src/gromacs/gmxlib/nonbonded/nb_kernel.h

   1 /*
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   5  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
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  35 #ifndef _nb_kernel_h_
  36 #define _nb_kernel_h_
  37
  38 #include "gromacs/legacyheaders/types/forcerec.h"
  39 #include "gromacs/legacyheaders/types/mdatom.h"
  40 #include "gromacs/legacyheaders/types/nblist.h"
  41 #include "gromacs/legacyheaders/types/nrnb.h"
  42 #include "gromacs/math/vectypes.h"
  43 #include "gromacs/topology/block.h"
  44 #include "gromacs/utility/real.h"
  45
  46 #ifdef __cplusplus
  47 extern "C" {
  48 #endif
  49 #if 0
  50 } /* fixes auto-indentation problems */
  51 #endif
  52
  53 /* Structure to collect kernel data not available in forcerec or mdatoms structures.
  54  * This is only used inside the nonbonded module.
  55  */
  56 typedef struct
  57 {
  58     int                flags;
  59     t_blocka *         exclusions;
  60     real *             lambda;
  61     real *             dvdl;
  62
  63     /* pointers to tables */
  64     t_forcetable *     table_elec;
  65     t_forcetable *     table_vdw;
  66     t_forcetable *     table_elec_vdw;
  67
  68     /* potentials */
  69     real *             energygrp_elec;
  70     real *             energygrp_vdw;
  71     real *             energygrp_polarization;
  72 }
  73 nb_kernel_data_t;
  74
  75
  76 typedef void
  77     nb_kernel_t (t_nblist *                nlist,
  78                  rvec *                    x,
  79                  rvec *                    f,
  80                  t_forcerec *              fr,
  81                  t_mdatoms *               mdatoms,
  82                  nb_kernel_data_t *        kernel_data,
  83                  t_nrnb *                  nrnb);
  84
  85
  86 /* Structure with a kernel pointer and settings. This cannot be abstract
  87  * since we define the kernel list statically for each architecture in a header,
  88  * and use it to set up the kernel hash functions to find kernels.
  89  *
  90  * The electrostatics/vdw names should be obvious and correspond to the
  91  * forms of the interactions calculated in this function, and the interaction
  92  * modifiers describe switch/shift and similar alterations. Geometry refers
  93  * to whether this kernel calculates interactions between single particles or
  94  * waters (groups of 3/4 atoms) for better performance. Finally, the VF string
  95  * selects whether the kernel calculates only potential, only force, or both
  96  *
  97  * The allowed values for kernel interactions are described by the
  98  * enumerated types gmx_nbkernel_elec and gmx_nbkernel_vdw (see types/enums.h).
  99  * Note that these are deliberately NOT identical to the interactions the
 100  * user can set, since some user-specified interactions will be tabulated, and
 101  * Lennard-Jones and Buckingham use different kernels while their setting in
 102  * the input is decided by nonbonded parameter formats rather than mdp options.
 103  *
 104  * The interaction modifiers are described by the eintmod enum type, while
 105  * the kernel geometry is decided from the neighborlist geometry, which is
 106  * described by the enum gmx_nblist_kernel_geometry (again, see types/enums.h).
 107  * The
 108  *
 109  * Note that any particular implementation of kernels might not support all of
 110  * these strings. In fact, some might not be supported by any architecture yet.
 111  * The whole point of using strings and hashes is that we do not have to define a
 112  * unique set of strings in a single place. Thus, as long as you implement a
 113  * corresponding kernel, you could in theory provide any string you want.
 114  */
 115 typedef struct nb_kernel_info
 116 {
 117     nb_kernel_t *   kernelptr;
 118     const char *    kernelname;
 119     const char *    architecture;     /* e.g. "C", "SSE", "BlueGene", etc. */
 120
 121     const char *    electrostatics;
 122     const char *    electrostatics_modifier;
 123     const char *    vdw;
 124     const char *    vdw_modifier;
 125     const char *    geometry;
 126     const char *    other;  /* Any extra info you want/need to select a kernel */
 127     const char *    vf;     /* "PotentialAndForce", "Potential", or "Force" */
 128 }
 129 nb_kernel_info_t;
 130
 131
 132 void
 133 nb_kernel_list_add_kernels(nb_kernel_info_t *   new_kernelinfo,
 134                            int                  new_size);
 135
 136 int
 137 nb_kernel_list_hash_init(void);
 138
 139 /* Return a function pointer to the nonbonded kernel pointer with
 140  * settings according to the text strings provided. GROMACS does not guarantee
 141  * the existence of accelerated kernels for any combination, so the return value
 142  * can be NULL.
 143  * In that case, you can try a different/lower-level acceleration, and
 144  * eventually you need to prepare to fall back to generic kernels or change
 145  * your settings and try again.
 146  *
 147  * The names of the text strings are obviously meant to reflect settings in
 148  * GROMACS, but inside this routine they are merely used as a set of text
 149  * strings not defined here. The routine will simply compare the arguments with
 150  * the contents of the corresponding strings in the nb_kernel_list_t structure.
 151  *
 152  * This function does not check whether the kernel in question can run on the
 153  * present architecture since that would require a slow cpuid call for every
 154  * single invocation.
 155  */
 156 nb_kernel_t *
 157 nb_kernel_list_findkernel(FILE *              log,
 158                           const char *        architecture,
 159                           const char *        electrostatics,
 160                           const char *        electrostatics_modifier,
 161                           const char *        vdw,
 162                           const char *        vdw_modifier,
 163                           const char *        geometry,
 164                           const char *        other,
 165                           const char *        vf);
 166
 167
 168
 169 #ifdef __cplusplus
 170 }
 171 #endif
 172
 173 #endif /* _nb_kernel_h_ */