/*$Id: essl.c,v 1.49 2001/08/07 03:02:47 balay Exp $*/

/* 
        Provides an interface to the IBM RS6000 Essl sparse solver

*/
#include "src/mat/impls/aij/seq/aij.h"
/* #include <essl.h> This doesn't work!  */

typedef struct {
  int         n,nz;
  PetscScalar *a;
  int         *ia;
  int         *ja;
  int         lna;
  int         iparm[5];
  PetscReal   rparm[5];
  PetscReal   oparm[5];
  PetscScalar *aux;
  int         naux;

  int (*MatAssemblyEnd)(Mat,MatAssemblyType);
  int (*MatLUFactorSymbolic)(Mat,IS,IS,MatFactorInfo*,Mat*);
  int (*MatDestroy)(Mat);
  PetscTruth CleanUpESSL;
} Mat_SeqAIJ_Essl;

EXTERN_C_BEGIN
#undef __FUNCT__
#define __FUNCT__ "MatConvert_Essl_SeqAIJ"
int MatConvert_Essl_SeqAIJ(Mat A,MatType type,Mat *newmat) {
  int             ierr;
  Mat             B=*newmat;
  Mat_SeqAIJ_Essl *essl = (Mat_SeqAIJ_Essl*)A->spptr;
  
  PetscFunctionBegin;
  if (B != A) {
    ierr = MatDuplicate(A,MAT_COPY_VALUES,&B);
  } else {
    B->ops->matassemblyend   = essl->MatAssemblyEnd;
    B->ops->lufactorsymbolic = essl->MatLUFactorSymbolic;
    B->ops->destroy          = essl->MatDestroy;

    /* free the Essl datastructures */
    ierr = PetscFree(essl);CHKERRQ(ierr);
    ierr = PetscObjectChangeTypeName((PetscObject)B,MATSEQAIJ);CHKERRQ(ierr);
  }
  *newmat = B;
  PetscFunctionReturn(0);
}
EXTERN_C_END  

#undef __FUNCT__  
#define __FUNCT__ "MatDestroy_SeqAIJ_Essl"
int MatDestroy_SeqAIJ_Essl(Mat A)
{
  int             ierr;
  Mat_SeqAIJ_Essl *essl = (Mat_SeqAIJ_Essl*)A->spptr;

  PetscFunctionBegin;
  if (essl->CleanUpESSL) {
    ierr = PetscFree(essl->a);CHKERRQ(ierr);
  }
  ierr = MatConvert_Essl_SeqAIJ(A,MATSEQAIJ,&A);
  ierr = (*A->ops->destroy)(A);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__  
#define __FUNCT__ "MatSolve_SeqAIJ_Essl"
int MatSolve_SeqAIJ_Essl(Mat A,Vec b,Vec x)
{
  Mat_SeqAIJ_Essl *essl = (Mat_SeqAIJ_Essl*)A->spptr;
  PetscScalar     *xx;
  int             ierr,m,zero = 0;

  PetscFunctionBegin;
  ierr = VecGetLocalSize(b,&m);CHKERRQ(ierr);
  ierr = VecCopy(b,x);CHKERRQ(ierr);
  ierr = VecGetArray(x,&xx);CHKERRQ(ierr);
  dgss(&zero,&A->n,essl->a,essl->ia,essl->ja,&essl->lna,xx,essl->aux,&essl->naux);
  ierr = VecRestoreArray(x,&xx);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__  
#define __FUNCT__ "MatLUFactorNumeric_SeqAIJ_Essl"
int MatLUFactorNumeric_SeqAIJ_Essl(Mat A,Mat *F)
{
  Mat_SeqAIJ      *aa = (Mat_SeqAIJ*)(A)->data;
  Mat_SeqAIJ_Essl *essl = (Mat_SeqAIJ_Essl*)(*F)->spptr;
  int             i,ierr,one = 1;

  PetscFunctionBegin;
  /* copy matrix data into silly ESSL data structure (1-based Frotran style) */
  for (i=0; i<A->m+1; i++) essl->ia[i] = aa->i[i] + 1;
  for (i=0; i<aa->nz; i++) essl->ja[i]  = aa->j[i] + 1;
 
  ierr = PetscMemcpy(essl->a,aa->a,(aa->nz)*sizeof(PetscScalar));CHKERRQ(ierr);
  
  /* set Essl options */
  essl->iparm[0] = 1; 
  essl->iparm[1] = 5;
  essl->iparm[2] = 1;
  essl->iparm[3] = 0;
  essl->rparm[0] = 1.e-12;
  essl->rparm[1] = A->lupivotthreshold;

  dgsf(&one,&A->m,&essl->nz,essl->a,essl->ia,essl->ja,&essl->lna,essl->iparm,
               essl->rparm,essl->oparm,essl->aux,&essl->naux);

  PetscFunctionReturn(0);
}

#undef __FUNCT__  
#define __FUNCT__ "MatLUFactorSymbolic_SeqAIJ_Essl"
int MatLUFactorSymbolic_SeqAIJ_Essl(Mat A,IS r,IS c,MatFactorInfo *info,Mat *F)
{
  Mat             B;
  Mat_SeqAIJ      *a = (Mat_SeqAIJ*)A->data;
  int             ierr,len;
  Mat_SeqAIJ_Essl *essl;
  PetscReal       f = 1.0;

