xref: /petsc/src/mat/impls/aij/seq/seqcusparse/cusparsematimpl.h (revision fea72eb484973f5c3972bfccf4548d391b9aa7c2)

#if !defined(CUSPARSEMATIMPL)
  #define CUSPARSEMATIMPL

  #include <petscpkg_version.h>
  #include <petsc/private/cudavecimpl.h>
  #include <petscaijdevice.h>

  #include <cusparse_v2.h>

  #include <algorithm>
  #include <vector>

  #include <thrust/device_vector.h>
  #include <thrust/device_ptr.h>
  #include <thrust/device_malloc_allocator.h>
  #include <thrust/transform.h>
  #include <thrust/functional.h>
  #include <thrust/sequence.h>
  #include <thrust/system/system_error.h>

  #define PetscCallThrust(body) \
    do { \
      try { \
        body; \
      } catch (thrust::system_error & e) { \
        SETERRQ(PETSC_COMM_SELF, PETSC_ERR_LIB, "Error in Thrust %s", e.what()); \
      } \
    } while (0)

  #if defined(PETSC_USE_COMPLEX)
    #if defined(PETSC_USE_REAL_SINGLE)
const cuComplex PETSC_CUSPARSE_ONE  = {1.0f, 0.0f};
const cuComplex PETSC_CUSPARSE_ZERO = {0.0f, 0.0f};
      #define cusparseXcsrilu02_bufferSize(a, b, c, d, e, f, g, h, i)  cusparseCcsrilu02_bufferSize(a, b, c, d, (cuComplex *)e, f, g, h, i)
      #define cusparseXcsrilu02_analysis(a, b, c, d, e, f, g, h, i, j) cusparseCcsrilu02_analysis(a, b, c, d, (cuComplex *)e, f, g, h, i, j)
      #define cusparseXcsrilu02(a, b, c, d, e, f, g, h, i, j)          cusparseCcsrilu02(a, b, c, d, (cuComplex *)e, f, g, h, i, j)
      #define cusparseXcsric02_bufferSize(a, b, c, d, e, f, g, h, i)   cusparseCcsric02_bufferSize(a, b, c, d, (cuComplex *)e, f, g, h, i)
      #define cusparseXcsric02_analysis(a, b, c, d, e, f, g, h, i, j)  cusparseCcsric02_analysis(a, b, c, d, (cuComplex *)e, f, g, h, i, j)
      #define cusparseXcsric02(a, b, c, d, e, f, g, h, i, j)           cusparseCcsric02(a, b, c, d, (cuComplex *)e, f, g, h, i, j)
    #elif defined(PETSC_USE_REAL_DOUBLE)
const cuDoubleComplex PETSC_CUSPARSE_ONE  = {1.0, 0.0};
const cuDoubleComplex PETSC_CUSPARSE_ZERO = {0.0, 0.0};
      #define cusparseXcsrilu02_bufferSize(a, b, c, d, e, f, g, h, i)  cusparseZcsrilu02_bufferSize(a, b, c, d, (cuDoubleComplex *)e, f, g, h, i)
      #define cusparseXcsrilu02_analysis(a, b, c, d, e, f, g, h, i, j) cusparseZcsrilu02_analysis(a, b, c, d, (cuDoubleComplex *)e, f, g, h, i, j)
      #define cusparseXcsrilu02(a, b, c, d, e, f, g, h, i, j)          cusparseZcsrilu02(a, b, c, d, (cuDoubleComplex *)e, f, g, h, i, j)
      #define cusparseXcsric02_bufferSize(a, b, c, d, e, f, g, h, i)   cusparseZcsric02_bufferSize(a, b, c, d, (cuDoubleComplex *)e, f, g, h, i)
      #define cusparseXcsric02_analysis(a, b, c, d, e, f, g, h, i, j)  cusparseZcsric02_analysis(a, b, c, d, (cuDoubleComplex *)e, f, g, h, i, j)
      #define cusparseXcsric02(a, b, c, d, e, f, g, h, i, j)           cusparseZcsric02(a, b, c, d, (cuDoubleComplex *)e, f, g, h, i, j)
    #endif
  #else
const PetscScalar PETSC_CUSPARSE_ONE  = 1.0;
const PetscScalar PETSC_CUSPARSE_ZERO = 0.0;
    #if defined(PETSC_USE_REAL_SINGLE)
      #define cusparseXcsrilu02_bufferSize cusparseScsrilu02_bufferSize
      #define cusparseXcsrilu02_analysis   cusparseScsrilu02_analysis
      #define cusparseXcsrilu02            cusparseScsrilu02
      #define cusparseXcsric02_bufferSize  cusparseScsric02_bufferSize
      #define cusparseXcsric02_analysis    cusparseScsric02_analysis
      #define cusparseXcsric02             cusparseScsric02
    #elif defined(PETSC_USE_REAL_DOUBLE)
      #define cusparseXcsrilu02_bufferSize cusparseDcsrilu02_bufferSize
      #define cusparseXcsrilu02_analysis   cusparseDcsrilu02_analysis
      #define cusparseXcsrilu02            cusparseDcsrilu02
      #define cusparseXcsric02_bufferSize  cusparseDcsric02_bufferSize
      #define cusparseXcsric02_analysis    cusparseDcsric02_analysis
      #define cusparseXcsric02             cusparseDcsric02
    #endif
  #endif

  #if PETSC_PKG_CUDA_VERSION_GE(9, 0, 0)
    #define csrsvInfo_t              csrsv2Info_t
    #define cusparseCreateCsrsvInfo  cusparseCreateCsrsv2Info
    #define cusparseDestroyCsrsvInfo cusparseDestroyCsrsv2Info
    #if defined(PETSC_USE_COMPLEX)
      #if defined(PETSC_USE_REAL_SINGLE)
        #define cusparseXcsrsv_buffsize(a, b, c, d, e, f, g, h, i, j)          cusparseCcsrsv2_bufferSize(a, b, c, d, e, (cuComplex *)(f), g, h, i, j)
        #define cusparseXcsrsv_analysis(a, b, c, d, e, f, g, h, i, j, k)       cusparseCcsrsv2_analysis(a, b, c, d, e, (const cuComplex *)(f), g, h, i, j, k)
        #define cusparseXcsrsv_solve(a, b, c, d, e, f, g, h, i, j, k, l, m, n) cusparseCcsrsv2_solve(a, b, c, d, (const cuComplex *)(e), f, (const cuComplex *)(g), h, i, j, (const cuComplex *)(k), (cuComplex *)(l), m, n)
      #elif defined(PETSC_USE_REAL_DOUBLE)
        #define cusparseXcsrsv_buffsize(a, b, c, d, e, f, g, h, i, j)          cusparseZcsrsv2_bufferSize(a, b, c, d, e, (cuDoubleComplex *)(f), g, h, i, j)
        #define cusparseXcsrsv_analysis(a, b, c, d, e, f, g, h, i, j, k)       cusparseZcsrsv2_analysis(a, b, c, d, e, (const cuDoubleComplex *)(f), g, h, i, j, k)
        #define cusparseXcsrsv_solve(a, b, c, d, e, f, g, h, i, j, k, l, m, n) cusparseZcsrsv2_solve(a, b, c, d, (const cuDoubleComplex *)(e), f, (const cuDoubleComplex *)(g), h, i, j, (const cuDoubleComplex *)(k), (cuDoubleComplex *)(l), m, n)
      #endif
    #else /* not complex */
      #if defined(PETSC_USE_REAL_SINGLE)
        #define cusparseXcsrsv_buffsize cusparseScsrsv2_bufferSize
        #define cusparseXcsrsv_analysis cusparseScsrsv2_analysis
        #define cusparseXcsrsv_solve    cusparseScsrsv2_solve
      #elif defined(PETSC_USE_REAL_DOUBLE)
        #define cusparseXcsrsv_buffsize cusparseDcsrsv2_bufferSize
        #define cusparseXcsrsv_analysis cusparseDcsrsv2_analysis
        #define cusparseXcsrsv_solve    cusparseDcsrsv2_solve
      #endif
    #endif
  #else
    #define csrsvInfo_t              cusparseSolveAnalysisInfo_t
    #define cusparseCreateCsrsvInfo  cusparseCreateSolveAnalysisInfo
    #define cusparseDestroyCsrsvInfo cusparseDestroySolveAnalysisInfo
    #if defined(PETSC_USE_COMPLEX)
      #if defined(PETSC_USE_REAL_SINGLE)
        #define cusparseXcsrsv_solve(a, b, c, d, e, f, g, h, i, j, k) cusparseCcsrsv_solve((a), (b), (c), (cuComplex *)(d), (e), (cuComplex *)(f), (g), (h), (i), (cuComplex *)(j), (cuComplex *)(k))
        #define cusparseXcsrsv_analysis(a, b, c, d, e, f, g, h, i)    cusparseCcsrsv_analysis((a), (b), (c), (d), (e), (cuComplex *)(f), (g), (h), (i))
      #elif defined(PETSC_USE_REAL_DOUBLE)
        #define cusparseXcsrsv_solve(a, b, c, d, e, f, g, h, i, j, k) cusparseZcsrsv_solve((a), (b), (c), (cuDoubleComplex *)(d), (e), (cuDoubleComplex *)(f), (g), (h), (i), (cuDoubleComplex *)(j), (cuDoubleComplex *)(k))
        #define cusparseXcsrsv_analysis(a, b, c, d, e, f, g, h, i)    cusparseZcsrsv_analysis((a), (b), (c), (d), (e), (cuDoubleComplex *)(f), (g), (h), (i))
      #endif
    #else /* not complex */
      #if defined(PETSC_USE_REAL_SINGLE)
        #define cusparseXcsrsv_solve    cusparseScsrsv_solve
        #define cusparseXcsrsv_analysis cusparseScsrsv_analysis
      #elif defined(PETSC_USE_REAL_DOUBLE)
        #define cusparseXcsrsv_solve    cusparseDcsrsv_solve
        #define cusparseXcsrsv_analysis cusparseDcsrsv_analysis
      #endif
    #endif
  #endif

