remove references to -DLAMMPS_SMALLSMALL and trigger error when used

cmake/CMakeLists.txt

@@ -431,8 +431,8 @@ else()
   target_link_libraries(lammps PUBLIC mpi_stubs)
 endif()
 
-set(LAMMPS_SIZES "smallbig" CACHE STRING "LAMMPS integer sizes (smallsmall: all 32-bit, smallbig: 64-bit #atoms #timesteps, bigbig: also 64-bit imageint, 64-bit atom ids)")
+set(LAMMPS_SIZES "smallbig" CACHE STRING "LAMMPS integer sizes (smallbig: 64-bit #atoms #timesteps, bigbig: also 64-bit imageint, 64-bit atom ids)")
-set(LAMMPS_SIZES_VALUES smallbig bigbig smallsmall)
+set(LAMMPS_SIZES_VALUES smallbig bigbig)
 set_property(CACHE LAMMPS_SIZES PROPERTY STRINGS ${LAMMPS_SIZES_VALUES})
 validate_option(LAMMPS_SIZES LAMMPS_SIZES_VALUES)
 string(TOUPPER ${LAMMPS_SIZES} LAMMPS_SIZES)

cmake/Modules/LAMMPSInterfacePlugin.cmake

@@ -260,8 +260,8 @@ endif()
 
 ################
 # integer size selection
-set(LAMMPS_SIZES "smallbig" CACHE STRING "LAMMPS integer sizes (smallsmall: all 32-bit, smallbig: 64-bit #atoms #timesteps, bigbig: also 64-bit imageint, 64-bit atom ids)")
+set(LAMMPS_SIZES "smallbig" CACHE STRING "LAMMPS integer sizes (smallbig: 64-bit #atoms #timesteps, bigbig: also 64-bit imageint, 64-bit atom ids)")
-set(LAMMPS_SIZES_VALUES smallbig bigbig smallsmall)
+set(LAMMPS_SIZES_VALUES smallbig bigbig)
 set_property(CACHE LAMMPS_SIZES PROPERTY STRINGS ${LAMMPS_SIZES_VALUES})
 validate_option(LAMMPS_SIZES LAMMPS_SIZES_VALUES)
 string(TOUPPER ${LAMMPS_SIZES} LAMMPS_SIZES)

doc/src/Build_extras.rst

@@ -255,11 +255,10 @@ Traditional make
 
 Before building LAMMPS, you must build the GPU library in ``lib/gpu``\ .
 You can do this manually if you prefer; follow the instructions in
-``lib/gpu/README``.  Note that the GPU library uses MPI calls, so you must
+``lib/gpu/README``.  Note that the GPU library uses MPI calls, so you
-use the same MPI library (or the STUBS library) settings as the main
+must use the same MPI library (or the STUBS library) settings as the
-LAMMPS code.  This also applies to the ``-DLAMMPS_BIGBIG``\ ,
+main LAMMPS code.  This also applies to the ``-DLAMMPS_BIGBIG`` or
-``-DLAMMPS_SMALLBIG``\ , or ``-DLAMMPS_SMALLSMALL`` settings in whichever
+``-DLAMMPS_SMALLBIG`` settings in whichever Makefile you use.
-Makefile you use.
 
 You can also build the library in one step from the ``lammps/src`` dir,
 using a command like these, which simply invokes the ``lib/gpu/Install.py``

doc/src/Build_settings.rst

@@ -315,7 +315,7 @@ large counters can become before "rolling over".  The default setting of
 
       .. code-block:: bash
 
-         -D LAMMPS_SIZES=value   # smallbig (default) or bigbig or smallsmall
+         -D LAMMPS_SIZES=value   # smallbig (default) or bigbig
 
       If the variable is not set explicitly, "smallbig" is used.
 
@@ -326,7 +326,7 @@ large counters can become before "rolling over".  The default setting of
 
       .. code-block:: make
 
-         LMP_INC = -DLAMMPS_SMALLBIG    # or -DLAMMPS_BIGBIG or -DLAMMPS_SMALLSMALL
+         LMP_INC = -DLAMMPS_SMALLBIG    # or -DLAMMPS_BIGBIG
 
       The default setting is ``-DLAMMPS_SMALLBIG`` if nothing is specified
 
@@ -335,34 +335,27 @@ LAMMPS system size restrictions
 
 .. list-table::
    :header-rows: 1
-   :widths: 18 27 28 27
+   :widths: 27 36 37
    :align: center
 
