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37 #ifndef _nbnxn_kernel_simd_utils_h_
38 #define _nbnxn_kernel_simd_utils_h_
40 /*! \brief Provides hardware-specific utility routines for the SIMD kernels.
42 * Defines all functions, typedefs, constants and macros that have
43 * explicit dependencies on the j-cluster size, precision, or SIMD
44 * width. This includes handling diagonal, Newton and topology
47 * The functionality which depends on the j-cluster size is:
50 * energy group pair energy storage
53 #if !defined GMX_NBNXN_SIMD_2XNN && !defined GMX_NBNXN_SIMD_4XN
54 #error "Must define an NBNxN kernel flavour before including NBNxN kernel utility functions"
57 #ifdef GMX_SIMD_REFERENCE_PLAIN_C
59 /* Set the stride for the lookup of the two LJ parameters from their
61 * Note that currently only arrays with stride 2 and 4 are available.
62 * Since the reference code does not require alignment, we can always use 2.
64 static const int nbfp_stride = 2;
66 /* Align a stack-based thread-local working array. */
67 static gmx_inline int *
68 prepare_table_load_buffer(const int *array)
73 #include "nbnxn_kernel_simd_utils_ref.h"
75 #else /* GMX_SIMD_REFERENCE_PLAIN_C */
78 /* Include x86 SSE2 compatible SIMD functions */
80 /* Set the stride for the lookup of the two LJ parameters from their
81 * (padded) array. We use the minimum supported SIMD memory alignment.
83 #if defined GMX_DOUBLE
84 static const int nbfp_stride = 2;
86 static const int nbfp_stride = 4;
89 /* Align a stack-based thread-local working array. Table loads on
90 * full-width AVX_256 use the array, but other implementations do
92 static gmx_inline int *
93 prepare_table_load_buffer(const int *array)
95 #if defined GMX_X86_AVX_256 && !defined GMX_USE_HALF_WIDTH_SIMD_HERE
96 return gmx_simd_align_int(array);
102 #if defined GMX_X86_AVX_256 && !defined GMX_USE_HALF_WIDTH_SIMD_HERE
104 /* With full AVX-256 SIMD, half SIMD-width table loads are optimal */
105 #if GMX_SIMD_WIDTH_HERE == 8
110 Berk, 2xnn.c had the following code, but I think it is safe to remove now, given the code immediately above.
112 #if defined GMX_X86_AVX_256 && !defined GMX_DOUBLE
113 / * AVX-256 single precision 2x(4+4) kernel,
114 * we can do half SIMD-width aligned FDV0 table loads.
121 #include "nbnxn_kernel_simd_utils_x86_256d.h"
122 #else /* GMX_DOUBLE */
123 #include "nbnxn_kernel_simd_utils_x86_256s.h"
124 #endif /* GMX_DOUBLE */
126 #else /* defined GMX_X86_AVX_256 && !defined GMX_USE_HALF_WIDTH_SIMD_HERE */
128 /* We use the FDV0 table layout when we can use aligned table loads */
129 #if GMX_SIMD_WIDTH_HERE == 4
134 #include "nbnxn_kernel_simd_utils_x86_128d.h"
135 #else /* GMX_DOUBLE */
136 #include "nbnxn_kernel_simd_utils_x86_128s.h"
137 #endif /* GMX_DOUBLE */
139 #endif /* defined GMX_X86_AVX_256 && !defined GMX_USE_HALF_WIDTH_SIMD_HERE */
141 #else /* GMX_X86_SSE2 */
143 #if GMX_SIMD_WIDTH_HERE > 4
144 static const int nbfp_stride = 4;
146 static const int nbfp_stride = GMX_SIMD_WIDTH_HERE;
149 #endif /* GMX_X86_SSE2 */
150 #endif /* GMX_SIMD_REFERENCE_PLAIN_C */
154 /* Add energy register to possibly multiple terms in the energy array */
155 static inline void add_ener_grp(gmx_mm_pr e_S, real *v, const int *offset_jj)
159 /* We need to balance the number of store operations with
160 * the rapidly increases number of combinations of energy groups.
161 * We add to a temporary buffer for 1 i-group vs 2 j-groups.
163 for (jj = 0; jj < (UNROLLJ/2); jj++)
167 v_S = gmx_load_pr(v+offset_jj[jj]+jj*GMX_SIMD_WIDTH_HERE);
168 gmx_store_pr(v+offset_jj[jj]+jj*GMX_SIMD_WIDTH_HERE, gmx_add_pr(v_S, e_S));
173 #if defined GMX_NBNXN_SIMD_2XNN && defined UNROLLJ
174 /* As add_ener_grp, but for two groups of UNROLLJ/2 stored in
175 * a single SIMD register.
178 add_ener_grp_halves(gmx_mm_pr e_S, real *v0, real *v1, const int *offset_jj)
180 gmx_mm_hpr e_S0, e_S1;
183 gmx_pr_to_2hpr(e_S, &e_S0, &e_S1);
185 for (jj = 0; jj < (UNROLLJ/2); jj++)
189 gmx_load_hpr(&v_S, v0+offset_jj[jj]+jj*GMX_SIMD_WIDTH_HERE/2);
190 gmx_store_hpr(v0+offset_jj[jj]+jj*GMX_SIMD_WIDTH_HERE/2, gmx_add_hpr(v_S, e_S0));
192 for (jj = 0; jj < (UNROLLJ/2); jj++)
196 gmx_load_hpr(&v_S, v1+offset_jj[jj]+jj*GMX_SIMD_WIDTH_HERE/2);
197 gmx_store_hpr(v1+offset_jj[jj]+jj*GMX_SIMD_WIDTH_HERE/2, gmx_add_hpr(v_S, e_S1));
202 #endif /* _nbnxn_kernel_simd_utils_h_ */