Actual source code: crl.c

  1: #define PETSCMAT_DLL

  3: /*
  4:   Defines a matrix-vector product for the MATSEQAIJCRL matrix class.
  5:   This class is derived from the MATSEQAIJ class and retains the 
  6:   compressed row storage (aka Yale sparse matrix format) but augments 
  7:   it with a column oriented storage that is more efficient for 
  8:   matrix vector products on Vector machines.

 10:   CRL stands for constant row length (that is the same number of columns
 11:   is kept (padded with zeros) for each row of the sparse matrix.
 12: */
 13:  #include src/mat/impls/aij/seq/crl/crl.h

 17: PetscErrorCode MatDestroy_SeqCRL(Mat A)
 18: {
 20:   Mat_CRL        *crl = (Mat_CRL *) A->spptr;

 22:   /* We are going to convert A back into a SEQAIJ matrix, since we are 
 23:    * eventually going to use MatDestroy() to destroy everything 
 24:    * that is not specific to CRL.
 25:    * In preparation for this, reset the operations pointers in A to 
 26:    * their SeqAIJ versions. */
 27:   A->ops->assemblyend = crl->AssemblyEnd;
 28:   A->ops->destroy     = crl->MatDestroy;
 29:   A->ops->duplicate   = crl->MatDuplicate;

 31:   /* Free everything in the Mat_CRL data structure. */
 32:   PetscFree2(crl->acols,crl->icols);

 34:   /* Change the type of A back to SEQAIJ and use MatDestroy() 
 35:    * to destroy everything that remains. */
 36:   PetscObjectChangeTypeName( (PetscObject)A, MATSEQAIJ);
 37:   /* Note that I don't call MatSetType().  I believe this is because that 
 38:    * is only to be called when *building* a matrix. */
 39:   (*A->ops->destroy)(A);
 40:   return(0);
 41: }

 43: PetscErrorCode MatDuplicate_CRL(Mat A, MatDuplicateOption op, Mat *M)
 44: {
 46:   Mat_CRL        *crl = (Mat_CRL *) A->spptr;

 49:   (*crl->MatDuplicate)(A,op,M);
 50:   SETERRQ(PETSC_ERR_SUP,"Cannot duplicate CRL matrices yet");
 51:   return(0);
 52: }

 56: PetscErrorCode SeqCRL_create_crl(Mat A)
 57: {
 58:   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)(A)->data;
 59:   Mat_CRL        *crl = (Mat_CRL*) A->spptr;
 60:   PetscInt       m = A->rmap.n;  /* Number of rows in the matrix. */
 61:   PetscInt       *aj = a->j;  /* From the CSR representation; points to the beginning  of each row. */
 62:   PetscInt       i, j,rmax = a->rmax,*icols, *ilen = a->ilen;
 63:   PetscScalar    *aa = a->a,*acols;

 67:   crl->nz   = a->nz;
 68:   crl->m    = A->rmap.n;
 69:   crl->rmax = rmax;
 70:   PetscMalloc2(rmax*m,PetscScalar,&crl->acols,rmax*m,PetscInt,&crl->icols);
 71:   acols = crl->acols;
 72:   icols = crl->icols;
 73:   for (i=0; i<m; i++) {
 74:     for (j=0; j<ilen[i]; j++) {
 75:       acols[j*m+i] = *aa++;
 76:       icols[j*m+i] = *aj++;
 77:     }
 78:     for (;j<rmax; j++) { /* empty column entries */
 79:       acols[j*m+i] = 0.0;
 80:       icols[j*m+i] = (j) ? icols[(j-1)*m+i] : 0;  /* handle case where row is EMPTY */
 81:     }
 82:   }
 83:   PetscInfo2(A,"Percentage of 0's introduced for vectorized multiply %G. Rmax= %D\n",1.0-((double)a->nz)/((double)(rmax*m)),rmax);
 84:   return(0);
 85: }

 89: PetscErrorCode MatAssemblyEnd_SeqCRL(Mat A, MatAssemblyType mode)
 90: {
 92:   Mat_CRL        *crl = (Mat_CRL*) A->spptr;
 93:   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;

 96:   if (mode == MAT_FLUSH_ASSEMBLY) return(0);
 97: 
 98:   /* Since a MATSEQCRL matrix is really just a MATSEQAIJ with some 
 99:    * extra information, call the AssemblyEnd routine for a MATSEQAIJ. 
100:    * I'm not sure if this is the best way to do this, but it avoids 
101:    * a lot of code duplication.
102:    * I also note that currently MATSEQCRL doesn't know anything about 
103:    * the Mat_CompressedRow data structure that SeqAIJ now uses when there 
104:    * are many zero rows.  If the SeqAIJ assembly end routine decides to use 
105:    * this, this may break things.  (Don't know... haven't looked at it.) */
106:   a->inode.use = PETSC_FALSE;
107:   (*crl->AssemblyEnd)(A, mode);

109:   /* Now calculate the permutation and grouping information. */
110:   SeqCRL_create_crl(A);
111:   return(0);
112: }

114:  #include src/inline/dot.h

118: PetscErrorCode MatMult_CRL(Mat A,Vec xx,Vec yy)
119: {
120:   Mat_CRL        *crl = (Mat_CRL*) A->spptr;
121:   PetscInt       m = crl->m;  /* Number of rows in the matrix. */
122:   PetscInt       rmax = crl->rmax,*icols = crl->icols;
123:   PetscScalar    *acols = crl->acols;
125:   PetscScalar    *x,*y;
126: #if !defined(PETSC_USE_FORTRAN_KERNEL_MULTCRL)
127:   PetscInt       i,j,ii;
128: #endif


