OpenBLAS/kernel/arm64/bgemv_n_sve_v3x4.c

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#include "common.h"

#include <arm_sve.h>
#include <arm_neon.h>

#define UPDATE_PTRSx2 \
    a_ptr1 = a_ptr0 + lda;

#define UPDATE_PTRSx4 \
    UPDATE_PTRSx2 \
    a_ptr2 = a_ptr1 + lda; \
    a_ptr3 = a_ptr2 + lda;

#define UPDATE_PTRSx8 \
    UPDATE_PTRSx4 \
    a_ptr4 = a_ptr3 + lda; \
    a_ptr5 = a_ptr4 + lda; \
    a_ptr6 = a_ptr5 + lda; \
    a_ptr7 = a_ptr6 + lda;

#define LANESx2(MACRO, offset) \
    MACRO(offset, 0) \
    MACRO(offset, 1)

#define LANESx4(MACRO, offset) \
    LANESx2(MACRO, offset) \
    MACRO(offset, 2) \
    MACRO(offset, 3)

#define LANESx8(MACRO, offset) \
    LANESx4(MACRO, offset) \
    MACRO(offset, 4) \
    MACRO(offset, 5) \
    MACRO(offset, 6) \
    MACRO(offset, 7)

#define LOAD_A_VEC(offset, vec) \
    svbfloat16_t a_vec ## offset ## vec = svld1(pg_full, &a_ptr ## vec[i] + offset * sve_size_bf16);

#define UPDATE_ACCUMULATORS_FROM_LANE(offset, lane) \
    acc ## offset ## 0 = svbfmlalb_lane(acc ## offset ## 0, a_vec ## offset ## lane, x_vec, lane); \
    acc ## offset ## 1 = svbfmlalt_lane(acc ## offset ## 1, a_vec ## offset ## lane, x_vec, lane);

#define INIT_ACCUMULATORS(offset) \
    svfloat32_t acc ## offset ## 0 = svdup_f32(0.0); \
    svfloat32_t acc ## offset ## 1 = svdup_f32(0.0);

#define UPDATE_ACCUMULATORS(offset) \
    acc ## offset ## 0 = svbfmlalb(acc ## offset ## 0, a_vec ## offset ## 0, x_vec); \
    acc ## offset ## 1 = svbfmlalt(acc ## offset ## 1, a_vec ## offset ## 0, x_vec);

#define STORE_ACCUMULATORS(offset) \
    svbfloat16_t acc ## offset ## 0_bf16 = svcvt_bf16_x(pg_full, acc ## offset ## 0); \
    svbfloat16_t acc ## offset ## 1_bf16 = svcvt_bf16_x(pg_full, acc ## offset ## 1); \
    svbfloat16_t combined ## offset = svtrn1(acc ## offset ## 0_bf16, acc ## offset ## 1_bf16); \
    svst1(pg_full, &y[i] + offset * sve_size_bf16, combined ## offset);

#define ALPHA_OP(offset) \
    acc ## offset ## 0 = svmul_x(pg_full, acc ## offset ## 0, svalpha); \
    acc ## offset ## 1 = svmul_x(pg_full, acc ## offset ## 1, svalpha);

#define BETA_OP(offset) \
    svbfloat16_t y_vec ## offset = svld1(pg_full, &y[i] + offset * sve_size_bf16); \
    acc ## offset ## 0 = svbfmlalb(acc ## offset ## 0, svbeta16, y_vec ## offset); \
    acc ## offset ## 1 = svbfmlalt(acc ## offset ## 1, svbeta16, y_vec ## offset);

int CNAME(BLASLONG m, BLASLONG n, FLOAT alpha, IFLOAT *a_in, BLASLONG lda, IFLOAT *x_in, BLASLONG inc_x, FLOAT beta, FLOAT *y_in, BLASLONG inc_y) 
{
    BLASLONG ix;
    bfloat16_t *a_ptr0, *a_ptr1, *a_ptr2, *a_ptr3, *a_ptr4, *a_ptr5, *a_ptr6, *a_ptr7;
    BLASLONG sve_size_bf16 = svcnth();
    BLASLONG sve_size2_bf16 = sve_size_bf16 * 2;
    BLASLONG sve_size3_bf16 = sve_size_bf16 * 3;
    svbool_t pg_full = svptrue_b16();
    svbool_t pg_tail = svwhilelt_b16_s64(0, m % sve_size_bf16);

