Actual source code: crl.c

petsc-3.8.3 2017-12-09
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  2: /*
  3:   Defines a matrix-vector product for the MATSEQAIJCRL matrix class.
  4:   This class is derived from the MATSEQAIJ class and retains the
  5:   compressed row storage (aka Yale sparse matrix format) but augments
  6:   it with a column oriented storage that is more efficient for
  7:   matrix vector products on Vector machines.

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

 14: PetscErrorCode MatDestroy_SeqAIJCRL(Mat A)
 15: {
 17:   Mat_AIJCRL     *aijcrl = (Mat_AIJCRL*) A->spptr;

 19:   /* Free everything in the Mat_AIJCRL data structure. */
 20:   if (aijcrl) {
 21:     PetscFree2(aijcrl->acols,aijcrl->icols);
 22:   }
 23:   PetscFree(A->spptr);
 24:   PetscObjectChangeTypeName((PetscObject)A, MATSEQAIJ);
 25:   MatDestroy_SeqAIJ(A);
 26:   return(0);
 27: }

 29: PetscErrorCode MatDuplicate_AIJCRL(Mat A, MatDuplicateOption op, Mat *M)
 30: {
 32:   SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Cannot duplicate AIJCRL matrices yet");
 33:   return(0);
 34: }

 36: PetscErrorCode MatSeqAIJCRL_create_aijcrl(Mat A)
 37: {
 38:   Mat_SeqAIJ     *a      = (Mat_SeqAIJ*)(A)->data;
 39:   Mat_AIJCRL     *aijcrl = (Mat_AIJCRL*) A->spptr;
 40:   PetscInt       m       = A->rmap->n; /* Number of rows in the matrix. */
 41:   PetscInt       *aj     = a->j; /* From the CSR representation; points to the beginning  of each row. */
 42:   PetscInt       i, j,rmax = a->rmax,*icols, *ilen = a->ilen;
 43:   MatScalar      *aa = a->a;
 44:   PetscScalar    *acols;

 48:   aijcrl->nz   = a->nz;
 49:   aijcrl->m    = A->rmap->n;
 50:   aijcrl->rmax = rmax;

 52:   PetscFree2(aijcrl->acols,aijcrl->icols);
 53:   PetscMalloc2(rmax*m,&aijcrl->acols,rmax*m,&aijcrl->icols);
 54:   acols = aijcrl->acols;
 55:   icols = aijcrl->icols;
 56:   for (i=0; i<m; i++) {
 57:     for (j=0; j<ilen[i]; j++) {
 58:       acols[j*m+i] = *aa++;
 59:       icols[j*m+i] = *aj++;
 60:     }
 61:     for (; j<rmax; j++) { /* empty column entries */
 62:       acols[j*m+i] = 0.0;
 63:       icols[j*m+i] = (j) ? icols[(j-1)*m+i] : 0;  /* handle case where row is EMPTY */
 64:     }
 65:   }
 66:   PetscInfo2(A,"Percentage of 0's introduced for vectorized multiply %g. Rmax= %D\n",1.0-((double)a->nz)/((double)(rmax*m)),rmax);
 67:   return(0);
 68: }

 70: PetscErrorCode MatAssemblyEnd_SeqAIJCRL(Mat A, MatAssemblyType mode)
 71: {
 73:   Mat_SeqAIJ     *a = (Mat_SeqAIJ*)A->data;

 76:   a->inode.use = PETSC_FALSE;

 78:   MatAssemblyEnd_SeqAIJ(A,mode);
 79:   if (mode == MAT_FLUSH_ASSEMBLY) return(0);

 81:   /* Now calculate the permutation and grouping information. */
 82:   MatSeqAIJCRL_create_aijcrl(A);
 83:   return(0);
 84: }

 86: #include <../src/mat/impls/aij/seq/crl/ftn-kernels/fmultcrl.h>

 88: /*
 89:     Shared by both sequential and parallel versions of CRL matrix: MATMPIAIJCRL and MATSEQAIJCRL
 90:     - the scatter is used only in the parallel version

 92: */
 93: PetscErrorCode MatMult_AIJCRL(Mat A,Vec xx,Vec yy)
 94: {
 95:   Mat_AIJCRL        *aijcrl = (Mat_AIJCRL*) A->spptr;
 96:   PetscInt          m       = aijcrl->m; /* Number of rows in the matrix. */
 97:   PetscInt          rmax    = aijcrl->rmax,*icols = aijcrl->icols;
 98:   PetscScalar       *acols  = aijcrl->acols;
 99:   PetscErrorCode    ierr;
100:   PetscScalar       *y;
101:   const PetscScalar *x;
102: #if !defined(PETSC_USE_FORTRAN_KERNEL_MULTCRL)
103:   PetscInt          i,j,ii;
104: #endif

106: #if defined(PETSC_HAVE_PRAGMA_DISJOINT)
107: #pragma disjoint(*x,*y,*aa)
108: #endif