    * -
      - smallbig
      - bigbig
-     - smallsmall
    * - Total atom count
      - :math:`2^{63}` atoms (= :math:`9.223 \cdot 10^{18}`)
      - :math:`2^{63}` atoms (= :math:`9.223 \cdot 10^{18}`)
-     - :math:`2^{31}` atoms (= :math:`2.147 \cdot 10^9`)
    * - Total timesteps
      - :math:`2^{63}` steps (= :math:`9.223 \cdot 10^{18}`)
      - :math:`2^{63}` steps (= :math:`9.223 \cdot 10^{18}`)
-     - :math:`2^{31}` steps (= :math:`2.147 \cdot 10^9`)
    * - Atom ID values
      - :math:`1 \le i \le 2^{31} (= 2.147 \cdot 10^9)`
      - :math:`1 \le i \le 2^{63} (= 9.223 \cdot 10^{18})`
-     - :math:`1 \le i \le 2^{31} (= 2.147 \cdot 10^9)`
    * - Image flag values
      - :math:`-512 \le i \le 511`
      - :math:`- 1\,048\,576 \le i \le 1\,048\,575`
-     - :math:`-512 \le i \le 511`
 
 The "bigbig" setting increases the size of image flags and atom IDs over
-"smallbig" and the "smallsmall" setting is only needed if your machine
+the default "smallbig" setting.
-does not support 64-bit integers or incurs performance penalties when
-using them.
 
 These are limits for the core of the LAMMPS code, specific features or
 some styles may impose additional limits.  The :ref:`ATC

doc/src/Errors_messages.rst

@@ -6233,8 +6233,9 @@ Doc page with :doc:`WARNING messages <Errors_warnings>`
    Atom IDs must be positive integers.
 
 *One or more atom IDs is too big*
-   The limit on atom IDs is set by the SMALLBIG, BIGBIG, SMALLSMALL
+   The limit on atom IDs is set by the SMALLBIG, BIGBIG
-   setting in your LAMMPS build.  See the :doc:`Build settings <Build_settings>` page for more info.
+   setting in your LAMMPS build.  See the
+   :doc:`Build settings <Build_settings>` page for more info.
 
 *One or more atom IDs is zero*
    Either all atoms IDs must be zero or none of them.

doc/src/Fortran.rst

@@ -2773,8 +2773,7 @@ Procedures Bound to the :f:type:`lammps` Derived Type
         END SUBROUTINE external_callback
       END INTERFACE
 
-   where ``c_bigint`` is ``c_int`` if ``-DLAMMPS_SMALLSMALL`` was used and
+   where ``c_bigint`` is ``c_int64_t`` and ``c_tagint`` is ``c_int64_t`` if
-   ``c_int64_t`` otherwise; and ``c_tagint`` is ``c_int64_t`` if
    ``-DLAMMPS_BIGBIG`` was used and ``c_int`` otherwise.
 
    The argument *caller* to :f:subr:`set_fix_external_callback` is unlimited

doc/src/Library_add.rst

@@ -19,9 +19,9 @@ there are now a few requirements for including new changes or extensions.
     be added.
   - New features should also be implemented and documented not just
     for the C interface, but also the Python and Fortran interfaces.
-  - All additions should work and be compatible with ``-DLAMMPS_BIGBIG``,
+  - All additions should work and be compatible with
-    ``-DLAMMPS_SMALLBIG``, ``-DLAMMPS_SMALLSMALL`` as well as when
+    ``-DLAMMPS_BIGBIG``, ``-DLAMMPS_SMALLBIG`` as well as when compiling
-    compiling with and without MPI support.
+    with and without MPI support.
   - The ``library.h`` file should be kept compatible to C code at
     a level similar to C89. Its interfaces may not reference any
     custom data types (e.g. ``bigint``, ``tagint``, and so on) that

