Date: 2025-03-28T21:11:11+00:00

Actual source code: zutils.c

      1: #include <petsc/private/fortranimpl.h>

      3: /*MC
      4:    PetscFortranAddr - a variable type in Fortran that can hold a
      5:      regular C pointer.

      7:    Note:
      8:     Used, for example, as the file argument in `PetscFOpen()`

     10:    Level: beginner

     12: .seealso:  `PetscOffset`, `PetscInt`
     13: M*/
     14: /*MC
     15:    PetscOffset - a variable type in Fortran used with `VecGetArray()`
     16:      and `ISGetIndices()`

     18:    Level: beginner

     20: .seealso:  `PetscFortranAddr`, `PetscInt`
     21: M*/

     23: /*
     24:     This is code for translating PETSc memory addresses to integer offsets
     25:     for Fortran.
     26: */
     27: char *PETSC_NULL_CHARACTER_Fortran     = NULL;
     28: void *PETSC_NULL_INTEGER_Fortran       = NULL;
     29: void *PETSC_NULL_SCALAR_Fortran        = NULL;
     30: void *PETSC_NULL_DOUBLE_Fortran        = NULL;
     31: void *PETSC_NULL_REAL_Fortran          = NULL;
     32: void *PETSC_NULL_BOOL_Fortran          = NULL;
     33: void *PETSC_NULL_ENUM_Fortran          = NULL;
     34: void *PETSC_NULL_INTEGER_ARRAY_Fortran = NULL;
     35: void *PETSC_NULL_SCALAR_ARRAY_Fortran  = NULL;
     36: void *PETSC_NULL_REAL_ARRAY_Fortran    = NULL;

     38: EXTERN_C_BEGIN
     39: void (*PETSC_NULL_FUNCTION_Fortran)(void) = NULL;
     40: EXTERN_C_END
     41: void *PETSC_NULL_MPI_COMM_Fortran = NULL;

     43: size_t PetscIntAddressToFortran(const PetscInt *base, const PetscInt *addr)
     44: {
     45:   size_t tmp1 = (size_t)base, tmp2 = 0;
     46:   size_t tmp3 = (size_t)addr;
     47:   size_t itmp2;

     49: #if !defined(PETSC_HAVE_CRAY90_POINTER)
     50:   if (tmp3 > tmp1) {
     51:     tmp2  = (tmp3 - tmp1) / sizeof(PetscInt);
     52:     itmp2 = (size_t)tmp2;
     53:   } else {
     54:     tmp2  = (tmp1 - tmp3) / sizeof(PetscInt);
     55:     itmp2 = -((size_t)tmp2);
     56:   }
     57: #else
     58:   if (tmp3 > tmp1) {
     59:     tmp2  = (tmp3 - tmp1);
     60:     itmp2 = (size_t)tmp2;
     61:   } else {
     62:     tmp2  = (tmp1 - tmp3);
     63:     itmp2 = -((size_t)tmp2);
     64:   }
     65: #endif

     67:   if (base + itmp2 != addr) {
     68:     PetscCallAbort(PETSC_COMM_SELF, (*PetscErrorPrintf)("PetscIntAddressToFortran:C and Fortran arrays are\n"));
     69:     PetscCallAbort(PETSC_COMM_SELF, (*PetscErrorPrintf)("not commonly aligned or are too far apart to be indexed \n"));
     70:     PetscCallAbort(PETSC_COMM_SELF, (*PetscErrorPrintf)("by an integer. Locations: C %zu Fortran %zu\n", tmp1, tmp3));
     71:     PETSCABORT(PETSC_COMM_WORLD, PETSC_ERR_PLIB);
     72:   }
     73:   return itmp2;
     74: }

     76: PetscInt *PetscIntAddressFromFortran(const PetscInt *base, size_t addr)
     77: {
     78:   return (PetscInt *)(base + addr);
     79: }

     81: /*
     82:        obj - PETSc object on which request is made
     83:        base - Fortran array address
     84:        addr - C array address
     85:        res  - will contain offset from C to Fortran
     86:        shift - number of bytes that prevent base and addr from being commonly aligned
     87:        N - size of the array

     89:        align indicates alignment relative to PetscScalar, 1 means aligned on PetscScalar, 2 means aligned on 2 PetscScalar etc
     90: */
     91: PetscErrorCode PetscScalarAddressToFortran(PetscObject obj, PetscInt align, PetscScalar *base, PetscScalar *addr, PetscInt N, size_t *res)
     92: {
     93:   size_t   tmp1 = (size_t)base, tmp2;
     94:   size_t   tmp3 = (size_t)addr;
     95:   size_t   itmp2;
     96:   PetscInt shift;

     98:   PetscFunctionBegin;
     99: #if !defined(PETSC_HAVE_CRAY90_POINTER)
    100:   if (tmp3 > tmp1) { /* C is bigger than Fortran */
    101:     tmp2  = (tmp3 - tmp1) / sizeof(PetscScalar);
    102:     itmp2 = (size_t)tmp2;
    103:     shift = (align * sizeof(PetscScalar) - (PetscInt)((tmp3 - tmp1) % (align * sizeof(PetscScalar)))) % (align * sizeof(PetscScalar));
    104:   } else {
    105:     tmp2  = (tmp1 - tmp3) / sizeof(PetscScalar);
    106:     itmp2 = -((size_t)tmp2);
    107:     shift = (PetscInt)((tmp1 - tmp3) % (align * sizeof(PetscScalar)));
    108:   }
    109: #else
    110:   if (tmp3 > tmp1) { /* C is bigger than Fortran */
    111:     tmp2  = (tmp3 - tmp1);
    112:     itmp2 = (size_t)tmp2;
    113:   } else {
    114:     tmp2  = (tmp1 - tmp3);
    115:     itmp2 = -((size_t)tmp2);
    116:   }
    117:   shift = 0;
    118: #endif

