5917560e17
The GCC4.3 branch contains some optimization fixes that were not considered regressions and therefore were never backported. We are bringing a couple of them that are under GPLv2 since they were made before the license switch upstream. While here, add the GCC revision numbers in the log. Discussed with: jkim MFC after: 1 week
4018 lines
112 KiB
C
4018 lines
112 KiB
C
/* SSA-PRE for trees.
|
|
Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
|
|
Contributed by Daniel Berlin <dan@dberlin.org> and Steven Bosscher
|
|
<stevenb@suse.de>
|
|
|
|
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 2, 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 COPYING. If not, write to
|
|
the Free Software Foundation, 51 Franklin Street, Fifth Floor,
|
|
Boston, MA 02110-1301, USA. */
|
|
|
|
#include "config.h"
|
|
#include "system.h"
|
|
#include "coretypes.h"
|
|
#include "tm.h"
|
|
#include "ggc.h"
|
|
#include "tree.h"
|
|
#include "basic-block.h"
|
|
#include "diagnostic.h"
|
|
#include "tree-inline.h"
|
|
#include "tree-flow.h"
|
|
#include "tree-gimple.h"
|
|
#include "tree-dump.h"
|
|
#include "timevar.h"
|
|
#include "fibheap.h"
|
|
#include "hashtab.h"
|
|
#include "tree-iterator.h"
|
|
#include "real.h"
|
|
#include "alloc-pool.h"
|
|
#include "tree-pass.h"
|
|
#include "flags.h"
|
|
#include "bitmap.h"
|
|
#include "langhooks.h"
|
|
#include "cfgloop.h"
|
|
|
|
/* TODO:
|
|
|
|
1. Avail sets can be shared by making an avail_find_leader that
|
|
walks up the dominator tree and looks in those avail sets.
|
|
This might affect code optimality, it's unclear right now.
|
|
2. Strength reduction can be performed by anticipating expressions
|
|
we can repair later on.
|
|
3. We can do back-substitution or smarter value numbering to catch
|
|
commutative expressions split up over multiple statements.
|
|
4. ANTIC_SAFE_LOADS could be a lot smarter than it is now.
|
|
Right now, it is simply calculating loads that occur before
|
|
any store in a block, instead of loads that occur before
|
|
stores that affect them. This is relatively more expensive, and
|
|
it's not clear how much more it will buy us.
|
|
*/
|
|
|
|
/* For ease of terminology, "expression node" in the below refers to
|
|
every expression node but MODIFY_EXPR, because MODIFY_EXPR's represent
|
|
the actual statement containing the expressions we care about, and
|
|
we cache the value number by putting it in the expression. */
|
|
|
|
/* Basic algorithm
|
|
|
|
First we walk the statements to generate the AVAIL sets, the
|
|
EXP_GEN sets, and the tmp_gen sets. EXP_GEN sets represent the
|
|
generation of values/expressions by a given block. We use them
|
|
when computing the ANTIC sets. The AVAIL sets consist of
|
|
SSA_NAME's that represent values, so we know what values are
|
|
available in what blocks. AVAIL is a forward dataflow problem. In
|
|
SSA, values are never killed, so we don't need a kill set, or a
|
|
fixpoint iteration, in order to calculate the AVAIL sets. In
|
|
traditional parlance, AVAIL sets tell us the downsafety of the
|
|
expressions/values.
|
|
|
|
Next, we generate the ANTIC sets. These sets represent the
|
|
anticipatable expressions. ANTIC is a backwards dataflow
|
|
problem.An expression is anticipatable in a given block if it could
|
|
be generated in that block. This means that if we had to perform
|
|
an insertion in that block, of the value of that expression, we
|
|
could. Calculating the ANTIC sets requires phi translation of
|
|
expressions, because the flow goes backwards through phis. We must
|
|
iterate to a fixpoint of the ANTIC sets, because we have a kill
|
|
set. Even in SSA form, values are not live over the entire
|
|
function, only from their definition point onwards. So we have to
|
|
remove values from the ANTIC set once we go past the definition
|
|
point of the leaders that make them up.
|
|
compute_antic/compute_antic_aux performs this computation.
|
|
|
|
Third, we perform insertions to make partially redundant
|
|
expressions fully redundant.
|
|
|
|
An expression is partially redundant (excluding partial
|
|
anticipation) if:
|
|
|
|
1. It is AVAIL in some, but not all, of the predecessors of a
|
|
given block.
|
|
2. It is ANTIC in all the predecessors.
|
|
|
|
In order to make it fully redundant, we insert the expression into
|
|
the predecessors where it is not available, but is ANTIC.
|
|
insert/insert_aux performs this insertion.
|
|
|
|
Fourth, we eliminate fully redundant expressions.
|
|
This is a simple statement walk that replaces redundant
|
|
calculations with the now available values. */
|
|
|
|
/* Representations of value numbers:
|
|
|
|
Value numbers are represented using the "value handle" approach.
|
|
This means that each SSA_NAME (and for other reasons to be
|
|
disclosed in a moment, expression nodes) has a value handle that
|
|
can be retrieved through get_value_handle. This value handle, *is*
|
|
the value number of the SSA_NAME. You can pointer compare the
|
|
value handles for equivalence purposes.
|
|
|
|
For debugging reasons, the value handle is internally more than
|
|
just a number, it is a VAR_DECL named "value.x", where x is a
|
|
unique number for each value number in use. This allows
|
|
expressions with SSA_NAMES replaced by value handles to still be
|
|
pretty printed in a sane way. They simply print as "value.3 *
|
|
value.5", etc.
|
|
|
|
Expression nodes have value handles associated with them as a
|
|
cache. Otherwise, we'd have to look them up again in the hash
|
|
table This makes significant difference (factor of two or more) on
|
|
some test cases. They can be thrown away after the pass is
|
|
finished. */
|
|
|
|
/* Representation of expressions on value numbers:
|
|
|
|
In some portions of this code, you will notice we allocate "fake"
|
|
analogues to the expression we are value numbering, and replace the
|
|
operands with the values of the expression. Since we work on
|
|
values, and not just names, we canonicalize expressions to value
|
|
expressions for use in the ANTIC sets, the EXP_GEN set, etc.
|
|
|
|
This is theoretically unnecessary, it just saves a bunch of
|
|
repeated get_value_handle and find_leader calls in the remainder of
|
|
the code, trading off temporary memory usage for speed. The tree
|
|
nodes aren't actually creating more garbage, since they are
|
|
allocated in a special pools which are thrown away at the end of
|
|
this pass.
|
|
|
|
All of this also means that if you print the EXP_GEN or ANTIC sets,
|
|
you will see "value.5 + value.7" in the set, instead of "a_55 +
|
|
b_66" or something. The only thing that actually cares about
|
|
seeing the value leaders is phi translation, and it needs to be
|
|
able to find the leader for a value in an arbitrary block, so this
|
|
"value expression" form is perfect for it (otherwise you'd do
|
|
get_value_handle->find_leader->translate->get_value_handle->find_leader).*/
|
|
|
|
|
|
/* Representation of sets:
|
|
|
|
There are currently two types of sets used, hopefully to be unified soon.
|
|
The AVAIL sets do not need to be sorted in any particular order,
|
|
and thus, are simply represented as two bitmaps, one that keeps
|
|
track of values present in the set, and one that keeps track of
|
|
expressions present in the set.
|
|
|
|
The other sets are represented as doubly linked lists kept in topological
|
|
order, with an optional supporting bitmap of values present in the
|
|
set. The sets represent values, and the elements can be values or
|
|
expressions. The elements can appear in different sets, but each
|
|
element can only appear once in each set.
|
|
|
|
Since each node in the set represents a value, we also want to be
|
|
able to map expression, set pairs to something that tells us
|
|
whether the value is present is a set. We use a per-set bitmap for
|
|
that. The value handles also point to a linked list of the
|
|
expressions they represent via a tree annotation. This is mainly
|
|
useful only for debugging, since we don't do identity lookups. */
|
|
|
|
|
|
static bool in_fre = false;
|
|
|
|
/* A value set element. Basically a single linked list of
|
|
expressions/values. */
|
|
typedef struct value_set_node
|
|
{
|
|
/* An expression. */
|
|
tree expr;
|
|
|
|
/* A pointer to the next element of the value set. */
|
|
struct value_set_node *next;
|
|
} *value_set_node_t;
|
|
|
|
|
|
/* A value set. This is a singly linked list of value_set_node
|
|
elements with a possible bitmap that tells us what values exist in
|
|
the set. This set must be kept in topologically sorted order. */
|
|
typedef struct value_set
|
|
{
|
|
/* The head of the list. Used for iterating over the list in
|
|
order. */
|
|
value_set_node_t head;
|
|
|
|
/* The tail of the list. Used for tail insertions, which are
|
|
necessary to keep the set in topologically sorted order because
|
|
of how the set is built. */
|
|
value_set_node_t tail;
|
|
|
|
/* The length of the list. */
|
|
size_t length;
|
|
|
|
/* True if the set is indexed, which means it contains a backing
|
|
bitmap for quick determination of whether certain values exist in the
|
|
set. */
|
|
bool indexed;
|
|
|
|
/* The bitmap of values that exist in the set. May be NULL in an
|
|
empty or non-indexed set. */
|
|
bitmap values;
|
|
|
|
} *value_set_t;
|
|
|
|
|
|
/* An unordered bitmap set. One bitmap tracks values, the other,
|
|
expressions. */
|
|
typedef struct bitmap_set
|
|
{
|
|
bitmap expressions;
|
|
bitmap values;
|
|
} *bitmap_set_t;
|
|
|
|
/* Sets that we need to keep track of. */
|
|
typedef struct bb_value_sets
|
|
{
|
|
/* The EXP_GEN set, which represents expressions/values generated in
|
|
a basic block. */
|
|
value_set_t exp_gen;
|
|
|
|
/* The PHI_GEN set, which represents PHI results generated in a
|
|
basic block. */
|
|
bitmap_set_t phi_gen;
|
|
|
|
/* The TMP_GEN set, which represents results/temporaries generated
|
|
in a basic block. IE the LHS of an expression. */
|
|
bitmap_set_t tmp_gen;
|
|
|
|
/* The AVAIL_OUT set, which represents which values are available in
|
|
a given basic block. */
|
|
bitmap_set_t avail_out;
|
|
|
|
/* The ANTIC_IN set, which represents which values are anticipatable
|
|
in a given basic block. */
|
|
value_set_t antic_in;
|
|
|
|
/* The NEW_SETS set, which is used during insertion to augment the
|
|
AVAIL_OUT set of blocks with the new insertions performed during
|
|
the current iteration. */
|
|
bitmap_set_t new_sets;
|
|
|
|
/* The RVUSE sets, which are used during ANTIC computation to ensure
|
|
that we don't mark loads ANTIC once they have died. */
|
|
bitmap rvuse_in;
|
|
bitmap rvuse_out;
|
|
bitmap rvuse_gen;
|
|
bitmap rvuse_kill;
|
|
|
|
/* For actually occurring loads, as long as they occur before all the
|
|
other stores in the block, we know they are antic at the top of
|
|
the block, regardless of RVUSE_KILL. */
|
|
value_set_t antic_safe_loads;
|
|
} *bb_value_sets_t;
|
|
|
|
#define EXP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->exp_gen
|
|
#define PHI_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->phi_gen
|
|
#define TMP_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->tmp_gen
|
|
#define AVAIL_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->avail_out
|
|
#define ANTIC_IN(BB) ((bb_value_sets_t) ((BB)->aux))->antic_in
|
|
#define RVUSE_IN(BB) ((bb_value_sets_t) ((BB)->aux))->rvuse_in
|
|
#define RVUSE_GEN(BB) ((bb_value_sets_t) ((BB)->aux))->rvuse_gen
|
|
#define RVUSE_KILL(BB) ((bb_value_sets_t) ((BB)->aux))->rvuse_kill
|
|
#define RVUSE_OUT(BB) ((bb_value_sets_t) ((BB)->aux))->rvuse_out
|
|
#define NEW_SETS(BB) ((bb_value_sets_t) ((BB)->aux))->new_sets
|
|
#define ANTIC_SAFE_LOADS(BB) ((bb_value_sets_t) ((BB)->aux))->antic_safe_loads
|
|
|
|
/* This structure is used to keep track of statistics on what
|
|
optimization PRE was able to perform. */
|
|
static struct
|
|
{
|
|
/* The number of RHS computations eliminated by PRE. */
|
|
int eliminations;
|
|
|
|
/* The number of new expressions/temporaries generated by PRE. */
|
|
int insertions;
|
|
|
|
/* The number of new PHI nodes added by PRE. */
|
|
int phis;
|
|
|
|
/* The number of values found constant. */
|
|
int constified;
|
|
|
|
} pre_stats;
|
|
|
|
|
|
static tree bitmap_find_leader (bitmap_set_t, tree);
|
|
static tree find_leader (value_set_t, tree);
|
|
static void value_insert_into_set (value_set_t, tree);
|
|
static void bitmap_value_insert_into_set (bitmap_set_t, tree);
|
|
static void bitmap_value_replace_in_set (bitmap_set_t, tree);
|
|
static void insert_into_set (value_set_t, tree);
|
|
static void bitmap_set_copy (bitmap_set_t, bitmap_set_t);
|
|
static bool bitmap_set_contains_value (bitmap_set_t, tree);
|
|
static bitmap_set_t bitmap_set_new (void);
|
|
static value_set_t set_new (bool);
|
|
static bool is_undefined_value (tree);
|
|
static tree create_expression_by_pieces (basic_block, tree, tree);
|
|
static tree find_or_generate_expression (basic_block, tree, tree);
|
|
|
|
|
|
/* We can add and remove elements and entries to and from sets
|
|
and hash tables, so we use alloc pools for them. */
|
|
|
|
static alloc_pool value_set_pool;
|
|
static alloc_pool bitmap_set_pool;
|
|
static alloc_pool value_set_node_pool;
|
|
static alloc_pool binary_node_pool;
|
|
static alloc_pool unary_node_pool;
|
|
static alloc_pool reference_node_pool;
|
|
static alloc_pool comparison_node_pool;
|
|
static alloc_pool expression_node_pool;
|
|
static alloc_pool list_node_pool;
|
|
static alloc_pool modify_expr_node_pool;
|
|
static bitmap_obstack grand_bitmap_obstack;
|
|
|
|
/* To avoid adding 300 temporary variables when we only need one, we
|
|
only create one temporary variable, on demand, and build ssa names
|
|
off that. We do have to change the variable if the types don't
|
|
match the current variable's type. */
|
|
static tree pretemp;
|
|
static tree storetemp;
|
|
static tree mergephitemp;
|
|
static tree prephitemp;
|
|
|
|
/* Set of blocks with statements that have had its EH information
|
|
cleaned up. */
|
|
static bitmap need_eh_cleanup;
|
|
|
|
/* The phi_translate_table caches phi translations for a given
|
|
expression and predecessor. */
|
|
|
|
static htab_t phi_translate_table;
|
|
|
|
/* A three tuple {e, pred, v} used to cache phi translations in the
|
|
phi_translate_table. */
|
|
|
|
typedef struct expr_pred_trans_d
|
|
{
|
|
/* The expression. */
|
|
tree e;
|
|
|
|
/* The predecessor block along which we translated the expression. */
|
|
basic_block pred;
|
|
|
|
/* vuses associated with the expression. */
|
|
VEC (tree, gc) *vuses;
|
|
|
|
/* The value that resulted from the translation. */
|
|
tree v;
|
|
|
|
|
|
/* The hashcode for the expression, pred pair. This is cached for
|
|
speed reasons. */
|
|
hashval_t hashcode;
|
|
} *expr_pred_trans_t;
|
|
|
|
/* Return the hash value for a phi translation table entry. */
|
|
|
|
static hashval_t
|
|
expr_pred_trans_hash (const void *p)
|
|
{
|
|
const expr_pred_trans_t ve = (expr_pred_trans_t) p;
|
|
return ve->hashcode;
|
|
}
|
|
|
|
/* Return true if two phi translation table entries are the same.
