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Merge tag 'v3.7.5'

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Three new commits:

commit 8358090292
Author: Paul Eggert <eggert@cs.ucla.edu>
Date:   Wed Jan 20 18:30:16 2021 -0800

    c: port to HP-UX 11.23

commit 2c294c1325
Author: Vincent Imbimbo <vmi6@cornell.edu>
Date:   Sat Jan 23 13:25:18 2021 -0500

    cex: fix state-item pruning

commit c22902e360
Author: Akim Demaille <akim.demaille@gmail.com>
Date:   Sat Jan 23 18:40:15 2021 +0100

    tables: fix handling for useless tokens
This commit is contained in:
Akim Demaille
2021-01-24 09:22:49 +01:00
parent fb144c021c 2fac23b9dd
commit c94456986d
5 changed files with 130 additions and 48 deletions
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59
src/state-item.c
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@@ -384,11 +384,10 @@ disable_state_item (state_item *si)
bitset_free (si->prods);
}
/* disable all transitions and productions that can only be
* reached through this state_item.
*/
/* Disable all state_item paths that lead to/from SI and nowhere
else. */
static void
prune_forward (const state_item *si)
prune_state_item (const state_item *si)
{
state_item_list queue =
gl_list_create (GL_LINKED_LIST, NULL, NULL, NULL, true, 1,
@@ -398,8 +397,16 @@ prune_forward (const state_item *si)
{
state_item *dsi = (state_item *) gl_list_get_at (queue, 0);
gl_list_remove_at (queue, 0);
if (dsi->trans >= 0)
gl_list_add_last (queue, &state_items[dsi->trans]);
if (SI_DISABLED (dsi - state_items))
continue;
if (dsi->trans >= 0 && !SI_DISABLED (dsi->trans))
{
const state_item *trans = &state_items[dsi->trans];
bitset_reset (trans->revs, dsi - state_items);
if (bitset_empty_p (trans->revs))
gl_list_add_last (queue, trans);
}
if (dsi->prods)
{
@@ -407,32 +414,15 @@ prune_forward (const state_item *si)
state_item_number sin;
BITSET_FOR_EACH (biter, dsi->prods, sin, 0)
{
if (SI_DISABLED (sin))
continue;
const state_item *prod = &state_items[sin];
bitset_reset (prod->revs, dsi - state_items);
if (bitset_empty_p (prod->revs))
gl_list_add_last (queue, prod);
}
}
if (dsi != si)
disable_state_item (dsi);
}
gl_list_free (queue);
}
/* disable all state_item paths that lead to
* si and nowhere else.
*/
static void
prune_backward (const state_item *si)
{
state_item_list queue =
gl_list_create (GL_LINKED_LIST, NULL, NULL, NULL, true, 1,
(const void **) &si);
while (gl_list_size (queue) > 0)
{
state_item *dsi = (state_item *) gl_list_get_at (queue, 0);
gl_list_remove_at (queue, 0);
bitset_iterator biter;
state_item_number sin;
BITSET_FOR_EACH (biter, dsi->revs, sin, 0)
@@ -440,7 +430,9 @@ prune_backward (const state_item *si)
if (SI_DISABLED (sin))
continue;
state_item *rev = &state_items[sin];
if (rev->prods)
if (&state_items[rev->trans] == dsi)
gl_list_add_last (queue, rev);
else if (rev->prods)
{
bitset_reset (rev->prods, dsi - state_items);
if (bitset_empty_p (rev->prods))
@@ -449,16 +441,13 @@ prune_backward (const state_item *si)
else
gl_list_add_last (queue, rev);
}
if (dsi != si)
disable_state_item (dsi);
disable_state_item (dsi);
}
gl_list_free (queue);
}
/*
To make searches more efficient, we can prune away paths that are
caused by disabled transitions.
*/
/* To make searches more efficient, prune away paths that are caused
by disabled transitions. */
static void
prune_disabled_paths (void)
{
@@ -466,11 +455,7 @@ prune_disabled_paths (void)
{
state_item *si = &state_items[i];
if (si->trans == -1 && item_number_is_symbol_number (*si->item))
{
prune_forward (si);
prune_backward (si);
disable_state_item (si);
}
prune_state_item (si);
}
}