OpenBLAS/kernel/riscv64/izamax_vector.c

/***************************************************************************
Copyright (c) 2020, The OpenBLAS Project
All rights reserved.
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modification, are permitted provided that the following conditions are
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2. Redistributions in binary form must reproduce the above copyright
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3. Neither the name of the OpenBLAS project nor the names of
its contributors may be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBLAS PROJECT OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
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*****************************************************************************/

#include "common.h"
#include <math.h>

#if defined(DOUBLE)

#define RVV_EFLOAT RVV_E64
#define FLOAT_V_T float64xm8_t
#define VLSEV_FLOAT vlsev_float64xm8
#define VFREDMAXVS_FLOAT vfredmaxvs_float64xm8
#define MASK_T e64xm8_t
#define VMFLTVF_FLOAT vmfltvf_e64xm8_float64xm8
#define VMFLTVV_FLOAT vmfltvv_e64xm8_float64xm8
#define VFMVVF_FLOAT vfmvvf_float64xm8
#define VFRSUBVF_MASK_FLOAT vfrsubvf_mask_float64xm8
#define VFMAXVV_FLOAT vfmaxvv_float64xm8
#define VMFGEVF_FLOAT vmfgevf_e64xm8_float64xm8
#define VMFIRSTM vmfirstm_e64xm8
#define UINT_V_T uint64xm8_t
#define VIDV_MASK_UINT vidv_mask_uint64xm8
#define VIDV_UINT vidv_uint64xm8
#define VADDVX_MASK_UINT vaddvx_mask_uint64xm8
#define VADDVX_UINT vaddvx_uint64xm8
#define VFADDVV_FLOAT vfaddvv_float64xm8
#define VMVVX_UINT vmvvx_uint64xm8
#else

#define ABS fabsf
#define RVV_EFLOAT RVV_E32
#define FLOAT_V_T float32xm8_t
#define VLSEV_FLOAT vlsev_float32xm8
#define VFREDMAXVS_FLOAT vfredmaxvs_float32xm8
#define MASK_T e32xm8_t
#define VMFLTVF_FLOAT vmfltvf_e32xm8_float32xm8
#define VMFLTVV_FLOAT vmfltvv_e32xm8_float32xm8
#define VFMVVF_FLOAT vfmvvf_float32xm8
#define VFRSUBVF_MASK_FLOAT vfrsubvf_mask_float32xm8
#define VFMAXVV_FLOAT vfmaxvv_float32xm8
#define VMFGEVF_FLOAT vmfgevf_e32xm8_float32xm8
#define VMFIRSTM vmfirstm_e32xm8
#define UINT_V_T uint32xm8_t
#define VIDV_MASK_UINT vidv_mask_uint32xm8
#define VIDV_UINT vidv_uint32xm8
#define VADDVX_MASK_UINT vaddvx_mask_uint32xm8
#define VADDVX_UINT vaddvx_uint32xm8
#define VFADDVV_FLOAT vfaddvv_float32xm8
#define VMVVX_UINT vmvvx_uint32xm8
#endif

#define RVV_M RVV_M8

BLASLONG CNAME(BLASLONG n, FLOAT *x, BLASLONG inc_x)
{
	BLASLONG i=0, j=0;
	FLOAT maxf=0.0;
        unsigned int max_index = 0;
	if (n <= 0 || inc_x <= 0) return(max_index);

        FLOAT_V_T vx0, vx1, v_max;
        UINT_V_T v_max_index;
        MASK_T mask0, mask1;
        unsigned int gvl = 0;
        gvl = vsetvli(n, RVV_EFLOAT, RVV_M);
        v_max_index = VMVVX_UINT(0, gvl);
        v_max = VFMVVF_FLOAT(-1, gvl);
        BLASLONG stride_x = inc_x * 2 * sizeof(FLOAT);
        BLASLONG inc_xv = gvl * inc_x * 2;
        BLASLONG ix = 0;
        for(i=0,j=0; i < n/gvl; i++){
                vx0 = VLSEV_FLOAT(&x[ix], stride_x, gvl);
                //fabs(vector)
                mask0 = VMFLTVF_FLOAT(vx0, 0, gvl);
                vx0 = VFRSUBVF_MASK_FLOAT(vx0, vx0, 0, mask0, gvl);
/*
#if defined(DOUBLE)
asm volatile(
        "vor.vv     v0, %1, %1\n\t"
        "vsetvli    x0, %3, e64,m8 \n\t"
        "vfrsub.vf  %0, %0, %2, v0.t \n\t"
        :"+v"(vx0)
        :"v"(mask0), "f"(zero), "r"(gvl)
        :"v0");
#else
asm volatile(
        "vor.vv     v0, %1, %1\n\t"
        "vsetvli    x0, %3, e32,m8 \n\t"
        "vfrsub.vf  %0, %0, %2, v0.t \n\t"
        :"+v"(vx0)
        :"v"(mask0), "f"(zero), "r"(gvl)
        :"v0");
#endif
*/
                vx1 = VLSEV_FLOAT(&x[ix+1], stride_x, gvl);
                //fabs(vector)
                mask1 = VMFLTVF_FLOAT(vx1, 0, gvl);
                vx1 = VFRSUBVF_MASK_FLOAT(vx1, vx1, 0, mask1, gvl);
/*
#if defined(DOUBLE)
asm volatile(
        "vor.vv     v0, %1, %1\n\t"
        "vsetvli    x0, %3, e64,m8 \n\t"
        "vfrsub.vf  %0, %0, %2, v0.t \n\t"
        :"+v"(vx1)
        :"v"(mask1), "f"(zero), "r"(gvl)
        :"v0");
#else
asm volatile(
        "vor.vv     v0, %1, %1\n\t"
        "vsetvli    x0, %3, e32,m8 \n\t"
        "vfrsub.vf  %0, %0, %2, v0.t \n\t"
        :"+v"(vx1)
        :"v"(mask1), "f"(zero), "r"(gvl)
        :"v0");
#endif
*/
                vx0 = VFADDVV_FLOAT(vx0, vx1, gvl);

