Prepare for radical source tree reorganization.zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 310 insertions, 0 deletions

diff --git a/REORG.TODO/stdlib/msort.c b/REORG.TODO/stdlib/msort.c
new file mode 100644
index 0000000000..c00f389601
--- /dev/null
+++ b/REORG.TODO/stdlib/msort.c
@@ -0,0 +1,310 @@
+/* An alternative to qsort, with an identical interface.
+   This file is part of the GNU C Library.
+   Copyright (C) 1992-2017 Free Software Foundation, Inc.
+   Written by Mike Haertel, September 1988.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <alloca.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <memcopy.h>
+#include <errno.h>
+#include <atomic.h>
+
+struct msort_param
+{
+  size_t s;
+  size_t var;
+  __compar_d_fn_t cmp;
+  void *arg;
+  char *t;
+};
+static void msort_with_tmp (const struct msort_param *p, void *b, size_t n);
+
+static void
+msort_with_tmp (const struct msort_param *p, void *b, size_t n)
+{
+  char *b1, *b2;
+  size_t n1, n2;
+
+  if (n <= 1)
+    return;
+
+  n1 = n / 2;
+  n2 = n - n1;
+  b1 = b;
+  b2 = (char *) b + (n1 * p->s);
+
+  msort_with_tmp (p, b1, n1);
+  msort_with_tmp (p, b2, n2);
+
+  char *tmp = p->t;
+  const size_t s = p->s;
+  __compar_d_fn_t cmp = p->cmp;
+  void *arg = p->arg;
+  switch (p->var)
+    {
+    case 0:
+      while (n1 > 0 && n2 > 0)
+	{
+	  if ((*cmp) (b1, b2, arg) <= 0)
+	    {
+	      *(uint32_t *) tmp = *(uint32_t *) b1;
+	      b1 += sizeof (uint32_t);
+	      --n1;
+	    }
+	  else
+	    {
+	      *(uint32_t *) tmp = *(uint32_t *) b2;
+	      b2 += sizeof (uint32_t);
+	      --n2;
+	    }
+	  tmp += sizeof (uint32_t);
+	}
+      break;
+    case 1:
+      while (n1 > 0 && n2 > 0)
+	{
+	  if ((*cmp) (b1, b2, arg) <= 0)
+	    {
+	      *(uint64_t *) tmp = *(uint64_t *) b1;
+	      b1 += sizeof (uint64_t);
+	      --n1;
+	    }
+	  else
+	    {
+	      *(uint64_t *) tmp = *(uint64_t *) b2;
+	      b2 += sizeof (uint64_t);
+	      --n2;
+	    }
+	  tmp += sizeof (uint64_t);
+	}
+      break;
+    case 2:
+      while (n1 > 0 && n2 > 0)
+	{
+	  unsigned long *tmpl = (unsigned long *) tmp;
+	  unsigned long *bl;
+
+	  tmp += s;
+	  if ((*cmp) (b1, b2, arg) <= 0)
+	    {
+	      bl = (unsigned long *) b1;
+	      b1 += s;
+	      --n1;
+	    }
+	  else
+	    {
+	      bl = (unsigned long *) b2;
+	      b2 += s;
+	      --n2;
+	    }
+	  while (tmpl < (unsigned long *) tmp)
+	    *tmpl++ = *bl++;
+	}
+      break;
+    case 3:
+      while (n1 > 0 && n2 > 0)
+	{
+	  if ((*cmp) (*(const void **) b1, *(const void **) b2, arg) <= 0)
+	    {
+	      *(void **) tmp = *(void **) b1;
+	      b1 += sizeof (void *);
+	      --n1;
+	    }
+	  else
+	    {
+	      *(void **) tmp = *(void **) b2;
+	      b2 += sizeof (void *);
+	      --n2;
+	    }
+	  tmp += sizeof (void *);
+	}
+      break;
+    default:
+      while (n1 > 0 && n2 > 0)
+	{
+	  if ((*cmp) (b1, b2, arg) <= 0)
+	    {
+	      tmp = (char *) __mempcpy (tmp, b1, s);
+	      b1 += s;
+	      --n1;
+	    }
+	  else
+	    {
+	      tmp = (char *) __mempcpy (tmp, b2, s);
+	      b2 += s;
+	      --n2;
+	    }
+	}
+      break;
+    }
+
+  if (n1 > 0)
+    memcpy (tmp, b1, n1 * s);
+  memcpy (b, p->t, (n - n2) * s);
+}
+
+
+void
+__qsort_r (void *b, size_t n, size_t s, __compar_d_fn_t cmp, void *arg)
+{
+  size_t size = n * s;
+  char *tmp = NULL;
+  struct msort_param p;
+
+  /* For large object sizes use indirect sorting.  */
+  if (s > 32)
+    size = 2 * n * sizeof (void *) + s;
+
+  if (size < 1024)
+    /* The temporary array is small, so put it on the stack.  */
+    p.t = __alloca (size);
+  else
+    {
+      /* We should avoid allocating too much memory since this might
+	 have to be backed up by swap space.  */
+      static long int phys_pages;
+      static int pagesize;
+
+      if (pagesize == 0)
+	{
+	  phys_pages = __sysconf (_SC_PHYS_PAGES);
+
+	  if (phys_pages == -1)
+	    /* Error while determining the memory size.  So let's
+	       assume there is enough memory.  Otherwise the
+	       implementer should provide a complete implementation of
+	       the `sysconf' function.  */
+	    phys_pages = (long int) (~0ul >> 1);
+
+	  /* The following determines that we will never use more than
+	     a quarter of the physical memory.  */
+	  phys_pages /= 4;
+
+	  /* Make sure phys_pages is written to memory.  */
+	  atomic_write_barrier ();
+
+	  pagesize = __sysconf (_SC_PAGESIZE);
+	}
+
+      /* Just a comment here.  We cannot compute
+	   phys_pages * pagesize
+	   and compare the needed amount of memory against this value.
