source: CIVL/examples/amg/csr/csr_add.c@ 1aaefd4

#include <stdlib.h>
/*
Required source files:
f1      : AMG2013/test/steve_test.c
f2      : AMG2013/seq_mv/seq_mv.h
f9      : /include/abc/stdlib.h
f10     : /include/abc/stdio.h
f11     : /include/abc/civl-stdio.cvh
f97     : AMG2013/seq_mv/csr_matop.c
f98     : AMG2013/seq_mv/csr_matrix.c
f158    : AMG2013/utilities/hypre_error.c
f159    : AMG2013/utilities/hypre_memory.c

Entities used from f1: AMG2013/test/steve_test.c :
  main

Entities used from f2: AMG2013/seq_mv/seq_mv.h :
  hypre_CSRMatrix

Entities used from f9: /include/abc/stdlib.h :
  size_t
  free
  calloc

Entities used from f10: /include/abc/stdio.h :
  fflush
  stdout
  printf

Entities used from f11: /include/abc/civl-stdio.cvh :
  FILE

Entities used from f97: AMG2013/seq_mv/csr_matop.c :
  hypre_CSRMatrixAdd

Entities used from f98: AMG2013/seq_mv/csr_matrix.c :
  hypre_CSRMatrixCreate
  hypre_CSRMatrixInitialize

Entities used from f158: AMG2013/utilities/hypre_error.c :
  hypre_error_handler
  hypre__global_error

Entities used from f159: AMG2013/utilities/hypre_memory.c :
  hypre_Free
  hypre_CAlloc
  hypre_OutOfMemory

 */

// Preliminaries ....

// from hyper_memory.c.
// Somewhat simplified by sfs to remove call to hyper_error.
char * hypre_CAlloc( int count, int elt_size ) {
  char *ptr;
  int   size = count*elt_size;

  if (size > 0) {
    ptr = calloc(count, elt_size);
  } else {
    ptr = NULL;
  }
  return ptr;
}

// from hypre_memory.h:
#define hypre_CTAlloc(type, count) \
( (type *)hypre_CAlloc((unsigned int)(count), (unsigned int)sizeof(type)) )

// from hyper_memory.c:
void
hypre_Free( char *ptr )
{
   if (ptr)
   {
#ifdef HYPRE_USE_UMALLOC
      int threadid = hypre_GetThreadID();

      _ufree_(ptr);
#else
      free(ptr);
#endif
   }
}

// from hyper_memory.h:
#define hypre_TFree(ptr) \
( hypre_Free((char *)ptr), ptr = NULL )



// from csr_matrix.h:
typedef struct {
  double  *data;
  int     *i;
  int     *j;
  int      num_rows;
  int      num_cols;
  int      num_nonzeros;

  /* for compressing rows in matrix multiplication  */
  int     *rownnz;
  int      num_rownnz;

  /* Does the CSRMatrix create/destroy `data', `i', `j'? */
  int      owns_data;
} hypre_CSRMatrix;

/*--------------------------------------------------------------------------
 * Accessor functions for the CSR Matrix structure
 *--------------------------------------------------------------------------*/

#define hypre_CSRMatrixData(matrix)         ((matrix) -> data)
#define hypre_CSRMatrixI(matrix)            ((matrix) -> i)
#define hypre_CSRMatrixJ(matrix)            ((matrix) -> j)
#define hypre_CSRMatrixNumRows(matrix)      ((matrix) -> num_rows)
#define hypre_CSRMatrixNumCols(matrix)      ((matrix) -> num_cols)
#define hypre_CSRMatrixNumNonzeros(matrix)  ((matrix) -> num_nonzeros)
#define hypre_CSRMatrixRownnz(matrix)       ((matrix) -> rownnz)
#define hypre_CSRMatrixNumRownnz(matrix)    ((matrix) -> num_rownnz)
#define hypre_CSRMatrixOwnsData(matrix)     ((matrix) -> owns_data)


// from csr_matop.c:

hypre_CSRMatrix *
hypre_CSRMatrixCreate( int num_rows,
                       int num_cols,
                       int num_nonzeros )
{
   hypre_CSRMatrix  *matrix;

   matrix = hypre_CTAlloc(hypre_CSRMatrix, 1);

   hypre_CSRMatrixData(matrix) = NULL;
   hypre_CSRMatrixI(matrix)    = NULL;
   hypre_CSRMatrixJ(matrix)    = NULL;
   hypre_CSRMatrixRownnz(matrix) = NULL;
   hypre_CSRMatrixNumRows(matrix) = num_rows;
   hypre_CSRMatrixNumCols(matrix) = num_cols;
   hypre_CSRMatrixNumNonzeros(matrix) = num_nonzeros;

