summaryrefslogtreecommitdiffstats
path: root/drivers/bus/ifpga
stat options
Period:
Authors:

Commits per author per week (path 'drivers/bus/ifpga')

AuthorW24 2024W25 2024W26 2024W27 2024Total
Total00000
='n33' href='#n33'>33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269
/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * Imported into CLIB by Eliot Dresselhaus from:
 *
 *  This file is part of
 *	MakeIndex - A formatter and format independent index processor
 *
 *  This file is public domain software donated by
 *  Nelson Beebe (beebe@science.utah.edu).
 *
 *  modifications copyright (c) 2003 Cisco Systems, Inc.
 */

#include <vppinfra/clib.h>

/*
 * qsort.c: Our own version of the system qsort routine which is faster by an
 * average of 25%, with lows and highs of 10% and 50%. The THRESHold below is
 * the insertion sort threshold, and has been adjusted for records of size 48
 * bytes. The MTHREShold is where we stop finding a better median.
 */

#define THRESH  4		/* threshold for insertion */
#define MTHRESH 6		/* threshold for median */

typedef struct
{
  word qsz;			/* size of each record */
  word thresh;			/* THRESHold in chars */
  word mthresh;			/* MTHRESHold in chars */
  int (*qcmp) (const void *, const void *);	/* the comparison routine */
} qst_t;

static void qst (qst_t * q, char *base, char *max);

/*
 * qqsort: First, set up some global parameters for qst to share.
 * Then, quicksort with qst(), and then a cleanup insertion sort ourselves.
 * Sound simple?  It's not...
 */

void
qsort (void *base, uword n, uword size,
       int (*compar) (const void *, const void *))
{
  char *i;
  char *j;
  char *lo;
  char *hi;
  char *min;
  char c;
  char *max;
  qst_t _q, *q = &_q;

  if (n <= 1)
    return;

  q->qsz = size;
  q->qcmp = compar;
  q->thresh = q->qsz * THRESH;
  q->mthresh = q->qsz * MTHRESH;
  max = base + n * q->qsz;
  if (n >= THRESH)
    {
      qst (q, base, max);
      hi = base + q->thresh;
    }
  else
    {
      hi = max;
    }
  /*
   * First put smallest element, which must be in the first THRESH, in the
   * first position as a sentinel.  This is done just by searching the
   * first THRESH elements (or the first n if n < THRESH), finding the min,
   * and swapping it into the first position.
   */
  for (j = lo = base; (lo += q->qsz) < hi;)
    {
      if ((*compar) (j, lo) > 0)
	j = lo;
    }
  if (j != base)
    {				/* swap j into place */
      for (i = base, hi = base + q->qsz; i < hi;)
	{
	  c = *j;
	  *j++ = *i;
	  *i++ = c;
	}
    }
  /*
   * With our sentinel in place, we now run the following hyper-fast
   * insertion sort. For each remaining element, min, from [1] to [n-1],
   * set hi to the index of the element AFTER which this one goes. Then, do
   * the standard insertion sort shift on a character at a time basis for
   * each element in the frob.
   */
  for (min = base; (hi = min += q->qsz) < max;)
    {
      while ((*q->qcmp) (hi -= q->qsz, min) > 0);
      if ((hi += q->qsz) != min)
	{
	  for (lo = min + q->qsz; --lo >= min;)
	    {
	      c = *lo;
	      for (i = j = lo; (j -= q->qsz) >= hi; i = j)
		*i = *j;
	      *i = c;
	    }
	}
    }
}



/*
 * qst: Do a quicksort.  First, find the median element, and put that one in
 * the first place as the discriminator.  (This "median" is just the median
 * of the first, last and middle elements).  (Using this median instead of
 * the first element is a big win). Then, the usual partitioning/swapping,
 * followed by moving the discriminator into the right place.  Then, figure
 * out the sizes of the two partitions, do the smaller one recursively and the
 * larger one via a repeat of this code.  Stopping when there are less than
 * THRESH elements in a partition and cleaning up with an insertion sort (in
 * our caller) is a huge win. All data swaps are done in-line, which is
 * space-losing but time-saving. (And there are only three places where this
 * is done).
 */

static void
qst (qst_t * q, char *base, char *max)
{
  char *i;
  char *j;
  char *jj;
  char *mid;
  int ii;
  char c;
  char *tmp;
  int lo;
  int hi;
  int qsz = q->qsz;

  lo = (int) (max - base);	/* number of elements as chars */
  do
    {
      /*
       * At the top here, lo is the number of characters of elements in the
       * current partition.  (Which should be max - base). Find the median
       * of the first, last, and middle element and make that the middle
       * element.  Set j to largest of first and middle.  If max is larger
       * than that guy, then it's that guy, else compare max with loser of
       * first and take larger.  Things are set up to prefer the middle,
       * then the first in case of ties.
       */
      mid = i = base + qsz * ((unsigned) (lo / qsz) >> 1);
      if (lo >= q->mthresh)
	{
	  j = ((*q->qcmp) ((jj = base), i) > 0 ? jj : i);
	  if ((*q->qcmp) (j, (tmp = max - qsz)) > 0)
	    {
	      /* switch to first loser */
	      j = (j == jj ? i : jj);
	      if ((*q->qcmp) (j, tmp) < 0)
		j = tmp;
	    }
	  if (j != i)
	    {
	      ii = qsz;
	      do
		{
		  c = *i;
		  *i++ = *j;
		  *j++ = c;
		}
	      while (--ii);
	    }
	}
      /* Semi-standard quicksort partitioning/swapping */
      for (i = base, j = max - qsz;;)
	{
	  while (i < mid && (*q->qcmp) (i, mid) <= 0)
	    i += qsz;
	  while (j > mid)
	    {
	      if ((*q->qcmp) (mid, j) <= 0)
		{
		  j -= qsz;
		  continue;
		}
	      tmp = i + qsz;	/* value of i after swap */
	      if (i == mid)
		{		/* j <-> mid, new mid is j */
		  mid = jj = j;
		}
	      else
		{		/* i <-> j */
		  jj = j;
		  j -= qsz;
		}
	      goto swap;
	    }
	  if (i == mid)
	    {
	      break;
	    }
	  else
	    {			/* i <-> mid, new mid is i */
	      jj = mid;
	      tmp = mid = i;	/* value of i after swap */
	      j -= qsz;
	    }
	swap:
	  ii = qsz;
	  do
	    {
	      c = *i;
	      *i++ = *jj;
	      *jj++ = c;
	    }
	  while (--ii);
	  i = tmp;
	}
      /*
       * Look at sizes of the two partitions, do the smaller one first by
       * recursion, then do the larger one by making sure lo is its size,
       * base and max are update correctly, and branching back. But only
       * repeat (recursively or by branching) if the partition is of at
       * least size THRESH.
       */
      i = (j = mid) + qsz;
      if ((lo = (int) (j - base)) <= (hi = (int) (max - i)))
	{
	  if (lo >= q->thresh)
	    qst (q, base, j);
	  base = i;
	  lo = hi;
	}
      else
	{
	  if (hi >= q->thresh)
	    qst (q, i, max);
	  max = j;
	}
    }
  while (lo >= q->thresh);
}

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */