qp_plugins_scemama/devel/ccsd_gpu/gpu.c

#include <stdio.h>
#include <stdlib.h>
#include <cublas_v2.h>
#include <cuda_runtime.h>


#define BLOCK_SIZE 16

void dgemm_(char*, char*, int*, int*, int*, double*, double*, int*, double*, int*,
		double*, double*, int*);




void gpu_dgemm(char transa, char transb, int m, int n, int k, double alpha,
                  double* A, int lda, double* B, int ldb, double beta, double* C, int ldc)
{
    cublasHandle_t handle;
    cublasCreate(&handle);

    double * d_A;
    double * d_B;
    double * d_C;
    cublasOperation_t ta, tb;

    if (transa == 'N') {
      cudaMalloc((void**)&d_A, lda*k*sizeof(double));
      cublasSetMatrix(m, k, sizeof(double), A, lda, d_A, lda);
      ta = CUBLAS_OP_N;
    } else {
      cudaMalloc((void**)&d_A, lda*m*sizeof(double));
      cublasSetMatrix(k, m, sizeof(double), A, lda, d_A, lda);
      ta = CUBLAS_OP_T;
    }

    if (transb == 'N') {
      cudaMalloc((void**)&d_B, ldb*n*sizeof(double));
      cublasSetMatrix(k, n, sizeof(double), B, ldb, d_B, ldb);
      tb = CUBLAS_OP_N;
    } else {
      cudaMalloc((void**)&d_B, ldb*k*sizeof(double));
      cublasSetMatrix(n, k, sizeof(double), B, ldb, d_B, ldb);
      tb = CUBLAS_OP_T;
    }

    cudaMalloc((void**)&d_C, ldc*n*sizeof(double));
    if (beta != 0.) {
      cublasSetMatrix(m, n, sizeof(double), C, ldc, d_C, ldc);
    }

    cublasDgemm(handle, ta, tb, m, n, k, &alpha, d_A, lda, d_B, ldb, &beta, d_C, ldc);

    cublasGetMatrix(m, n,  sizeof(double), d_C, ldc, C, ldc);

    cudaFree(d_A);
    cudaFree(d_B);
    cudaFree(d_C);
    cublasDestroy(handle);
}

void compute_r2_space_chol_gpu(const int nO, const int nV, const int cholesky_mo_num,
                double* t1,
                double* tau,
                double* cc_space_v_vo_chol,
                double* cc_space_v_vv_chol,
                double* r2)
{
    int m,n,k, lda, ldb, ldc;
    double alpha, beta;
    double* A;
    double* B;
    double* C;

    cublasHandle_t handle;
    cublasCreate(&handle);

    double* d_tau;
    lda = nO * nO;
    cudaMalloc((void **)&d_tau, lda * nV * nV * sizeof(double));
    cublasSetMatrix(nO*nO, nV*nV, sizeof(double), tau, lda, d_tau, lda);

    double* d_r2;
    lda = nO * nO;
    cudaMalloc((void **)&d_r2, lda * nV * nV * sizeof(double));

    double* d_cc_space_v_vv_chol;
    lda = cholesky_mo_num * nV;
    cudaMalloc((void **)&d_cc_space_v_vv_chol, lda * nV * sizeof(double));
    cublasSetMatrix(cholesky_mo_num*nV, nV, sizeof(double), cc_space_v_vv_chol, lda, d_cc_space_v_vv_chol, lda);

    double* d_cc_space_v_vo_chol;
    lda = cholesky_mo_num * nV;
    cudaMalloc((void **)&d_cc_space_v_vo_chol, lda * nO * sizeof(double));
    cublasSetMatrix(cholesky_mo_num*nV, nO, sizeof(double), cc_space_v_vo_chol, lda, d_cc_space_v_vo_chol, lda);

    double* d_t1;
    lda = nO;
    cudaMalloc((void **)&d_t1, nO * nV * sizeof(double));
    cublasSetMatrix(nO, nV, sizeof(double), t1, lda, d_t1, lda);

    double* d_tmp_cc;
    lda = cholesky_mo_num * nV;
    cudaMalloc((void **)&d_tmp_cc, lda * nV * sizeof(double));

    alpha=1.0; beta=0.0;
    m=cholesky_mo_num*nV;  n=nV;  k=nO;
    A = d_cc_space_v_vo_chol; B = d_t1; C = d_tmp_cc;
    cublasDgemm(handle, CUBLAS_OP_N, CUBLAS_OP_N, m, n, k, &alpha, A, m, B, k, &beta, C, m);
    cublasDestroy(handle);

