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/* List management for the GCC expander.
Copyright (C) 1987-2019 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC 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 General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
static void free_list (rtx *, rtx *);
/* Functions for maintaining cache-able lists of EXPR_LIST and INSN_LISTs. */
/* An INSN_LIST containing all INSN_LISTs allocated but currently unused. */
static GTY ((deletable)) rtx unused_insn_list;
/* An EXPR_LIST containing all EXPR_LISTs allocated but currently unused. */
static GTY ((deletable)) rtx unused_expr_list;
/* This function will free an entire list of either EXPR_LIST, INSN_LIST
or DEPS_LIST nodes. This is to be used only on lists that consist
exclusively of nodes of one type only. This is only called by
free_EXPR_LIST_list, free_INSN_LIST_list and free_DEPS_LIST_list. */
static void
free_list (rtx *listp, rtx *unused_listp)
{
rtx link, prev_link;
prev_link = *listp;
link = XEXP (prev_link, 1);
gcc_assert (unused_listp != &unused_insn_list
|| GET_CODE (prev_link) == INSN_LIST);
while (link)
{
gcc_assert (unused_listp != &unused_insn_list
|| GET_CODE (prev_link) == INSN_LIST);
prev_link = link;
link = XEXP (link, 1);
}
XEXP (prev_link, 1) = *unused_listp;
*unused_listp = *listp;
*listp = 0;
}
/* Find corresponding to ELEM node in the list pointed to by LISTP.
This node must exist in the list. Returns pointer to that node. */
static rtx *
find_list_elem (rtx elem, rtx *listp)
{
while (XEXP (*listp, 0) != elem)
listp = &XEXP (*listp, 1);
return listp;
}
/* Remove the node pointed to by LISTP from the list. */
static void
remove_list_node (rtx *listp)
{
rtx node;
node = *listp;
*listp = XEXP (node, 1);
XEXP (node, 1) = 0;
}
/* Removes corresponding to ELEM node from the list pointed to by LISTP.
Returns that node. */
rtx
remove_list_elem (rtx elem, rtx *listp)
{
rtx node;
listp = find_list_elem (elem, listp);
node = *listp;
remove_list_node (listp);
return node;
}
/* This call is used in place of a gen_rtx_INSN_LIST. If there is a cached
node available, we'll use it, otherwise a call to gen_rtx_INSN_LIST
is made. */
rtx_insn_list *
alloc_INSN_LIST (rtx val, rtx next)
{
rtx_insn_list *r;
if (unused_insn_list)
{
r = as_a <rtx_insn_list *> (unused_insn_list);
unused_insn_list = r->next ();
XEXP (r, 0) = val;
XEXP (r, 1) = next;
PUT_REG_NOTE_KIND (r, VOIDmode);
gcc_assert (GET_CODE (r) == INSN_LIST);
}
else
r = gen_rtx_INSN_LIST (VOIDmode, val, next);
return r;
}
/* This call is used in place of a gen_rtx_EXPR_LIST. If there is a cached
node available, we'll use it, otherwise a call to gen_rtx_EXPR_LIST
is made. */
rtx_expr_list *
alloc_EXPR_LIST (int kind, rtx val, rtx next)
{
rtx_expr_list *r;
if (unused_expr_list)
{
r = as_a <rtx_expr_list *> (unused_expr_list);
unused_expr_list = XEXP (r, 1);
XEXP (r, 0) = val;
XEXP (r, 1) = next;
PUT_REG_NOTE_KIND (r, kind);
}
else
r = gen_rtx_EXPR_LIST ((machine_mode) kind, val, next);
return r;
}
/* This function will free up an entire list of EXPR_LIST nodes. */
void
free_EXPR_LIST_list (rtx_expr_list **listp)
{
if (*listp == 0)
return;
free_list ((rtx *)listp, &unused_expr_list);
}
/* This function will free up an entire list of INSN_LIST nodes. */
void
free_INSN_LIST_list (rtx_insn_list **listp)
{
if (*listp == 0)
return;
free_list ((rtx *)listp, &unused_insn_list);
}
/* Make a copy of the INSN_LIST list LINK and return it. */
rtx_insn_list *
copy_INSN_LIST (rtx_insn_list *link)
{
rtx_insn_list *new_queue;
rtx_insn_list **pqueue = &new_queue;
for (; link; link = link->next ())
{
rtx_insn *x = link->insn ();
rtx_insn_list *newlink = alloc_INSN_LIST (x, NULL);
*pqueue = newlink;
pqueue = (rtx_insn_list **)&XEXP (newlink, 1);
}
*pqueue = NULL;
return new_queue;
}
/* Duplicate the INSN_LIST elements of COPY and prepend them to OLD. */
rtx_insn_list *
concat_INSN_LIST (rtx_insn_list *copy, rtx_insn_list *old)
{
rtx_insn_list *new_rtx = old;
for (; copy ; copy = copy->next ())
{
new_rtx = alloc_INSN_LIST (copy->insn (), new_rtx);
PUT_REG_NOTE_KIND (new_rtx, REG_NOTE_KIND (copy));
}
return new_rtx;
}
/* This function will free up an individual EXPR_LIST node. */
void
free_EXPR_LIST_node (rtx ptr)
{
XEXP (ptr, 1) = unused_expr_list;
unused_expr_list = ptr;
}
/* This function will free up an individual INSN_LIST node. */
void
free_INSN_LIST_node (rtx ptr)
{
gcc_assert (GET_CODE (ptr) == INSN_LIST);
XEXP (ptr, 1) = unused_insn_list;
unused_insn_list = ptr;
}
/* Remove and free corresponding to ELEM node in the INSN_LIST pointed to
by LISTP. */
void
remove_free_INSN_LIST_elem (rtx_insn *elem, rtx_insn_list **listp)
{
free_INSN_LIST_node (remove_list_elem (elem, (rtx *)listp));
}
/* Remove and free the first node in the INSN_LIST pointed to by LISTP. */
rtx_insn *
remove_free_INSN_LIST_node (rtx_insn_list **listp)
{
rtx_insn_list *node = *listp;
rtx_insn *elem = node->insn ();
remove_list_node ((rtx *)listp);
free_INSN_LIST_node (node);
return elem;
}
/* Remove and free the first node in the EXPR_LIST pointed to by LISTP. */
rtx
remove_free_EXPR_LIST_node (rtx_expr_list **listp)
{
rtx_expr_list *node = *listp;
rtx elem = XEXP (node, 0);
remove_list_node ((rtx *)listp);
free_EXPR_LIST_node (node);
return elem;
}
#include "gt-lists.h"