster pairs in 4 to optimize memory usage.
69 * To change this, also change nbnxn_cj4_t in include/types/nbnxn_pairlist.h.
71 #define NBNXN_GPU_JGROUP_SIZE 4
72 #define NBNXN_GPU_JGROUP_SIZE_2LOG 2
74 /* To avoid NaN when excluded atoms are at zero distance, we add a small
75 * number to r^2. NBNXN_AVOID_SING_R2_INC^-3 should fit in real.
78 #define NBNXN_AVOID_SING_R2_INC 1.0e-12f
80 /* The double prec. x86 SIMD kernels use a single prec. invsqrt, so > 1e-38 */
81 #define NBNXN_AVOID_SING_R2_INC 1.0e-36
84 /* Coulomb force table size chosen such that it fits along the non-bonded
85 parameters in the texture cache. */
86 #define GPU_EWALD_COULOMB_FORCE_TABLE_SIZE 1536
89 /* Strides for x/f with xyz and xyzq coordinate (and charge) storage */
92 /* Size of packs of x, y or z with SSE/AVX packed coords/forces */
95 /* Strides for a pack of 4 and 8 coordinates/forces */
96 #define STRIDE_P4 (DIM*PACK_X4)
97 #define STRIDE_P8 (DIM*PACK_X8)
99 /* Index of atom a into the SSE/AVX coordinate/force array */
100 #define X4_IND_A(a) (STRIDE_P4*((a) >> 2) + ((a) & (PACK_X4 - 1)))
101 #define X8_IND_A(a) (STRIDE_P8*((a) >> 3) + ((a) & (PACK_X8 - 1)))