  #if PETSC_PKG_CUDA_VERSION_GE(11, 0, 0)
    #define cusparse_csr2csc cusparseCsr2cscEx2
    #if defined(PETSC_USE_COMPLEX)
      #if defined(PETSC_USE_REAL_SINGLE)
        #define cusparse_scalartype                                                             CUDA_C_32F
        #define cusparse_csr_spgeam(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t) cusparseCcsrgeam2(a, b, c, (cuComplex *)d, e, f, (cuComplex *)g, h, i, (cuComplex *)j, k, l, (cuComplex *)m, n, o, p, (cuComplex *)q, r, s, t)
        #define cusparse_csr_spgeam_bufferSize(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t) \
          cusparseCcsrgeam2_bufferSizeExt(a, b, c, (cuComplex *)d, e, f, (cuComplex *)g, h, i, (cuComplex *)j, k, l, (cuComplex *)m, n, o, p, (cuComplex *)q, r, s, t)
      #elif defined(PETSC_USE_REAL_DOUBLE)
        #define cusparse_scalartype CUDA_C_64F
        #define cusparse_csr_spgeam(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t) \
          cusparseZcsrgeam2(a, b, c, (cuDoubleComplex *)d, e, f, (cuDoubleComplex *)g, h, i, (cuDoubleComplex *)j, k, l, (cuDoubleComplex *)m, n, o, p, (cuDoubleComplex *)q, r, s, t)
        #define cusparse_csr_spgeam_bufferSize(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t) \
          cusparseZcsrgeam2_bufferSizeExt(a, b, c, (cuDoubleComplex *)d, e, f, (cuDoubleComplex *)g, h, i, (cuDoubleComplex *)j, k, l, (cuDoubleComplex *)m, n, o, p, (cuDoubleComplex *)q, r, s, t)
      #endif
    #else /* not complex */
      #if defined(PETSC_USE_REAL_SINGLE)
        #define cusparse_scalartype            CUDA_R_32F
        #define cusparse_csr_spgeam            cusparseScsrgeam2
        #define cusparse_csr_spgeam_bufferSize cusparseScsrgeam2_bufferSizeExt
      #elif defined(PETSC_USE_REAL_DOUBLE)
        #define cusparse_scalartype            CUDA_R_64F
        #define cusparse_csr_spgeam            cusparseDcsrgeam2
        #define cusparse_csr_spgeam_bufferSize cusparseDcsrgeam2_bufferSizeExt
      #endif
    #endif
  #else
    #if defined(PETSC_USE_COMPLEX)
      #if defined(PETSC_USE_REAL_SINGLE)
        #define cusparse_csr_spmv(a, b, c, d, e, f, g, h, i, j, k, l, m)                        cusparseCcsrmv((a), (b), (c), (d), (e), (cuComplex *)(f), (g), (cuComplex *)(h), (i), (j), (cuComplex *)(k), (cuComplex *)(l), (cuComplex *)(m))
        #define cusparse_csr_spmm(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p)               cusparseCcsrmm((a), (b), (c), (d), (e), (f), (cuComplex *)(g), (h), (cuComplex *)(i), (j), (k), (cuComplex *)(l), (m), (cuComplex *)(n), (cuComplex *)(o), (p))
        #define cusparse_csr2csc(a, b, c, d, e, f, g, h, i, j, k, l)                            cusparseCcsr2csc((a), (b), (c), (d), (cuComplex *)(e), (f), (g), (cuComplex *)(h), (i), (j), (k), (l))
        #define cusparse_hyb_spmv(a, b, c, d, e, f, g, h)                                       cusparseChybmv((a), (b), (cuComplex *)(c), (d), (e), (cuComplex *)(f), (cuComplex *)(g), (cuComplex *)(h))
        #define cusparse_csr2hyb(a, b, c, d, e, f, g, h, i, j)                                  cusparseCcsr2hyb((a), (b), (c), (d), (cuComplex *)(e), (f), (g), (h), (i), (j))
        #define cusparse_hyb2csr(a, b, c, d, e, f)                                              cusparseChyb2csr((a), (b), (c), (cuComplex *)(d), (e), (f))