|
|
P1 and P2 should point to the expr_pred_trans_t's to be compared.*/
|
|
|
|
static int
|
|
expr_pred_trans_eq (const void *p1, const void *p2)
|
|
{
|
|
const expr_pred_trans_t ve1 = (expr_pred_trans_t) p1;
|
|
const expr_pred_trans_t ve2 = (expr_pred_trans_t) p2;
|
|
basic_block b1 = ve1->pred;
|
|
basic_block b2 = ve2->pred;
|
|
int i;
|
|
tree vuse1;
|
|
|
|
/* If they are not translations for the same basic block, they can't
|
|
be equal. */
|
|
if (b1 != b2)
|
|
return false;
|
|
|
|
|
|
/* If they are for the same basic block, determine if the
|
|
expressions are equal. */
|
|
if (!expressions_equal_p (ve1->e, ve2->e))
|
|
return false;
|
|
|
|
/* Make sure the vuses are equivalent. */
|
|
if (ve1->vuses == ve2->vuses)
|
|
return true;
|
|
|
|
if (VEC_length (tree, ve1->vuses) != VEC_length (tree, ve2->vuses))
|
|
return false;
|
|
|
|
for (i = 0; VEC_iterate (tree, ve1->vuses, i, vuse1); i++)
|
|
{
|
|
if (VEC_index (tree, ve2->vuses, i) != vuse1)
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/* Search in the phi translation table for the translation of
|
|
expression E in basic block PRED with vuses VUSES.
|
|
Return the translated value, if found, NULL otherwise. */
|
|
|
|
static inline tree
|
|
phi_trans_lookup (tree e, basic_block pred, VEC (tree, gc) *vuses)
|
|
{
|
|
void **slot;
|
|
struct expr_pred_trans_d ept;
|
|
|
|
ept.e = e;
|
|
ept.pred = pred;
|
|
ept.vuses = vuses;
|
|
ept.hashcode = vn_compute (e, (unsigned long) pred);
|
|
slot = htab_find_slot_with_hash (phi_translate_table, &ept, ept.hashcode,
|
|
NO_INSERT);
|
|
if (!slot)
|
|
return NULL;
|
|
else
|
|
return ((expr_pred_trans_t) *slot)->v;
|
|
}
|
|
|
|
|
|
/* Add the tuple mapping from {expression E, basic block PRED, vuses VUSES} to
|
|
value V, to the phi translation table. */
|
|
|
|
static inline void
|
|
phi_trans_add (tree e, tree v, basic_block pred, VEC (tree, gc) *vuses)
|
|
{
|
|
void **slot;
|
|
expr_pred_trans_t new_pair = XNEW (struct expr_pred_trans_d);
|
|
new_pair->e = e;
|
|
new_pair->pred = pred;
|
|
new_pair->vuses = vuses;
|
|
new_pair->v = v;
|
|
new_pair->hashcode = vn_compute (e, (unsigned long) pred);
|
|
slot = htab_find_slot_with_hash (phi_translate_table, new_pair,
|
|
new_pair->hashcode, INSERT);
|
|
if (*slot)
|
|
free (*slot);
|
|
*slot = (void *) new_pair;
|
|
}
|
|
|
|
|
|
/* Add expression E to the expression set of value V. */
|
|
|
|
void
|
|
add_to_value (tree v, tree e)
|
|
{
|
|
/* Constants have no expression sets. */
|
|
if (is_gimple_min_invariant (v))
|
|
return;
|
|
|
|
if (VALUE_HANDLE_EXPR_SET (v) == NULL)
|
|
VALUE_HANDLE_EXPR_SET (v) = set_new (false);
|
|
|
|
insert_into_set (VALUE_HANDLE_EXPR_SET (v), e);
|
|
}
|
|
|
|
|
|
/* Return true if value V exists in the bitmap for SET. */
|
|
|
|
static inline bool
|
|
value_exists_in_set_bitmap (value_set_t set, tree v)
|
|
{
|
|
if (!set->values)
|
|
return false;
|
|
|
|
return bitmap_bit_p (set->values, VALUE_HANDLE_ID (v));
|
|
}
|
|
|
|
|
|
/* Remove value V from the bitmap for SET. */
|
|
|
|
static void
|
|
value_remove_from_set_bitmap (value_set_t set, tree v)
|
|
{
|
|
gcc_assert (set->indexed);
|
|
|
|
if (!set->values)
|
|
return;
|
|
|
|
bitmap_clear_bit (set->values, VALUE_HANDLE_ID (v));
|
|
}
|
|
|
|
|
|
/* Insert the value number V into the bitmap of values existing in
|
|
SET. */
|
|
|
|
static inline void
|
|
value_insert_into_set_bitmap (value_set_t set, tree v)
|
|
{
|
|
gcc_assert (set->indexed);
|
|
|
|
if (set->values == NULL)
|
|
set->values = BITMAP_ALLOC (&grand_bitmap_obstack);
|
|
|
|
bitmap_set_bit (set->values, VALUE_HANDLE_ID (v));
|
|
}
|
|
|
|
|
|
/* Create a new bitmap set and return it. */
|
|
|
|
static bitmap_set_t
|
|
bitmap_set_new (void)
|
|
{
|
|
bitmap_set_t ret = (bitmap_set_t) pool_alloc (bitmap_set_pool);
|
|
ret->expressions = BITMAP_ALLOC (&grand_bitmap_obstack);
|
|
ret->values = BITMAP_ALLOC (&grand_bitmap_obstack);
|
|
return ret;
|
|
}
|
|
|
|
/* Create a new set. */
|
|
|
|
static value_set_t
|
|
set_new (bool indexed)
|
|
{
|
|
value_set_t ret;
|
|
ret = (value_set_t) pool_alloc (value_set_pool);
|
|
ret->head = ret->tail = NULL;
|
|
ret->length = 0;
|
|
ret->indexed = indexed;
|
|
ret->values = NULL;
|
|
return ret;
|
|
}
|
|
|
|
/* Insert an expression EXPR into a bitmapped set. */
|
|
|
|
static void
|
|
bitmap_insert_into_set (bitmap_set_t set, tree expr)
|
|
{
|
|
tree val;
|
|
/* XXX: For now, we only let SSA_NAMES into the bitmap sets. */
|
|
gcc_assert (TREE_CODE (expr) == SSA_NAME);
|
|
val = get_value_handle (expr);
|
|
|
|
gcc_assert (val);
|
|
if (!is_gimple_min_invariant (val))
|
|
{
|
|
bitmap_set_bit (set->values, VALUE_HANDLE_ID (val));
|
|
bitmap_set_bit (set->expressions, SSA_NAME_VERSION (expr));
|
|
}
|
|
}
|
|
|
|
/* Insert EXPR into SET. */
|
|
|
|
static void
|
|
insert_into_set (value_set_t set, tree expr)
|
|
{
|
|
value_set_node_t newnode = (value_set_node_t) pool_alloc (value_set_node_pool);
|
|
tree val = get_value_handle (expr);
|
|
gcc_assert (val);
|
|
|
|
if (is_gimple_min_invariant (val))
|
|
return;
|
|
|
|
/* For indexed sets, insert the value into the set value bitmap.
|
|
For all sets, add it to the linked list and increment the list
|
|
length. */
|
|
if (set->indexed)
|
|
value_insert_into_set_bitmap (set, val);
|
|
|
|
newnode->next = NULL;
|
|
newnode->expr = expr;
|
|
set->length ++;
|
|
if (set->head == NULL)
|
|
{
|
|
set->head = set->tail = newnode;
|
|
}
|
|
else
|
|
{
|
|
set->tail->next = newnode;
|
|
set->tail = newnode;
|
|
}
|
|
}
|
|
|
|
/* Copy a bitmapped set ORIG, into bitmapped set DEST. */
|
|
|
|
static void
|
|
bitmap_set_copy (bitmap_set_t dest, bitmap_set_t orig)
|
|
{
|
|
bitmap_copy (dest->expressions, orig->expressions);
|
|
bitmap_copy (dest->values, orig->values);
|
|
}
|
|
|
|
/* Perform bitmapped set operation DEST &= ORIG. */
|
|
|
|
static void
|
|
bitmap_set_and (bitmap_set_t dest, bitmap_set_t orig)
|
|
{
|
|
bitmap_iterator bi;
|
|
unsigned int i;
|
|
bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack);
|
|
|
|
bitmap_and_into (dest->values, orig->values);
|
|
bitmap_copy (temp, dest->expressions);
|
|
EXECUTE_IF_SET_IN_BITMAP (temp, 0, i, bi)
|
|
{
|
|
tree name = ssa_name (i);
|
|
tree val = get_value_handle (name);
|
|
if (!bitmap_bit_p (dest->values, VALUE_HANDLE_ID (val)))
|
|
bitmap_clear_bit (dest->expressions, i);
|
|
}
|
|
BITMAP_FREE (temp);
|
|
}
|
|
|
|
/* Perform bitmapped value set operation DEST = DEST & ~ORIG. */
|
|
|
|
static void
|
|
bitmap_set_and_compl (bitmap_set_t dest, bitmap_set_t orig)
|
|
{
|
|
bitmap_iterator bi;
|
|
unsigned int i;
|
|
bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack);
|
|
|
|
bitmap_and_compl_into (dest->values, orig->values);
|
|
bitmap_copy (temp, dest->expressions);
|
|
EXECUTE_IF_SET_IN_BITMAP (temp, 0, i, bi)
|
|
{
|
|
tree name = ssa_name (i);
|
|
tree val = get_value_handle (name);
|
|
if (!bitmap_bit_p (dest->values, VALUE_HANDLE_ID (val)))
|
|
bitmap_clear_bit (dest->expressions, i);
|
|
}
|
|
BITMAP_FREE (temp);
|
|
}
|
|
|
|
/* Return true if the bitmap set SET is empty. */
|
|
|
|
static bool
|
|
bitmap_set_empty_p (bitmap_set_t set)
|
|
{
|
|
return bitmap_empty_p (set->values);
|
|
}
|
|
|
|
/* Copy the set ORIG to the set DEST. */
|
|
|
|
static void
|
|
set_copy (value_set_t dest, value_set_t orig)
|
|
{
|
|
value_set_node_t node;
|
|
|
|
if (!orig || !orig->head)
|
|
return;
|
|
|
|
for (node = orig->head;
|
|
node;
|
|
node = node->next)
|
|
{
|
|
insert_into_set (dest, node->expr);
|
|
}
|
|
}
|
|
|
|
/* Remove EXPR from SET. */
|
|
|
|
static void
|
|
set_remove (value_set_t set, tree expr)
|
|
{
|
|
value_set_node_t node, prev;
|
|
|
|
/* Remove the value of EXPR from the bitmap, decrement the set
|
|
length, and remove it from the actual double linked list. */
|
|
value_remove_from_set_bitmap (set, get_value_handle (expr));
|
|
set->length--;
|
|
prev = NULL;
|
|
for (node = set->head;
|
|
node != NULL;
|
|
prev = node, node = node->next)
|
|
{
|
|
if (node->expr == expr)
|
|
{
|
|
if (prev == NULL)
|
|
set->head = node->next;
|
|
else
|
|
prev->next= node->next;
|
|
|
|
if (node == set->tail)
|
|
set->tail = prev;
|
|
pool_free (value_set_node_pool, node);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Return true if SET contains the value VAL. */
|
|
|
|
static bool
|
|
set_contains_value (value_set_t set, tree val)
|
|
{
|
|
/* All constants are in every set. */
|
|
if (is_gimple_min_invariant (val))
|
|
return true;
|
|
|
|
if (!set || set->length == 0)
|
|
return false;
|
|
|
|
return value_exists_in_set_bitmap (set, val);
|
|
}
|
|
|
|
/* Return true if bitmapped set SET contains the expression EXPR. */
|
|
static bool
|
|
bitmap_set_contains (bitmap_set_t set, tree expr)
|
|
{
|
|
/* All constants are in every set. */
|
|
if (is_gimple_min_invariant (get_value_handle (expr)))
|
|
return true;
|
|
|
|
/* XXX: Bitmapped sets only contain SSA_NAME's for now. */
|
|
if (TREE_CODE (expr) != SSA_NAME)
|
|
return false;
|
|
return bitmap_bit_p (set->expressions, SSA_NAME_VERSION (expr));
|
|
}
|
|
|
|
|
|
/* Return true if bitmapped set SET contains the value VAL. */
|
|
|
|
static bool
|
|
bitmap_set_contains_value (bitmap_set_t set, tree val)
|
|
{
|
|
if (is_gimple_min_invariant (val))
|
|
return true;
|
|
return bitmap_bit_p (set->values, VALUE_HANDLE_ID (val));
|
|
}
|
|
|
|
/* Replace an instance of value LOOKFOR with expression EXPR in SET. */
|
|
|
|
static void
|
|
bitmap_set_replace_value (bitmap_set_t set, tree lookfor, tree expr)
|
|
{
|
|
value_set_t exprset;
|
|
value_set_node_t node;
|
|
if (is_gimple_min_invariant (lookfor))
|
|
return;
|
|
if (!bitmap_set_contains_value (set, lookfor))
|
|
return;
|
|
|
|
/* The number of expressions having a given value is usually
|
|
significantly less than the total number of expressions in SET.
|
|
Thus, rather than check, for each expression in SET, whether it
|
|
has the value LOOKFOR, we walk the reverse mapping that tells us
|
|
what expressions have a given value, and see if any of those
|
|
expressions are in our set. For large testcases, this is about
|
|
5-10x faster than walking the bitmap. If this is somehow a
|
|
significant lose for some cases, we can choose which set to walk
|
|
based on the set size. */
|
|
exprset = VALUE_HANDLE_EXPR_SET (lookfor);
|
|
for (node = exprset->head; node; node = node->next)
|
|
{
|
|
if (TREE_CODE (node->expr) == SSA_NAME)
|
|
{
|
|
if (bitmap_bit_p (set->expressions, SSA_NAME_VERSION (node->expr)))
|
|
{
|
|
bitmap_clear_bit (set->expressions, SSA_NAME_VERSION (node->expr));
|
|
bitmap_set_bit (set->expressions, SSA_NAME_VERSION (expr));
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Subtract bitmapped set B from value set A, and return the new set. */
|
|
|
|
static value_set_t
|
|
bitmap_set_subtract_from_value_set (value_set_t a, bitmap_set_t b,
|
|
bool indexed)
|
|
{
|
|
value_set_t ret = set_new (indexed);
|
|
value_set_node_t node;
|
|
for (node = a->head;
|
|
node;
|
|
node = node->next)
|
|
{
|
|
if (!bitmap_set_contains (b, node->expr))
|
|
insert_into_set (ret, node->expr);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* Return true if two sets are equal. */
|
|
|
|
static bool
|
|
set_equal (value_set_t a, value_set_t b)
|
|
{
|
|
value_set_node_t node;
|
|
|
|
if (a->length != b->length)
|
|
return false;
|
|
for (node = a->head;
|
|
node;
|
|
node = node->next)
|
|
{
|
|
if (!set_contains_value (b, get_value_handle (node->expr)))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
|
|
and add it otherwise. */
|
|
|
|
static void
|
|
bitmap_value_replace_in_set (bitmap_set_t set, tree expr)
|
|
{
|
|
tree val = get_value_handle (expr);
|
|
if (bitmap_set_contains_value (set, val))
|
|
bitmap_set_replace_value (set, val, expr);
|
|
else
|
|
bitmap_insert_into_set (set, expr);
|
|
}
|
|
|
|
/* Insert EXPR into SET if EXPR's value is not already present in
|
|
SET. */
|
|
|
|
static void
|
|
bitmap_value_insert_into_set (bitmap_set_t set, tree expr)
|
|
{
|
|
tree val = get_value_handle (expr);
|
|
|
|
if (is_gimple_min_invariant (val))
|
|
return;
|
|
|
|
if (!bitmap_set_contains_value (set, val))
|
|
bitmap_insert_into_set (set, expr);
|
|
}
|
|
|
|
/* Insert the value for EXPR into SET, if it doesn't exist already. */
|
|
|
|
static void
|
|
value_insert_into_set (value_set_t set, tree expr)
|
|
{
|
|
tree val = get_value_handle (expr);
|
|
|
|
/* Constant and invariant values exist everywhere, and thus,
|
|
actually keeping them in the sets is pointless. */
|
|
if (is_gimple_min_invariant (val))
|
|
return;
|
|
|
|
if (!set_contains_value (set, val))
|
|
insert_into_set (set, expr);
|
|
}
|
|
|
|
|
|
/* Print out SET to OUTFILE. */
|
|
|
|
static void
|
|
bitmap_print_value_set (FILE *outfile, bitmap_set_t set,
|
|
const char *setname, int blockindex)
|
|
{
|
|
fprintf (outfile, "%s[%d] := { ", setname, blockindex);
|
|
if (set)
|
|
{
|
|
bool first = true;
|
|
unsigned i;
|
|
bitmap_iterator bi;
|
|
|
|
EXECUTE_IF_SET_IN_BITMAP (set->expressions, 0, i, bi)
|
|
{
|
|
if (!first)
|
|
fprintf (outfile, ", ");
|
|
first = false;
|
|
print_generic_expr (outfile, ssa_name (i), 0);
|
|
|
|
fprintf (outfile, " (");
|
|
print_generic_expr (outfile, get_value_handle (ssa_name (i)), 0);
|
|
fprintf (outfile, ") ");
|
|
}
|
|
}
|
|
fprintf (outfile, " }\n");
|
|
}
|
|
/* Print out the value_set SET to OUTFILE. */
|
|
|
|
static void
|
|
print_value_set (FILE *outfile, value_set_t set,
|
|
const char *setname, int blockindex)
|
|
{
|
|
value_set_node_t node;
|
|
fprintf (outfile, "%s[%d] := { ", setname, blockindex);
|
|
if (set)
|
|
{
|
|
for (node = set->head;
|
|
node;
|
|
node = node->next)
|
|
{
|
|
print_generic_expr (outfile, node->expr, 0);
|
|
|
|
fprintf (outfile, " (");
|
|
print_generic_expr (outfile, get_value_handle (node->expr), 0);
|
|
fprintf (outfile, ") ");
|
|
|
|
if (node->next)
|
|
fprintf (outfile, ", ");
|
|
}
|
|
}
|
|
|
|
fprintf (outfile, " }\n");
|
|
}
|
|
|
|
/* Print out the expressions that have VAL to OUTFILE. */
|
|
|
|
void
|
|
print_value_expressions (FILE *outfile, tree val)
|
|
{
|
|
if (VALUE_HANDLE_EXPR_SET (val))
|
|
{
|
|
char s[10];
|
|
sprintf (s, "VH.%04d", VALUE_HANDLE_ID (val));
|
|
print_value_set (outfile, VALUE_HANDLE_EXPR_SET (val), s, 0);
|
|
}
|
|
}
|
|
|
|
|
|
void
|
|
debug_value_expressions (tree val)
|
|
{
|
|
print_value_expressions (stderr, val);
|
|
}
|
|
|
|
|
|
void debug_value_set (value_set_t, const char *, int);
|
|
|
|
void
|
|
debug_value_set (value_set_t set, const char *setname, int blockindex)
|
|
{
|
|
print_value_set (stderr, set, setname, blockindex);
|
|
}
|
|
|
|
/* Return the folded version of T if T, when folded, is a gimple
|
|
min_invariant. Otherwise, return T. */
|
|
|
|
static tree
|
|
fully_constant_expression (tree t)
|
|
{
|
|
tree folded;
|
|
folded = fold (t);
|
|
if (folded && is_gimple_min_invariant (folded))
|
|
return folded;
|
|
return t;
|
|
}
|
|
|
|
/* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
|
|
For example, this can copy a list made of TREE_LIST nodes.
