OpenBLAS/kernel/riscv64/znrm2_rvv.c

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#include "common.h"

#if !defined(DOUBLE)
#define VSETVL(n)           __riscv_vsetvl_e32m4(n)
#define VSETVL_MAX          __riscv_vsetvlmax_e32m4()
#define FLOAT_V_T           vfloat32m4_t
#define FLOAT_V_T_M1        vfloat32m1_t
#define MASK_T              vbool8_t
#define VLEV_FLOAT          __riscv_vle32_v_f32m4
#define VLSEV_FLOAT         __riscv_vlse32_v_f32m4
#define VFREDSUM_FLOAT      __riscv_vfredusum_vs_f32m4_f32m1_tu
#define VFMACCVV_FLOAT_TU   __riscv_vfmacc_vv_f32m4_tu
#define VFMVVF_FLOAT        __riscv_vfmv_v_f_f32m4
#define VFMVVF_FLOAT_M1     __riscv_vfmv_v_f_f32m1
#define VMFIRSTM            __riscv_vfirst_m_b8
#define VFREDMAXVS_FLOAT_TU __riscv_vfredmax_vs_f32m4_f32m1_tu
#define VFMVFS_FLOAT        __riscv_vfmv_f_s_f32m1_f32
#define VMFGTVF_FLOAT       __riscv_vmfgt_vf_f32m4_b8
#define VFDIVVF_FLOAT       __riscv_vfdiv_vf_f32m4
#define VFABSV_FLOAT        __riscv_vfabs_v_f32m4
#else
#define VSETVL(n)           __riscv_vsetvl_e64m4(n)
#define VSETVL_MAX          __riscv_vsetvlmax_e64m4()
#define FLOAT_V_T           vfloat64m4_t
#define FLOAT_V_T_M1        vfloat64m1_t
#define MASK_T              vbool16_t
#define VLEV_FLOAT          __riscv_vle64_v_f64m4
#define VLSEV_FLOAT         __riscv_vlse64_v_f64m4
#define VFREDSUM_FLOAT      __riscv_vfredusum_vs_f64m4_f64m1_tu
#define VFMACCVV_FLOAT_TU   __riscv_vfmacc_vv_f64m4_tu
#define VFMVVF_FLOAT        __riscv_vfmv_v_f_f64m4
#define VFMVVF_FLOAT_M1     __riscv_vfmv_v_f_f64m1
#define VMFIRSTM            __riscv_vfirst_m_b16
#define VFREDMAXVS_FLOAT_TU __riscv_vfredmax_vs_f64m4_f64m1_tu
#define VFMVFS_FLOAT        __riscv_vfmv_f_s_f64m1_f64
#define VMFGTVF_FLOAT       __riscv_vmfgt_vf_f64m4_b16
#define VFDIVVF_FLOAT       __riscv_vfdiv_vf_f64m4
#define VFABSV_FLOAT        __riscv_vfabs_v_f64m4
#endif

FLOAT CNAME(BLASLONG n, FLOAT *x, BLASLONG inc_x)
{
	BLASLONG i=0, j=0;

	if (n <= 0 || inc_x == 0) return(0.0);

    FLOAT_V_T vr, v0, v_zero;
    unsigned int gvl = 0;
    FLOAT_V_T_M1 v_res, v_z0;
    gvl = VSETVL_MAX;
    v_res = VFMVVF_FLOAT_M1(0, gvl);
    v_z0 = VFMVVF_FLOAT_M1(0, gvl);

