OpenBLAS/kernel/zarch/idamin.c

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

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

#if defined(DOUBLE)
#define ABS fabs
#else
#define ABS fabsf
#endif

static BLASLONG idamin_kernel_32(BLASLONG n, FLOAT *x, FLOAT *amin)
{
    BLASLONG iamin;

    __asm__ volatile (
        "vl     %%v0,0(%3)               \n\t"
        "vflpdb %%v0,%%v0                \n\t"
        "vleig  %%v1,0,0                 \n\t"
        "vleig  %%v1,1,1                 \n\t"
        "vrepig %%v2,16                  \n\t"
        "vzero  %%v3                     \n\t"
        "vleig  %%v24,0,0                \n\t"
        "vleig  %%v24,1,1                \n\t"
        "vleig  %%v25,2,0                \n\t"
        "vleig  %%v25,3,1                \n\t"
        "vleig  %%v26,4,0                \n\t"
        "vleig  %%v26,5,1                \n\t"
        "vleig  %%v27,6,0                \n\t"
        "vleig  %%v27,7,1                \n\t"
        "vleig  %%v28,8,0                \n\t"
        "vleig  %%v28,9,1                \n\t"
        "vleig  %%v29,10,0               \n\t"
        "vleig  %%v29,11,1               \n\t"
        "vleig  %%v30,12,0               \n\t"
        "vleig  %%v30,13,1               \n\t"
        "vleig  %%v31,14,0               \n\t"
        "vleig  %%v31,15,1               \n\t"
        "srlg  %%r0,%2,5                 \n\t"
        "xgr %%r1,%%r1                   \n\t"
        "0:                              \n\t"
        "pfd 1, 1024(%%r1,%3)            \n\t"

        "vl  %%v16,0(%%r1,%3)            \n\t"
        "vl  %%v17,16(%%r1,%3)           \n\t"
        "vl  %%v18,32(%%r1,%3)           \n\t"
        "vl  %%v19,48(%%r1,%3)           \n\t"
        "vl  %%v20,64(%%r1,%3)           \n\t"
        "vl  %%v21,80(%%r1,%3)           \n\t"
        "vl  %%v22,96(%%r1,%3)           \n\t"
        "vl  %%v23,112(%%r1,%3)          \n\t"
        "vflpdb  %%v16, %%v16            \n\t"
        "vflpdb  %%v17, %%v17            \n\t"
        "vflpdb  %%v18, %%v18            \n\t"
        "vflpdb  %%v19, %%v19            \n\t"
        "vflpdb  %%v20, %%v20            \n\t"
        "vflpdb  %%v21, %%v21            \n\t"
        "vflpdb  %%v22, %%v22            \n\t"
        "vflpdb  %%v23, %%v23            \n\t"
        
        "vfchedb  %%v4,%%v17,%%v16       \n\t"
        "vfchedb  %%v5,%%v19,%%v18       \n\t"
        "vfchedb  %%v6,%%v21,%%v20       \n\t"
        "vfchedb  %%v7,%%v23,%%v22       \n\t"
        "vsel    %%v16,%%v16,%%v17,%%v4  \n\t"
        "vsel    %%v4,%%v24,%%v25,%%v4   \n\t"
        "vsel    %%v17,%%v18,%%v19,%%v5  \n\t"
        "vsel    %%v5,%%v26,%%v27,%%v5   \n\t"
        "vsel    %%v18,%%v20,%%v21,%%v6  \n\t"
        "vsel    %%v6,%%v28,%%v29,%%v6   \n\t"
        "vsel    %%v19,%%v22,%%v23,%%v7  \n\t"
        "vsel    %%v7,%%v30,%%v31,%%v7   \n\t"

        "vfchedb  %%v20,%%v17,%%v16      \n\t"
        "vfchedb  %%v21,%%v19,%%v18      \n\t"
        "vsel    %%v16,%%v16,%%v17,%%v20 \n\t"
        "vsel    %%v4,%%v4,%%v5,%%v20    \n\t"
        "vsel    %%v17,%%v18,%%v19,%%v21 \n\t"
        "vsel    %%v5,%%v6,%%v7,%%v21    \n\t"

        "vfchedb  %%v18,%%v17,%%v16      \n\t"
        "vsel    %%v16,%%v16,%%v17,%%v18 \n\t"
        "vsel    %%v4,%%v4,%%v5,%%v18    \n\t"
        "vag     %%v4,%%v4,%%v3          \n\t"

        "vfchedb  %%v5,%%v16,%%v0        \n\t"
        "vsel    %%v0,%%v0,%%v16,%%v5    \n\t"
        "vsel    %%v1,%%v1,%%v4,%%v5     \n\t"
        "vag     %%v3,%%v3,%%v2          \n\t"