|
|
Allocates the nodes in list_node_pool*/
|
|
|
|
static tree
|
|
pool_copy_list (tree list)
|
|
{
|
|
tree head;
|
|
tree prev, next;
|
|
|
|
if (list == 0)
|
|
return 0;
|
|
head = (tree) pool_alloc (list_node_pool);
|
|
|
|
memcpy (head, list, tree_size (list));
|
|
prev = head;
|
|
|
|
next = TREE_CHAIN (list);
|
|
while (next)
|
|
{
|
|
TREE_CHAIN (prev) = (tree) pool_alloc (list_node_pool);
|
|
memcpy (TREE_CHAIN (prev), next, tree_size (next));
|
|
prev = TREE_CHAIN (prev);
|
|
next = TREE_CHAIN (next);
|
|
}
|
|
return head;
|
|
}
|
|
|
|
/* Translate the vuses in the VUSES vector backwards through phi
|
|
nodes, so that they have the value they would have in BLOCK. */
|
|
|
|
static VEC(tree, gc) *
|
|
translate_vuses_through_block (VEC (tree, gc) *vuses, basic_block block)
|
|
{
|
|
tree oldvuse;
|
|
VEC(tree, gc) *result = NULL;
|
|
int i;
|
|
|
|
for (i = 0; VEC_iterate (tree, vuses, i, oldvuse); i++)
|
|
{
|
|
tree phi = SSA_NAME_DEF_STMT (oldvuse);
|
|
if (TREE_CODE (phi) == PHI_NODE)
|
|
{
|
|
edge e = find_edge (block, bb_for_stmt (phi));
|
|
if (e)
|
|
{
|
|
tree def = PHI_ARG_DEF (phi, e->dest_idx);
|
|
if (def != oldvuse)
|
|
{
|
|
if (!result)
|
|
result = VEC_copy (tree, gc, vuses);
|
|
VEC_replace (tree, result, i, def);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (result)
|
|
{
|
|
sort_vuses (result);
|
|
return result;
|
|
}
|
|
return vuses;
|
|
|
|
}
|
|
/* Translate EXPR using phis in PHIBLOCK, so that it has the values of
|
|
the phis in PRED. Return NULL if we can't find a leader for each
|
|
part of the translated expression. */
|
|
|
|
static tree
|
|
phi_translate (tree expr, value_set_t set, basic_block pred,
|
|
basic_block phiblock)
|
|
{
|
|
tree phitrans = NULL;
|
|
tree oldexpr = expr;
|
|
if (expr == NULL)
|
|
return NULL;
|
|
|
|
if (is_gimple_min_invariant (expr))
|
|
return expr;
|
|
|
|
/* Phi translations of a given expression don't change. */
|
|
if (EXPR_P (expr))
|
|
{
|
|
tree vh;
|
|
|
|
vh = get_value_handle (expr);
|
|
if (vh && TREE_CODE (vh) == VALUE_HANDLE)
|
|
phitrans = phi_trans_lookup (expr, pred, VALUE_HANDLE_VUSES (vh));
|
|
else
|
|
phitrans = phi_trans_lookup (expr, pred, NULL);
|
|
}
|
|
else
|
|
phitrans = phi_trans_lookup (expr, pred, NULL);
|
|
|
|
if (phitrans)
|
|
return phitrans;
|
|
|
|
switch (TREE_CODE_CLASS (TREE_CODE (expr)))
|
|
{
|
|
case tcc_expression:
|
|
{
|
|
if (TREE_CODE (expr) != CALL_EXPR)
|
|
return NULL;
|
|
else
|
|
{
|
|
tree oldop0 = TREE_OPERAND (expr, 0);
|
|
tree oldarglist = TREE_OPERAND (expr, 1);
|
|
tree oldop2 = TREE_OPERAND (expr, 2);
|
|
tree newop0;
|
|
tree newarglist;
|
|
tree newop2 = NULL;
|
|
tree oldwalker;
|
|
tree newwalker;
|
|
tree newexpr;
|
|
tree vh = get_value_handle (expr);
|
|
bool listchanged = false;
|
|
bool invariantarg = false;
|
|
VEC (tree, gc) *vuses = VALUE_HANDLE_VUSES (vh);
|
|
VEC (tree, gc) *tvuses;
|
|
|
|
/* Call expressions are kind of weird because they have an
|
|
argument list. We don't want to value number the list
|
|
as one value number, because that doesn't make much
|
|
sense, and just breaks the support functions we call,
|
|
which expect TREE_OPERAND (call_expr, 2) to be a
|
|
TREE_LIST. */
|
|
|
|
newop0 = phi_translate (find_leader (set, oldop0),
|
|
set, pred, phiblock);
|
|
if (newop0 == NULL)
|
|
return NULL;
|
|
if (oldop2)
|
|
{
|
|
newop2 = phi_translate (find_leader (set, oldop2),
|
|
set, pred, phiblock);
|
|
if (newop2 == NULL)
|
|
return NULL;
|
|
}
|
|
|
|
/* phi translate the argument list piece by piece.
|
|
|
|
We could actually build the list piece by piece here,
|
|
but it's likely to not be worth the memory we will save,
|
|
unless you have millions of call arguments. */
|
|
|
|
newarglist = pool_copy_list (oldarglist);
|
|
for (oldwalker = oldarglist, newwalker = newarglist;
|
|
oldwalker && newwalker;
|
|
oldwalker = TREE_CHAIN (oldwalker),
|
|
newwalker = TREE_CHAIN (newwalker))
|
|
{
|
|
|
|
tree oldval = TREE_VALUE (oldwalker);
|
|
tree newval;
|
|
if (oldval)
|
|
{
|
|
/* This may seem like a weird place for this
|
|
check, but it's actually the easiest place to
|
|
do it. We can't do it lower on in the
|
|
recursion because it's valid for pieces of a
|
|
component ref to be of AGGREGATE_TYPE, as long
|
|
as the outermost one is not.
|
|
To avoid *that* case, we have a check for
|
|
AGGREGATE_TYPE_P in insert_aux. However, that
|
|
check will *not* catch this case because here
|
|
it occurs in the argument list. */
|
|
if (AGGREGATE_TYPE_P (TREE_TYPE (oldval)))
|
|
return NULL;
|
|
newval = phi_translate (find_leader (set, oldval),
|
|
set, pred, phiblock);
|
|
if (newval == NULL)
|
|
return NULL;
|
|
if (newval != oldval)
|
|
{
|
|
listchanged = true;
|
|
invariantarg |= is_gimple_min_invariant (newval);
|
|
TREE_VALUE (newwalker) = get_value_handle (newval);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* In case of new invariant args we might try to fold the call
|
|
again. */
|
|
if (invariantarg)
|
|
{
|
|
tree tmp = fold_ternary (CALL_EXPR, TREE_TYPE (expr),
|
|
newop0, newarglist, newop2);
|
|
if (tmp)
|
|
{
|
|
STRIP_TYPE_NOPS (tmp);
|
|
if (is_gimple_min_invariant (tmp))
|
|
return tmp;
|
|
}
|
|
}
|
|
|
|
if (listchanged)
|
|
vn_lookup_or_add (newarglist, NULL);
|
|
|
|
tvuses = translate_vuses_through_block (vuses, pred);
|
|
|
|
if (listchanged || (newop0 != oldop0) || (oldop2 != newop2)
|
|
|| vuses != tvuses)
|
|
{
|
|
newexpr = (tree) pool_alloc (expression_node_pool);
|
|
memcpy (newexpr, expr, tree_size (expr));
|
|
TREE_OPERAND (newexpr, 0) = newop0 == oldop0 ? oldop0 : get_value_handle (newop0);
|
|
TREE_OPERAND (newexpr, 1) = listchanged ? newarglist : oldarglist;
|
|
TREE_OPERAND (newexpr, 2) = newop2 == oldop2 ? oldop2 : get_value_handle (newop2);
|
|
newexpr->common.ann = NULL;
|
|
vn_lookup_or_add_with_vuses (newexpr, tvuses);
|
|
expr = newexpr;
|
|
phi_trans_add (oldexpr, newexpr, pred, tvuses);
|
|
}
|
|
}
|
|
}
|
|
return expr;
|
|
|
|
case tcc_declaration:
|
|
{
|
|
VEC (tree, gc) * oldvuses = NULL;
|
|
VEC (tree, gc) * newvuses = NULL;
|
|
|
|
oldvuses = VALUE_HANDLE_VUSES (get_value_handle (expr));
|
|
if (oldvuses)
|
|
newvuses = translate_vuses_through_block (oldvuses, pred);
|
|
|
|
if (oldvuses != newvuses)
|
|
vn_lookup_or_add_with_vuses (expr, newvuses);
|
|
|
|
phi_trans_add (oldexpr, expr, pred, newvuses);
|
|
}
|
|
return expr;
|
|
|
|
case tcc_reference:
|
|
{
|
|
tree oldop0 = TREE_OPERAND (expr, 0);
|
|
tree oldop1 = NULL;
|
|
tree newop0;
|
|
tree newop1 = NULL;
|
|
tree oldop2 = NULL;
|
|
tree newop2 = NULL;
|
|
tree oldop3 = NULL;
|
|
tree newop3 = NULL;
|
|
tree newexpr;
|
|
VEC (tree, gc) * oldvuses = NULL;
|
|
VEC (tree, gc) * newvuses = NULL;
|
|
|
|
if (TREE_CODE (expr) != INDIRECT_REF
|
|
&& TREE_CODE (expr) != COMPONENT_REF
|
|
&& TREE_CODE (expr) != ARRAY_REF)
|
|
return NULL;
|
|
|
|
newop0 = phi_translate (find_leader (set, oldop0),
|
|
set, pred, phiblock);
|
|
if (newop0 == NULL)
|
|
return NULL;
|
|
|
|
if (TREE_CODE (expr) == ARRAY_REF)
|
|
{
|
|
oldop1 = TREE_OPERAND (expr, 1);
|
|
newop1 = phi_translate (find_leader (set, oldop1),
|
|
set, pred, phiblock);
|
|
|
|
if (newop1 == NULL)
|
|
return NULL;
|
|
oldop2 = TREE_OPERAND (expr, 2);
|
|
if (oldop2)
|
|
{
|
|
newop2 = phi_translate (find_leader (set, oldop2),
|
|
set, pred, phiblock);
|
|
|
|
if (newop2 == NULL)
|
|
return NULL;
|
|
}
|
|
oldop3 = TREE_OPERAND (expr, 3);
|
|
if (oldop3)
|
|
{
|
|
newop3 = phi_translate (find_leader (set, oldop3),
|
|
set, pred, phiblock);
|
|
|
|
if (newop3 == NULL)
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
oldvuses = VALUE_HANDLE_VUSES (get_value_handle (expr));
|
|
if (oldvuses)
|
|
newvuses = translate_vuses_through_block (oldvuses, pred);
|
|
|
|
if (newop0 != oldop0 || newvuses != oldvuses
|
|
|| newop1 != oldop1
|
|
|| newop2 != oldop2
|
|
|| newop3 != oldop3)
|
|
{
|
|
tree t;
|
|
|
|
newexpr = pool_alloc (reference_node_pool);
|
|
memcpy (newexpr, expr, tree_size (expr));
|
|
TREE_OPERAND (newexpr, 0) = get_value_handle (newop0);
|
|
if (TREE_CODE (expr) == ARRAY_REF)
|
|
{
|
|
TREE_OPERAND (newexpr, 1) = get_value_handle (newop1);
|
|
if (newop2)
|
|
TREE_OPERAND (newexpr, 2) = get_value_handle (newop2);
|
|
if (newop3)
|
|
TREE_OPERAND (newexpr, 3) = get_value_handle (newop3);
|
|
}
|
|
|
|
t = fully_constant_expression (newexpr);
|
|
|
|
if (t != newexpr)
|
|
{
|
|
pool_free (reference_node_pool, newexpr);
|
|
newexpr = t;
|
|
}
|
|
else
|
|
{
|
|
newexpr->common.ann = NULL;
|
|
vn_lookup_or_add_with_vuses (newexpr, newvuses);
|
|
}
|
|
expr = newexpr;
|
|
phi_trans_add (oldexpr, newexpr, pred, newvuses);
|
|
}
|
|
}
|
|
return expr;
|
|
break;
|
|
|
|
case tcc_binary:
|
|
case tcc_comparison:
|
|
{
|
|
tree oldop1 = TREE_OPERAND (expr, 0);
|
|
tree oldop2 = TREE_OPERAND (expr, 1);
|
|
tree newop1;
|
|
tree newop2;
|
|
tree newexpr;
|
|
|
|
newop1 = phi_translate (find_leader (set, oldop1),
|
|
set, pred, phiblock);
|
|
if (newop1 == NULL)
|
|
return NULL;
|
|
newop2 = phi_translate (find_leader (set, oldop2),
|
|
set, pred, phiblock);
|
|
if (newop2 == NULL)
|
|
return NULL;
|
|
if (newop1 != oldop1 || newop2 != oldop2)
|
|
{
|
|
tree t;
|
|
newexpr = (tree) pool_alloc (binary_node_pool);
|
|
memcpy (newexpr, expr, tree_size (expr));
|
|
TREE_OPERAND (newexpr, 0) = newop1 == oldop1 ? oldop1 : get_value_handle (newop1);
|
|
TREE_OPERAND (newexpr, 1) = newop2 == oldop2 ? oldop2 : get_value_handle (newop2);
|
|
t = fully_constant_expression (newexpr);
|
|
if (t != newexpr)
|
|
{
|
|
pool_free (binary_node_pool, newexpr);
|
|
newexpr = t;
|
|
}
|
|
else
|
|
{
|
|
newexpr->common.ann = NULL;
|
|
vn_lookup_or_add (newexpr, NULL);
|
|
}
|
|
expr = newexpr;
|
|
phi_trans_add (oldexpr, newexpr, pred, NULL);
|
|
}
|
|
}
|
|
return expr;
|
|
|
|
case tcc_unary:
|
|
{
|
|
tree oldop1 = TREE_OPERAND (expr, 0);
|
|
tree newop1;
|
|
tree newexpr;
|
|
|
|
newop1 = phi_translate (find_leader (set, oldop1),
|
|
set, pred, phiblock);
|
|
if (newop1 == NULL)
|
|
return NULL;
|
|
if (newop1 != oldop1)
|
|
{
|
|
tree t;
|
|
newexpr = (tree) pool_alloc (unary_node_pool);
|
|
memcpy (newexpr, expr, tree_size (expr));
|
|
TREE_OPERAND (newexpr, 0) = get_value_handle (newop1);
|
|
t = fully_constant_expression (newexpr);
|
|
if (t != newexpr)
|
|
{
|
|
pool_free (unary_node_pool, newexpr);
|
|
newexpr = t;
|
|
}
|
|
else
|
|
{
|
|
newexpr->common.ann = NULL;
|
|
vn_lookup_or_add (newexpr, NULL);
|
|
}
|
|
expr = newexpr;
|
|
phi_trans_add (oldexpr, newexpr, pred, NULL);
|
|
}
|
|
}
|
|
return expr;
|
|
|
|
case tcc_exceptional:
|
|
{
|
|
tree phi = NULL;
|
|
edge e;
|
|
gcc_assert (TREE_CODE (expr) == SSA_NAME);
|
|
if (TREE_CODE (SSA_NAME_DEF_STMT (expr)) == PHI_NODE)
|
|
phi = SSA_NAME_DEF_STMT (expr);
|
|
else
|
|
return expr;
|
|
|
|
e = find_edge (pred, bb_for_stmt (phi));
|
|
if (e)
|
|
{
|
|
if (is_undefined_value (PHI_ARG_DEF (phi, e->dest_idx)))
|
|
return NULL;
|
|
vn_lookup_or_add (PHI_ARG_DEF (phi, e->dest_idx), NULL);
|
|
return PHI_ARG_DEF (phi, e->dest_idx);
|
|
}
|
|
}
|
|
return expr;
|
|
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
}
|
|
|
|
/* For each expression in SET, translate the value handles through phi nodes
|
|
in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
|
|
expressions in DEST. */
|
|
|
|
static void
|
|
phi_translate_set (value_set_t dest, value_set_t set, basic_block pred,
|
|
basic_block phiblock)
|
|
{
|
|
value_set_node_t node;
|
|
for (node = set->head;
|
|
node;
|
|
node = node->next)
|
|
{
|
|
tree translated;
|
|
|
|
translated = phi_translate (node->expr, set, pred, phiblock);
|
|
|
|
/* Don't add constants or empty translations to the cache, since
|
|
we won't look them up that way, or use the result, anyway. */
|
|
if (translated && !is_gimple_min_invariant (translated))
|
|
{
|
|
tree vh = get_value_handle (translated);
|
|
VEC (tree, gc) *vuses;
|
|
|
|
/* The value handle itself may also be an invariant, in
|
|
which case, it has no vuses. */
|
|
vuses = !is_gimple_min_invariant (vh)
|
|
? VALUE_HANDLE_VUSES (vh) : NULL;
|
|
phi_trans_add (node->expr, translated, pred, vuses);
|
|
}
|
|
|
|
if (translated != NULL)
|
|
value_insert_into_set (dest, translated);
|
|
}
|
|
}
|
|
|
|
/* Find the leader for a value (i.e., the name representing that
|
|
value) in a given set, and return it. Return NULL if no leader is
|
|
found. */
|
|
|
|
static tree
|
|
bitmap_find_leader (bitmap_set_t set, tree val)
|
|
{
|
|
if (val == NULL)
|
|
return NULL;
|
|
|
|
if (is_gimple_min_invariant (val))
|
|
return val;
|
|
if (bitmap_set_contains_value (set, val))
|
|
{
|
|
/* Rather than walk the entire bitmap of expressions, and see
|
|
whether any of them has the value we are looking for, we look
|
|
at the reverse mapping, which tells us the set of expressions
|
|
that have a given value (IE value->expressions with that
|
|
value) and see if any of those expressions are in our set.
