xref: /petsc/src/sys/ftn-custom/zutils.c (revision b122ec5aa1bd4469eb4e0673542fb7de3f411254)

#include <petsc/private/fortranimpl.h>

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

   Notes:
    Used, for example, as the file argument in PetscFOpen()

   Level: beginner

.seealso:  PetscOffset, PetscInt
M*/
/*MC
   PetscOffset - a variable type in Fortran used with VecGetArray()
     and ISGetIndices()

   Level: beginner

.seealso:  PetscFortranAddr, PetscInt
M*/

/*
    This is code for translating PETSc memory addresses to integer offsets
    for Fortran.
*/
char *PETSC_NULL_CHARACTER_Fortran = 0;
void *PETSC_NULL_INTEGER_Fortran   = 0;
void *PETSC_NULL_SCALAR_Fortran    = 0;
void *PETSC_NULL_DOUBLE_Fortran    = 0;
void *PETSC_NULL_REAL_Fortran      = 0;
void *PETSC_NULL_BOOL_Fortran      = 0;
EXTERN_C_BEGIN
void (*PETSC_NULL_FUNCTION_Fortran)(void) = 0;
EXTERN_C_END
void *PETSC_NULL_MPI_COMM_Fortran   = 0;

size_t PetscIntAddressToFortran(const PetscInt *base,const PetscInt *addr)
{
  size_t tmp1 = (size_t) base,tmp2 = 0;
  size_t tmp3 = (size_t) addr;
  size_t itmp2;

#if !defined(PETSC_HAVE_CRAY90_POINTER)
  if (tmp3 > tmp1) {
    tmp2  = (tmp3 - tmp1)/sizeof(PetscInt);
    itmp2 = (size_t) tmp2;
  } else {
    tmp2  = (tmp1 - tmp3)/sizeof(PetscInt);
    itmp2 = -((size_t) tmp2);
  }
#else
  if (tmp3 > tmp1) {
    tmp2  = (tmp3 - tmp1);
    itmp2 = (size_t) tmp2;
  } else {
    tmp2  = (tmp1 - tmp3);
    itmp2 = -((size_t) tmp2);
  }
#endif

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

PetscInt *PetscIntAddressFromFortran(const PetscInt *base,size_t addr)
{
  return (PetscInt *)(base + addr);
}

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

       align indicates alignment relative to PetscScalar, 1 means aligned on PetscScalar, 2 means aligned on 2 PetscScalar etc
*/
PetscErrorCode PetscScalarAddressToFortran(PetscObject obj,PetscInt align,PetscScalar *base,PetscScalar *addr,PetscInt N,size_t *res)
{
  size_t   tmp1 = (size_t) base,tmp2;
  size_t   tmp3 = (size_t) addr;
  size_t   itmp2;
  PetscInt shift;

#if !defined(PETSC_HAVE_CRAY90_POINTER)
  if (tmp3 > tmp1) {  /* C is bigger than Fortran */
    tmp2  = (tmp3 - tmp1)/sizeof(PetscScalar);
    itmp2 = (size_t) tmp2;
    shift = (align*sizeof(PetscScalar) - (PetscInt)((tmp3 - tmp1) % (align*sizeof(PetscScalar)))) % (align*sizeof(PetscScalar));
  } else {
    tmp2  = (tmp1 - tmp3)/sizeof(PetscScalar);
    itmp2 = -((size_t) tmp2);
    shift = (PetscInt)((tmp1 - tmp3) % (align*sizeof(PetscScalar)));
  }
#else
  if (tmp3 > tmp1) {  /* C is bigger than Fortran */
    tmp2  = (tmp3 - tmp1);
    itmp2 = (size_t) tmp2;
  } else {
    tmp2  = (tmp1 - tmp3);
    itmp2 = -((size_t) tmp2);
  }
  shift = 0;
#endif

  if (shift) {
    /*
        Fortran and C not PetscScalar aligned,recover by copying values into
        memory that is aligned with the Fortran
    */
    PetscScalar    *work;
    PetscContainer container;

    CHKERRQ(PetscMalloc1(N+align,&work));

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

    /* shift work by that number of bytes */
    work = (PetscScalar*)(((char*)work) + shift);
    CHKERRQ(PetscArraycpy(work,addr,N));

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

    CHKERRQ(PetscContainerCreate(PETSC_COMM_SELF,&container));
    CHKERRQ(PetscContainerSetPointer(container,addr));
    CHKERRQ(PetscObjectCompose(obj,"GetArrayPtr",(PetscObject)container));

    tmp3 = (size_t) work;
    if (tmp3 > tmp1) {  /* C is bigger than Fortran */
      tmp2  = (tmp3 - tmp1)/sizeof(PetscScalar);
      itmp2 = (size_t) tmp2;
      shift = (align*sizeof(PetscScalar) - (PetscInt)((tmp3 - tmp1) % (align*sizeof(PetscScalar)))) % (align*sizeof(PetscScalar));
    } else {
      tmp2  = (tmp1 - tmp3)/sizeof(PetscScalar);
      itmp2 = -((size_t) tmp2);
      shift = (PetscInt)((tmp1 - tmp3) % (align*sizeof(PetscScalar)));
    }
    if (shift) {
      (*PetscErrorPrintf)("PetscScalarAddressToFortran:C and Fortran arrays are\n");
      (*PetscErrorPrintf)("not commonly aligned.\n");
      (*PetscErrorPrintf)("Locations/sizeof(PetscScalar): C %g Fortran %g\n",(double)(((PetscReal)tmp3)/(PetscReal)sizeof(PetscScalar)),(double)(((PetscReal)tmp1)/(PetscReal)sizeof(PetscScalar)));
      PETSCABORT(PETSC_COMM_WORLD,PETSC_ERR_PLIB);
    }
    CHKERRQ(PetscInfo(obj,"Efficiency warning, copying array in XXXGetArray() due\n\
    to alignment differences between C and Fortran\n"));
  }
  *res = itmp2;
  return 0;
}

/*
    obj - the PETSc object where the scalar pointer came from
    base - the Fortran array address
    addr - the Fortran offset from base
    N    - the amount of data

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

  CHKERRQ(PetscObjectQuery(obj,"GetArrayPtr",(PetscObject*)&container));
  if (container) {
    CHKERRQ(PetscContainerGetPointer(container,(void**)lx));
    tlx  = base + addr;

    shift = *(PetscInt*)*lx;
    CHKERRQ(PetscArraycpy(*lx,tlx,N));
    tlx   = (PetscScalar*)(((char*)tlx) - shift);

    CHKERRQ(PetscFree(tlx));
    CHKERRQ(PetscContainerDestroy(&container));
    CHKERRQ(PetscObjectCompose(obj,"GetArrayPtr",0));
  } else {
    *lx = base + addr;
  }
  return 0;
}

#if defined(PETSC_HAVE_FORTRAN_CAPS)
#define petscisinfornanscalar_          PETSCISINFORNANSCALAR
#define petscisinfornanreal_            PETSCISINFORNANREAL
#elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
#define petscisinfornanscalar_          petscisinfornanscalar
#define petscisinfornanreal_            petscisinfornanreal
#endif

PETSC_EXTERN PetscBool petscisinfornanscalar_(PetscScalar *v)
{
  return (PetscBool) PetscIsInfOrNanScalar(*v);
}

PETSC_EXTERN PetscBool petscisinfornanreal_(PetscReal *v)
{
  return (PetscBool) PetscIsInfOrNanReal(*v);
}