fortran/lammps.f90

@@ -334,14 +334,6 @@ MODULE LIBLAMMPS
 
   ! Interface templates for fix external callbacks
   ABSTRACT INTERFACE
-    SUBROUTINE external_callback_smallsmall(caller, timestep, ids, x, fexternal)
-      IMPORT :: c_int, c_double
-      CLASS(*), INTENT(INOUT) :: caller
-      INTEGER(c_int), INTENT(IN) :: timestep
-      INTEGER(c_int), DIMENSION(:), INTENT(IN) :: ids
-      REAL(c_double), DIMENSION(:,:), INTENT(IN) :: x
-      REAL(c_double), DIMENSION(:,:), INTENT(OUT) :: fexternal
-    END SUBROUTINE external_callback_smallsmall
     SUBROUTINE external_callback_smallbig(caller, timestep, ids, x, fexternal)
       IMPORT :: c_int, c_double, c_int64_t
       CLASS(*), INTENT(INOUT) :: caller
@@ -363,8 +355,6 @@ MODULE LIBLAMMPS
   ! Derived type for fix external callback data
   TYPE fix_external_data
     CHARACTER(LEN=:), ALLOCATABLE :: id
-    PROCEDURE(external_callback_smallsmall), NOPASS, POINTER :: &
-      callback_smallsmall => NULL()
     PROCEDURE(external_callback_smallbig), NOPASS, POINTER :: &
       callback_smallbig => NULL()
     PROCEDURE(external_callback_bigbig), NOPASS, POINTER :: &
@@ -2262,7 +2252,7 @@ CONTAINS
     CALL lammps_free(Cname)
   END SUBROUTINE lmp_scatter_atoms_subset_double
 
-  ! equivalent function to lammps_gather_bonds (LAMMPS_SMALLSMALL or SMALLBIG)
+  ! equivalent function to lammps_gather_bonds (LAMMPS_SMALLBIG)
   SUBROUTINE lmp_gather_bonds_small(self, data)
     CLASS(lammps), INTENT(IN) :: self
     INTEGER(c_int), DIMENSION(:), ALLOCATABLE, TARGET, INTENT(OUT) :: data
@@ -2304,7 +2294,7 @@ CONTAINS
     CALL lammps_gather_bonds(self%handle, Cdata)
   END SUBROUTINE lmp_gather_bonds_big
 
-  ! equivalent function to lammps_gather_angles (LAMMPS_SMALLSMALL or SMALLBIG)
+  ! equivalent function to lammps_gather_angles (LAMMPS_SMALLBIG)
   SUBROUTINE lmp_gather_angles_small(self, data)
     CLASS(lammps), INTENT(IN) :: self
     INTEGER(c_int), DIMENSION(:), ALLOCATABLE, TARGET, INTENT(OUT) :: data
@@ -2346,7 +2336,7 @@ CONTAINS
     CALL lammps_gather_angles(self%handle, Cdata)
   END SUBROUTINE lmp_gather_angles_big
 
-  ! equivalent function to lammps_gather_dihedrals (LAMMPS_SMALLSMALL or SMALLBIG)
+  ! equivalent function to lammps_gather_dihedrals (LAMMPS_SMALLBIG)
   SUBROUTINE lmp_gather_dihedrals_small(self, data)
     CLASS(lammps), INTENT(IN) :: self
     INTEGER(c_int), DIMENSION(:), ALLOCATABLE, TARGET, INTENT(OUT) :: data
@@ -2388,7 +2378,7 @@ CONTAINS
     CALL lammps_gather_dihedrals(self%handle, Cdata)
   END SUBROUTINE lmp_gather_dihedrals_big
 
-  ! equivalent function to lammps_gather_impropers (LAMMPS_SMALLSMALL or SMALLBIG)
+  ! equivalent function to lammps_gather_impropers (LAMMPS_SMALLBIG)
   SUBROUTINE lmp_gather_impropers_small(self, data)
     CLASS(lammps), INTENT(IN) :: self
     INTEGER(c_int), DIMENSION(:), ALLOCATABLE, TARGET, INTENT(OUT) :: data
@@ -2763,7 +2753,7 @@ CONTAINS
     IF (tagint_size /= 4_c_int .AND. (PRESENT(id) .OR. PRESENT(image))) THEN
       CALL lmp_error(self, LMP_ERROR_ALL + LMP_ERROR_WORLD, &
         'Unable to create_atoms; your id/image array types are incompatible&
-        & with LAMMPS_SMALLBIG and LAMMPS_SMALLSMALL [Fortran/create_atoms]')
+        & with LAMMPS_SMALLBIG [Fortran/create_atoms]')
     END IF
     n = SIZE(type, KIND=c_int)
     IF (PRESENT(bexpand)) THEN
@@ -3360,7 +3350,7 @@ CONTAINS
     construct_fix_external_data%id = ' '
   END FUNCTION construct_fix_external_data
 
-  ! equivalent function to lammps_set_fix_external_callback for -DSMALLSMALL
+  ! equivalent function to lammps_set_fix_external_callback
   ! note that "caller" is wrapped into a fix_external_data derived type along
   ! with the fix id and the Fortran calling function.
   SUBROUTINE lmp_set_fix_external_callback(self, id, callback, caller)
@@ -3394,11 +3384,7 @@ CONTAINS
     ext_data(this_fix)%id = id
     ext_data(this_fix)%lammps_instance => self
 