|
|
The number of expressions per value is usually significantly
|
|
less than the number of expressions in the set. In fact, for
|
|
large testcases, doing it this way is roughly 5-10x faster
|
|
than walking the bitmap.
|
|
If this is somehow a significant lose for some cases, we can
|
|
choose which set to walk based on which set is smaller. */
|
|
value_set_t exprset;
|
|
value_set_node_t node;
|
|
exprset = VALUE_HANDLE_EXPR_SET (val);
|
|
for (node = exprset->head; node; node = node->next)
|
|
{
|
|
if (TREE_CODE (node->expr) == SSA_NAME)
|
|
{
|
|
if (bitmap_bit_p (set->expressions,
|
|
SSA_NAME_VERSION (node->expr)))
|
|
return node->expr;
|
|
}
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
|
|
/* Find the leader for a value (i.e., the name representing that
|
|
value) in a given set, and return it. Return NULL if no leader is
|
|
found. */
|
|
|
|
static tree
|
|
find_leader (value_set_t set, tree val)
|
|
{
|
|
value_set_node_t node;
|
|
|
|
if (val == NULL)
|
|
return NULL;
|
|
|
|
/* Constants represent themselves. */
|
|
if (is_gimple_min_invariant (val))
|
|
return val;
|
|
|
|
if (set->length == 0)
|
|
return NULL;
|
|
|
|
if (value_exists_in_set_bitmap (set, val))
|
|
{
|
|
for (node = set->head;
|
|
node;
|
|
node = node->next)
|
|
{
|
|
if (get_value_handle (node->expr) == val)
|
|
return node->expr;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Given the vuse representative map, MAP, and an SSA version number,
|
|
ID, return the bitmap of names ID represents, or NULL, if none
|
|
exists. */
|
|
|
|
static bitmap
|
|
get_representative (bitmap *map, int id)
|
|
{
|
|
if (map[id] != NULL)
|
|
return map[id];
|
|
return NULL;
|
|
}
|
|
|
|
/* A vuse is anticipable at the top of block x, from the bottom of the
|
|
block, if it reaches the top of the block, and is not killed in the
|
|
block. In effect, we are trying to see if the vuse is transparent
|
|
backwards in the block. */
|
|
|
|
static bool
|
|
vuses_dies_in_block_x (VEC (tree, gc) *vuses, basic_block block)
|
|
{
|
|
int i;
|
|
tree vuse;
|
|
|
|
for (i = 0; VEC_iterate (tree, vuses, i, vuse); i++)
|
|
{
|
|
/* Any places where this is too conservative, are places
|
|
where we created a new version and shouldn't have. */
|
|
|
|
if (!bitmap_bit_p (RVUSE_IN (block), SSA_NAME_VERSION (vuse))
|
|
|| bitmap_bit_p (RVUSE_KILL (block), SSA_NAME_VERSION (vuse)))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/* Determine if the expression EXPR is valid in SET. This means that
|
|
we have a leader for each part of the expression (if it consists of
|
|
values), or the expression is an SSA_NAME.
|
|
|
|
NB: We never should run into a case where we have SSA_NAME +
|
|
SSA_NAME or SSA_NAME + value. The sets valid_in_set is called on,
|
|
the ANTIC sets, will only ever have SSA_NAME's or value expressions
|
|
(IE VALUE1 + VALUE2, *VALUE1, VALUE1 < VALUE2) */
|
|
|
|
static bool
|
|
valid_in_set (value_set_t set, tree expr, basic_block block)
|
|
{
|
|
tree vh = get_value_handle (expr);
|
|
switch (TREE_CODE_CLASS (TREE_CODE (expr)))
|
|
{
|
|
case tcc_binary:
|
|
case tcc_comparison:
|
|
{
|
|
tree op1 = TREE_OPERAND (expr, 0);
|
|
tree op2 = TREE_OPERAND (expr, 1);
|
|
return set_contains_value (set, op1) && set_contains_value (set, op2);
|
|
}
|
|
|
|
case tcc_unary:
|
|
{
|
|
tree op1 = TREE_OPERAND (expr, 0);
|
|
return set_contains_value (set, op1);
|
|
}
|
|
|
|
case tcc_expression:
|
|
{
|
|
if (TREE_CODE (expr) == CALL_EXPR)
|
|
{
|
|
tree op0 = TREE_OPERAND (expr, 0);
|
|
tree arglist = TREE_OPERAND (expr, 1);
|
|
tree op2 = TREE_OPERAND (expr, 2);
|
|
|
|
/* Check the non-list operands first. */
|
|
if (!set_contains_value (set, op0)
|
|
|| (op2 && !set_contains_value (set, op2)))
|
|
return false;
|
|
|
|
/* Now check the operands. */
|
|
for (; arglist; arglist = TREE_CHAIN (arglist))
|
|
{
|
|
if (!set_contains_value (set, TREE_VALUE (arglist)))
|
|
return false;
|
|
}
|
|
return !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh), block);
|
|
}
|
|
return false;
|
|
}
|
|
|
|
case tcc_reference:
|
|
{
|
|
if (TREE_CODE (expr) == INDIRECT_REF
|
|
|| TREE_CODE (expr) == COMPONENT_REF
|
|
|| TREE_CODE (expr) == ARRAY_REF)
|
|
{
|
|
tree op0 = TREE_OPERAND (expr, 0);
|
|
gcc_assert (is_gimple_min_invariant (op0)
|
|
|| TREE_CODE (op0) == VALUE_HANDLE);
|
|
if (!set_contains_value (set, op0))
|
|
return false;
|
|
if (TREE_CODE (expr) == ARRAY_REF)
|
|
{
|
|
tree op1 = TREE_OPERAND (expr, 1);
|
|
tree op2 = TREE_OPERAND (expr, 2);
|
|
tree op3 = TREE_OPERAND (expr, 3);
|
|
gcc_assert (is_gimple_min_invariant (op1)
|
|
|| TREE_CODE (op1) == VALUE_HANDLE);
|
|
if (!set_contains_value (set, op1))
|
|
return false;
|
|
gcc_assert (!op2 || is_gimple_min_invariant (op2)
|
|
|| TREE_CODE (op2) == VALUE_HANDLE);
|
|
if (op2
|
|
&& !set_contains_value (set, op2))
|
|
return false;
|
|
gcc_assert (!op3 || is_gimple_min_invariant (op3)
|
|
|| TREE_CODE (op3) == VALUE_HANDLE);
|
|
if (op3
|
|
&& !set_contains_value (set, op3))
|
|
return false;
|
|
}
|
|
return set_contains_value (ANTIC_SAFE_LOADS (block),
|
|
vh)
|
|
|| !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh),
|
|
block);
|
|
}
|
|
}
|
|
return false;
|
|
|
|
case tcc_exceptional:
|
|
gcc_assert (TREE_CODE (expr) == SSA_NAME);
|
|
return true;
|
|
|
|
case tcc_declaration:
|
|
return !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh), block);
|
|
|
|
default:
|
|
/* No other cases should be encountered. */
|
|
gcc_unreachable ();
|
|
}
|
|
}
|
|
|
|
/* Clean the set of expressions that are no longer valid in SET. This
|
|
means expressions that are made up of values we have no leaders for
|
|
in SET. */
|
|
|
|
static void
|
|
clean (value_set_t set, basic_block block)
|
|
{
|
|
value_set_node_t node;
|
|
value_set_node_t next;
|
|
node = set->head;
|
|
while (node)
|
|
{
|
|
next = node->next;
|
|
if (!valid_in_set (set, node->expr, block))
|
|
set_remove (set, node->expr);
|
|
node = next;
|
|
}
|
|
}
|
|
|
|
static sbitmap has_abnormal_preds;
|
|
|
|
/* Compute the ANTIC set for BLOCK.
|
|
|
|
If succs(BLOCK) > 1 then
|
|
ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
|
|
else if succs(BLOCK) == 1 then
|
|
ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
|
|
|
|
ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
|
|
|
|
XXX: It would be nice to either write a set_clear, and use it for
|
|
ANTIC_OUT, or to mark the antic_out set as deleted at the end
|
|
of this routine, so that the pool can hand the same memory back out
|
|
again for the next ANTIC_OUT. */
|
|
|
|
static bool
|
|
compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
|
|
{
|
|
basic_block son;
|
|
bool changed = false;
|
|
value_set_t S, old, ANTIC_OUT;
|
|
value_set_node_t node;
|
|
|
|
ANTIC_OUT = S = NULL;
|
|
|
|
/* If any edges from predecessors are abnormal, antic_in is empty,
|
|
so do nothing. */
|
|
if (block_has_abnormal_pred_edge)
|
|
goto maybe_dump_sets;
|
|
|
|
old = set_new (false);
|
|
set_copy (old, ANTIC_IN (block));
|
|
ANTIC_OUT = set_new (true);
|
|
|
|
/* If the block has no successors, ANTIC_OUT is empty. */
|
|
if (EDGE_COUNT (block->succs) == 0)
|
|
;
|
|
/* If we have one successor, we could have some phi nodes to
|
|
translate through. */
|
|
else if (single_succ_p (block))
|
|
{
|
|
phi_translate_set (ANTIC_OUT, ANTIC_IN (single_succ (block)),
|
|
block, single_succ (block));
|
|
}
|
|
/* If we have multiple successors, we take the intersection of all of
|
|
them. */
|
|
else
|
|
{
|
|
VEC(basic_block, heap) * worklist;
|
|
edge e;
|
|
size_t i;
|
|
basic_block bprime, first;
|
|
edge_iterator ei;
|
|
|
|
worklist = VEC_alloc (basic_block, heap, EDGE_COUNT (block->succs));
|
|
FOR_EACH_EDGE (e, ei, block->succs)
|
|
VEC_quick_push (basic_block, worklist, e->dest);
|
|
first = VEC_index (basic_block, worklist, 0);
|
|
set_copy (ANTIC_OUT, ANTIC_IN (first));
|
|
|
|
for (i = 1; VEC_iterate (basic_block, worklist, i, bprime); i++)
|
|
{
|
|
node = ANTIC_OUT->head;
|
|
while (node)
|
|
{
|
|
tree val;
|
|
value_set_node_t next = node->next;
|
|
|
|
val = get_value_handle (node->expr);
|
|
if (!set_contains_value (ANTIC_IN (bprime), val))
|
|
set_remove (ANTIC_OUT, node->expr);
|
|
node = next;
|
|
}
|
|
}
|
|
VEC_free (basic_block, heap, worklist);
|
|
}
|
|
|
|
/* Generate ANTIC_OUT - TMP_GEN. */
|
|
S = bitmap_set_subtract_from_value_set (ANTIC_OUT, TMP_GEN (block), false);
|
|
|
|
/* Start ANTIC_IN with EXP_GEN - TMP_GEN */
|
|
ANTIC_IN (block) = bitmap_set_subtract_from_value_set (EXP_GEN (block),
|
|
TMP_GEN (block),
|
|
true);
|
|
|
|
/* Then union in the ANTIC_OUT - TMP_GEN values,
|
|
to get ANTIC_OUT U EXP_GEN - TMP_GEN */
|
|
for (node = S->head; node; node = node->next)
|
|
value_insert_into_set (ANTIC_IN (block), node->expr);
|
|
|
|
clean (ANTIC_IN (block), block);
|
|
if (!set_equal (old, ANTIC_IN (block)))
|
|
changed = true;
|
|
|
|
maybe_dump_sets:
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
if (ANTIC_OUT)
|
|
print_value_set (dump_file, ANTIC_OUT, "ANTIC_OUT", block->index);
|
|
|
|
if (ANTIC_SAFE_LOADS (block))
|
|
print_value_set (dump_file, ANTIC_SAFE_LOADS (block),
|
|
"ANTIC_SAFE_LOADS", block->index);
|
|
print_value_set (dump_file, ANTIC_IN (block), "ANTIC_IN", block->index);
|
|
|
|
if (S)
|
|
print_value_set (dump_file, S, "S", block->index);
|
|
}
|
|
|
|
for (son = first_dom_son (CDI_POST_DOMINATORS, block);
|
|
son;
|
|
son = next_dom_son (CDI_POST_DOMINATORS, son))
|
|
{
|
|
changed |= compute_antic_aux (son,
|
|
TEST_BIT (has_abnormal_preds, son->index));
|
|
}
|
|
return changed;
|
|
}
|
|
|
|
/* Compute ANTIC sets. */
|
|
|
|
static void
|
|
compute_antic (void)
|
|
{
|
|
bool changed = true;
|
|
int num_iterations = 0;
|
|
basic_block block;
|
|
|
|
/* If any predecessor edges are abnormal, we punt, so antic_in is empty.