131: #if defined(PETSC_HAVE_PRAGMA_DISJOINT)
132: #pragma disjoint(*x,*y,*aa)
133: #endif

136:   if (crl->xscat) {
137:     VecCopy(xx,crl->xwork);
138:     /* get remote values needed for local part of multiply */
139:     VecScatterBegin(xx,crl->fwork,INSERT_VALUES,SCATTER_FORWARD,crl->xscat);
140:     VecScatterEnd(xx,crl->fwork,INSERT_VALUES,SCATTER_FORWARD,crl->xscat);
141:     xx = crl->xwork;
142:   };

144:   VecGetArray(xx,&x);
145:   VecGetArray(yy,&y);

147: #if defined(PETSC_USE_FORTRAN_KERNEL_MULTCRL)
148:   fortranmultcrl_(&m,&rmax,x,y,icols,acols);
149: #else

151:   /* first column */
152:   for (j=0; j<m; j++) {
153:     y[j] = acols[j]*x[icols[j]];
154:   }

156:   /* other columns */
157: #if defined(PETSC_HAVE_CRAYC)
158: #pragma _CRI preferstream
159: #endif
160:   for (i=1; i<rmax; i++) {
161:     ii = i*m;
162: #if defined(PETSC_HAVE_CRAYC)
163: #pragma _CRI prefervector
164: #endif
165:     for (j=0; j<m; j++) {
166:       y[j] = y[j] + acols[ii+j]*x[icols[ii+j]];
167:     }
168:   }
169: #if defined(PETSC_HAVE_CRAYC)
170: #pragma _CRI ivdep
171: #endif

173: #endif
174:   PetscLogFlops(2*crl->nz - m);
175:   VecRestoreArray(xx,&x);
176:   VecRestoreArray(yy,&y);
177:   return(0);
178: }


181: /* MatConvert_SeqAIJ_SeqCRL converts a SeqAIJ matrix into a 
182:  * SeqCRL matrix.  This routine is called by the MatCreate_SeqCRL() 
183:  * routine, but can also be used to convert an assembled SeqAIJ matrix 
184:  * into a SeqCRL one. */
188: PetscErrorCode  MatConvert_SeqAIJ_SeqCRL(Mat A,MatType type,MatReuse reuse,Mat *newmat)
189: {
191:   Mat            B = *newmat;
192:   Mat_CRL        *crl;

195:   if (reuse == MAT_INITIAL_MATRIX) {
196:     MatDuplicate(A,MAT_COPY_VALUES,&B);
197:   }

199:   PetscNew(Mat_CRL,&crl);
200:   B->spptr = (void *) crl;

202:   crl->AssemblyEnd  = A->ops->assemblyend;
203:   crl->MatDestroy   = A->ops->destroy;
204:   crl->MatDuplicate = A->ops->duplicate;

206:   /* Set function pointers for methods that we inherit from AIJ but override. */
207:   B->ops->duplicate   = MatDuplicate_CRL;
208:   B->ops->assemblyend = MatAssemblyEnd_SeqCRL;
209:   B->ops->destroy     = MatDestroy_SeqCRL;
210:   B->ops->mult        = MatMult_CRL;

212:   /* If A has already been assembled, compute the permutation. */
213:   if (A->assembled == PETSC_TRUE) {
214:     SeqCRL_create_crl(B);
215:   }
216:   PetscObjectChangeTypeName((PetscObject)B,MATSEQCRL);
217:   *newmat = B;
218:   return(0);
219: }


225: /*@C
226:    MatCreateSeqCRL - Creates a sparse matrix of type SEQCRL.
227:    This type inherits from AIJ, but stores some additional
228:    information that is used to allow better vectorization of 
229:    the matrix-vector product. At the cost of increased storage, the AIJ formatted 
230:    matrix can be copied to a format in which pieces of the matrix are 
231:    stored in ELLPACK format, allowing the vectorized matrix multiply 
232:    routine to use stride-1 memory accesses.  As with the AIJ type, it is 
233:    important to preallocate matrix storage in order to get good assembly 
234:    performance.
235:    
236:    Collective on MPI_Comm

238:    Input Parameters:
239: +  comm - MPI communicator, set to PETSC_COMM_SELF
240: .  m - number of rows
241: .  n - number of columns
242: .  nz - number of nonzeros per row (same for all rows)
243: -  nnz - array containing the number of nonzeros in the various rows 
244:          (possibly different for each row) or PETSC_NULL

246:    Output Parameter:
247: .  A - the matrix 

249:    Notes:
250:    If nnz is given then nz is ignored

252:    Level: intermediate

254: .keywords: matrix, cray, sparse, parallel

256: .seealso: MatCreate(), MatCreateMPICSRPERM(), MatSetValues()
257: @*/
258: PetscErrorCode  MatCreateSeqCRL(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt nz,const PetscInt nnz[],Mat *A)
259: {

263:   MatCreate(comm,A);
264:   MatSetSizes(*A,m,n,m,n);
265:   MatSetType(*A,MATSEQCRL);
266:   MatSeqAIJSetPreallocation_SeqAIJ(*A,nz,(PetscInt*)nnz);
267:   return(0);
268: }


274: PetscErrorCode  MatCreate_SeqCRL(Mat A)
275: {

279:   MatSetType(A,MATSEQAIJ);
280:   MatConvert_SeqAIJ_SeqCRL(A,MATSEQCRL,MAT_REUSE_MATRIX,&A);
281:   return(0);
282: }