-    IF (SIZE_TAGINT == 4_c_int .AND. SIZE_BIGINT == 4_c_int) THEN
+    IF (SIZE_TAGINT == 8_c_int .AND. SIZE_BIGINT == 8_c_int) THEN
-      ! -DSMALLSMALL
-      c_callback = C_FUNLOC(callback_wrapper_smallsmall)
-      CALL set_fix_external_callback_smallsmall(this_fix, callback)
-    ELSE IF (SIZE_TAGINT == 8_c_int .AND. SIZE_BIGINT == 8_c_int) THEN
       ! -DBIGBIG
       c_callback = C_FUNLOC(callback_wrapper_bigbig)
       CALL set_fix_external_callback_bigbig(this_fix, callback)
@@ -3420,12 +3406,6 @@ CONTAINS
   END SUBROUTINE lmp_set_fix_external_callback
 
   ! Wrappers to assign callback pointers with explicit interfaces
-  SUBROUTINE set_fix_external_callback_smallsmall(id, callback)
-    INTEGER, INTENT(IN) :: id
-    PROCEDURE(external_callback_smallsmall) :: callback
-
-    ext_data(id)%callback_smallsmall => callback
-  END SUBROUTINE set_fix_external_callback_smallsmall
 
   SUBROUTINE set_fix_external_callback_smallbig(id, callback)
     INTEGER, INTENT(IN) :: id
@@ -3450,9 +3430,7 @@ CONTAINS
     DO i = 1, SIZE(ext_data) - 1
       c_id = f2c_string(ext_data(i)%id)
       c_caller = C_LOC(ext_data(i))
-      IF (SIZE_TAGINT == 4_c_int .AND. SIZE_BIGINT == 4_c_int) THEN
+      IF (SIZE_TAGINT == 8_c_int .AND. SIZE_BIGINT == 8_c_int) THEN
-        c_callback = C_FUNLOC(callback_wrapper_smallsmall)
-      ELSE IF (SIZE_TAGINT == 8_c_int .AND. SIZE_BIGINT == 8_c_int) THEN
         c_callback = C_FUNLOC(callback_wrapper_bigbig)
       ELSE
         c_callback = C_FUNLOC(callback_wrapper_smallbig)
@@ -3464,34 +3442,6 @@ CONTAINS
   END SUBROUTINE rebind_external_callback_data
 
   ! companions to lmp_set_fix_external_callback to change interface
-  SUBROUTINE callback_wrapper_smallsmall(caller, timestep, nlocal, ids, x, &
-      fexternal) BIND(C)
-    TYPE(c_ptr), INTENT(IN), VALUE :: caller
-    INTEGER(c_int), INTENT(IN), VALUE :: timestep
-    INTEGER(c_int), INTENT(IN), VALUE :: nlocal
-    TYPE(c_ptr), INTENT(IN), VALUE :: ids, x, fexternal
-    TYPE(c_ptr), DIMENSION(:), POINTER :: x0, f0
-    INTEGER(c_int), DIMENSION(:), POINTER :: f_ids => NULL()
-    REAL(c_double), DIMENSION(:,:), POINTER :: f_x => NULL(), &
-        f_fexternal => NULL()
-    TYPE(fix_external_data), POINTER :: f_caller => NULL()
-
-    CALL C_F_POINTER(ids, f_ids, [nlocal])
-    CALL C_F_POINTER(x, x0, [nlocal])
-    CALL C_F_POINTER(x0(1), f_x, [3, nlocal])
-    CALL C_F_POINTER(fexternal, f0, [nlocal])
-    CALL C_F_POINTER(f0(1), f_fexternal, [3, nlocal])
-    IF (C_ASSOCIATED(caller)) THEN
-      CALL C_F_POINTER(caller, f_caller)
-      CALL f_caller%callback_smallsmall(f_caller%caller, timestep, f_ids, &
-        f_x, f_fexternal)
-    ELSE
-      CALL lmp_error(f_caller%lammps_instance, &
-        LMP_ERROR_ALL + LMP_ERROR_WORLD, &
-        'Got null pointer from "caller"; this should never happen;&
-        & please report a bug')
-    END IF
-  END SUBROUTINE callback_wrapper_smallsmall
 