|
|
We pre-build the map of blocks with incoming abnormal edges here. */
|
|
has_abnormal_preds = sbitmap_alloc (last_basic_block);
|
|
sbitmap_zero (has_abnormal_preds);
|
|
FOR_EACH_BB (block)
|
|
{
|
|
edge_iterator ei;
|
|
edge e;
|
|
|
|
FOR_EACH_EDGE (e, ei, block->preds)
|
|
if (e->flags & EDGE_ABNORMAL)
|
|
{
|
|
SET_BIT (has_abnormal_preds, block->index);
|
|
break;
|
|
}
|
|
|
|
/* While we are here, give empty ANTIC_IN sets to each block. */
|
|
ANTIC_IN (block) = set_new (true);
|
|
}
|
|
/* At the exit block we anticipate nothing. */
|
|
ANTIC_IN (EXIT_BLOCK_PTR) = set_new (true);
|
|
|
|
while (changed)
|
|
{
|
|
num_iterations++;
|
|
changed = false;
|
|
changed = compute_antic_aux (EXIT_BLOCK_PTR, false);
|
|
}
|
|
|
|
sbitmap_free (has_abnormal_preds);
|
|
|
|
if (dump_file && (dump_flags & TDF_STATS))
|
|
fprintf (dump_file, "compute_antic required %d iterations\n", num_iterations);
|
|
}
|
|
|
|
/* Print the names represented by the bitmap NAMES, to the file OUT. */
|
|
static void
|
|
dump_bitmap_of_names (FILE *out, bitmap names)
|
|
{
|
|
bitmap_iterator bi;
|
|
unsigned int i;
|
|
|
|
fprintf (out, " { ");
|
|
EXECUTE_IF_SET_IN_BITMAP (names, 0, i, bi)
|
|
{
|
|
print_generic_expr (out, ssa_name (i), 0);
|
|
fprintf (out, " ");
|
|
}
|
|
fprintf (out, "}\n");
|
|
}
|
|
|
|
/* Compute a set of representative vuse versions for each phi. This
|
|
is so we can compute conservative kill sets in terms of all vuses
|
|
that are killed, instead of continually walking chains.
|
|
|
|
We also have to be able kill all names associated with a phi when
|
|
the phi dies in order to ensure we don't generate overlapping
|
|
live ranges, which are not allowed in virtual SSA. */
|
|
|
|
static bitmap *vuse_names;
|
|
static void
|
|
compute_vuse_representatives (void)
|
|
{
|
|
tree phi;
|
|
basic_block bb;
|
|
VEC (tree, heap) *phis = NULL;
|
|
bool changed = true;
|
|
size_t i;
|
|
|
|
FOR_EACH_BB (bb)
|
|
{
|
|
for (phi = phi_nodes (bb);
|
|
phi;
|
|
phi = PHI_CHAIN (phi))
|
|
if (!is_gimple_reg (PHI_RESULT (phi)))
|
|
VEC_safe_push (tree, heap, phis, phi);
|
|
}
|
|
|
|
while (changed)
|
|
{
|
|
changed = false;
|
|
|
|
for (i = 0; VEC_iterate (tree, phis, i, phi); i++)
|
|
{
|
|
size_t ver = SSA_NAME_VERSION (PHI_RESULT (phi));
|
|
use_operand_p usep;
|
|
ssa_op_iter iter;
|
|
|
|
if (vuse_names[ver] == NULL)
|
|
{
|
|
vuse_names[ver] = BITMAP_ALLOC (&grand_bitmap_obstack);
|
|
bitmap_set_bit (vuse_names[ver], ver);
|
|
}
|
|
FOR_EACH_PHI_ARG (usep, phi, iter, SSA_OP_ALL_USES)
|
|
{
|
|
tree use = USE_FROM_PTR (usep);
|
|
bitmap usebitmap = get_representative (vuse_names,
|
|
SSA_NAME_VERSION (use));
|
|
if (usebitmap != NULL)
|
|
{
|
|
changed |= bitmap_ior_into (vuse_names[ver],
|
|
usebitmap);
|
|
}
|
|
else
|
|
{
|
|
changed |= !bitmap_bit_p (vuse_names[ver],
|
|
SSA_NAME_VERSION (use));
|
|
if (changed)
|
|
bitmap_set_bit (vuse_names[ver],
|
|
SSA_NAME_VERSION (use));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
for (i = 0; VEC_iterate (tree, phis, i, phi); i++)
|
|
{
|
|
bitmap reps = get_representative (vuse_names,
|
|
SSA_NAME_VERSION (PHI_RESULT (phi)));
|
|
if (reps)
|
|
{
|
|
print_generic_expr (dump_file, PHI_RESULT (phi), 0);
|
|
fprintf (dump_file, " represents ");
|
|
dump_bitmap_of_names (dump_file, reps);
|
|
}
|
|
}
|
|
VEC_free (tree, heap, phis);
|
|
}
|
|
|
|
/* Compute reaching vuses and antic safe loads. RVUSE computation is
|
|
is a small bit of iterative dataflow to determine what virtual uses
|
|
reach what blocks. Because we can't generate overlapping virtual
|
|
uses, and virtual uses *do* actually die, this ends up being faster
|
|
in most cases than continually walking the virtual use/def chains
|
|
to determine whether we are inside a block where a given virtual is
|
|
still available to be used.
|
|
|
|
ANTIC_SAFE_LOADS are those loads that actually occur before any kill to
|
|
their vuses in the block,and thus, are safe at the top of the
|
|
block.
|
|
|
|
An example:
|
|
|
|
<block begin>
|
|
b = *a
|
|
*a = 9
|
|
<block end>
|
|
|
|
b = *a is an antic safe load because it still safe to consider it
|
|
ANTIC at the top of the block.
|
|
|
|
We currently compute a conservative approximation to
|
|
ANTIC_SAFE_LOADS. We compute those loads that occur before *any*
|
|
stores in the block. This is not because it is difficult to
|
|
compute the precise answer, but because it is expensive. More
|
|
testing is necessary to determine whether it is worth computing the
|
|
precise answer. */
|
|
|
|
static void
|
|
compute_rvuse_and_antic_safe (void)
|
|
{
|
|
|
|
size_t i;
|
|
tree phi;
|
|
basic_block bb;
|
|
int *postorder;
|
|
bool changed = true;
|
|
unsigned int *first_store_uid;
|
|
|
|
first_store_uid = xcalloc (n_basic_blocks, sizeof (unsigned int));
|
|
|
|
compute_vuse_representatives ();
|
|
|
|
FOR_ALL_BB (bb)
|
|
{
|
|
RVUSE_IN (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
|
|
RVUSE_GEN (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
|
|
RVUSE_KILL (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
|
|
RVUSE_OUT (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
|
|
ANTIC_SAFE_LOADS (bb) = NULL;
|
|
}
|
|
|
|
/* Mark live on entry */
|
|
for (i = 0; i < num_ssa_names; i++)
|
|
{
|
|
tree name = ssa_name (i);
|
|
if (name && !is_gimple_reg (name)
|
|
&& IS_EMPTY_STMT (SSA_NAME_DEF_STMT (name)))
|
|
bitmap_set_bit (RVUSE_OUT (ENTRY_BLOCK_PTR),
|
|
SSA_NAME_VERSION (name));
|
|
}
|
|
|
|
/* Compute local sets for reaching vuses.
|
|
GEN(block) = generated in block and not locally killed.
|
|
KILL(block) = set of vuses killed in block.
|
|
*/
|
|
|
|
FOR_EACH_BB (bb)
|
|
{
|
|
block_stmt_iterator bsi;
|
|
ssa_op_iter iter;
|
|
def_operand_p defp;
|
|
use_operand_p usep;
|
|
|
|
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
|
|
{
|
|
tree stmt = bsi_stmt (bsi);
|
|
|
|
if (first_store_uid[bb->index] == 0
|
|
&& !ZERO_SSA_OPERANDS (stmt, SSA_OP_VMAYUSE | SSA_OP_VMAYDEF
|
|
| SSA_OP_VMUSTDEF | SSA_OP_VMUSTKILL))
|
|
{
|
|
first_store_uid[bb->index] = stmt_ann (stmt)->uid;
|
|
}
|
|
|
|
|
|
FOR_EACH_SSA_USE_OPERAND (usep, stmt, iter, SSA_OP_VIRTUAL_KILLS
|
|
| SSA_OP_VMAYUSE)
|
|
{
|
|
tree use = USE_FROM_PTR (usep);
|
|
bitmap repbit = get_representative (vuse_names,
|
|
SSA_NAME_VERSION (use));
|
|
if (repbit != NULL)
|
|
{
|
|
bitmap_and_compl_into (RVUSE_GEN (bb), repbit);
|
|
bitmap_ior_into (RVUSE_KILL (bb), repbit);
|
|
}
|
|
else
|
|
{
|
|
bitmap_set_bit (RVUSE_KILL (bb), SSA_NAME_VERSION (use));
|
|
bitmap_clear_bit (RVUSE_GEN (bb), SSA_NAME_VERSION (use));
|
|
}
|
|
}
|
|
FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_VIRTUAL_DEFS)
|
|
{
|
|
tree def = DEF_FROM_PTR (defp);
|
|
bitmap_set_bit (RVUSE_GEN (bb), SSA_NAME_VERSION (def));
|
|
}
|
|
}
|
|
}
|
|
|
|
FOR_EACH_BB (bb)
|
|
{
|
|
for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
|
|
{
|
|
if (!is_gimple_reg (PHI_RESULT (phi)))
|
|
{
|
|
edge e;
|
|
edge_iterator ei;
|
|
|
|
tree def = PHI_RESULT (phi);
|
|
/* In reality, the PHI result is generated at the end of
|
|
each predecessor block. This will make the value
|
|
LVUSE_IN for the bb containing the PHI, which is
|
|
correct. */
|
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
|
bitmap_set_bit (RVUSE_GEN (e->src), SSA_NAME_VERSION (def));
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Solve reaching vuses.
|
|
|
|
RVUSE_IN[BB] = Union of RVUSE_OUT of predecessors.
|
|
RVUSE_OUT[BB] = RVUSE_GEN[BB] U (RVUSE_IN[BB] - RVUSE_KILL[BB])
|
|
*/
|
|
postorder = XNEWVEC (int, n_basic_blocks - NUM_FIXED_BLOCKS);
|
|
pre_and_rev_post_order_compute (NULL, postorder, false);
|
|
|
|
changed = true;
|
|
while (changed)
|
|
{
|
|
int j;
|
|
changed = false;
|
|
for (j = 0; j < n_basic_blocks - NUM_FIXED_BLOCKS; j++)
|
|
{
|
|
edge e;
|
|
edge_iterator ei;
|
|
bb = BASIC_BLOCK (postorder[j]);
|
|
|
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
|
bitmap_ior_into (RVUSE_IN (bb), RVUSE_OUT (e->src));
|
|
|
|
changed |= bitmap_ior_and_compl (RVUSE_OUT (bb),
|
|
RVUSE_GEN (bb),
|
|
RVUSE_IN (bb),
|
|
RVUSE_KILL (bb));
|
|
}
|
|
}
|
|
free (postorder);
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
FOR_ALL_BB (bb)
|
|
{
|
|
fprintf (dump_file, "RVUSE_IN (%d) =", bb->index);
|
|
dump_bitmap_of_names (dump_file, RVUSE_IN (bb));
|
|
|
|
fprintf (dump_file, "RVUSE_KILL (%d) =", bb->index);
|
|
dump_bitmap_of_names (dump_file, RVUSE_KILL (bb));
|
|
|
|
fprintf (dump_file, "RVUSE_GEN (%d) =", bb->index);
|
|
dump_bitmap_of_names (dump_file, RVUSE_GEN (bb));
|
|
|
|
fprintf (dump_file, "RVUSE_OUT (%d) =", bb->index);
|
|
dump_bitmap_of_names (dump_file, RVUSE_OUT (bb));
|
|
}
|
|
}
|
|
|
|
FOR_EACH_BB (bb)
|
|
{
|
|
value_set_node_t node;
|
|
if (bitmap_empty_p (RVUSE_KILL (bb)))
|
|
continue;
|
|
|
|
for (node = EXP_GEN (bb)->head; node; node = node->next)
|
|
{
|
|
if (REFERENCE_CLASS_P (node->expr))
|
|
{
|
|
tree vh = get_value_handle (node->expr);
|
|
tree maybe = bitmap_find_leader (AVAIL_OUT (bb), vh);
|
|
|
|
if (maybe)
|
|
{
|
|
tree def = SSA_NAME_DEF_STMT (maybe);
|
|
|
|
if (bb_for_stmt (def) != bb)
|
|
continue;
|
|
|
|
if (TREE_CODE (def) == PHI_NODE
|
|
|| stmt_ann (def)->uid < first_store_uid[bb->index])
|
|
{
|
|
if (ANTIC_SAFE_LOADS (bb) == NULL)
|
|
ANTIC_SAFE_LOADS (bb) = set_new (true);
|
|
value_insert_into_set (ANTIC_SAFE_LOADS (bb),
|
|
node->expr);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
free (first_store_uid);
|
|
}
|
|
|
|
/* Return true if we can value number the call in STMT. This is true
|
|
if we have a pure or constant call. */
|
|
|
|
static bool
|
|
can_value_number_call (tree stmt)
|
|
{
|
|
tree call = get_call_expr_in (stmt);
|
|
|
|
if (call_expr_flags (call) & (ECF_PURE | ECF_CONST))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/* Return true if OP is a tree which we can perform value numbering
|
|
on. */
|
|
|
|
static bool
|
|
can_value_number_operation (tree op)
|
|
{
|
|
return UNARY_CLASS_P (op)
|
|
|| BINARY_CLASS_P (op)
|
|
|| COMPARISON_CLASS_P (op)
|
|
|| REFERENCE_CLASS_P (op)
|
|
|| (TREE_CODE (op) == CALL_EXPR
|
|
&& can_value_number_call (op));
|
|
}
|
|
|
|
|
|
/* Return true if OP is a tree which we can perform PRE on
|
|
on. This may not match the operations we can value number, but in
|
|
a perfect world would. */
|
|
|
|
static bool
|
|
can_PRE_operation (tree op)
|
|
{
|
|
return UNARY_CLASS_P (op)
|
|
|| BINARY_CLASS_P (op)
|
|
|| COMPARISON_CLASS_P (op)
|
|
|| TREE_CODE (op) == INDIRECT_REF
|
|
|| TREE_CODE (op) == COMPONENT_REF
|
|
|| TREE_CODE (op) == CALL_EXPR
|
|
|| TREE_CODE (op) == ARRAY_REF;
|
|
}
|
|
|
|
|
|
/* Inserted expressions are placed onto this worklist, which is used
|
|
for performing quick dead code elimination of insertions we made
|
|
that didn't turn out to be necessary. */
|
|
static VEC(tree,heap) *inserted_exprs;
|
|
|
|
/* Pool allocated fake store expressions are placed onto this
|
|
worklist, which, after performing dead code elimination, is walked
|
|
to see which expressions need to be put into GC'able memory */
|
|
static VEC(tree, heap) *need_creation;
|
|
|
|
/* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
|
|
COMPONENT_REF or INDIRECT_REF or ARRAY_REF portion, because we'd end up with
|
|
trying to rename aggregates into ssa form directly, which is a no
|
|
no.
|
|
|
|
Thus, this routine doesn't create temporaries, it just builds a
|
|
single access expression for the array, calling
|
|
find_or_generate_expression to build the innermost pieces.
|
|
|
|
This function is a subroutine of create_expression_by_pieces, and
|
|
should not be called on it's own unless you really know what you
|
|
are doing.