    FLOAT scale = 0.0, ssq = 0.0;
    MASK_T mask;
    BLASLONG index = 0;
    if (inc_x == 1) {
        BLASLONG n2 = n * 2;
        gvl = VSETVL(n2);
        vr = VFMVVF_FLOAT(0, gvl);
        v_zero = VFMVVF_FLOAT(0, gvl);
        for (i=0,j=0; i<n2/gvl; i++) {
            v0 = VLEV_FLOAT(&x[j], gvl);
            //fabs(vector)
            v0 = VFABSV_FLOAT(v0, gvl);
            //if scale change
            mask = VMFGTVF_FLOAT(v0, scale, gvl);
            index = VMFIRSTM(mask, gvl);
            if (index == -1) { //no elements greater than scale
                if (scale != 0.0) {
                    v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                    vr = VFMACCVV_FLOAT_TU(vr, v0, v0, gvl);
                }
            } else { // found greater element
                //ssq in vector vr: vr[0]
                v_res = VFREDSUM_FLOAT(v_res, vr, v_z0, gvl);
                //total ssq before current vector
                ssq += VFMVFS_FLOAT(v_res);
                //find max
                v_res = VFREDMAXVS_FLOAT_TU(v_res, v0, v_z0, gvl);
                //update ssq before max_index
                ssq = ssq * (scale/VFMVFS_FLOAT(v_res))*(scale/VFMVFS_FLOAT(v_res));
                //update scale
                scale = VFMVFS_FLOAT(v_res);
                //ssq in vector vr
                v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                vr = VFMACCVV_FLOAT_TU(v_zero, v0, v0, gvl);
            }
            j += gvl;
        }
        //ssq in vector vr: vr[0]
        v_res = VFREDSUM_FLOAT(v_res, vr, v_z0, gvl);
        //total ssq now
        ssq += VFMVFS_FLOAT(v_res);

        //tail
        if(j < n2){
            gvl = VSETVL(n2-j);
            v0 = VLEV_FLOAT(&x[j], gvl);
            // fabs(vector)
            v0 = VFABSV_FLOAT(v0, gvl);
            // if scale change
            mask = VMFGTVF_FLOAT(v0, scale, gvl);
            index = VMFIRSTM(mask, gvl);
            if (index == -1) {//no elements greater than scale
                if(scale != 0.0)
                    v0 = VFDIVVF_FLOAT(v0, scale, gvl);
            } else { //found greater element
                //find max
                v_res = VFREDMAXVS_FLOAT_TU(v_res, v0, v_z0, gvl);
                //update ssq before max_index
                ssq = ssq * (scale/VFMVFS_FLOAT(v_res))*(scale/VFMVFS_FLOAT(v_res));
                //update scale
                scale = VFMVFS_FLOAT(v_res);
                v0 = VFDIVVF_FLOAT(v0, scale, gvl);
            }
            vr = VFMACCVV_FLOAT_TU(v_zero, v0, v0, gvl);
            //ssq in vector vr: vr[0]
            v_res = VFREDSUM_FLOAT(v_res, vr, v_z0, gvl);
            //total ssq now
            ssq += VFMVFS_FLOAT(v_res);
        }
    } else {
        gvl = VSETVL(n);
        vr = VFMVVF_FLOAT(0, gvl);
        v_zero = VFMVVF_FLOAT(0, gvl);
        unsigned int stride_x = inc_x * sizeof(FLOAT) * 2;
        int idx = 0, inc_v = inc_x * gvl * 2;
        for (i=0,j=0; i<n/gvl; i++) {
            v0 = VLSEV_FLOAT(&x[idx], stride_x, gvl);
            // fabs(vector)
            v0 = VFABSV_FLOAT(v0, gvl);
            //if scale change
            mask = VMFGTVF_FLOAT(v0, scale, gvl);
            index = VMFIRSTM(mask, gvl);
            if (index == -1) { // no elements greater than scale
                if(scale != 0.0){
                    v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                    vr = VFMACCVV_FLOAT_TU(vr, v0, v0, gvl);
                }
            } else {//found greater element
                //ssq in vector vr: vr[0]
                v_res = VFREDSUM_FLOAT(v_res, vr, v_z0, gvl);
                //total ssq before current vector
                ssq += VFMVFS_FLOAT(v_res);
                //find max
                v_res = VFREDMAXVS_FLOAT_TU(v_res, v0, v_z0, gvl);
                //update ssq before max_index
                ssq = ssq * (scale/VFMVFS_FLOAT(v_res))*(scale/VFMVFS_FLOAT(v_res));
                //update scale
                scale = VFMVFS_FLOAT(v_res);
                //ssq in vector vr
                v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                vr = VFMACCVV_FLOAT_TU(v_zero, v0, v0, gvl);
            }

