OpenBLAS/kernel/x86_64/shdot.c

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#include "common.h"

#if defined(COOPERLAKE)
#include "shdot_microk_cooperlake.c"
#endif

static float shdot_compute(BLASLONG n, bfloat16 *x, BLASLONG inc_x, bfloat16 *y, BLASLONG inc_y)
{
    float d = 0.0;

#ifdef HAVE_SHDOT_ACCL_KERNEL
    if ((inc_x == 1) && (inc_y == 1)) {
        return shdot_accl_kernel(n, x, y);
    }
#endif

    float * x_fp32 = malloc(sizeof(float)*n);
    float * y_fp32 = malloc(sizeof(float)*n);

    SBF16TOS_K(n, x, inc_x, x_fp32, 1);
    SBF16TOS_K(n, y, inc_y, y_fp32, 1);

    d = SDOTU_K(n, x_fp32, 1, y_fp32, 1);

    free(x_fp32);
    free(y_fp32);

    return d;
}

#if defined(SMP)
static int shdot_thread_func(BLASLONG n, BLASLONG dummy0, BLASLONG dummy1, bfloat16 dummy2,
		            bfloat16 *x, BLASLONG inc_x, bfloat16 *y, BLASLONG inc_y,
			    float *result, BLASLONG dummy3)
{
    *(float *)result = shdot_compute(n, x, inc_x, y, inc_y);
    return 0;
}

extern int blas_level1_thread_with_return_value(int mode, BLASLONG m, BLASLONG n, BLASLONG k, void *alpha,
                            void *a, BLASLONG lda, void *b, BLASLONG ldb, void *c, BLASLONG ldc,
			    int (*function)(), int nthreads);
#endif

float CNAME(BLASLONG n, bfloat16 *x, BLASLONG inc_x, bfloat16 *y, BLASLONG inc_y)
{
    float dot_result = 0.0;

    if (n <= 0)  return 0.0;

#if defined(SMP)
    int nthreads;
    int thread_thres = 40960;
    bfloat16 dummy_alpha;
#endif

#if defined(SMP)
    if (inc_x == 0 || inc_y == 0 || n <= thread_thres)
        nthreads = 1;
    else
        nthreads = num_cpu_avail(1);

    int best_threads = (int) (n/(float)thread_thres + 0.5);

    if (best_threads < nthreads) {
        nthreads = best_threads;
    }

    if (nthreads <= 1) {
        dot_result = shdot_compute(n, x, inc_x, y, inc_y);
    } else {
        char thread_result[MAX_CPU_NUMBER * sizeof(double) * 2];
        int mode = BLAS_BFLOAT16 | BLAS_REAL;
        blas_level1_thread_with_return_value(mode, n, 0, 0, &dummy_alpha,
                                             x, inc_x, y, inc_y, thread_result, 0,
                                             (void *)shdot_thread_func, nthreads);
        float * ptr = (float *)thread_result;
        for (int i = 0; i < nthreads; i++) {
            dot_result += (*ptr);
            ptr = (float *)(((char *)ptr) + sizeof(double) * 2);
        }
    }
#else
    dot_result = shdot_compute(n, x, inc_x, y, inc_y);
#endif

    return dot_result;
}