|
|
*/
|
|
static tree
|
|
create_component_ref_by_pieces (basic_block block, tree expr, tree stmts)
|
|
{
|
|
tree genop = expr;
|
|
tree folded;
|
|
|
|
if (TREE_CODE (genop) == VALUE_HANDLE)
|
|
{
|
|
tree found = bitmap_find_leader (AVAIL_OUT (block), expr);
|
|
if (found)
|
|
return found;
|
|
}
|
|
|
|
if (TREE_CODE (genop) == VALUE_HANDLE)
|
|
genop = VALUE_HANDLE_EXPR_SET (expr)->head->expr;
|
|
|
|
switch TREE_CODE (genop)
|
|
{
|
|
case ARRAY_REF:
|
|
{
|
|
tree op0;
|
|
tree op1, op2, op3;
|
|
op0 = create_component_ref_by_pieces (block,
|
|
TREE_OPERAND (genop, 0),
|
|
stmts);
|
|
op1 = TREE_OPERAND (genop, 1);
|
|
if (TREE_CODE (op1) == VALUE_HANDLE)
|
|
op1 = find_or_generate_expression (block, op1, stmts);
|
|
op2 = TREE_OPERAND (genop, 2);
|
|
if (op2 && TREE_CODE (op2) == VALUE_HANDLE)
|
|
op2 = find_or_generate_expression (block, op2, stmts);
|
|
op3 = TREE_OPERAND (genop, 3);
|
|
if (op3 && TREE_CODE (op3) == VALUE_HANDLE)
|
|
op3 = find_or_generate_expression (block, op3, stmts);
|
|
folded = build4 (ARRAY_REF, TREE_TYPE (genop), op0, op1,
|
|
op2, op3);
|
|
return folded;
|
|
}
|
|
case COMPONENT_REF:
|
|
{
|
|
tree op0;
|
|
tree op1;
|
|
op0 = create_component_ref_by_pieces (block,
|
|
TREE_OPERAND (genop, 0),
|
|
stmts);
|
|
op1 = VALUE_HANDLE_EXPR_SET (TREE_OPERAND (genop, 1))->head->expr;
|
|
folded = fold_build3 (COMPONENT_REF, TREE_TYPE (genop), op0, op1,
|
|
NULL_TREE);
|
|
return folded;
|
|
}
|
|
break;
|
|
case INDIRECT_REF:
|
|
{
|
|
tree op1 = TREE_OPERAND (genop, 0);
|
|
tree genop1 = find_or_generate_expression (block, op1, stmts);
|
|
|
|
folded = fold_build1 (TREE_CODE (genop), TREE_TYPE (genop),
|
|
genop1);
|
|
return folded;
|
|
}
|
|
break;
|
|
case VAR_DECL:
|
|
case PARM_DECL:
|
|
case RESULT_DECL:
|
|
case SSA_NAME:
|
|
case STRING_CST:
|
|
return genop;
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* Find a leader for an expression, or generate one using
|
|
create_expression_by_pieces if it's ANTIC but
|
|
complex.
|
|
BLOCK is the basic_block we are looking for leaders in.
|
|
EXPR is the expression to find a leader or generate for.
|
|
STMTS is the statement list to put the inserted expressions on.
|
|
Returns the SSA_NAME of the LHS of the generated expression or the
|
|
leader. */
|
|
|
|
static tree
|
|
find_or_generate_expression (basic_block block, tree expr, tree stmts)
|
|
{
|
|
tree genop = bitmap_find_leader (AVAIL_OUT (block), expr);
|
|
|
|
/* If it's still NULL, it must be a complex expression, so generate
|
|
it recursively. */
|
|
if (genop == NULL)
|
|
{
|
|
genop = VALUE_HANDLE_EXPR_SET (expr)->head->expr;
|
|
|
|
gcc_assert (can_PRE_operation (genop));
|
|
genop = create_expression_by_pieces (block, genop, stmts);
|
|
}
|
|
return genop;
|
|
}
|
|
|
|
#define NECESSARY(stmt) stmt->common.asm_written_flag
|
|
/* Create an expression in pieces, so that we can handle very complex
|
|
expressions that may be ANTIC, but not necessary GIMPLE.
|
|
BLOCK is the basic block the expression will be inserted into,
|
|
EXPR is the expression to insert (in value form)
|
|
STMTS is a statement list to append the necessary insertions into.
|
|
|
|
This function will die if we hit some value that shouldn't be
|
|
ANTIC but is (IE there is no leader for it, or its components).
|
|
This function may also generate expressions that are themselves
|
|
partially or fully redundant. Those that are will be either made
|
|
fully redundant during the next iteration of insert (for partially
|
|
redundant ones), or eliminated by eliminate (for fully redundant
|
|
ones). */
|
|
|
|
static tree
|
|
create_expression_by_pieces (basic_block block, tree expr, tree stmts)
|
|
{
|
|
tree temp, name;
|
|
tree folded, forced_stmts, newexpr;
|
|
tree v;
|
|
tree_stmt_iterator tsi;
|
|
|
|
switch (TREE_CODE_CLASS (TREE_CODE (expr)))
|
|
{
|
|
case tcc_expression:
|
|
{
|
|
tree op0, op2;
|
|
tree arglist;
|
|
tree genop0, genop2;
|
|
tree genarglist;
|
|
tree walker, genwalker;
|
|
|
|
gcc_assert (TREE_CODE (expr) == CALL_EXPR);
|
|
genop2 = NULL;
|
|
|
|
op0 = TREE_OPERAND (expr, 0);
|
|
arglist = TREE_OPERAND (expr, 1);
|
|
op2 = TREE_OPERAND (expr, 2);
|
|
|
|
genop0 = find_or_generate_expression (block, op0, stmts);
|
|
genarglist = copy_list (arglist);
|
|
for (walker = arglist, genwalker = genarglist;
|
|
genwalker && walker;
|
|
genwalker = TREE_CHAIN (genwalker), walker = TREE_CHAIN (walker))
|
|
{
|
|
TREE_VALUE (genwalker)
|
|
= find_or_generate_expression (block, TREE_VALUE (walker),
|
|
stmts);
|
|
}
|
|
|
|
if (op2)
|
|
genop2 = find_or_generate_expression (block, op2, stmts);
|
|
folded = fold_build3 (TREE_CODE (expr), TREE_TYPE (expr),
|
|
genop0, genarglist, genop2);
|
|
break;
|
|
|
|
|
|
}
|
|
break;
|
|
case tcc_reference:
|
|
{
|
|
if (TREE_CODE (expr) == COMPONENT_REF
|
|
|| TREE_CODE (expr) == ARRAY_REF)
|
|
{
|
|
folded = create_component_ref_by_pieces (block, expr, stmts);
|
|
}
|
|
else
|
|
{
|
|
tree op1 = TREE_OPERAND (expr, 0);
|
|
tree genop1 = find_or_generate_expression (block, op1, stmts);
|
|
|
|
folded = fold_build1 (TREE_CODE (expr), TREE_TYPE (expr),
|
|
genop1);
|
|
}
|
|
break;
|
|
}
|
|
|
|
case tcc_binary:
|
|
case tcc_comparison:
|
|
{
|
|
tree op1 = TREE_OPERAND (expr, 0);
|
|
tree op2 = TREE_OPERAND (expr, 1);
|
|
tree genop1 = find_or_generate_expression (block, op1, stmts);
|
|
tree genop2 = find_or_generate_expression (block, op2, stmts);
|
|
folded = fold_build2 (TREE_CODE (expr), TREE_TYPE (expr),
|
|
genop1, genop2);
|
|
break;
|
|
}
|
|
|
|
case tcc_unary:
|
|
{
|
|
tree op1 = TREE_OPERAND (expr, 0);
|
|
tree genop1 = find_or_generate_expression (block, op1, stmts);
|
|
folded = fold_build1 (TREE_CODE (expr), TREE_TYPE (expr),
|
|
genop1);
|
|
break;
|
|
}
|
|
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
/* Force the generated expression to be a sequence of GIMPLE
|
|
statements.
|
|
We have to call unshare_expr because force_gimple_operand may
|
|
modify the tree we pass to it. */
|
|
newexpr = force_gimple_operand (unshare_expr (folded), &forced_stmts,
|
|
false, NULL);
|
|
|
|
/* If we have any intermediate expressions to the value sets, add them
|
|
to the value sets and chain them on in the instruction stream. */
|
|
if (forced_stmts)
|
|
{
|
|
tsi = tsi_start (forced_stmts);
|
|
for (; !tsi_end_p (tsi); tsi_next (&tsi))
|
|
{
|
|
tree stmt = tsi_stmt (tsi);
|
|
tree forcedname = TREE_OPERAND (stmt, 0);
|
|
tree forcedexpr = TREE_OPERAND (stmt, 1);
|
|
tree val = vn_lookup_or_add (forcedexpr, NULL);
|
|
|
|
VEC_safe_push (tree, heap, inserted_exprs, stmt);
|
|
vn_add (forcedname, val);
|
|
bitmap_value_replace_in_set (NEW_SETS (block), forcedname);
|
|
bitmap_value_replace_in_set (AVAIL_OUT (block), forcedname);
|
|
mark_new_vars_to_rename (stmt);
|
|
}
|
|
tsi = tsi_last (stmts);
|
|
tsi_link_after (&tsi, forced_stmts, TSI_CONTINUE_LINKING);
|
|
}
|
|
|
|
/* Build and insert the assignment of the end result to the temporary
|
|
that we will return. */
|
|
if (!pretemp || TREE_TYPE (expr) != TREE_TYPE (pretemp))
|
|
{
|
|
pretemp = create_tmp_var (TREE_TYPE (expr), "pretmp");
|
|
get_var_ann (pretemp);
|
|
}
|
|
|
|
temp = pretemp;
|
|
add_referenced_var (temp);
|
|
|
|
if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
|
|
DECL_COMPLEX_GIMPLE_REG_P (temp) = 1;
|
|
|
|
newexpr = build2 (MODIFY_EXPR, TREE_TYPE (expr), temp, newexpr);
|
|
name = make_ssa_name (temp, newexpr);
|
|
TREE_OPERAND (newexpr, 0) = name;
|
|
NECESSARY (newexpr) = 0;
|
|
|
|
tsi = tsi_last (stmts);
|
|
tsi_link_after (&tsi, newexpr, TSI_CONTINUE_LINKING);
|
|
VEC_safe_push (tree, heap, inserted_exprs, newexpr);
|
|
mark_new_vars_to_rename (newexpr);
|
|
|
|
/* Add a value handle to the temporary.
|
|
The value may already exist in either NEW_SETS, or AVAIL_OUT, because
|
|
we are creating the expression by pieces, and this particular piece of
|
|
the expression may have been represented. There is no harm in replacing
|
|
here. */
|
|
v = get_value_handle (expr);
|
|
vn_add (name, v);
|
|
bitmap_value_replace_in_set (NEW_SETS (block), name);
|
|
bitmap_value_replace_in_set (AVAIL_OUT (block), name);
|
|
|
|
pre_stats.insertions++;
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Inserted ");
|
|
print_generic_expr (dump_file, newexpr, 0);
|
|
fprintf (dump_file, " in predecessor %d\n", block->index);
|
|
}
|
|
|
|
return name;
|
|
}
|
|
|
|
/* Insert the to-be-made-available values of NODE for each
|
|
predecessor, stored in AVAIL, into the predecessors of BLOCK, and
|
|
merge the result with a phi node, given the same value handle as
|
|
NODE. Return true if we have inserted new stuff. */
|
|
|
|
static bool
|
|
insert_into_preds_of_block (basic_block block, value_set_node_t node,
|
|
tree *avail)
|
|
{
|
|
tree val = get_value_handle (node->expr);
|
|
edge pred;
|
|
bool insertions = false;
|
|
bool nophi = false;
|
|
basic_block bprime;
|
|
tree eprime;
|
|
edge_iterator ei;
|
|
tree type = TREE_TYPE (avail[EDGE_PRED (block, 0)->src->index]);
|
|
tree temp;
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Found partial redundancy for expression ");
|
|
print_generic_expr (dump_file, node->expr, 0);
|
|
fprintf (dump_file, " (");
|
|
print_generic_expr (dump_file, val, 0);
|
|
fprintf (dump_file, ")");
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
/* Make sure we aren't creating an induction variable. */
|
|
if (block->loop_depth > 0 && EDGE_COUNT (block->preds) == 2
|
|
&& TREE_CODE_CLASS (TREE_CODE (node->expr)) != tcc_reference )
|
|
{
|
|
bool firstinsideloop = false;
|
|
bool secondinsideloop = false;
|
|
firstinsideloop = flow_bb_inside_loop_p (block->loop_father,
|
|
EDGE_PRED (block, 0)->src);
|
|
secondinsideloop = flow_bb_inside_loop_p (block->loop_father,
|
|
EDGE_PRED (block, 1)->src);
|
|
/* Induction variables only have one edge inside the loop. */
|
|
if (firstinsideloop ^ secondinsideloop)
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
|
|
nophi = true;
|
|
}
|
|
}
|
|
|
|
|
|
/* Make the necessary insertions. */
|
|
FOR_EACH_EDGE (pred, ei, block->preds)
|
|
{
|
|
tree stmts = alloc_stmt_list ();
|
|
tree builtexpr;
|
|
bprime = pred->src;
|
|
eprime = avail[bprime->index];
|
|
|
|
if (can_PRE_operation (eprime))
|
|
{
|
|
#ifdef ENABLE_CHECKING
|
|
tree vh;
|
|
|
|
/* eprime may be an invariant. */
|
|
vh = TREE_CODE (eprime) == VALUE_HANDLE
|
|
? eprime
|
|
: get_value_handle (eprime);
|
|
|
|
/* ensure that the virtual uses we need reach our block. */
|
|
if (TREE_CODE (vh) == VALUE_HANDLE)
|
|
{
|
|
int i;
|
|
tree vuse;
|
|
for (i = 0;
|
|
VEC_iterate (tree, VALUE_HANDLE_VUSES (vh), i, vuse);
|
|
i++)
|
|
{
|
|
size_t id = SSA_NAME_VERSION (vuse);
|
|
gcc_assert (bitmap_bit_p (RVUSE_OUT (bprime), id)
|
|
|| IS_EMPTY_STMT (SSA_NAME_DEF_STMT (vuse)));
|
|
}
|
|
}
|
|
#endif
|
|
builtexpr = create_expression_by_pieces (bprime,
|
|
eprime,
|
|
stmts);
|
|
bsi_insert_on_edge (pred, stmts);
|
|
avail[bprime->index] = builtexpr;
|
|
insertions = true;
|
|
}
|
|
}
|
|
/* If we didn't want a phi node, and we made insertions, we still have
|
|
inserted new stuff, and thus return true. If we didn't want a phi node,
|
|
and didn't make insertions, we haven't added anything new, so return
|
|
false. */
|
|
if (nophi && insertions)
|
|
return true;
|
|
else if (nophi && !insertions)
|
|
return false;
|
|
|
|
/* Now build a phi for the new variable. */
|
|
if (!prephitemp || TREE_TYPE (prephitemp) != type)
|
|
{
|
|
prephitemp = create_tmp_var (type, "prephitmp");
|
|
get_var_ann (prephitemp);
|
|
}
|
|
|
|
temp = prephitemp;
|
|
add_referenced_var (temp);
|
|
|
|
if (TREE_CODE (type) == COMPLEX_TYPE)
|
|
DECL_COMPLEX_GIMPLE_REG_P (temp) = 1;
|
|
temp = create_phi_node (temp, block);
|
|
|
|
NECESSARY (temp) = 0;
|
|
VEC_safe_push (tree, heap, inserted_exprs, temp);
|
|
FOR_EACH_EDGE (pred, ei, block->preds)
|
|
add_phi_arg (temp, avail[pred->src->index], pred);
|
|
|
|
vn_add (PHI_RESULT (temp), val);
|
|
|
|
/* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
|
|
this insertion, since we test for the existence of this value in PHI_GEN
|
|
before proceeding with the partial redundancy checks in insert_aux.
|
|
|
|
The value may exist in AVAIL_OUT, in particular, it could be represented
|
|
by the expression we are trying to eliminate, in which case we want the
|
|
replacement to occur. If it's not existing in AVAIL_OUT, we want it
|
|
inserted there.
|
|
|
|
Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
|
|
this block, because if it did, it would have existed in our dominator's
|
|
AVAIL_OUT, and would have been skipped due to the full redundancy check.
|
|
*/
|
|
|
|
bitmap_insert_into_set (PHI_GEN (block),
|
|
PHI_RESULT (temp));
|
|
bitmap_value_replace_in_set (AVAIL_OUT (block),
|
|
PHI_RESULT (temp));
|
|
bitmap_insert_into_set (NEW_SETS (block),
|
|
PHI_RESULT (temp));
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Created phi ");
|
|
print_generic_expr (dump_file, temp, 0);
|
|
fprintf (dump_file, " in block %d\n", block->index);
|
|
}
|
|
pre_stats.phis++;
|
|
return true;
|
|
}
|
|
|
|
|
|
|
|
/* Perform insertion of partially redundant values.
