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

#define ABS fabsf

static FLOAT samax_kernel_64(BLASLONG n, FLOAT *x) {
  FLOAT amax;

  __asm__("vl     %%v0,0(%[x])\n\t"
    "srlg   %[n],%[n],6\n\t"
    "xgr %%r1,%%r1\n\t"
    "0:\n\t"
    "pfd 1, 1024(%%r1,%[x])\n\t"
    "vl  %%v16,0(%%r1,%[x])\n\t"
    "vl  %%v17,16(%%r1,%[x])\n\t"
    "vl  %%v18,32(%%r1,%[x])\n\t"
    "vl  %%v19,48(%%r1,%[x])\n\t"
    "vl  %%v20,64(%%r1,%[x])\n\t"
    "vl  %%v21,80(%%r1,%[x])\n\t"
    "vl  %%v22,96(%%r1,%[x])\n\t"
    "vl  %%v23,112(%%r1,%[x])\n\t"
    "vl  %%v24,128(%%r1,%[x])\n\t"
    "vl  %%v25,144(%%r1,%[x])\n\t"
    "vl  %%v26,160(%%r1,%[x])\n\t"
    "vl  %%v27,176(%%r1,%[x])\n\t"
    "vl  %%v28,192(%%r1,%[x])\n\t"
    "vl  %%v29,208(%%r1,%[x])\n\t"
    "vl  %%v30,224(%%r1,%[x])\n\t"
    "vl  %%v31,240(%%r1,%[x])\n\t"
    "vfmaxsb  %%v16,%%v16,%%v24,8\n\t"
    "vfmaxsb  %%v17,%%v17,%%v25,8\n\t"
    "vfmaxsb  %%v18,%%v18,%%v26,8\n\t"
    "vfmaxsb  %%v19,%%v19,%%v27,8\n\t"
    "vfmaxsb  %%v20,%%v20,%%v28,8\n\t"
    "vfmaxsb  %%v21,%%v21,%%v29,8\n\t"
    "vfmaxsb  %%v22,%%v22,%%v30,8\n\t"
    "vfmaxsb  %%v23,%%v23,%%v31,8\n\t"
    "vfmaxsb  %%v16,%%v16,%%v20,8\n\t"
    "vfmaxsb  %%v17,%%v17,%%v21,8\n\t"
    "vfmaxsb  %%v18,%%v18,%%v22,8\n\t"
    "vfmaxsb  %%v19,%%v19,%%v23,8\n\t"
    "vfmaxsb  %%v16,%%v16,%%v18,8\n\t"
    "vfmaxsb  %%v17,%%v17,%%v19,8\n\t"
    "vfmaxsb  %%v16,%%v16,%%v17,8\n\t"
    "vfmaxsb  %%v0,%%v0,%%v16,8\n\t"
    "agfi    %%r1, 256\n\t"
    "brctg   %[n], 0b\n\t"
    "veslg   %%v16,%%v0,32\n\t"
    "vfmaxsb %%v0,%%v0,%%v16,8\n\t"
    "vrepf   %%v16,%%v0,2\n\t"
    "wfmaxsb %%v0,%%v0,%%v16,8\n\t"
    "lper    %[amax],%%f0"
    : [amax] "=f"(amax),[n] "+&r"(n)
    : "m"(*(const FLOAT (*)[n]) x),[x] "a"(x)
    : "cc", "r1", "v0", "v16", "v17", "v18", "v19", "v20", "v21", "v22",
       "v23", "v24", "v25", "v26", "v27", "v28", "v29", "v30", "v31");

  return amax;
}

FLOAT CNAME(BLASLONG n, FLOAT *x, BLASLONG inc_x) {
  BLASLONG i = 0;
  BLASLONG j = 0;
  FLOAT maxf = 0.0;

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

  if (inc_x == 1) {

    BLASLONG n1 = n & -64;
    if (n1 > 0) {

      maxf = samax_kernel_64(n1, x);

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

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

  } else {

    maxf = ABS(x[0]);

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

      if (ABS(x[i]) > maxf) {
        maxf = ABS(x[i]);
      }
      if (ABS(x[i + inc_x]) > maxf) {
        maxf = ABS(x[i + inc_x]);
      }
      if (ABS(x[i + 2 * inc_x]) > maxf) {
        maxf = ABS(x[i + 2 * inc_x]);
      }
      if (ABS(x[i + 3 * inc_x]) > maxf) {
        maxf = ABS(x[i + 3 * inc_x]);
      }

      i += inc_x * 4;

      j += 4;

    }

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