+	   The problem is that some systems might have more physical
+	   memory then can be represented with a `size_t' value (when
+	   measured in bytes.  */
+
+      /* If the memory requirements are too high don't allocate memory.  */
+      if (size / pagesize > (size_t) phys_pages)
+	{
+	  _quicksort (b, n, s, cmp, arg);
+	  return;
+	}
+
+      /* It's somewhat large, so malloc it.  */
+      int save = errno;
+      tmp = malloc (size);
+      __set_errno (save);
+      if (tmp == NULL)
+	{
+	  /* Couldn't get space, so use the slower algorithm
+	     that doesn't need a temporary array.  */
+	  _quicksort (b, n, s, cmp, arg);
+	  return;
+	}
+      p.t = tmp;
+    }
+
+  p.s = s;
+  p.var = 4;
+  p.cmp = cmp;
+  p.arg = arg;
+
+  if (s > 32)
+    {
+      /* Indirect sorting.  */
+      char *ip = (char *) b;
+      void **tp = (void **) (p.t + n * sizeof (void *));
+      void **t = tp;
+      void *tmp_storage = (void *) (tp + n);
+
+      while ((void *) t < tmp_storage)
+	{
+	  *t++ = ip;
+	  ip += s;
+	}
+      p.s = sizeof (void *);
+      p.var = 3;
+      msort_with_tmp (&p, p.t + n * sizeof (void *), n);
+
+      /* tp[0] .. tp[n - 1] is now sorted, copy around entries of
+	 the original array.  Knuth vol. 3 (2nd ed.) exercise 5.2-10.  */
+      char *kp;
+      size_t i;
+      for (i = 0, ip = (char *) b; i < n; i++, ip += s)
+	if ((kp = tp[i]) != ip)
+	  {
+	    size_t j = i;
+	    char *jp = ip;
+	    memcpy (tmp_storage, ip, s);
+
+	    do
+	      {
+		size_t k = (kp - (char *) b) / s;
+		tp[j] = jp;
+		memcpy (jp, kp, s);
+		j = k;
+		jp = kp;
+		kp = tp[k];
+	      }
+	    while (kp != ip);
+
+	    tp[j] = jp;
+	    memcpy (jp, tmp_storage, s);
+	  }
+    }
+  else
+    {
+      if ((s & (sizeof (uint32_t) - 1)) == 0
+	  && ((char *) b - (char *) 0) % __alignof__ (uint32_t) == 0)
+	{
+	  if (s == sizeof (uint32_t))
+	    p.var = 0;
+	  else if (s == sizeof (uint64_t)
+		   && ((char *) b - (char *) 0) % __alignof__ (uint64_t) == 0)
+	    p.var = 1;
+	  else if ((s & (sizeof (unsigned long) - 1)) == 0
+		   && ((char *) b - (char *) 0)
+		      % __alignof__ (unsigned long) == 0)
+	    p.var = 2;
+	}
+      msort_with_tmp (&p, b, n);
+    }
+  free (tmp);
+}
+libc_hidden_def (__qsort_r)
+weak_alias (__qsort_r, qsort_r)
+
+
+void
+qsort (void *b, size_t n, size_t s, __compar_fn_t cmp)
+{
+  return __qsort_r (b, n, s, (__compar_d_fn_t) cmp, NULL);
+}
+libc_hidden_def (qsort)