|
|
For BLOCK, do the following:
|
|
1. Propagate the NEW_SETS of the dominator into the current block.
|
|
If the block has multiple predecessors,
|
|
2a. Iterate over the ANTIC expressions for the block to see if
|
|
any of them are partially redundant.
|
|
2b. If so, insert them into the necessary predecessors to make
|
|
the expression fully redundant.
|
|
2c. Insert a new PHI merging the values of the predecessors.
|
|
2d. Insert the new PHI, and the new expressions, into the
|
|
NEW_SETS set.
|
|
3. Recursively call ourselves on the dominator children of BLOCK.
|
|
|
|
*/
|
|
|
|
static bool
|
|
insert_aux (basic_block block)
|
|
{
|
|
basic_block son;
|
|
bool new_stuff = false;
|
|
|
|
if (block)
|
|
{
|
|
basic_block dom;
|
|
dom = get_immediate_dominator (CDI_DOMINATORS, block);
|
|
if (dom)
|
|
{
|
|
unsigned i;
|
|
bitmap_iterator bi;
|
|
bitmap_set_t newset = NEW_SETS (dom);
|
|
if (newset)
|
|
{
|
|
/* Note that we need to value_replace both NEW_SETS, and
|
|
AVAIL_OUT. For both the case of NEW_SETS, the value may be
|
|
represented by some non-simple expression here that we want
|
|
to replace it with. */
|
|
EXECUTE_IF_SET_IN_BITMAP (newset->expressions, 0, i, bi)
|
|
{
|
|
bitmap_value_replace_in_set (NEW_SETS (block), ssa_name (i));
|
|
bitmap_value_replace_in_set (AVAIL_OUT (block), ssa_name (i));
|
|
}
|
|
}
|
|
if (!single_pred_p (block))
|
|
{
|
|
value_set_node_t node;
|
|
for (node = ANTIC_IN (block)->head;
|
|
node;
|
|
node = node->next)
|
|
{
|
|
if (can_PRE_operation (node->expr)
|
|
&& !AGGREGATE_TYPE_P (TREE_TYPE (node->expr)))
|
|
{
|
|
tree *avail;
|
|
tree val;
|
|
bool by_some = false;
|
|
bool cant_insert = false;
|
|
bool all_same = true;
|
|
tree first_s = NULL;
|
|
edge pred;
|
|
basic_block bprime;
|
|
tree eprime = NULL_TREE;
|
|
edge_iterator ei;
|
|
|
|
val = get_value_handle (node->expr);
|
|
if (bitmap_set_contains_value (PHI_GEN (block), val))
|
|
continue;
|
|
if (bitmap_set_contains_value (AVAIL_OUT (dom), val))
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file, "Found fully redundant value\n");
|
|
continue;
|
|
}
|
|
|
|
avail = XCNEWVEC (tree, last_basic_block);
|
|
FOR_EACH_EDGE (pred, ei, block->preds)
|
|
{
|
|
tree vprime;
|
|
tree edoubleprime;
|
|
|
|
/* This can happen in the very weird case
|
|
that our fake infinite loop edges have caused a
|
|
critical edge to appear. */
|
|
if (EDGE_CRITICAL_P (pred))
|
|
{
|
|
cant_insert = true;
|
|
break;
|
|
}
|
|
bprime = pred->src;
|
|
eprime = phi_translate (node->expr,
|
|
ANTIC_IN (block),
|
|
bprime, block);
|
|
|
|
/* eprime will generally only be NULL if the
|
|
value of the expression, translated
|
|
through the PHI for this predecessor, is
|
|
undefined. If that is the case, we can't
|
|
make the expression fully redundant,
|
|
because its value is undefined along a
|
|
predecessor path. We can thus break out
|
|
early because it doesn't matter what the
|
|
rest of the results are. */
|
|
if (eprime == NULL)
|
|
{
|
|
cant_insert = true;
|
|
break;
|
|
}
|
|
|
|
eprime = fully_constant_expression (eprime);
|
|
vprime = get_value_handle (eprime);
|
|
gcc_assert (vprime);
|
|
edoubleprime = bitmap_find_leader (AVAIL_OUT (bprime),
|
|
vprime);
|
|
if (edoubleprime == NULL)
|
|
{
|
|
avail[bprime->index] = eprime;
|
|
all_same = false;
|
|
}
|
|
else
|
|
{
|
|
avail[bprime->index] = edoubleprime;
|
|
by_some = true;
|
|
if (first_s == NULL)
|
|
first_s = edoubleprime;
|
|
else if (!operand_equal_p (first_s, edoubleprime,
|
|
0))
|
|
all_same = false;
|
|
}
|
|
}
|
|
/* If we can insert it, it's not the same value
|
|
already existing along every predecessor, and
|
|
it's defined by some predecessor, it is
|
|
partially redundant. */
|
|
if (!cant_insert && !all_same && by_some)
|
|
{
|
|
if (insert_into_preds_of_block (block, node, avail))
|
|
new_stuff = true;
|
|
}
|
|
/* If all edges produce the same value and that value is
|
|
an invariant, then the PHI has the same value on all
|
|
edges. Note this. */
|
|
else if (!cant_insert && all_same && eprime
|
|
&& is_gimple_min_invariant (eprime)
|
|
&& !is_gimple_min_invariant (val))
|
|
{
|
|
value_set_t exprset = VALUE_HANDLE_EXPR_SET (val);
|
|
value_set_node_t node;
|
|
|
|
for (node = exprset->head; node; node = node->next)
|
|
{
|
|
if (TREE_CODE (node->expr) == SSA_NAME)
|
|
{
|
|
vn_add (node->expr, eprime);
|
|
pre_stats.constified++;
|
|
}
|
|
}
|
|
}
|
|
free (avail);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
for (son = first_dom_son (CDI_DOMINATORS, block);
|
|
son;
|
|
son = next_dom_son (CDI_DOMINATORS, son))
|
|
{
|
|
new_stuff |= insert_aux (son);
|
|
}
|
|
|
|
return new_stuff;
|
|
}
|
|
|
|
/* Perform insertion of partially redundant values. */
|
|
|
|
static void
|
|
insert (void)
|
|
{
|
|
bool new_stuff = true;
|
|
basic_block bb;
|
|
int num_iterations = 0;
|
|
|
|
FOR_ALL_BB (bb)
|
|
NEW_SETS (bb) = bitmap_set_new ();
|
|
|
|
while (new_stuff)
|
|
{
|
|
num_iterations++;
|
|
new_stuff = false;
|
|
new_stuff = insert_aux (ENTRY_BLOCK_PTR);
|
|
}
|
|
if (num_iterations > 2 && dump_file && (dump_flags & TDF_STATS))
|
|
fprintf (dump_file, "insert required %d iterations\n", num_iterations);
|
|
}
|
|
|
|
|
|
/* Return true if VAR is an SSA variable with no defining statement in
|
|
this procedure, *AND* isn't a live-on-entry parameter. */
|
|
|
|
static bool
|
|
is_undefined_value (tree expr)
|
|
{
|
|
return (TREE_CODE (expr) == SSA_NAME
|
|
&& IS_EMPTY_STMT (SSA_NAME_DEF_STMT (expr))
|
|
/* PARM_DECLs and hard registers are always defined. */
|
|
&& TREE_CODE (SSA_NAME_VAR (expr)) != PARM_DECL);
|
|
}
|
|
|
|
|
|
/* Given an SSA variable VAR and an expression EXPR, compute the value
|
|
number for EXPR and create a value handle (VAL) for it. If VAR and
|
|
EXPR are not the same, associate VAL with VAR. Finally, add VAR to
|
|
S1 and its value handle to S2.
|
|
|
|
VUSES represent the virtual use operands associated with EXPR (if
|
|
any). */
|
|
|
|
static inline void
|
|
add_to_sets (tree var, tree expr, tree stmt, bitmap_set_t s1,
|
|
bitmap_set_t s2)
|
|
{
|
|
tree val = vn_lookup_or_add (expr, stmt);
|
|
|
|
/* VAR and EXPR may be the same when processing statements for which
|
|
we are not computing value numbers (e.g., non-assignments, or
|
|
statements that make aliased stores). In those cases, we are
|
|
only interested in making VAR available as its own value. */
|
|
if (var != expr)
|
|
vn_add (var, val);
|
|
|
|
if (s1)
|
|
bitmap_insert_into_set (s1, var);
|
|
bitmap_value_insert_into_set (s2, var);
|
|
}
|
|
|
|
|
|
/* Given a unary or binary expression EXPR, create and return a new
|
|
expression with the same structure as EXPR but with its operands
|
|
replaced with the value handles of each of the operands of EXPR.
|
|
|
|
VUSES represent the virtual use operands associated with EXPR (if
|
|
any). Insert EXPR's operands into the EXP_GEN set for BLOCK. */
|
|
|
|
static inline tree
|
|
create_value_expr_from (tree expr, basic_block block, tree stmt)
|
|
{
|
|
int i;
|
|
enum tree_code code = TREE_CODE (expr);
|
|
tree vexpr;
|
|
alloc_pool pool;
|
|
|
|
gcc_assert (TREE_CODE_CLASS (code) == tcc_unary
|
|
|| TREE_CODE_CLASS (code) == tcc_binary
|
|
|| TREE_CODE_CLASS (code) == tcc_comparison
|
|
|| TREE_CODE_CLASS (code) == tcc_reference
|
|
|| TREE_CODE_CLASS (code) == tcc_expression
|
|
|| TREE_CODE_CLASS (code) == tcc_exceptional
|
|
|| TREE_CODE_CLASS (code) == tcc_declaration);
|
|
|
|
if (TREE_CODE_CLASS (code) == tcc_unary)
|
|
pool = unary_node_pool;
|
|
else if (TREE_CODE_CLASS (code) == tcc_reference)
|
|
pool = reference_node_pool;
|
|
else if (TREE_CODE_CLASS (code) == tcc_binary)
|
|
pool = binary_node_pool;
|
|
else if (TREE_CODE_CLASS (code) == tcc_comparison)
|
|
pool = comparison_node_pool;
|
|
else if (TREE_CODE_CLASS (code) == tcc_exceptional)
|
|
{
|
|
gcc_assert (code == TREE_LIST);
|
|
pool = list_node_pool;
|
|
}
|
|
else
|
|
{
|
|
gcc_assert (code == CALL_EXPR);
|
|
pool = expression_node_pool;
|
|
}
|
|
|
|
vexpr = (tree) pool_alloc (pool);
|
|
memcpy (vexpr, expr, tree_size (expr));
|
|
|
|
/* This case is only for TREE_LIST's that appear as part of
|
|
CALL_EXPR's. Anything else is a bug, but we can't easily verify
|
|
this, hence this comment. TREE_LIST is not handled by the
|
|
general case below is because they don't have a fixed length, or
|
|
operands, so you can't access purpose/value/chain through
|
|
TREE_OPERAND macros. */
|
|
|
|
if (code == TREE_LIST)
|
|
{
|
|
tree op = NULL_TREE;
|
|
tree temp = NULL_TREE;
|
|
if (TREE_CHAIN (vexpr))
|
|
temp = create_value_expr_from (TREE_CHAIN (vexpr), block, stmt);
|
|
TREE_CHAIN (vexpr) = temp ? temp : TREE_CHAIN (vexpr);
|
|
|
|
|
|
/* Recursively value-numberize reference ops. */
|
|
if (REFERENCE_CLASS_P (TREE_VALUE (vexpr)))
|
|
{
|
|
tree tempop;
|
|
op = TREE_VALUE (vexpr);
|
|
tempop = create_value_expr_from (op, block, stmt);
|
|
op = tempop ? tempop : op;
|
|
|
|
TREE_VALUE (vexpr) = vn_lookup_or_add (op, stmt);
|
|
}
|
|
else
|
|
{
|
|
op = TREE_VALUE (vexpr);
|
|
TREE_VALUE (vexpr) = vn_lookup_or_add (TREE_VALUE (vexpr), NULL);
|
|
}
|
|
/* This is the equivalent of inserting op into EXP_GEN like we
|
|
do below */
|
|
if (!is_undefined_value (op))
|
|
value_insert_into_set (EXP_GEN (block), op);
|
|
|
|
return vexpr;
|
|
}
|
|
|
|
for (i = 0; i < TREE_CODE_LENGTH (code); i++)
|
|
{
|
|
tree val, op;
|
|
|
|
op = TREE_OPERAND (expr, i);
|
|
if (op == NULL_TREE)
|
|
continue;
|
|
|
|
/* Recursively value-numberize reference ops and tree lists. */
|
|
if (REFERENCE_CLASS_P (op))
|
|
{
|
|
tree tempop = create_value_expr_from (op, block, stmt);
|
|
op = tempop ? tempop : op;
|
|
val = vn_lookup_or_add (op, stmt);
|
|
}
|
|
else if (TREE_CODE (op) == TREE_LIST)
|
|
{
|
|
tree tempop;
|
|
|
|
gcc_assert (TREE_CODE (expr) == CALL_EXPR);
|
|
tempop = create_value_expr_from (op, block, stmt);
|
|
|
|
op = tempop ? tempop : op;
|
|
vn_lookup_or_add (op, NULL);
|
|
/* Unlike everywhere else, we do *not* want to replace the
|
|
TREE_LIST itself with a value number, because support
|
|
functions we call will blow up. */
|
|
val = op;
|
|
}
|
|
else
|
|
/* Create a value handle for OP and add it to VEXPR. */
|
|
val = vn_lookup_or_add (op, NULL);
|
|
|
|
if (!is_undefined_value (op) && TREE_CODE (op) != TREE_LIST)
|
|
value_insert_into_set (EXP_GEN (block), op);
|
|
|
|
if (TREE_CODE (val) == VALUE_HANDLE)
|
|
TREE_TYPE (val) = TREE_TYPE (TREE_OPERAND (vexpr, i));
|
|
|
|
TREE_OPERAND (vexpr, i) = val;
|
|
}
|
|
|
|
return vexpr;
|
|
}
|
|
|
|
|
|
|
|
/* Insert extra phis to merge values that are fully available from
|
|
preds of BLOCK, but have no dominating representative coming from
|
|
block DOM. */
|
|
|
|
static void
|
|
insert_extra_phis (basic_block block, basic_block dom)
|
|
{
|
|
|
|
if (!single_pred_p (block))
|
|
{
|
|
edge e;
|
|
edge_iterator ei;
|
|
bool first = true;
|
|
bitmap_set_t tempset = bitmap_set_new ();
|
|
|
|
FOR_EACH_EDGE (e, ei, block->preds)
|
|
{
|
|
/* We cannot handle abnormal incoming edges correctly. */
|
|
if (e->flags & EDGE_ABNORMAL)
|
|
return;
|
|
|
|
if (first)
|
|
{
|
|
bitmap_set_copy (tempset, AVAIL_OUT (e->src));
|
|
first = false;
|
|
}
|
|
else
|
|
bitmap_set_and (tempset, AVAIL_OUT (e->src));
|
|
}
|
|
|
|
if (dom)
|
|
bitmap_set_and_compl (tempset, AVAIL_OUT (dom));
|
|
|
|
if (!bitmap_set_empty_p (tempset))
|
|
{
|
|
unsigned int i;
|
|
bitmap_iterator bi;
|
|
|
|
EXECUTE_IF_SET_IN_BITMAP (tempset->expressions, 0, i, bi)
|
|
{
|
|
tree name = ssa_name (i);
|
|
tree val = get_value_handle (name);
|
|
tree temp;
|
|
|
|
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
|
|
continue;
|
|
|
|
if (!mergephitemp
|
|
|| TREE_TYPE (name) != TREE_TYPE (mergephitemp))
|
|
{
|
|
mergephitemp = create_tmp_var (TREE_TYPE (name),
|
|
"mergephitmp");
|
|
get_var_ann (mergephitemp);
|
|
}
|
|
temp = mergephitemp;
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Creating phi ");
|
|
print_generic_expr (dump_file, temp, 0);
|
|
fprintf (dump_file, " to merge available but not dominating values ");
|
|
}
|
|
|
|
add_referenced_var (temp);
|
|
temp = create_phi_node (temp, block);
|
|
NECESSARY (temp) = 0;
|
|
VEC_safe_push (tree, heap, inserted_exprs, temp);
|
|
|
|
FOR_EACH_EDGE (e, ei, block->preds)
|
|
{
|
|
tree leader = bitmap_find_leader (AVAIL_OUT (e->src), val);
|
|
|
|
gcc_assert (leader);
|
|
add_phi_arg (temp, leader, e);
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
print_generic_expr (dump_file, leader, 0);
|
|
fprintf (dump_file, " in block %d,", e->src->index);
|
|
}
|
|
}
|
|
|
|
vn_add (PHI_RESULT (temp), val);
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Given a statement STMT and its right hand side which is a load, try
|
|
to look for the expression stored in the location for the load, and
|
|
return true if a useful equivalence was recorded for LHS. */
|
|
|
|
static bool
|
|
try_look_through_load (tree lhs, tree mem_ref, tree stmt, basic_block block)
|
|
{
|
|
tree store_stmt = NULL;
|
|
tree rhs;
|
|
ssa_op_iter i;
|
|
tree vuse;
|
|
|
|
FOR_EACH_SSA_TREE_OPERAND (vuse, stmt, i, SSA_OP_VIRTUAL_USES)
|
|
{
|
|
tree def_stmt;
|
|
|
|
gcc_assert (TREE_CODE (vuse) == SSA_NAME);
|
|
def_stmt = SSA_NAME_DEF_STMT (vuse);
|
|
|
|
/* If there is no useful statement for this VUSE, we'll not find a
|
|
useful expression to return either. Likewise, if there is a
|
|
statement but it is not a simple assignment or it has virtual
|
|
uses, we can stop right here. Note that this means we do
|
|
not look through PHI nodes, which is intentional. */
|
|
if (!def_stmt
|
|
|| TREE_CODE (def_stmt) != MODIFY_EXPR
|
|
|| !ZERO_SSA_OPERANDS (def_stmt, SSA_OP_VIRTUAL_USES))
|
|
return false;
|
|
|
|
/* If this is not the same statement as one we have looked at for
|
|
another VUSE of STMT already, we have two statements producing
|
|
something that reaches our STMT. */
|
|
if (store_stmt && store_stmt != def_stmt)
|
|
return false;
|
|
else
|
|
{
|
|
/* Is this a store to the exact same location as the one we are
|
|
loading from in STMT? */
|
|
if (!operand_equal_p (TREE_OPERAND (def_stmt, 0), mem_ref, 0))
|
|
return false;
|
|
|
|
/* Otherwise remember this statement and see if all other VUSEs
|
|
come from the same statement. */
|
|
store_stmt = def_stmt;
|
|
}
|
|
}
|
|
|
|
/* Alright then, we have visited all VUSEs of STMT and we've determined
|
|
that all of them come from the same statement STORE_STMT. See if there
|
|
is a useful expression we can deduce from STORE_STMT. */
|
|
rhs = TREE_OPERAND (store_stmt, 1);
|
|
if ((TREE_CODE (rhs) == SSA_NAME
|
|
&& !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs))
|
|
|| is_gimple_min_invariant (rhs)
|
|
|| TREE_CODE (rhs) == ADDR_EXPR
|
|
|| TREE_INVARIANT (rhs))
|
|
{
|
|
|
|
/* Yay! Compute a value number for the RHS of the statement and
|
|
add its value to the AVAIL_OUT set for the block. Add the LHS
|
|
to TMP_GEN. */
|
|
add_to_sets (lhs, rhs, store_stmt, TMP_GEN (block), AVAIL_OUT (block));
|
|
if (TREE_CODE (rhs) == SSA_NAME
|
|
&& !is_undefined_value (rhs))
|
|
value_insert_into_set (EXP_GEN (block), rhs);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Return a copy of NODE that is stored in the temporary alloc_pool's.
