xref: /petsc/src/sys/ftn-custom/zutils.c (revision d71ae5a4db6382e7f06317b8d368875286fe9008)
1 #include <petsc/private/fortranimpl.h>
2 
3 /*MC
4    PetscFortranAddr - a variable type in Fortran that can hold a
5      regular C pointer.
6 
7    Note:
8     Used, for example, as the file argument in `PetscFOpen()`
9 
10    Level: beginner
11 
12 .seealso:  `PetscOffset`, `PetscInt`
13 M*/
14 /*MC
15    PetscOffset - a variable type in Fortran used with `VecGetArray()`
16      and `ISGetIndices()`
17 
18    Level: beginner
19 
20 .seealso:  `PetscFortranAddr`, `PetscInt`
21 M*/
22 
23 /*
24     This is code for translating PETSc memory addresses to integer offsets
25     for Fortran.
26 */
27 char *PETSC_NULL_CHARACTER_Fortran = 0;
28 void *PETSC_NULL_INTEGER_Fortran   = 0;
29 void *PETSC_NULL_SCALAR_Fortran    = 0;
30 void *PETSC_NULL_DOUBLE_Fortran    = 0;
31 void *PETSC_NULL_REAL_Fortran      = 0;
32 void *PETSC_NULL_BOOL_Fortran      = 0;
33 EXTERN_C_BEGIN
34 void (*PETSC_NULL_FUNCTION_Fortran)(void) = 0;
35 EXTERN_C_END
36 void *PETSC_NULL_MPI_COMM_Fortran   = 0;
37 
38 size_t PetscIntAddressToFortran(const PetscInt *base,const PetscInt *addr)
39 {
40   size_t tmp1 = (size_t) base,tmp2 = 0;
41   size_t tmp3 = (size_t) addr;
42   size_t itmp2;
43 
44 #if !defined(PETSC_HAVE_CRAY90_POINTER)
45   if (tmp3 > tmp1) {
46     tmp2  = (tmp3 - tmp1)/sizeof(PetscInt);
47     itmp2 = (size_t) tmp2;
48   } else {
49     tmp2  = (tmp1 - tmp3)/sizeof(PetscInt);
50     itmp2 = -((size_t) tmp2);
51   }
52 #else
53   if (tmp3 > tmp1) {
54     tmp2  = (tmp3 - tmp1);
55     itmp2 = (size_t) tmp2;
56   } else {
57     tmp2  = (tmp1 - tmp3);
58     itmp2 = -((size_t) tmp2);
59   }
60 #endif
61 
62   if (base + itmp2 != addr) {
63     (*PetscErrorPrintf)("PetscIntAddressToFortran:C and Fortran arrays are\n");
64     (*PetscErrorPrintf)("not commonly aligned or are too far apart to be indexed \n");
65     (*PetscErrorPrintf)("by an integer. Locations: C %zu Fortran %zu\n",tmp1,tmp3);
66     PETSCABORT(PETSC_COMM_WORLD,PETSC_ERR_PLIB);
67   }
68   return itmp2;
69 }
70 
71 PetscInt *PetscIntAddressFromFortran(const PetscInt *base,size_t addr)
72 {
73   return (PetscInt *)(base + addr);
74 }
75 
76 /*
77        obj - PETSc object on which request is made
78        base - Fortran array address
79        addr - C array address
80        res  - will contain offset from C to Fortran
81        shift - number of bytes that prevent base and addr from being commonly aligned
82        N - size of the array
83 
84        align indicates alignment relative to PetscScalar, 1 means aligned on PetscScalar, 2 means aligned on 2 PetscScalar etc
85 */
86 PetscErrorCode PetscScalarAddressToFortran(PetscObject obj,PetscInt align,PetscScalar *base,PetscScalar *addr,PetscInt N,size_t *res)
87 {
88   size_t   tmp1 = (size_t) base,tmp2;
89   size_t   tmp3 = (size_t) addr;
90   size_t   itmp2;
91   PetscInt shift;
92 
93 #if !defined(PETSC_HAVE_CRAY90_POINTER)
94   if (tmp3 > tmp1) {  /* C is bigger than Fortran */
95     tmp2  = (tmp3 - tmp1)/sizeof(PetscScalar);
96     itmp2 = (size_t) tmp2;
97     shift = (align*sizeof(PetscScalar) - (PetscInt)((tmp3 - tmp1) % (align*sizeof(PetscScalar)))) % (align*sizeof(PetscScalar));
98   } else {
99     tmp2  = (tmp1 - tmp3)/sizeof(PetscScalar);
100     itmp2 = -((size_t) tmp2);
101     shift = (PetscInt)((tmp1 - tmp3) % (align*sizeof(PetscScalar)));
102   }
103 #else
104   if (tmp3 > tmp1) {  /* C is bigger than Fortran */
105     tmp2  = (tmp3 - tmp1);
106     itmp2 = (size_t) tmp2;
107   } else {
108     tmp2  = (tmp1 - tmp3);
109     itmp2 = -((size_t) tmp2);
110   }
111   shift = 0;
112 #endif
113 
114   if (shift) {
115     /*
116         Fortran and C not PetscScalar aligned,recover by copying values into
117         memory that is aligned with the Fortran
118     */