    120:   if (shift) {
    121:     /*
    122:         Fortran and C not PetscScalar aligned,recover by copying values into
    123:         memory that is aligned with the Fortran
    124:     */
    125:     PetscScalar   *work;
    126:     PetscContainer container;

    128:     PetscCall(PetscMalloc1(N + align, &work));

    130:     /* recompute shift for newly allocated space */
    131:     tmp3 = (size_t)work;
    132:     if (tmp3 > tmp1) { /* C is bigger than Fortran */
    133:       shift = (align * sizeof(PetscScalar) - (PetscInt)((tmp3 - tmp1) % (align * sizeof(PetscScalar)))) % (align * sizeof(PetscScalar));
    134:     } else {
    135:       shift = (PetscInt)((tmp1 - tmp3) % (align * sizeof(PetscScalar)));
    136:     }

    138:     /* shift work by that number of bytes */
    139:     work = (PetscScalar *)(((char *)work) + shift);
    140:     PetscCall(PetscArraycpy(work, addr, N));

    142:     /* store in the first location in addr how much you shift it */
    143:     ((PetscInt *)addr)[0] = shift;

    145:     PetscCall(PetscContainerCreate(PETSC_COMM_SELF, &container));
    146:     PetscCall(PetscContainerSetPointer(container, addr));
    147:     PetscCall(PetscObjectCompose(obj, "GetArrayPtr", (PetscObject)container));

    149:     tmp3 = (size_t)work;
    150:     if (tmp3 > tmp1) { /* C is bigger than Fortran */
    151:       tmp2  = (tmp3 - tmp1) / sizeof(PetscScalar);
    152:       itmp2 = (size_t)tmp2;
    153:       shift = (align * sizeof(PetscScalar) - (PetscInt)((tmp3 - tmp1) % (align * sizeof(PetscScalar)))) % (align * sizeof(PetscScalar));
    154:     } else {
    155:       tmp2  = (tmp1 - tmp3) / sizeof(PetscScalar);
    156:       itmp2 = -((size_t)tmp2);
    157:       shift = (PetscInt)((tmp1 - tmp3) % (align * sizeof(PetscScalar)));
    158:     }
    159:     if (shift) {
    160:       PetscCall((*PetscErrorPrintf)("PetscScalarAddressToFortran:C and Fortran arrays are\n"));
    161:       PetscCall((*PetscErrorPrintf)("not commonly aligned.\n"));
    162:       PetscCall((*PetscErrorPrintf)("Locations/sizeof(PetscScalar): C %g Fortran %g\n", (double)(((PetscReal)tmp3) / (PetscReal)sizeof(PetscScalar)), (double)(((PetscReal)tmp1) / (PetscReal)sizeof(PetscScalar))));
    163:       PETSCABORT(PETSC_COMM_WORLD, PETSC_ERR_PLIB);
    164:     }
    165:     PetscCall(PetscInfo(obj, "Efficiency warning, copying array in XXXGetArray() due\n\
    166:     to alignment differences between C and Fortran\n"));
    167:   }
    168:   *res = itmp2;
    169:   PetscFunctionReturn(PETSC_SUCCESS);
    170: }

    172: /*
    173:     obj - the PETSc object where the scalar pointer came from
    174:     base - the Fortran array address
    175:     addr - the Fortran offset from base
    176:     N    - the amount of data

    178:     lx   - the array space that is to be passed to XXXXRestoreArray()
    179: */
    180: PetscErrorCode PetscScalarAddressFromFortran(PetscObject obj, PetscScalar *base, size_t addr, PetscInt N, PetscScalar **lx)
    181: {
    182:   PetscInt       shift;
    183:   PetscContainer container;
    184:   PetscScalar   *tlx;

    186:   PetscFunctionBegin;
    187:   PetscCall(PetscObjectQuery(obj, "GetArrayPtr", (PetscObject *)&container));
    188:   if (container) {
    189:     PetscCall(PetscContainerGetPointer(container, (void **)lx));
    190:     tlx = base + addr;

    192:     shift = *(PetscInt *)*lx;
    193:     PetscCall(PetscArraycpy(*lx, tlx, N));
    194:     tlx = (PetscScalar *)((char *)tlx - shift);

    196:     PetscCall(PetscFree(tlx));
    197:     PetscCall(PetscContainerDestroy(&container));
    198:     PetscCall(PetscObjectCompose(obj, "GetArrayPtr", NULL));
    199:   } else {
    200:     *lx = base + addr;
    201:   }
    202:   PetscFunctionReturn(PETSC_SUCCESS);
    203: }

    205: #if defined(PETSC_HAVE_FORTRAN_CAPS)
    206:   #define petscisinfornanscalar_ PETSCISINFORNANSCALAR
    207:   #define petscisinfornanreal_   PETSCISINFORNANREAL
    208: #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
    209:   #define petscisinfornanscalar_ petscisinfornanscalar
    210:   #define petscisinfornanreal_   petscisinfornanreal
    211: #endif

    213: PETSC_EXTERN PetscBool petscisinfornanscalar_(PetscScalar *v)
    214: {
    215:   return (PetscBool)PetscIsInfOrNanScalar(*v);
    216: }

    218: PETSC_EXTERN PetscBool petscisinfornanreal_(PetscReal *v)
    219: {
    220:   return (PetscBool)PetscIsInfOrNanReal(*v);
    221: }