   /* set defaults */
   hypre_CSRMatrixOwnsData(matrix) = 1;
   hypre_CSRMatrixNumRownnz(matrix) = num_rows;
   

   return matrix;
}


// from csr_matop.c:

int 
hypre_CSRMatrixInitialize( hypre_CSRMatrix *matrix )
{
   int  num_rows     = hypre_CSRMatrixNumRows(matrix);
   int  num_nonzeros = hypre_CSRMatrixNumNonzeros(matrix);
   int  ierr=0;
   

   if ( ! hypre_CSRMatrixData(matrix) && num_nonzeros )
      hypre_CSRMatrixData(matrix) = hypre_CTAlloc(double, num_nonzeros);
   if ( ! hypre_CSRMatrixI(matrix) )
      hypre_CSRMatrixI(matrix)    = hypre_CTAlloc(int, num_rows + 1);
   if ( ! hypre_CSRMatrixJ(matrix) && num_nonzeros )
      hypre_CSRMatrixJ(matrix)    = hypre_CTAlloc(int, num_nonzeros);

   return ierr;
}


// from csr_matop.c:

hypre_CSRMatrix *
hypre_CSRMatrixAdd( hypre_CSRMatrix *A, hypre_CSRMatrix *B) {
  double     *A_data   = hypre_CSRMatrixData(A);
  int        *A_i      = hypre_CSRMatrixI(A);
  int        *A_j      = hypre_CSRMatrixJ(A);
  int         nrows_A  = hypre_CSRMatrixNumRows(A);
  int         ncols_A  = hypre_CSRMatrixNumCols(A);
  double     *B_data   = hypre_CSRMatrixData(B);
  int        *B_i      = hypre_CSRMatrixI(B);
  int        *B_j      = hypre_CSRMatrixJ(B);
  int         nrows_B  = hypre_CSRMatrixNumRows(B);
  int         ncols_B  = hypre_CSRMatrixNumCols(B);
  hypre_CSRMatrix *C;
  double     *C_data;
  int         *C_i;
  int        *C_j;
  int         ia, ib, ic, jcol, num_nonzeros;
  int          pos;
  int         *marker;

  marker = hypre_CTAlloc(int, ncols_A);
  C_i = hypre_CTAlloc(int, nrows_A+1);
  for (ia = 0; ia < ncols_A; ia++)
    marker[ia] = -1;
  num_nonzeros = 0;
  C_i[0] = 0;
  for (ic = 0; ic < nrows_A; ic++) {
    for (ia = A_i[ic]; ia < A_i[ic+1]; ia++) {
      jcol = A_j[ia];
      marker[jcol] = ic;
      num_nonzeros++;
    }
    for (ib = B_i[ic]; ib < B_i[ic+1]; ib++) {
      jcol = B_j[ib];
      if (marker[jcol] != ic) {
        marker[jcol] = ic;
        num_nonzeros++;
      }
    }
    C_i[ic+1] = num_nonzeros;
  }

  C = hypre_CSRMatrixCreate(nrows_A, ncols_A, num_nonzeros);
  hypre_CSRMatrixI(C) = C_i;
  hypre_CSRMatrixInitialize(C);
  C_j = hypre_CSRMatrixJ(C);
  C_data = hypre_CSRMatrixData(C);

  for (ia = 0; ia < ncols_A; ia++)
    marker[ia] = -1;
  pos = 0;

  /*
#pragma TASS joint invariant ic==spec.i;
#pragma TASS joint invariant                                            \
  forall {int i | 0<=i<ic}                                              \
  forall {int j | 0<=j<ncols_A}                                         \
  spec.C[i][j] = (exists k.(C_i[i]<=k && k<C_i[i+1] && j=C_j[k])) ? C_data[k] : 0.;
  */

  for (ic = 0; ic < nrows_A; ic++) {
    for (ia = A_i[ic]; ia < A_i[ic+1]; ia++) {
      jcol = A_j[ia];
      C_j[pos] = jcol;
      C_data[pos] = A_data[ia];
      marker[jcol] = pos;
      pos++;
    }
    for (ib = B_i[ic]; ib < B_i[ic+1]; ib++) {
      jcol = B_j[ib];
      if (marker[jcol] < C_i[ic]) {
        C_j[pos] = jcol;
        C_data[pos] = B_data[ib];
        marker[jcol] = pos;
        pos++;
      }
      else {
        C_data[marker[jcol]] += B_data[ib];
      }
    }
  }
  hypre_TFree(marker);
  return C;
}