OpenBLAS/kernel/riscv64/nrm2_vector.c

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#include "common.h"
#if !defined(DOUBLE)
#define RVV_EFLOAT RVV_E32
#define RVV_M RVV_M4
#define FLOAT_V_T float32xm4_t
#define VLEV_FLOAT vlev_float32xm4
#define VLSEV_FLOAT vlsev_float32xm4
#define VFREDSUM_FLOAT vfredsumvs_float32xm4
#define VFMACCVV_FLOAT vfmaccvv_float32xm4
#define VFMVVF_FLOAT vfmvvf_float32xm4
#define VFDOTVV_FLOAT vfdotvv_float32xm4
#define ABS fabsf
#define MASK_T e32xm4_t
#define VFRSUBVF_MASK_FLOAT vfrsubvf_mask_float32xm4
#define VMFGTVF_FLOAT vmfgtvf_e32xm4_float32xm4
#define VMFIRSTM vmfirstm_e32xm4
#define VFDIVVF_FLOAT vfdivvf_float32xm4
#define VMFLTVF_FLOAT vmfltvf_e32xm4_float32xm4
#define VFREDMAXVS_FLOAT vfredmaxvs_float32xm4
#else
#define RVV_EFLOAT RVV_E64
#define RVV_M RVV_M4
#define FLOAT_V_T float64xm4_t
#define VLEV_FLOAT vlev_float64xm4
#define VLSEV_FLOAT vlsev_float64xm4
#define VFREDSUM_FLOAT vfredsumvs_float64xm4
#define VFMACCVV_FLOAT vfmaccvv_float64xm4
#define VFMVVF_FLOAT vfmvvf_float64xm4
#define VFDOTVV_FLOAT vfdotvv_float64xm4
#define ABS fabs
#define MASK_T e64xm4_t
#define VFRSUBVF_MASK_FLOAT vfrsubvf_mask_float64xm4
#define VMFGTVF_FLOAT vmfgtvf_e64xm4_float64xm4
#define VMFIRSTM vmfirstm_e64xm4
#define VFDIVVF_FLOAT vfdivvf_float64xm4
#define VMFLTVF_FLOAT vmfltvf_e64xm4_float64xm4
#define VFREDMAXVS_FLOAT vfredmaxvs_float64xm4
#endif

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

	if ( n < 0 )  return(0.0);
        if(n == 1) return (ABS(x[0]));

        FLOAT_V_T vr, v0, v_zero;
        unsigned int gvl = 0;
        FLOAT scale = 0.0, ssq = 0.0;
        MASK_T mask;
        BLASLONG index = 0;
        if(inc_x == 1){
                gvl = vsetvli(n, RVV_EFLOAT, RVV_M);
                vr = VFMVVF_FLOAT(0, gvl);
                v_zero = VFMVVF_FLOAT(0, gvl);
                for(i=0,j=0; i<n/gvl; i++){
                        v0 = VLEV_FLOAT(&x[j], gvl);
                        //fabs(vector)
                        mask = VMFLTVF_FLOAT(v0, 0, gvl);
                        v0 = VFRSUBVF_MASK_FLOAT(v0, v0, 0, mask, 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(vr, v0, v0, gvl);
                                }
                        }else{//found greater element
                                //ssq in vector vr: vr[0]
                                vr = VFREDSUM_FLOAT(vr, v_zero, gvl);
                                //total ssq before current vector
                                ssq += vr[0];
                                //find max
                                vr = VFREDMAXVS_FLOAT(v0, v_zero, gvl);
                                //update ssq before max_index
                                ssq = ssq * (scale/vr[0])*(scale/vr[0]);
                                //update scale
                                scale = vr[0];
                                //ssq in vector vr
                                v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                                vr = VFMACCVV_FLOAT(v_zero, v0, v0, gvl);
                        }
                        j += gvl;
                }
                //ssq in vector vr: vr[0]
                vr = VFREDSUM_FLOAT(vr, v_zero, gvl);
                //total ssq now
                ssq += vr[0];

                //tail
                if(j < n){
                        gvl = vsetvli(n-j, RVV_EFLOAT, RVV_M);
                        v0 = VLEV_FLOAT(&x[j], gvl);
                        //fabs(vector)
                        mask = VMFLTVF_FLOAT(v0, 0, gvl);
                        v0 = VFRSUBVF_MASK_FLOAT(v0, v0, 0, mask, 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
                                vr = VFREDMAXVS_FLOAT(v0, v_zero, gvl);
                                //update ssq before max_index
                                ssq = ssq * (scale/vr[0])*(scale/vr[0]);
                                //update scale
                                scale = vr[0];
                                v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                        }
                        vr = VFMACCVV_FLOAT(v_zero, v0, v0, gvl);
                        //ssq in vector vr: vr[0]
                        vr = VFREDSUM_FLOAT(vr, v_zero, gvl);
                        //total ssq now
                        ssq += vr[0];
                }
        }else{
                gvl = vsetvli(n, RVV_EFLOAT, RVV_M);
                vr = VFMVVF_FLOAT(0, gvl);
                v_zero = VFMVVF_FLOAT(0, gvl);
                unsigned int stride_x = inc_x * sizeof(FLOAT);
                int idx = 0, inc_v = inc_x * gvl;
                for(i=0,j=0; i<n/gvl; i++){
                        v0 = VLSEV_FLOAT(&x[idx], stride_x, gvl);
                        //fabs(vector)
                        mask = VMFLTVF_FLOAT(v0, 0, gvl);
                        v0 = VFRSUBVF_MASK_FLOAT(v0, v0, 0, mask, 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(vr, v0, v0, gvl);
                                }
                        }else{//found greater element
                                //ssq in vector vr: vr[0]
                                vr = VFREDSUM_FLOAT(vr, v_zero, gvl);
                                //total ssq before current vector
                                ssq += vr[0];
                                //find max
                                vr = VFREDMAXVS_FLOAT(v0, v_zero, gvl);
                                //update ssq before max_index
                                ssq = ssq * (scale/vr[0])*(scale/vr[0]);
                                //update scale
                                scale = vr[0];
                                //ssq in vector vr
                                v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                                vr = VFMACCVV_FLOAT(v_zero, v0, v0, gvl);
                        }
                        j += gvl;
                        idx += inc_v;
                }
                //ssq in vector vr: vr[0]
                vr = VFREDSUM_FLOAT(vr, v_zero, gvl);
                //total ssq now
                ssq += vr[0];

                //tail
                if(j < n){
                        gvl = vsetvli(n-j, RVV_EFLOAT, RVV_M);
                        v0 = VLSEV_FLOAT(&x[idx], stride_x, gvl);
                        //fabs(vector)
                        mask = VMFLTVF_FLOAT(v0, 0, gvl);
                        v0 = VFRSUBVF_MASK_FLOAT(v0, v0, 0, mask, 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
                                vr = VFREDMAXVS_FLOAT(v0, v_zero, gvl);
                                //update ssq before max_index
                                ssq = ssq * (scale/vr[0])*(scale/vr[0]);
                                //update scale
                                scale = vr[0];
                                v0 = VFDIVVF_FLOAT(v0, scale, gvl);
                        }
                        vr = VFMACCVV_FLOAT(v_zero, v0, v0, gvl);
                        //ssq in vector vr: vr[0]
                        vr = VFREDSUM_FLOAT(vr, v_zero, gvl);
                        //total ssq now
                        ssq += vr[0];
                }
        }
	return(scale * sqrt(ssq));
}