                //index where element greater than v_max
                mask0 = VMFLTVV_FLOAT(v_max, vx0, gvl);
                v_max_index = VIDV_MASK_UINT(v_max_index, mask0, gvl);
/*
#if defined(DOUBLE)
asm volatile(
        "vor.vv v0, %1, %1 \n\t"
        "vsetvli x0, %2, e64,m8 \n\t"
        "vid.v %0, v0.t \n\t"
        :"+v"(v_max_index)
        :"v"(mask0), "r"(gvl)
        :"v0");
#else
asm volatile(
        "vor.vv v0, %1, %1 \n\t"
        "vsetvli x0, %2, e32,m8 \n\t"
        "vid.v %0, v0.t \n\t"
        :"+v"(v_max_index)
        :"v"(mask0), "r"(gvl)
        :"v0");
#endif
*/
                v_max_index = VADDVX_MASK_UINT(v_max_index, v_max_index, j, mask0, gvl);

                //update v_max and start_index j
                v_max = VFMAXVV_FLOAT(v_max, vx0, gvl);
                j += gvl;
                ix += inc_xv;
        }
        vx0 = VFMVVF_FLOAT(0, gvl);
        vx0 = VFREDMAXVS_FLOAT(v_max, vx0, gvl);
        maxf = vx0[0];
        mask0 = VMFGEVF_FLOAT(v_max, maxf, gvl);
        max_index = VMFIRSTM(mask0,gvl);
        max_index = v_max_index[max_index];

        if(j < n){
                gvl = vsetvli(n-j, RVV_EFLOAT, RVV_M);
                v_max_index = VMVVX_UINT(0, gvl);
                vx0 = VLSEV_FLOAT(&x[ix], stride_x, gvl);
                //fabs(vector)
                mask0 = VMFLTVF_FLOAT(vx0, 0, gvl);
                vx0 = VFRSUBVF_MASK_FLOAT(vx0, vx0, 0, mask0, gvl);
/*
#if defined(DOUBLE)
asm volatile(
        "vor.vv     v0, %1, %1\n\t"
        "vsetvli    x0, %3, e64,m8 \n\t"
        "vfrsub.vf  %0, %0, %2, v0.t \n\t"
        :"+v"(vx0)
        :"v"(mask0), "f"(zero), "r"(gvl)
        :"v0");
#else
asm volatile(
        "vor.vv     v0, %1, %1\n\t"
        "vsetvli    x0, %3, e32,m8 \n\t"
        "vfrsub.vf  %0, %0, %2, v0.t \n\t"
        :"+v"(vx0)
        :"v"(mask0), "f"(zero), "r"(gvl)
        :"v0");
#endif
*/
                vx1 = VLSEV_FLOAT(&x[ix+1], stride_x, gvl);
                //fabs(vector)
                mask1 = VMFLTVF_FLOAT(vx1, 0, gvl);
                vx1 = VFRSUBVF_MASK_FLOAT(vx1, vx1, 0, mask1, gvl);
/*
#if defined(DOUBLE)
asm volatile(
        "vor.vv     v0, %1, %1\n\t"
        "vsetvli    x0, %3, e64,m8 \n\t"
        "vfrsub.vf  %0, %0, %2, v0.t \n\t"
        :"+v"(vx1)
        :"v"(mask1), "f"(zero), "r"(gvl)
        :"v0");
#else
asm volatile(
        "vor.vv     v0, %1, %1\n\t"
        "vsetvli    x0, %3, e32,m8 \n\t"
        "vfrsub.vf  %0, %0, %2, v0.t \n\t"
        :"+v"(vx1)
        :"v"(mask1), "f"(zero), "r"(gvl)
        :"v0");
#endif
*/
                v_max = VFADDVV_FLOAT(vx0, vx1, gvl);
                vx0 = VFMVVF_FLOAT(0, gvl);
                vx0 = VFREDMAXVS_FLOAT(v_max, vx0, gvl);
                FLOAT cur_maxf = vx0[0];
                if(cur_maxf > maxf){
                        //tail index
                        v_max_index = VIDV_UINT(gvl);
                        v_max_index = VADDVX_UINT(v_max_index, j, gvl);

                        mask0 = VMFGEVF_FLOAT(v_max, cur_maxf, gvl);
                        max_index = VMFIRSTM(mask0,gvl);
                        max_index = v_max_index[max_index];
                }
        }
	return(max_index+1);
}