119     PetscScalar    *work;
120     PetscContainer container;
121 
122     PetscCall(PetscMalloc1(N+align,&work));
123 
124     /* recompute shift for newly allocated space */
125     tmp3 = (size_t) work;
126     if (tmp3 > tmp1) {  /* C is bigger than Fortran */
127       shift = (align*sizeof(PetscScalar) - (PetscInt)((tmp3 - tmp1) % (align*sizeof(PetscScalar)))) % (align*sizeof(PetscScalar));
128     } else {
129       shift = (PetscInt)((tmp1 - tmp3) % (align*sizeof(PetscScalar)));
130     }
131 
132     /* shift work by that number of bytes */
133     work = (PetscScalar*)(((char*)work) + shift);
134     PetscCall(PetscArraycpy(work,addr,N));
135 
136     /* store in the first location in addr how much you shift it */
137     ((PetscInt*)addr)[0] = shift;
138 
139     PetscCall(PetscContainerCreate(PETSC_COMM_SELF,&container));
140     PetscCall(PetscContainerSetPointer(container,addr));
141     PetscCall(PetscObjectCompose(obj,"GetArrayPtr",(PetscObject)container));
142 
143     tmp3 = (size_t) work;
144     if (tmp3 > tmp1) {  /* C is bigger than Fortran */
145       tmp2  = (tmp3 - tmp1)/sizeof(PetscScalar);
146       itmp2 = (size_t) tmp2;
147       shift = (align*sizeof(PetscScalar) - (PetscInt)((tmp3 - tmp1) % (align*sizeof(PetscScalar)))) % (align*sizeof(PetscScalar));
148     } else {
149       tmp2  = (tmp1 - tmp3)/sizeof(PetscScalar);
150       itmp2 = -((size_t) tmp2);
151       shift = (PetscInt)((tmp1 - tmp3) % (align*sizeof(PetscScalar)));
152     }
153     if (shift) {
154       (*PetscErrorPrintf)("PetscScalarAddressToFortran:C and Fortran arrays are\n");
155       (*PetscErrorPrintf)("not commonly aligned.\n");
156       (*PetscErrorPrintf)("Locations/sizeof(PetscScalar): C %g Fortran %g\n",(double)(((PetscReal)tmp3)/(PetscReal)sizeof(PetscScalar)),(double)(((PetscReal)tmp1)/(PetscReal)sizeof(PetscScalar)));
157       PETSCABORT(PETSC_COMM_WORLD,PETSC_ERR_PLIB);
158     }
159     PetscCall(PetscInfo(obj,"Efficiency warning, copying array in XXXGetArray() due\n\
160     to alignment differences between C and Fortran\n"));
161   }
162   *res = itmp2;
163   return 0;
164 }
165 
166 /*
167     obj - the PETSc object where the scalar pointer came from
168     base - the Fortran array address
169     addr - the Fortran offset from base
170     N    - the amount of data
171 
172     lx   - the array space that is to be passed to XXXXRestoreArray()
173 */
174 PetscErrorCode PetscScalarAddressFromFortran(PetscObject obj,PetscScalar *base,size_t addr,PetscInt N,PetscScalar **lx)
175 {
176   PetscInt       shift;
177   PetscContainer container;
178   PetscScalar    *tlx;
179 
180   PetscCall(PetscObjectQuery(obj,"GetArrayPtr",(PetscObject*)&container));
181   if (container) {
182     PetscCall(PetscContainerGetPointer(container,(void**)lx));
183     tlx  = base + addr;
184 
185     shift = *(PetscInt*)*lx;
186     PetscCall(PetscArraycpy(*lx,tlx,N));
187     tlx   = (PetscScalar*)(((char*)tlx) - shift);
188 
189     PetscCall(PetscFree(tlx));
190     PetscCall(PetscContainerDestroy(&container));
191     PetscCall(PetscObjectCompose(obj,"GetArrayPtr",0));
192   } else {
193     *lx = base + addr;
194   }
195   return 0;
196 }
197 
198 #if defined(PETSC_HAVE_FORTRAN_CAPS)
199 #define petscisinfornanscalar_          PETSCISINFORNANSCALAR
200 #define petscisinfornanreal_            PETSCISINFORNANREAL
201 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
202 #define petscisinfornanscalar_          petscisinfornanscalar
203 #define petscisinfornanreal_            petscisinfornanreal
204 #endif
205 
206 PETSC_EXTERN PetscBool petscisinfornanscalar_(PetscScalar *v)
207 {
208   return (PetscBool) PetscIsInfOrNanScalar(*v);
209 }
210 
211 PETSC_EXTERN PetscBool petscisinfornanreal_(PetscReal *v)
212 {
213   return (PetscBool) PetscIsInfOrNanReal(*v);
214 }
215