        "vl  %%v16,128(%%r1,%3)          \n\t"
        "vl  %%v17,144(%%r1,%3)          \n\t"
        "vl  %%v18,160(%%r1,%3)          \n\t"
        "vl  %%v19,176(%%r1,%3)          \n\t"
        "vl  %%v20,192(%%r1,%3)          \n\t"
        "vl  %%v21,208(%%r1,%3)          \n\t"
        "vl  %%v22,224(%%r1,%3)          \n\t"
        "vl  %%v23,240(%%r1,%3)          \n\t"
        "vflpdb  %%v16, %%v16            \n\t"
        "vflpdb  %%v17, %%v17            \n\t"
        "vflpdb  %%v18, %%v18            \n\t"
        "vflpdb  %%v19, %%v19            \n\t"
        "vflpdb  %%v20, %%v20            \n\t"
        "vflpdb  %%v21, %%v21            \n\t"
        "vflpdb  %%v22, %%v22            \n\t"
        "vflpdb  %%v23, %%v23            \n\t"

        "vfchedb  %%v4,%%v17,%%v16       \n\t"
        "vfchedb  %%v5,%%v19,%%v18       \n\t"
        "vfchedb  %%v6,%%v21,%%v20       \n\t"
        "vfchedb  %%v7,%%v23,%%v22       \n\t"
        "vsel    %%v16,%%v16,%%v17,%%v4  \n\t"
        "vsel    %%v4,%%v24,%%v25,%%v4   \n\t"
        "vsel    %%v17,%%v18,%%v19,%%v5  \n\t"
        "vsel    %%v5,%%v26,%%v27,%%v5   \n\t"
        "vsel    %%v18,%%v20,%%v21,%%v6  \n\t"
        "vsel    %%v6,%%v28,%%v29,%%v6   \n\t"
        "vsel    %%v19,%%v22,%%v23,%%v7  \n\t"
        "vsel    %%v7,%%v30,%%v31,%%v7   \n\t"

        "vfchedb  %%v20,%%v17,%%v16      \n\t"
        "vfchedb  %%v21,%%v19,%%v18      \n\t"
        "vsel    %%v16,%%v16,%%v17,%%v20 \n\t"
        "vsel    %%v4,%%v4,%%v5,%%v20    \n\t"
        "vsel    %%v17,%%v18,%%v19,%%v21 \n\t"
        "vsel    %%v5,%%v6,%%v7,%%v21    \n\t"

        "vfchedb  %%v18,%%v17,%%v16      \n\t"
        "vsel    %%v16,%%v16,%%v17,%%v18 \n\t"
        "vsel    %%v4,%%v4,%%v5,%%v18    \n\t"
        "vag     %%v4,%%v4,%%v3          \n\t"

        "vfchedb  %%v5,%%v16,%%v0        \n\t"
        "vsel    %%v0,%%v0,%%v16,%%v5    \n\t"
        "vsel    %%v1,%%v1,%%v4,%%v5     \n\t"
        "vag     %%v3,%%v3,%%v2          \n\t"

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

        "vrepg  %%v2,%%v0,1              \n\t"
        "vrepg  %%v3,%%v1,1              \n\t"
        "wfcdb  %%v2,%%v0                \n\t"
        "jne 1f                          \n\t"
        "vsteg  %%v0,%1,0                \n\t"
        "vmnlg  %%v0,%%v1,%%v3           \n\t"
        "vlgvg  %0,%%v0,0                \n\t"
        "j 2f                            \n\t"
        "1:                              \n\t"
        "wfchdb %%v4,%%v0,%%v2           \n\t"
        "vsel   %%v1,%%v3,%%v1,%%v4      \n\t"
        "vsel   %%v0,%%v2,%%v0,%%v4      \n\t"
        "std    %%f0,%1                  \n\t"
        "vlgvg  %0,%%v1,0                \n\t"
        "2:                              \n\t"
        "nop                                 "
        :"=r"(iamin),"=m"(*amin)
        :"r"(n),"ZR"((const FLOAT (*)[n])x)
        :"memory","cc","r0","r1","v0","v1","v2","v3","v4","v5","v6","v7","v16","v17","v18","v19","v20","v21","v22","v23","v24","v25","v26","v27","v28","v29","v30","v31"
    );

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

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

    if (inc_x == 1) {

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

            min = idamin_kernel_32(n1, x, &minf);

            i = n1;
        }
        else
        {
            min = 0;
            minf = ABS(x[0]);
            i++;
        }

        while (i < n) {
            if (ABS(x[i]) < minf) {
                min = i;
                minf = ABS(x[i]);
            }
            i++;
        }
        return (min + 1);

    } else {

        min = 0;
        minf = ABS(x[0]);

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

            if (ABS(x[i]) < minf) {
                min = j;
                minf = ABS(x[i]);
            }
            if (ABS(x[i + inc_x]) < minf) {
                min = j + 1;
                minf = ABS(x[i + inc_x]);
            }
            if (ABS(x[i + 2 * inc_x]) < minf) {
                min = j + 2;
                minf = ABS(x[i + 2 * inc_x]);
            }
            if (ABS(x[i + 3 * inc_x]) < minf) {
                min = j + 3;
                minf = ABS(x[i + 3 * inc_x]);
            }

            i += inc_x * 4;

            j += 4;

        }


        while (j < n) {
            if (ABS(x[i]) < minf) {
                min = j;
                minf = ABS(x[i]);
            }
            i += inc_x;
            j++;
        }
        return (min + 1);
    }
}