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aa9bc17601
BMakefiles and other bits will follow. Requested by: Andrey Chernov Made world by: Chuck Robey
109 lines
3.2 KiB
C
109 lines
3.2 KiB
C
/* Stack allocation routines. This is intended for machines without support
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for the `alloca' function.
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Copyright (C) 1996 Free Software Foundation, Inc.
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This file is part of the GNU MP Library.
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The GNU MP Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Library General Public License as published by
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the Free Software Foundation; either version 2 of the License, or (at your
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option) any later version.
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The GNU MP Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
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License for more details.
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You should have received a copy of the GNU Library General Public License
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along with the GNU MP Library; see the file COPYING.LIB. If not, write to
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the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
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MA 02111-1307, USA. */
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#include "stack-alloc.h"
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typedef struct tmp_stack tmp_stack;
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void *malloc ();
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static unsigned long max_total_allocation = 0;
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static unsigned long current_total_allocation = 0;
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static tmp_stack xxx = {&xxx, &xxx, 0};
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static tmp_stack *current = &xxx;
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/* Allocate a block of exactly <size> bytes. This should only be called
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through the TMP_ALLOC macro, which takes care of rounding/alignment. */
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void *
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__tmp_alloc (size)
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unsigned long size;
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{
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void *this;
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if (size > (char *) current->end - (char *) current->alloc_point)
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{
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void *chunk;
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tmp_stack *header;
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unsigned long chunk_size;
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unsigned long now;
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/* Allocate a chunk that makes the total current allocation somewhat
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larger than the maximum allocation ever. If size is very large, we
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allocate that much. */
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now = current_total_allocation + size;
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if (now > max_total_allocation)
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{
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/* We need more temporary memory than ever before. Increase
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for future needs. */
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now = now * 3 / 2;
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chunk_size = now - current_total_allocation + sizeof (tmp_stack);
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current_total_allocation = now;
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max_total_allocation = current_total_allocation;
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}
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else
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{
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chunk_size = max_total_allocation - current_total_allocation + sizeof (tmp_stack);
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current_total_allocation = max_total_allocation;
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}
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chunk = malloc (chunk_size);
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header = chunk;
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header->end = (char *) chunk + chunk_size;
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header->alloc_point = (char *) chunk + sizeof (tmp_stack);
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header->prev = current;
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current = header;
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}
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this = current->alloc_point;
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current->alloc_point = (char *) this + size;
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return this;
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}
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/* Typically called at function entry. <mark> is assigned so that __tmp_free
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can later be used to reclaim all subsecuently allocated storage. */
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void
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__tmp_mark (mark)
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tmp_marker *mark;
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{
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mark->which_chunk = current;
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mark->alloc_point = current->alloc_point;
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}
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/* Free everything allocated since <mark> was assigned by __tmp_mark */
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void
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__tmp_free (mark)
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tmp_marker *mark;
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{
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while (mark->which_chunk != current)
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{
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tmp_stack *tmp;
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tmp = current;
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current = tmp->prev;
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current_total_allocation -= (((char *) (tmp->end) - (char *) tmp)
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- sizeof (tmp_stack));
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free (tmp);
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}
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current->alloc_point = mark->alloc_point;
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}
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