    BLASLONG n8 = n & -8;
    BLASLONG n4 = n & -4;
    BLASLONG n2 = n & -2;
    
    bfloat16_t *a = (bfloat16_t*)a_in;
    bfloat16_t *x = (bfloat16_t*)x_in;
    bfloat16_t *y = (bfloat16_t*)y_in;

    bfloat16_t alpha_bf16, beta_bf16;
    memcpy(&alpha_bf16, &alpha, sizeof(bfloat16_t));
    memcpy(&beta_bf16, &beta, sizeof(bfloat16_t));
    float beta_f32 = vcvtah_f32_bf16(beta_bf16);
    float alpha_f32 = vcvtah_f32_bf16(alpha_bf16);
    svfloat32_t svalpha = svdup_f32(vcvtah_f32_bf16(alpha_bf16));
    svbfloat16_t svbeta16 = svdup_bf16(beta_bf16);
    
    BLASLONG i = 0;
    if (inc_y == 1) {
        for (; (i + sve_size3_bf16 - 1) < m; i+= sve_size3_bf16) {
            INIT_ACCUMULATORS(0);
            INIT_ACCUMULATORS(1);
            INIT_ACCUMULATORS(2);

            BLASLONG j = 0;
            ix = 0;
            a_ptr0 = a;
            UPDATE_PTRSx8;

            if (inc_x == 1) {
                for (; j < n4; j+= 4) {
                    uint64_t* x_u64 = (uint64_t*)&x[ix];
                    svbfloat16_t x_vec = svreinterpret_bf16_u64(svdup_u64(*x_u64));

                    LANESx4(LOAD_A_VEC, 0);
                    LANESx4(LOAD_A_VEC, 1);
                    LANESx4(LOAD_A_VEC, 2);
                    LANESx4(UPDATE_ACCUMULATORS_FROM_LANE, 0);
                    LANESx4(UPDATE_ACCUMULATORS_FROM_LANE, 1);
                    LANESx4(UPDATE_ACCUMULATORS_FROM_LANE, 2);

                    ix += 4;

                    a_ptr0 += 4 * lda;
                    UPDATE_PTRSx4;
                }

                for (; j < n2; j+= 2) {
                    uint32_t* x_u32 = (uint32_t*)&x[ix];
                    svbfloat16_t x_vec = svreinterpret_bf16_u32(svdup_u32(*x_u32));

                    LANESx2(LOAD_A_VEC, 0);
                    LANESx2(LOAD_A_VEC, 1);
                    LANESx2(LOAD_A_VEC, 2);
                    LANESx2(UPDATE_ACCUMULATORS_FROM_LANE, 0);
                    LANESx2(UPDATE_ACCUMULATORS_FROM_LANE, 1);
                    LANESx2(UPDATE_ACCUMULATORS_FROM_LANE, 2);

                    ix += 2;

                    a_ptr0 += 2 * lda;
                    UPDATE_PTRSx2;
                }
            }

            for (; j < n; j++) {
                svbfloat16_t x_vec = svdup_bf16(x[ix]);
                LOAD_A_VEC(0, 0);
                LOAD_A_VEC(1, 0);
                LOAD_A_VEC(2, 0);
                UPDATE_ACCUMULATORS(0);
                UPDATE_ACCUMULATORS(1);
                UPDATE_ACCUMULATORS(2);

                ix += inc_x;
                a_ptr0 += lda;
            }

            if (alpha_f32 != ONE) {
                ALPHA_OP(0);
                ALPHA_OP(1);
                ALPHA_OP(2);
            }
            if (beta_f32 != ZERO) {
                BETA_OP(0);
                BETA_OP(1);
                BETA_OP(2);
            }

            STORE_ACCUMULATORS(0);
            STORE_ACCUMULATORS(1);
            STORE_ACCUMULATORS(2);
        }

        for (; (i + sve_size_bf16 - 1) < m; i+= sve_size_bf16) {
            INIT_ACCUMULATORS(0);