        #define cusparse_csr_spgemm(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t) cusparseCcsrgemm(a, b, c, d, e, f, g, h, (cuComplex *)i, j, k, l, m, (cuComplex *)n, o, p, q, (cuComplex *)r, s, t)
        #define cusparse_csr_spgeam(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s)    cusparseCcsrgeam(a, b, c, (cuComplex *)d, e, f, (cuComplex *)g, h, i, (cuComplex *)j, k, l, (cuComplex *)m, n, o, p, (cuComplex *)q, r, s)
      #elif defined(PETSC_USE_REAL_DOUBLE)
        #define cusparse_csr_spmv(a, b, c, d, e, f, g, h, i, j, k, l, m) cusparseZcsrmv((a), (b), (c), (d), (e), (cuDoubleComplex *)(f), (g), (cuDoubleComplex *)(h), (i), (j), (cuDoubleComplex *)(k), (cuDoubleComplex *)(l), (cuDoubleComplex *)(m))
        #define cusparse_csr_spmm(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) \
          cusparseZcsrmm((a), (b), (c), (d), (e), (f), (cuDoubleComplex *)(g), (h), (cuDoubleComplex *)(i), (j), (k), (cuDoubleComplex *)(l), (m), (cuDoubleComplex *)(n), (cuDoubleComplex *)(o), (p))
        #define cusparse_csr2csc(a, b, c, d, e, f, g, h, i, j, k, l)                            cusparseZcsr2csc((a), (b), (c), (d), (cuDoubleComplex *)(e), (f), (g), (cuDoubleComplex *)(h), (i), (j), (k), (l))
        #define cusparse_hyb_spmv(a, b, c, d, e, f, g, h)                                       cusparseZhybmv((a), (b), (cuDoubleComplex *)(c), (d), (e), (cuDoubleComplex *)(f), (cuDoubleComplex *)(g), (cuDoubleComplex *)(h))
        #define cusparse_csr2hyb(a, b, c, d, e, f, g, h, i, j)                                  cusparseZcsr2hyb((a), (b), (c), (d), (cuDoubleComplex *)(e), (f), (g), (h), (i), (j))
        #define cusparse_hyb2csr(a, b, c, d, e, f)                                              cusparseZhyb2csr((a), (b), (c), (cuDoubleComplex *)(d), (e), (f))
        #define cusparse_csr_spgemm(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t) cusparseZcsrgemm(a, b, c, d, e, f, g, h, (cuDoubleComplex *)i, j, k, l, m, (cuDoubleComplex *)n, o, p, q, (cuDoubleComplex *)r, s, t)
        #define cusparse_csr_spgeam(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s) \
          cusparseZcsrgeam(a, b, c, (cuDoubleComplex *)d, e, f, (cuDoubleComplex *)g, h, i, (cuDoubleComplex *)j, k, l, (cuDoubleComplex *)m, n, o, p, (cuDoubleComplex *)q, r, s)
      #endif
    #else
      #if defined(PETSC_USE_REAL_SINGLE)
        #define cusparse_csr_spmv   cusparseScsrmv
        #define cusparse_csr_spmm   cusparseScsrmm
        #define cusparse_csr2csc    cusparseScsr2csc
        #define cusparse_hyb_spmv   cusparseShybmv
        #define cusparse_csr2hyb    cusparseScsr2hyb
        #define cusparse_hyb2csr    cusparseShyb2csr
        #define cusparse_csr_spgemm cusparseScsrgemm
        #define cusparse_csr_spgeam cusparseScsrgeam
      #elif defined(PETSC_USE_REAL_DOUBLE)
        #define cusparse_csr_spmv   cusparseDcsrmv
        #define cusparse_csr_spmm   cusparseDcsrmm
        #define cusparse_csr2csc    cusparseDcsr2csc
        #define cusparse_hyb_spmv   cusparseDhybmv
        #define cusparse_csr2hyb    cusparseDcsr2hyb
        #define cusparse_hyb2csr    cusparseDhyb2csr
        #define cusparse_csr_spgemm cusparseDcsrgemm
        #define cusparse_csr_spgeam cusparseDcsrgeam
      #endif
    #endif
  #endif