111:   if (aijcrl->xscat) {
112:     VecCopy(xx,aijcrl->xwork);
113:     /* get remote values needed for local part of multiply */
114:     VecScatterBegin(aijcrl->xscat,xx,aijcrl->fwork,INSERT_VALUES,SCATTER_FORWARD);
115:     VecScatterEnd(aijcrl->xscat,xx,aijcrl->fwork,INSERT_VALUES,SCATTER_FORWARD);
116:     xx   = aijcrl->xwork;
117:   }

119:   VecGetArrayRead(xx,&x);
120:   VecGetArray(yy,&y);

122: #if defined(PETSC_USE_FORTRAN_KERNEL_MULTCRL)
123:   fortranmultcrl_(&m,&rmax,x,y,icols,acols);
124: #else

126:   /* first column */
127:   for (j=0; j<m; j++) y[j] = acols[j]*x[icols[j]];

129:   /* other columns */
130: #if defined(PETSC_HAVE_CRAY_VECTOR)
131: #pragma _CRI preferstream
132: #endif
133:   for (i=1; i<rmax; i++) {
134:     ii = i*m;
135: #if defined(PETSC_HAVE_CRAY_VECTOR)
136: #pragma _CRI prefervector
137: #endif
138:     for (j=0; j<m; j++) y[j] = y[j] + acols[ii+j]*x[icols[ii+j]];
139:   }
140: #if defined(PETSC_HAVE_CRAY_VECTOR)
141: #pragma _CRI ivdep
142: #endif

144: #endif
145:   PetscLogFlops(2.0*aijcrl->nz - m);
146:   VecRestoreArrayRead(xx,&x);
147:   VecRestoreArray(yy,&y);
148:   return(0);
149: }


152: /* MatConvert_SeqAIJ_SeqAIJCRL converts a SeqAIJ matrix into a
153:  * SeqAIJCRL matrix.  This routine is called by the MatCreate_SeqAIJCRL()
154:  * routine, but can also be used to convert an assembled SeqAIJ matrix
155:  * into a SeqAIJCRL one. */
156: PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJCRL(Mat A,MatType type,MatReuse reuse,Mat *newmat)
157: {
159:   Mat            B = *newmat;
160:   Mat_AIJCRL     *aijcrl;
161:   PetscBool      sametype;

164:   if (reuse == MAT_INITIAL_MATRIX) {
165:     MatDuplicate(A,MAT_COPY_VALUES,&B);
166:   }
167:   PetscObjectTypeCompare((PetscObject)A,type,&sametype);
168:   if (sametype) return(0);

170:   PetscNewLog(B,&aijcrl);
171:   B->spptr = (void*) aijcrl;

173:   /* Set function pointers for methods that we inherit from AIJ but override. */
174:   B->ops->duplicate   = MatDuplicate_AIJCRL;
175:   B->ops->assemblyend = MatAssemblyEnd_SeqAIJCRL;
176:   B->ops->destroy     = MatDestroy_SeqAIJCRL;
177:   B->ops->mult        = MatMult_AIJCRL;

179:   /* If A has already been assembled, compute the permutation. */
180:   if (A->assembled) {
181:     MatSeqAIJCRL_create_aijcrl(B);
182:   }
183:   PetscObjectChangeTypeName((PetscObject)B,MATSEQAIJCRL);
184:   *newmat = B;
185:   return(0);
186: }

188: /*@C
189:    MatCreateSeqAIJCRL - Creates a sparse matrix of type SEQAIJCRL.
190:    This type inherits from AIJ, but stores some additional
191:    information that is used to allow better vectorization of
192:    the matrix-vector product. At the cost of increased storage, the AIJ formatted
193:    matrix can be copied to a format in which pieces of the matrix are
194:    stored in ELLPACK format, allowing the vectorized matrix multiply
195:    routine to use stride-1 memory accesses.  As with the AIJ type, it is
196:    important to preallocate matrix storage in order to get good assembly
197:    performance.

199:    Collective on MPI_Comm

201:    Input Parameters:
202: +  comm - MPI communicator, set to PETSC_COMM_SELF
203: .  m - number of rows
204: .  n - number of columns
205: .  nz - number of nonzeros per row (same for all rows)
206: -  nnz - array containing the number of nonzeros in the various rows
207:          (possibly different for each row) or NULL

209:    Output Parameter:
210: .  A - the matrix

212:    Notes:
213:    If nnz is given then nz is ignored

215:    Level: intermediate

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

219: .seealso: MatCreate(), MatCreateMPIAIJPERM(), MatSetValues()
220: @*/
221: PetscErrorCode  MatCreateSeqAIJCRL(MPI_Comm comm,PetscInt m,PetscInt n,PetscInt nz,const PetscInt nnz[],Mat *A)
222: {

226:   MatCreate(comm,A);
227:   MatSetSizes(*A,m,n,m,n);
228:   MatSetType(*A,MATSEQAIJCRL);
229:   MatSeqAIJSetPreallocation_SeqAIJ(*A,nz,nnz);
230:   return(0);
231: }

233: PETSC_EXTERN PetscErrorCode MatCreate_SeqAIJCRL(Mat A)
234: {

238:   MatSetType(A,MATSEQAIJ);
239:   MatConvert_SeqAIJ_SeqAIJCRL(A,MATSEQAIJCRL,MAT_INPLACE_MATRIX,&A);
240:   return(0);
241: }