            v0 = VLSEV_FLOAT(&x[idx+1], stride_x, gvl);
            //fabs(vector)
            v0 = VFABSV_FLOAT(v0, gvl);
            //if scale change
            mask = VMFGTVF_FLOAT(v0, scale, gvl);
            index = VMFIRSTM(mask, gvl);
            if (index == -1) { // no elements greater than scale
                if(scale != 0.0) {
                    v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                    vr = VFMACCVV_FLOAT_TU(vr, v0, v0, gvl);
                }
            } else { // found greater element
                //ssq in vector vr: vr[0]
                v_res = VFREDSUM_FLOAT(v_res, vr, v_z0, gvl);
                //total ssq before current vector
                ssq += VFMVFS_FLOAT(v_res);
                //find max
                v_res = VFREDMAXVS_FLOAT_TU(v_res, v0, v_z0, gvl);
                //update ssq before max_index
                ssq = ssq * (scale/VFMVFS_FLOAT(v_res))*(scale/VFMVFS_FLOAT(v_res));
                //update scale
                scale = VFMVFS_FLOAT(v_res);
                //ssq in vector vr
                v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                vr = VFMACCVV_FLOAT_TU(v_zero, v0, v0, gvl);
            }
            j += gvl;
            idx += inc_v;
        }
        //ssq in vector vr: vr[0]
        v_res = VFREDSUM_FLOAT(v_res, vr, v_z0, gvl);
        //total ssq now
        ssq += VFMVFS_FLOAT(v_res);

        //tail
        if (j < n) {
            gvl = VSETVL(n-j);
            v0 = VLSEV_FLOAT(&x[idx], stride_x, gvl);
            //fabs(vector)
            v0 = VFABSV_FLOAT(v0, gvl);
            //if scale change
            mask = VMFGTVF_FLOAT(v0, scale, gvl);
            index = VMFIRSTM(mask, gvl);
            if(index == -1) { // no elements greater than scale
                if(scale != 0.0) {
                    v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                    vr = VFMACCVV_FLOAT_TU(v_zero, v0, v0, gvl);
                }
            } else { // found greater element
                //find max
                v_res = VFREDMAXVS_FLOAT_TU(v_res, v0, v_z0, gvl);
                //update ssq before max_index
                ssq = ssq * (scale/VFMVFS_FLOAT(v_res))*(scale/VFMVFS_FLOAT(v_res));
                //update scale
                scale = VFMVFS_FLOAT(v_res);
                v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                vr = VFMACCVV_FLOAT_TU(v_zero, v0, v0, gvl);
            }

            v0 = VLSEV_FLOAT(&x[idx+1], stride_x, gvl);
            //fabs(vector)
            v0 = VFABSV_FLOAT(v0, gvl);
            //if scale change
            mask = VMFGTVF_FLOAT(v0, scale, gvl);
            index = VMFIRSTM(mask, gvl);
            if (index == -1) {//no elements greater than scale
                if(scale != 0.0) {
                    v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                    vr = VFMACCVV_FLOAT_TU(vr, v0, v0, gvl);
                }
            } else { // found greater element
                //ssq in vector vr: vr[0]
                v_res = VFREDSUM_FLOAT(v_res, vr, v_z0, gvl);
                //total ssq before current vector
                ssq += VFMVFS_FLOAT(v_res);
                //find max
                v_res = VFREDMAXVS_FLOAT_TU(v_res, v0, v_z0, gvl);
                //update ssq before max_index
                ssq = ssq * (scale/VFMVFS_FLOAT(v_res))*(scale/VFMVFS_FLOAT(v_res));
                //update scale
                scale = VFMVFS_FLOAT(v_res);
                v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                vr = VFMACCVV_FLOAT_TU(v_zero, v0, v0, gvl);
            }
            //ssq in vector vr: vr[0]
            v_res = VFREDSUM_FLOAT(v_res, vr, v_z0, gvl);
            //total ssq now
            ssq += VFMVFS_FLOAT(v_res);
        }
    }
	return(scale * sqrt(ssq));
}