   SUBROUTINE callback_wrapper_smallbig(caller, timestep, nlocal, ids, x, &
       fexternal) BIND(C)

src/info.cpp

@@ -304,8 +304,6 @@ void Info::command(int narg, char **arg)
     fputs("-DLAMMPS_BIGBIG\n",out);
 #elif defined(LAMMPS_SMALLBIG)
     fputs("-DLAMMPS_SMALLBIG\n",out);
-#else // defined(LAMMPS_SMALLSMALL)
-    fputs("-DLAMMPS_SMALLSMALL\n",out);
 #endif
     if (has_gzip_support()) utils::print(out,"\n{}\n",platform::compress_info());
 

src/lammps.cpp

@@ -688,11 +688,6 @@ LAMMPS::LAMMPS(int narg, char **arg, MPI_Comm communicator) :
       sizeof(tagint) != 8 || sizeof(bigint) != 8)
     error->all(FLERR,"Small to big integers are not sized correctly");
 #endif
-#ifdef LAMMPS_SMALLSMALL
-  if (sizeof(smallint) != 4 || sizeof(imageint) != 4 ||
-      sizeof(tagint) != 4 || sizeof(bigint) != 4)
-    error->all(FLERR,"Small to big integers are not sized correctly");
-#endif
 
   // create Kokkos class if KOKKOS installed, unless explicitly switched off
   // instantiation creates dummy Kokkos class if KOKKOS is not installed
@@ -1481,8 +1476,6 @@ void LAMMPS::print_config(FILE *fp)
   fputs("-DLAMMPS_BIGBIG\n",fp);
 #elif defined(LAMMPS_SMALLBIG)
   fputs("-DLAMMPS_SMALLBIG\n",fp);
-#else // defined(LAMMPS_SMALLSMALL)
-  fputs("-DLAMMPS_SMALLSMALL\n",fp);
 #endif
 
   utils::print(fp,"sizeof(smallint): {}-bit\n"

src/library.h

@@ -24,7 +24,7 @@
 /* We follow the behavior of regular LAMMPS compilation and assume
  * -DLAMMPS_SMALLBIG when no define is set. */
 
-#if !defined(LAMMPS_BIGBIG) && !defined(LAMMPS_SMALLBIG) && !defined(LAMMPS_SMALLSMALL)
+#if !defined(LAMMPS_BIGBIG) && !defined(LAMMPS_SMALLBIG)
 #define LAMMPS_SMALLBIG
 #endif
 

src/lmptype.h

@@ -80,10 +80,16 @@ static constexpr uint32_t MEMCPYMASK = (static_cast<uint32_t>(1) << 31) - 1U;
 
 // default to 32-bit smallint and other ints, 64-bit bigint
 
-#if !defined(LAMMPS_SMALLSMALL) && !defined(LAMMPS_BIGBIG) && !defined(LAMMPS_SMALLBIG)
+#if !defined(LAMMPS_BIGBIG) && !defined(LAMMPS_SMALLBIG)
 #define LAMMPS_SMALLBIG
 #endif
 
+// we no longer support LAMMPS_SMALLSMALL
+
+#if defined(LAMMPS_SMALLSMALL)
+#error LAMMPS no longer supports -DLAMMPS_SMALLSMALL
+#endif
+
 // allow user override of LONGLONG to LONG, necessary for some machines/MPI
 
 #ifdef LAMMPS_LONGLONG_TO_LONG
@@ -162,40 +168,6 @@ typedef int64_t bigint;
 
 #endif
 
-// for machines that do not support 64-bit ints
-// 32-bit smallint/imageint/tagint/bigint
-
-#ifdef LAMMPS_SMALLSMALL
-
-typedef int smallint;
-typedef int imageint;
-typedef int tagint;
-typedef int bigint;
-
-#define MAXSMALLINT INT_MAX
-#define MAXTAGINT INT_MAX
-#define MAXBIGINT INT_MAX
-#define MAXDOUBLEINT INT_MAX
-
-#define MPI_LMP_TAGINT MPI_INT
-#define MPI_LMP_IMAGEINT MPI_INT
-#define MPI_LMP_BIGINT MPI_INT
-
-#define TAGINT_FORMAT "%d"
-#define BIGINT_FORMAT "%d"
-
-#define LAMMPS_TAGINT LAMMPS_INT
-#define LAMMPS_TAGINT_2D LAMMPS_INT_2D
-#define LAMMPS_BIGINT LAMMPS_INT
-#define LAMMPS_BIGINT_2D LAMMPS_INT_2D
-
-#define IMGMASK 1023
-#define IMGMAX 512
-#define IMGBITS 10
-#define IMG2BITS 20
-
-#endif
-
 /** Data structure for packing 32-bit and 64-bit integers
  * into double (communication) buffers
  *