            BLASLONG j = 0;
            ix = 0;
            a_ptr0 = a;
            UPDATE_PTRSx8;

            if (inc_x == 1) {
                for (; j < n8; j+= 8) {
                    svbfloat16_t x_vec = svld1rq(pg_full, &x[ix]);
                    LANESx8(LOAD_A_VEC, 0);
                    LANESx8(UPDATE_ACCUMULATORS_FROM_LANE, 0);

                    ix += 8;

                    a_ptr0 += 8 * lda;
                    UPDATE_PTRSx8;
                }

                for (; j < n4; j+= 4) {
                    uint64_t* x_u64 = (uint64_t*)&x[ix];
                    svbfloat16_t x_vec = svreinterpret_bf16_u64(svdup_u64(*x_u64));

                    LANESx4(LOAD_A_VEC, 0);
                    LANESx4(UPDATE_ACCUMULATORS_FROM_LANE, 0);

                    ix += 4;

                    a_ptr0 += 4 * lda;
                    UPDATE_PTRSx4;
                }

                for (; j < n2; j+= 2) {
                    uint32_t* x_u32 = (uint32_t*)&x[ix];
                    svbfloat16_t x_vec = svreinterpret_bf16_u32(svdup_u32(*x_u32));

                    LANESx2(LOAD_A_VEC, 0);
                    LANESx2(UPDATE_ACCUMULATORS_FROM_LANE, 0);

                    ix += 2;

                    a_ptr0 += 2 * lda;
                    UPDATE_PTRSx2;
                }
            }

            for (; j < n; j++) {
                svbfloat16_t x_vec = svdup_bf16(x[ix]);
                LOAD_A_VEC(0, 0);
                UPDATE_ACCUMULATORS(0);

                ix += inc_x;
                a_ptr0 += lda;
            }

            if (alpha_f32 != ONE) {
                ALPHA_OP(0);
            }
            if (beta_f32 != ZERO) {
                BETA_OP(0);
            }

            STORE_ACCUMULATORS(0);
        }

        if (i < m) {
            svfloat32_t acc0 = svdup_f32(0.0);
            svfloat32_t acc1 = svdup_f32(0.0);

            ix = 0;
            a_ptr0 = a;
            for (BLASLONG j = 0; j < n; j++) {
                svbfloat16_t x_vec0 = svdup_bf16(x[ix]);
                svbfloat16_t a_vec0 = svld1(pg_tail, &a_ptr0[i]);

                acc0 = svbfmlalb(acc0, a_vec0, x_vec0);
                acc1 = svbfmlalt(acc1, a_vec0, x_vec0);

                ix += inc_x;
                a_ptr0 += lda;
            }

            if (alpha_f32 != ONE) {
                acc0 = svmul_x(pg_full, acc0, svalpha);
                acc1 = svmul_x(pg_full, acc1, svalpha);
            }
            if (beta_f32 != ZERO) {
                svbfloat16_t y_vec = svld1(pg_tail, &y[i]);
                acc0 = svbfmlalb(acc0, svbeta16, y_vec);
                acc1 = svbfmlalt(acc1, svbeta16, y_vec);
            }

            svbfloat16_t acc0_bf16 = svcvt_bf16_x(pg_full, acc0);
            svbfloat16_t acc1_bf16 = svcvt_bf16_x(pg_full, acc1);
            svbfloat16_t combined = svtrn1(acc0_bf16, acc1_bf16);
            svst1(pg_tail, &y[i], combined);
        }

        return 0;
    }

    // Scalar fallback
    BLASLONG iy = 0;
    for (; i < m; i++) {
        float temp = 0.0;

        ix = 0;
        a_ptr0 = a;
        for (BLASLONG j = 0; j < n; j++) {
            temp += vcvtah_f32_bf16(a_ptr0[i]) * vcvtah_f32_bf16(x[ix]);
            ix += inc_x;
            a_ptr0 += lda;
        }

        if (beta_f32 == ZERO) {
            y[iy] = vcvth_bf16_f32(alpha_f32 * temp);
        } else {
            y[iy] = vcvth_bf16_f32(alpha_f32 * temp + beta_f32 * vcvtah_f32_bf16(y[iy]));
        }

        iy += inc_y;
    }

    return (0);
}