  #define THRUSTINTARRAY32 thrust::device_vector<int>
  #define THRUSTINTARRAY   thrust::device_vector<PetscInt>
  #define THRUSTARRAY      thrust::device_vector<PetscScalar>

/* A CSR matrix structure */
struct CsrMatrix {
  PetscInt          num_rows;
  PetscInt          num_cols;
  PetscInt          num_entries;
  THRUSTINTARRAY32 *row_offsets;
  THRUSTINTARRAY32 *column_indices;
  THRUSTARRAY      *values;
};

/* This is struct holding the relevant data needed to a MatSolve */
struct Mat_SeqAIJCUSPARSETriFactorStruct {
  /* Data needed for triangular solve */
  cusparseMatDescr_t    descr;
  cusparseOperation_t   solveOp;
  CsrMatrix            *csrMat;
  csrsvInfo_t           solveInfo;
  cusparseSolvePolicy_t solvePolicy; /* whether level information is generated and used */
  int                   solveBufferSize;
  void                 *solveBuffer;
  size_t                csr2cscBufferSize; /* to transpose the triangular factor (only used for CUDA >= 11.0) */
  void                 *csr2cscBuffer;
  PetscScalar          *AA_h; /* managed host buffer for moving values to the GPU */
};

/* This is a larger struct holding all the triangular factors for a solve, transpose solve, and any indices used in a reordering */
struct Mat_SeqAIJCUSPARSETriFactors {
  Mat_SeqAIJCUSPARSETriFactorStruct *loTriFactorPtr;          /* pointer for lower triangular (factored matrix) on GPU */
  Mat_SeqAIJCUSPARSETriFactorStruct *upTriFactorPtr;          /* pointer for upper triangular (factored matrix) on GPU */
  Mat_SeqAIJCUSPARSETriFactorStruct *loTriFactorPtrTranspose; /* pointer for lower triangular (factored matrix) on GPU for the transpose (useful for BiCG) */
  Mat_SeqAIJCUSPARSETriFactorStruct *upTriFactorPtrTranspose; /* pointer for upper triangular (factored matrix) on GPU for the transpose (useful for BiCG)*/
  THRUSTINTARRAY                    *rpermIndices;            /* indices used for any reordering */
  THRUSTINTARRAY                    *cpermIndices;            /* indices used for any reordering */
  THRUSTARRAY                       *workVector;
  cusparseHandle_t                   handle;   /* a handle to the cusparse library */
  PetscInt                           nnz;      /* number of nonzeros ... need this for accurate logging between ICC and ILU */
  PetscScalar                       *a_band_d; /* GPU data for banded CSR LU factorization matrix diag(L)=1 */
  int                               *i_band_d; /* this could be optimized away */
  cudaDeviceProp                     dev_prop;
  PetscBool                          init_dev_prop;

