dmin.c

/***************************************************************************
Copyright (c) 2013-2017, The OpenBLAS Project
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*****************************************************************************/

#include "common.h"

static FLOAT dmin_kernel_32(BLASLONG n, FLOAT *x)
{
    FLOAT min;

    __asm__ volatile (
        "vl    %%v0,0(%2)                 \n\t"
        "srlg  %%r0,%1,5                  \n\t"
        "xgr %%r1,%%r1                    \n\t"
        "0:                               \n\t"
        "pfd 1, 1024(%%r1,%2)             \n\t"

        "vl  %%v16,0(%%r1,%2)             \n\t"
        "vl  %%v17,16(%%r1,%2)            \n\t"
        "vl  %%v18,32(%%r1,%2)            \n\t"
        "vl  %%v19,48(%%r1,%2)            \n\t"
        "vl  %%v20,64(%%r1,%2)            \n\t"
        "vl  %%v21,80(%%r1,%2)            \n\t"
        "vl  %%v22,96(%%r1,%2)            \n\t"
        "vl  %%v23,112(%%r1,%2)           \n\t"
        "vl  %%v24,128(%%r1,%2)           \n\t"
        "vl  %%v25,144(%%r1,%2)           \n\t"
        "vl  %%v26,160(%%r1,%2)           \n\t"
        "vl  %%v27,176(%%r1,%2)           \n\t"
        "vl  %%v28,192(%%r1,%2)           \n\t"
        "vl  %%v29,208(%%r1,%2)           \n\t"
        "vl  %%v30,224(%%r1,%2)           \n\t"
        "vl  %%v31,240(%%r1,%2)           \n\t"
        
        "vfmindb  %%v16,%%v16,%%v24,0     \n\t"
        "vfmindb  %%v17,%%v17,%%v25,0     \n\t"
        "vfmindb  %%v18,%%v18,%%v26,0     \n\t"
        "vfmindb  %%v19,%%v19,%%v27,0     \n\t"
        "vfmindb  %%v20,%%v20,%%v28,0     \n\t"
        "vfmindb  %%v21,%%v21,%%v29,0     \n\t"
        "vfmindb  %%v22,%%v22,%%v30,0     \n\t"
        "vfmindb  %%v23,%%v23,%%v31,0     \n\t"

        "vfmindb  %%v16,%%v16,%%v20,0     \n\t"
        "vfmindb  %%v17,%%v17,%%v21,0     \n\t"
        "vfmindb  %%v18,%%v18,%%v22,0     \n\t"
        "vfmindb  %%v19,%%v19,%%v23,0     \n\t"

        "vfmindb  %%v16,%%v16,%%v18,0     \n\t"
        "vfmindb  %%v17,%%v17,%%v19,0     \n\t"

        "vfmindb  %%v16,%%v16,%%v17,0     \n\t"

        "vfmindb  %%v0,%%v0,%%v16,0       \n\t"

        "agfi    %%r1, 256                \n\t"
        "brctg   %%r0, 0b                 \n\t"

        "vrepg   %%v16,%%v0,1             \n\t"
        "wfmindb %%v0,%%v0,%%v16,0        \n\t"
        "ldr    %0,%%f0                       "
        :"=f"(min)
        :"r"(n),"ZR"((const FLOAT (*)[n])x)
        :"memory","cc","r0","r1","v0","v16","v17","v18","v19","v20","v21","v22","v23","v24","v25","v26","v27","v28","v29","v30","v31"
    );

    return min;
}
 
FLOAT CNAME(BLASLONG n, FLOAT *x, BLASLONG inc_x) {
    BLASLONG i = 0;
    BLASLONG j = 0;
    FLOAT minf = 0.0;

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

    if (inc_x == 1) {

        BLASLONG n1 = n & -32;
        if (n1 > 0) {

            minf = dmin_kernel_32(n1, x);

            i = n1;
        }
        else
        {
            minf=x[0];
            i++;
        }

        while (i < n) {
            if (x[i] < minf) {
                minf = x[i];
            }
            i++;
        }
        return (minf);

    } else {

        minf=x[0];

        BLASLONG n1 = n & -4;
        while (j < n1) {

            if (x[i] < minf) {
                minf = x[i];
            }
            if (x[i + inc_x] < minf) {
                minf = x[i + inc_x];
            }
            if (x[i + 2 * inc_x] < minf) {
                minf = x[i + 2 * inc_x];
            }
            if (x[i + 3 * inc_x] < minf) {
                minf = x[i + 3 * inc_x];
            }

            i += inc_x * 4;

            j += 4;

        }


        while (j < n) {
            if (x[i] < minf) {
                minf = x[i];
            }
            i += inc_x;
            j++;
        }
        return (minf);
    }
}