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: }