  /* csrilu0/csric0 appeared in cusparse-8.0, but we use it along with cusparseSpSV,
     which first appeared in cusparse-11.5 with cuda-11.3.
  */
  PetscBool factorizeOnDevice; /* Do factorization on device or not */
  #if CUSPARSE_VERSION >= 11500
  PetscScalar *csrVal;
  int         *csrRowPtr, *csrColIdx; /* a,i,j of M. Using int since some cusparse APIs only support 32-bit indices */

  /* Mixed mat descriptor types? yes, different cusparse APIs use different types */
  cusparseMatDescr_t   matDescr_M;
  cusparseSpMatDescr_t spMatDescr_L, spMatDescr_U;
  cusparseSpSVDescr_t  spsvDescr_L, spsvDescr_Lt, spsvDescr_U, spsvDescr_Ut;

  cusparseDnVecDescr_t dnVecDescr_X, dnVecDescr_Y;
  PetscScalar         *X, *Y; /* data array of dnVec X and Y */

  /* Mixed size types? yes, CUDA-11.7.0 declared cusparseDcsrilu02_bufferSizeExt() that returns size_t but did not implement it! */
  int    factBufferSize_M; /* M ~= LU or LLt */
  size_t spsvBufferSize_L, spsvBufferSize_Lt, spsvBufferSize_U, spsvBufferSize_Ut;
  /* cusparse needs various buffers for factorization and solve of L, U, Lt, or Ut.
     So save memory, we share the factorization buffer with one of spsvBuffer_L/U.
  */
  void *factBuffer_M, *spsvBuffer_L, *spsvBuffer_U, *spsvBuffer_Lt, *spsvBuffer_Ut;

  csrilu02Info_t        ilu0Info_M;
  csric02Info_t         ic0Info_M;
  int                   structural_zero, numerical_zero;
  cusparseSolvePolicy_t policy_M;

  /* In MatSolveTranspose() for ILU0, we use the two flags to do on-demand solve */
  PetscBool createdTransposeSpSVDescr;    /* Have we created SpSV descriptors for Lt, Ut? */
  PetscBool updatedTransposeSpSVAnalysis; /* Have we updated SpSV analysis with the latest L, U values? */

  PetscLogDouble numericFactFlops; /* Estimated FLOPs in ILU0/ICC0 numeric factorization */
  #endif
};

struct Mat_CusparseSpMV {
  PetscBool initialized;    /* Don't rely on spmvBuffer != NULL to test if the struct is initialized, */
  size_t    spmvBufferSize; /* since I'm not sure if smvBuffer can be NULL even after cusparseSpMV_bufferSize() */
  void     *spmvBuffer;
  #if PETSC_PKG_CUDA_VERSION_GE(11, 0, 0)    /* these are present from CUDA 10.1, but PETSc code makes use of them from CUDA 11 on */
  cusparseDnVecDescr_t vecXDescr, vecYDescr; /* descriptor for the dense vectors in y=op(A)x */
  #endif
};

/* This is struct holding the relevant data needed to a MatMult */
struct Mat_SeqAIJCUSPARSEMultStruct {
  void              *mat;          /* opaque pointer to a matrix. This could be either a cusparseHybMat_t or a CsrMatrix */
  cusparseMatDescr_t descr;        /* Data needed to describe the matrix for a multiply */
  THRUSTINTARRAY    *cprowIndices; /* compressed row indices used in the parallel SpMV */
  PetscScalar       *alpha_one;    /* pointer to a device "scalar" storing the alpha parameter in the SpMV */
  PetscScalar       *beta_zero;    /* pointer to a device "scalar" storing the beta parameter in the SpMV as zero*/
  PetscScalar       *beta_one;     /* pointer to a device "scalar" storing the beta parameter in the SpMV as one */
  #if PETSC_PKG_CUDA_VERSION_GE(11, 0, 0)
  cusparseSpMatDescr_t matDescr;  /* descriptor for the matrix, used by SpMV and SpMM */
  Mat_CusparseSpMV     cuSpMV[3]; /* different Mat_CusparseSpMV structs for non-transpose, transpose, conj-transpose */
  Mat_SeqAIJCUSPARSEMultStruct() : matDescr(NULL)
  {
    for (int i = 0; i < 3; i++) cuSpMV[i].initialized = PETSC_FALSE;
  }
  #endif
};