    #pragma omp parallel
    {
        cublasHandle_t handle;
        cublasCreate(&handle);

        double* d_tmp_cc2;
        cudaMalloc((void **)&d_tmp_cc2, cholesky_mo_num*nV*sizeof(double));

        double* d_B1;
        cudaMalloc((void**)&d_B1, nV*nV*BLOCK_SIZE*sizeof(double));

        double* d_tmpB1;
        cudaMalloc((void**)&d_tmpB1, nV*BLOCK_SIZE*nV*sizeof(double));

        #pragma omp for
        for (size_t gam=0 ; gam<nV ; ++gam)
        {
           double* d_tmp_cc_ = &(d_tmp_cc[gam*nV*cholesky_mo_num]);
           double* d_cc_space_v_vv_chol_ = &(d_cc_space_v_vv_chol[gam*nV*cholesky_mo_num]);

           alpha = 1.0;
           beta = -1.0;
           A = d_cc_space_v_vv_chol_; lda = cholesky_mo_num;
           B = d_tmp_cc_; ldb = cholesky_mo_num;
           C = d_tmp_cc2 ; ldc = cholesky_mo_num;
           cublasDgeam(handle, CUBLAS_OP_N, CUBLAS_OP_N, cholesky_mo_num, nV, &alpha, A, lda, &beta, B, ldb, C, ldc);

           for (size_t iblock=0 ; iblock<nV ; iblock += BLOCK_SIZE)
           {
                const size_t mbs = BLOCK_SIZE < nV-iblock ? BLOCK_SIZE : nV-iblock;

                alpha=-1.0; beta=0.0;
                m=nV*mbs;  n=nV;  k=cholesky_mo_num;

                A=&(d_tmp_cc[iblock*cholesky_mo_num*nV]); lda=cholesky_mo_num;
                B=d_cc_space_v_vv_chol_; ldb=cholesky_mo_num;
                C=d_tmpB1 ; ldc=nV*BLOCK_SIZE;
                cublasDgemm(handle, CUBLAS_OP_T, CUBLAS_OP_N, m, n, k, &alpha, A, lda, B, lda, &beta, C, ldc);

                alpha=1.0; beta=1.0;
                m=nV*mbs;  n=nV;  k=cholesky_mo_num;

                A=&(d_cc_space_v_vv_chol[iblock*cholesky_mo_num*nV]); lda=cholesky_mo_num;
                B=d_tmp_cc2; ldb=cholesky_mo_num;
                C=d_tmpB1 ; ldc=nV*BLOCK_SIZE;
                cublasDgemm(handle, CUBLAS_OP_T, CUBLAS_OP_N, m, n, k, &alpha, A, lda, B, lda, &beta, C, ldc);

                for (size_t bet=iblock ; bet<(nV < iblock+BLOCK_SIZE ? nV : iblock+BLOCK_SIZE) ; ++bet)
                {

                  alpha = 1.0;
                  beta = 0.0;
                  A = &(d_tmpB1[nV*(bet-iblock)]); lda = nV*BLOCK_SIZE;
                  B = d_tmpB1; ldb = nV;
                  C = &(d_B1[nV*nV*(bet-iblock)]) ; ldc = nV;
                  cublasDgeam(handle, CUBLAS_OP_N, CUBLAS_OP_N, nV, nV, &alpha, A, lda, &beta, B, ldb, C, ldc);
               }

               alpha=1.0; beta=1.0;
               m=nO*nO;  n=mbs;  k=nV*nV;

               A=d_tau; lda=nO*nO;
               B=d_B1 ; ldb=nV*nV;
               C=&(d_r2[nO*nO*(iblock + nV*gam)]); ldc=nO*nO;
               cublasDgemm(handle, CUBLAS_OP_N, CUBLAS_OP_N, m, n, k, &alpha, A, lda, B, ldb, &beta, C, ldc);

           }
        }
        cublasDestroy(handle);
    }
    cudaFree(d_cc_space_v_vo_chol);
    cudaFree(d_cc_space_v_vv_chol);
    cudaFree(d_tau);
    cudaFree(d_t1);
    cudaFree(d_tmp_cc);

    double * r2_tmp = malloc(nO*nO*nV*nV*sizeof(double));
    lda=nO*nO;
    cublasGetMatrix(nO*nO, nV*nV, sizeof(double), d_r2, lda, r2_tmp, lda);
    for (size_t i=0 ; i<nO*nO*nV*nV ; ++i) {
      r2[i] += r2_tmp[i];
    }
    free(r2_tmp);

    cudaFree(d_r2);
}