  PetscFunctionBegin;
  if (A->N != A->M) SETERRQ(PETSC_ERR_ARG_SIZ,"matrix must be square"); 
  ierr = MatCreate(A->comm,PETSC_DECIDE,PETSC_DECIDE,A->m,A->n,&B);CHKERRQ(ierr);
  ierr = MatSetType(B,MATESSL);CHKERRQ(ierr);
  ierr = MatSeqAIJSetPreallocation(B,0,PETSC_NULL);CHKERRQ(ierr);

  B->ops->solve           = MatSolve_SeqAIJ_Essl;
  B->ops->lufactornumeric = MatLUFactorNumeric_SeqAIJ_Essl;
  B->factor               = FACTOR_LU;
  
  essl = (Mat_SeqAIJ_Essl *)(B->spptr);

  /* allocate the work arrays required by ESSL */
  f = info->fill;
  essl->nz   = a->nz;
  essl->lna  = (int)a->nz*f;
  essl->naux = 100 + 10*A->m;

  /* since malloc is slow on IBM we try a single malloc */
  len               = essl->lna*(2*sizeof(int)+sizeof(PetscScalar)) + essl->naux*sizeof(PetscScalar);
  ierr              = PetscMalloc(len,&essl->a);CHKERRQ(ierr);
  essl->aux         = essl->a + essl->lna;
  essl->ia          = (int*)(essl->aux + essl->naux);
  essl->ja          = essl->ia + essl->lna;
  essl->CleanUpESSL = PETSC_TRUE;

  PetscLogObjectMemory(B,len+sizeof(Mat_SeqAIJ_Essl));
  *F = B;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "MatAssemblyEnd_SeqAIJ_Essl"
int MatAssemblyEnd_SeqAIJ_Essl(Mat A,MatAssemblyType mode) {
  int             ierr;
  Mat_SeqAIJ_Essl *essl=(Mat_SeqAIJ_Essl*)(A->spptr);

  PetscFunctionBegin;
  ierr = (*essl->MatAssemblyEnd)(A,mode);CHKERRQ(ierr);

  essl->MatLUFactorSymbolic = A->ops->lufactorsymbolic;
  A->ops->lufactorsymbolic  = MatLUFactorSymbolic_SeqAIJ_Essl;
  PetscLogInfo(0,"Using ESSL for SeqAIJ LU factorization and solves");
  PetscFunctionReturn(0);
}

EXTERN_C_BEGIN
#undef __FUNCT__
#define __FUNCT__ "MatConvert_SeqAIJ_Essl"
int MatConvert_SeqAIJ_Essl(Mat A,MatType type,Mat *newmat) {
  Mat             B=*newmat;
  int             ierr;
  Mat_SeqAIJ_Essl *essl;

  PetscFunctionBegin;

  if (B != A) {
    ierr = MatDuplicate(A,MAT_COPY_VALUES,&B);CHKERRQ(ierr);
  }

  ierr                      = PetscNew(Mat_SeqAIJ_Essl,&essl);CHKERRQ(ierr);
  essl->MatAssemblyEnd      = A->ops->assemblyend;
  essl->MatLUFactorSymbolic = A->ops->lufactorsymbolic;
  essl->MatDestroy          = A->ops->destroy;
  essl->CleanUpESSL         = PETSC_FALSE;

  B->spptr                  = (void *)essl;
  B->ops->assemblyend       = MatAssemblyEnd_SeqAIJ_Essl;
  B->ops->lufactorsymbolic  = MatLUFactorSymbolic_SeqAIJ_Essl;
  B->ops->destroy           = MatDestroy_SeqAIJ_Essl;

  ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatConvert_seqaij_essl_C",
                                           "MatConvert_SeqAIJ_Essl",MatConvert_SeqAIJ_Essl);CHKERRQ(ierr);
  ierr = PetscObjectComposeFunctionDynamic((PetscObject)B,"MatConvert_essl_seqaij_C",
                                           "MatConvert_Essl_SeqAIJ",MatConvert_Essl_SeqAIJ);CHKERRQ(ierr);
  ierr = PetscObjectChangeTypeName((PetscObject)B,type);CHKERRQ(ierr);
  *newmat = B;
  PetscFunctionReturn(0);
}
EXTERN_C_END

/*MC
  MATESSL - a matrix type providing direct solvers (LU) for sequential matrices 
  via the external package ESSL.

  If ESSL is installed (see the manual for
  instructions on how to declare the existence of external packages),
  a matrix type can be constructed which invokes ESSL solvers.
  After calling MatCreate(...,A), simply call MatSetType(A,MATESSL).
  This matrix type is only supported for double precision real.

  This matrix inherits from MATSEQAIJ.  As a result, MatSeqAIJSetPreallocation is 
  supported for this matrix type.

  Options Database Keys:
. -mat_type essl - sets the matrix type to essl during a call to MatSetFromOptions()

   Level: beginner

.seealso: PCLU
M*/

EXTERN_C_BEGIN
#undef __FUNCT__
#define __FUNCT__ "MatCreate_SeqAIJ_Essl"
int MatCreate_SeqAIJ_Essl(Mat A) {
  int             ierr;

  PetscFunctionBegin;
  ierr = MatSetType(A,MATSEQAIJ);
  ierr = MatConvert_SeqAIJ_Essl(A,MATESSL,&A);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
EXTERN_C_END