/* This is a larger struct holding all the matrices for a SpMV, and SpMV Transpose */
struct Mat_SeqAIJCUSPARSE {
  Mat_SeqAIJCUSPARSEMultStruct *mat;            /* pointer to the matrix on the GPU */
  Mat_SeqAIJCUSPARSEMultStruct *matTranspose;   /* pointer to the matrix on the GPU (for the transpose ... useful for BiCG) */
  THRUSTARRAY                  *workVector;     /* pointer to a workvector to which we can copy the relevant indices of a vector we want to multiply */
  THRUSTINTARRAY32             *rowoffsets_gpu; /* rowoffsets on GPU in non-compressed-row format. It is used to convert CSR to CSC */
  PetscInt                      nrows;          /* number of rows of the matrix seen by GPU */
  MatCUSPARSEStorageFormat      format;         /* the storage format for the matrix on the device */
  PetscBool                     use_cpu_solve;  /* Use AIJ_Seq (I)LU solve */
  cudaStream_t                  stream;         /* a stream for the parallel SpMV ... this is not owned and should not be deleted */
  cusparseHandle_t              handle;         /* a handle to the cusparse library ... this may not be owned (if we're working in parallel i.e. multiGPUs) */
  PetscObjectState              nonzerostate;   /* track nonzero state to possibly recreate the GPU matrix */
  #if PETSC_PKG_CUDA_VERSION_GE(11, 0, 0)
  size_t               csr2cscBufferSize; /* stuff used to compute the matTranspose above */
  void                *csr2cscBuffer;     /* This is used as a C struct and is calloc'ed by PetscNew() */
  cusparseCsr2CscAlg_t csr2cscAlg;        /* algorithms can be selected from command line options */
  cusparseSpMVAlg_t    spmvAlg;
  cusparseSpMMAlg_t    spmmAlg;
  #endif
  THRUSTINTARRAY            *csr2csc_i;
  PetscSplitCSRDataStructure deviceMat; /* Matrix on device for, eg, assembly */

  /* Stuff for basic COO support */
  THRUSTINTARRAY *cooPerm;   /* permutation array that sorts the input coo entris by row and col */
  THRUSTINTARRAY *cooPerm_a; /* ordered array that indicate i-th nonzero (after sorting) is the j-th unique nonzero */

  /* Stuff for extended COO support */
  PetscBool   use_extended_coo; /* Use extended COO format */
  PetscCount *jmap_d;           /* perm[disp+jmap[i]..disp+jmap[i+1]) gives indices of entries in v[] associated with i-th nonzero of the matrix */
  PetscCount *perm_d;

  Mat_SeqAIJCUSPARSE() : use_extended_coo(PETSC_FALSE), perm_d(NULL), jmap_d(NULL) { }
};

PETSC_INTERN PetscErrorCode MatSeqAIJCUSPARSECopyToGPU(Mat);
PETSC_INTERN PetscErrorCode MatSetPreallocationCOO_SeqAIJCUSPARSE_Basic(Mat, PetscCount, PetscInt[], PetscInt[]);
PETSC_INTERN PetscErrorCode MatSetValuesCOO_SeqAIJCUSPARSE_Basic(Mat, const PetscScalar[], InsertMode);
PETSC_INTERN PetscErrorCode MatSeqAIJCUSPARSEMergeMats(Mat, Mat, MatReuse, Mat *);
PETSC_INTERN PetscErrorCode MatSeqAIJCUSPARSETriFactors_Reset(Mat_SeqAIJCUSPARSETriFactors_p *);

static inline bool isCudaMem(const void *data)
{
  cudaError_t                  cerr;
  struct cudaPointerAttributes attr;
  enum cudaMemoryType          mtype;
  cerr = cudaPointerGetAttributes(&attr, data); /* Do not check error since before CUDA 11.0, passing a host pointer returns cudaErrorInvalidValue */
  cudaGetLastError();                           /* Reset the last error */
  #if (CUDART_VERSION < 10000)
  mtype = attr.memoryType;
  #else
  mtype = attr.type;
  #endif
  if (cerr == cudaSuccess && mtype == cudaMemoryTypeDevice) return true;
  else return false;
}

#endif