Reorganisation of the source tree

[ghc-hetmet.git] / rts / gmp / stack-alloc.c

diff --git a/rts/gmp/stack-alloc.c b/rts/gmp/stack-alloc.c
new file mode 100644 (file)
index 0000000..9ab98fe
--- /dev/null
+++ b/rts/gmp/stack-alloc.c
@@ -0,0 +1,136 @@
+/* Stack allocation routines.  This is intended for machines without support
+   for the `alloca' function.
+
+Copyright (C) 1996, 1997, 1999, 2000 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP 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 MP 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 MP Library; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+#include "stack-alloc.h"
+
+#define __need_size_t
+#include <stddef.h>
+#undef __need_size_t
+
+/* gmp-impl.h and stack-alloc.h conflict when not USE_STACK_ALLOC, so these
+   declarations are copied here */
+#if __STDC__
+extern void *  (*__gmp_allocate_func) (size_t);
+extern void    (*__gmp_free_func) (void *, size_t);
+#else
+extern void *  (*__gmp_allocate_func) ();
+extern void    (*__gmp_free_func) ();
+#endif
+
+typedef struct tmp_stack tmp_stack;
+
+static unsigned long max_total_allocation = 0;
+static unsigned long current_total_allocation = 0;
+
+static tmp_stack xxx = {&xxx, &xxx, 0};
+static tmp_stack *current = &xxx;
+
+/* The rounded size of the header of each allocation block.  */
+#define HSIZ ((sizeof (tmp_stack) + __TMP_ALIGN - 1) & -__TMP_ALIGN)
+
+/* Allocate a block of exactly <size> bytes.  This should only be called
+   through the TMP_ALLOC macro, which takes care of rounding/alignment.  */
+void *
+#if __STDC__
+__gmp_tmp_alloc (unsigned long size)
+#else
+__gmp_tmp_alloc (size)
+     unsigned long size;
+#endif
+{
+  void *that;
+
+  if (size > (char *) current->end - (char *) current->alloc_point)
+    {
+      void *chunk;
+      tmp_stack *header;
+      unsigned long chunk_size;
+      unsigned long now;
+
+      /* Allocate a chunk that makes the total current allocation somewhat
+        larger than the maximum allocation ever.  If size is very large, we
+        allocate that much.  */
+
+      now = current_total_allocation + size;
+      if (now > max_total_allocation)
+       {
+         /* We need more temporary memory than ever before.  Increase
+            for future needs.  */
+         now = now * 3 / 2;
+         chunk_size = now - current_total_allocation + HSIZ;
+         current_total_allocation = now;
+         max_total_allocation = current_total_allocation;
+       }
+      else
+       {
+         chunk_size = max_total_allocation - current_total_allocation + HSIZ;
+         current_total_allocation = max_total_allocation;
+       }
+
+      chunk = (*__gmp_allocate_func) (chunk_size);
+      header = (tmp_stack *) chunk;
+      header->end = (char *) chunk + chunk_size;
+      header->alloc_point = (char *) chunk + HSIZ;
+      header->prev = current;
+      current = header;
+    }
+
+  that = current->alloc_point;
+  current->alloc_point = (char *) that + size;
+  return that;
+}
+
+/* Typically called at function entry.  <mark> is assigned so that
+   __gmp_tmp_free can later be used to reclaim all subsequently allocated
+   storage.  */
+void
+#if __STDC__
+__gmp_tmp_mark (tmp_marker *mark)
+#else
+__gmp_tmp_mark (mark)
+     tmp_marker *mark;
+#endif
+{
+  mark->which_chunk = current;
+  mark->alloc_point = current->alloc_point;
+}
+
+/* Free everything allocated since <mark> was assigned by __gmp_tmp_mark */
+void
+#if __STDC__
+__gmp_tmp_free (tmp_marker *mark)
+#else
+__gmp_tmp_free (mark)
+     tmp_marker *mark;
+#endif
+{
+  while (mark->which_chunk != current)
+    {
+      tmp_stack *tmp;
+
+      tmp = current;
+      current = tmp->prev;
+      current_total_allocation -= (((char *) (tmp->end) - (char *) tmp) - HSIZ);
+      (*__gmp_free_func) (tmp, (char *) tmp->end - (char *) tmp);
+    }
+  current->alloc_point = mark->alloc_point;
+}