|
|
This is made recursively true, so that the operands are stored in
|
|
the pool as well. */
|
|
|
|
static tree
|
|
poolify_tree (tree node)
|
|
{
|
|
switch (TREE_CODE (node))
|
|
{
|
|
case INDIRECT_REF:
|
|
{
|
|
tree temp = pool_alloc (reference_node_pool);
|
|
memcpy (temp, node, tree_size (node));
|
|
TREE_OPERAND (temp, 0) = poolify_tree (TREE_OPERAND (temp, 0));
|
|
return temp;
|
|
}
|
|
break;
|
|
case MODIFY_EXPR:
|
|
{
|
|
tree temp = pool_alloc (modify_expr_node_pool);
|
|
memcpy (temp, node, tree_size (node));
|
|
TREE_OPERAND (temp, 0) = poolify_tree (TREE_OPERAND (temp, 0));
|
|
TREE_OPERAND (temp, 1) = poolify_tree (TREE_OPERAND (temp, 1));
|
|
return temp;
|
|
}
|
|
break;
|
|
case SSA_NAME:
|
|
case INTEGER_CST:
|
|
case STRING_CST:
|
|
case REAL_CST:
|
|
case PARM_DECL:
|
|
case VAR_DECL:
|
|
case RESULT_DECL:
|
|
return node;
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
}
|
|
|
|
static tree modify_expr_template;
|
|
|
|
/* Allocate a MODIFY_EXPR with TYPE, and operands OP1, OP2 in the
|
|
alloc pools and return it. */
|
|
static tree
|
|
poolify_modify_expr (tree type, tree op1, tree op2)
|
|
{
|
|
if (modify_expr_template == NULL)
|
|
modify_expr_template = build2 (MODIFY_EXPR, type, op1, op2);
|
|
|
|
TREE_OPERAND (modify_expr_template, 0) = op1;
|
|
TREE_OPERAND (modify_expr_template, 1) = op2;
|
|
TREE_TYPE (modify_expr_template) = type;
|
|
|
|
return poolify_tree (modify_expr_template);
|
|
}
|
|
|
|
|
|
/* For each real store operation of the form
|
|
*a = <value> that we see, create a corresponding fake store of the
|
|
form storetmp_<version> = *a.
|
|
|
|
This enables AVAIL computation to mark the results of stores as
|
|
available. Without this, you'd need to do some computation to
|
|
mark the result of stores as ANTIC and AVAIL at all the right
|
|
points.
|
|
To save memory, we keep the store
|
|
statements pool allocated until we decide whether they are
|
|
necessary or not. */
|
|
|
|
static void
|
|
insert_fake_stores (void)
|
|
{
|
|
basic_block block;
|
|
|
|
FOR_ALL_BB (block)
|
|
{
|
|
block_stmt_iterator bsi;
|
|
for (bsi = bsi_start (block); !bsi_end_p (bsi); bsi_next (&bsi))
|
|
{
|
|
tree stmt = bsi_stmt (bsi);
|
|
|
|
/* We can't generate SSA names for stores that are complex
|
|
or aggregate. We also want to ignore things whose
|
|
virtual uses occur in abnormal phis. */
|
|
|
|
if (TREE_CODE (stmt) == MODIFY_EXPR
|
|
&& TREE_CODE (TREE_OPERAND (stmt, 0)) == INDIRECT_REF
|
|
&& !AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (stmt, 0)))
|
|
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (stmt, 0))) != COMPLEX_TYPE)
|
|
{
|
|
ssa_op_iter iter;
|
|
def_operand_p defp;
|
|
tree lhs = TREE_OPERAND (stmt, 0);
|
|
tree rhs = TREE_OPERAND (stmt, 1);
|
|
tree new;
|
|
bool notokay = false;
|
|
|
|
FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_VIRTUAL_DEFS)
|
|
{
|
|
tree defvar = DEF_FROM_PTR (defp);
|
|
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (defvar))
|
|
{
|
|
notokay = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (notokay)
|
|
continue;
|
|
|
|
if (!storetemp || TREE_TYPE (rhs) != TREE_TYPE (storetemp))
|
|
{
|
|
storetemp = create_tmp_var (TREE_TYPE (rhs), "storetmp");
|
|
get_var_ann (storetemp);
|
|
}
|
|
|
|
new = poolify_modify_expr (TREE_TYPE (stmt), storetemp, lhs);
|
|
|
|
lhs = make_ssa_name (storetemp, new);
|
|
TREE_OPERAND (new, 0) = lhs;
|
|
create_ssa_artficial_load_stmt (new, stmt);
|
|
|
|
NECESSARY (new) = 0;
|
|
VEC_safe_push (tree, heap, inserted_exprs, new);
|
|
VEC_safe_push (tree, heap, need_creation, new);
|
|
bsi_insert_after (&bsi, new, BSI_NEW_STMT);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Turn the pool allocated fake stores that we created back into real
|
|
GC allocated ones if they turned out to be necessary to PRE some
|
|
expressions. */
|
|
|
|
static void
|
|
realify_fake_stores (void)
|
|
{
|
|
unsigned int i;
|
|
tree stmt;
|
|
|
|
for (i = 0; VEC_iterate (tree, need_creation, i, stmt); i++)
|
|
{
|
|
if (NECESSARY (stmt))
|
|
{
|
|
block_stmt_iterator bsi;
|
|
tree newstmt;
|
|
|
|
/* Mark the temp variable as referenced */
|
|
add_referenced_var (SSA_NAME_VAR (TREE_OPERAND (stmt, 0)));
|
|
|
|
/* Put the new statement in GC memory, fix up the
|
|
SSA_NAME_DEF_STMT on it, and then put it in place of
|
|
the old statement before the store in the IR stream
|
|
as a plain ssa name copy. */
|
|
bsi = bsi_for_stmt (stmt);
|
|
bsi_prev (&bsi);
|
|
newstmt = build2 (MODIFY_EXPR, void_type_node,
|
|
TREE_OPERAND (stmt, 0),
|
|
TREE_OPERAND (bsi_stmt (bsi), 1));
|
|
SSA_NAME_DEF_STMT (TREE_OPERAND (newstmt, 0)) = newstmt;
|
|
bsi_insert_before (&bsi, newstmt, BSI_SAME_STMT);
|
|
bsi = bsi_for_stmt (stmt);
|
|
bsi_remove (&bsi, true);
|
|
}
|
|
else
|
|
release_defs (stmt);
|
|
}
|
|
}
|
|
|
|
/* Tree-combine a value number expression *EXPR_P that does a type
|
|
conversion with the value number expression of its operand.
|
|
Returns true, if *EXPR_P simplifies to a value number or
|
|
gimple min-invariant expression different from EXPR_P and
|
|
sets *EXPR_P to the simplified expression value number.
|
|
Otherwise returns false and does not change *EXPR_P. */
|
|
|
|
static bool
|
|
try_combine_conversion (tree *expr_p)
|
|
{
|
|
tree expr = *expr_p;
|
|
tree t;
|
|
|
|
if (!((TREE_CODE (expr) == NOP_EXPR
|
|
|| TREE_CODE (expr) == CONVERT_EXPR)
|
|
&& TREE_CODE (TREE_OPERAND (expr, 0)) == VALUE_HANDLE
|
|
&& !VALUE_HANDLE_VUSES (TREE_OPERAND (expr, 0))))
|
|
return false;
|
|
|
|
t = fold_unary (TREE_CODE (expr), TREE_TYPE (expr),
|
|
VALUE_HANDLE_EXPR_SET (TREE_OPERAND (expr, 0))->head->expr);
|
|
if (!t)
|
|
return false;
|
|
|
|
/* Strip useless type conversions, which is safe in the optimizers but
|
|
not generally in fold. */
|
|
STRIP_USELESS_TYPE_CONVERSION (t);
|
|
|
|
/* Disallow value expressions we have no value number for already, as
|
|
we would miss a leader for it here. */
|
|
if (!(TREE_CODE (t) == VALUE_HANDLE
|
|
|| is_gimple_min_invariant (t)))
|
|
t = vn_lookup (t, NULL);
|
|
|
|
if (t && t != expr)
|
|
{
|
|
*expr_p = t;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/* Compute the AVAIL set for all basic blocks.
|
|
|
|
This function performs value numbering of the statements in each basic
|
|
block. The AVAIL sets are built from information we glean while doing
|
|
this value numbering, since the AVAIL sets contain only one entry per
|
|
value.
|
|
|
|
AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
|
|
AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK]. */
|
|
|
|
static void
|
|
compute_avail (void)
|
|
{
|
|
basic_block block, son;
|
|
basic_block *worklist;
|
|
size_t sp = 0;
|
|
tree param;
|
|
/* For arguments with default definitions, we pretend they are
|
|
defined in the entry block. */
|
|
for (param = DECL_ARGUMENTS (current_function_decl);
|
|
param;
|
|
param = TREE_CHAIN (param))
|
|
{
|
|
if (default_def (param) != NULL)
|
|
{
|
|
tree def = default_def (param);
|
|
vn_lookup_or_add (def, NULL);
|
|
bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR), def);
|
|
bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR), def);
|
|
}
|
|
}
|
|
|
|
/* Likewise for the static chain decl. */
|
|
if (cfun->static_chain_decl)
|
|
{
|
|
param = cfun->static_chain_decl;
|
|
if (default_def (param) != NULL)
|
|
{
|
|
tree def = default_def (param);
|
|
vn_lookup_or_add (def, NULL);
|
|
bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR), def);
|
|
bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR), def);
|
|
}
|
|
}
|
|
|
|
/* Allocate the worklist. */
|
|
worklist = XNEWVEC (basic_block, n_basic_blocks);
|
|
|
|
/* Seed the algorithm by putting the dominator children of the entry
|
|
block on the worklist. */
|
|
for (son = first_dom_son (CDI_DOMINATORS, ENTRY_BLOCK_PTR);
|
|
son;
|
|
son = next_dom_son (CDI_DOMINATORS, son))
|
|
worklist[sp++] = son;
|
|
|
|
/* Loop until the worklist is empty. */
|
|
while (sp)
|
|
{
|
|
block_stmt_iterator bsi;
|
|
tree stmt, phi;
|
|
basic_block dom;
|
|
unsigned int stmt_uid = 1;
|
|
|
|
/* Pick a block from the worklist. */
|
|
block = worklist[--sp];
|
|
|
|
/* Initially, the set of available values in BLOCK is that of
|
|
its immediate dominator. */
|
|
dom = get_immediate_dominator (CDI_DOMINATORS, block);
|
|
if (dom)
|
|
bitmap_set_copy (AVAIL_OUT (block), AVAIL_OUT (dom));
|
|
|
|
if (!in_fre)
|
|
insert_extra_phis (block, dom);
|
|
|
|
/* Generate values for PHI nodes. */
|
|
for (phi = phi_nodes (block); phi; phi = PHI_CHAIN (phi))
|
|
/* We have no need for virtual phis, as they don't represent
|
|
actual computations. */
|
|
if (is_gimple_reg (PHI_RESULT (phi)))
|
|
add_to_sets (PHI_RESULT (phi), PHI_RESULT (phi), NULL,
|
|
PHI_GEN (block), AVAIL_OUT (block));
|
|
|
|
/* Now compute value numbers and populate value sets with all
|
|
the expressions computed in BLOCK. */
|
|
for (bsi = bsi_start (block); !bsi_end_p (bsi); bsi_next (&bsi))
|
|
{
|
|
stmt_ann_t ann;
|
|
ssa_op_iter iter;
|
|
tree op;
|
|
|
|
stmt = bsi_stmt (bsi);
|
|
ann = stmt_ann (stmt);
|
|
|
|
ann->uid = stmt_uid++;
|
|
|
|
/* For regular value numbering, we are only interested in
|
|
assignments of the form X_i = EXPR, where EXPR represents
|
|
an "interesting" computation, it has no volatile operands
|
|
and X_i doesn't flow through an abnormal edge. */
|
|
if (TREE_CODE (stmt) == MODIFY_EXPR
|
|
&& !ann->has_volatile_ops
|
|
&& TREE_CODE (TREE_OPERAND (stmt, 0)) == SSA_NAME
|
|
&& !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (TREE_OPERAND (stmt, 0)))
|
|
{
|
|
tree lhs = TREE_OPERAND (stmt, 0);
|
|
tree rhs = TREE_OPERAND (stmt, 1);
|
|
|
|
/* Try to look through loads. */
|
|
if (TREE_CODE (lhs) == SSA_NAME
|
|
&& !ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_USES)
|
|
&& try_look_through_load (lhs, rhs, stmt, block))
|
|
continue;
|
|
|
|
STRIP_USELESS_TYPE_CONVERSION (rhs);
|
|
if (can_value_number_operation (rhs))
|
|
{
|
|
/* For value numberable operation, create a
|
|
duplicate expression with the operands replaced
|
|
with the value handles of the original RHS. */
|
|
tree newt = create_value_expr_from (rhs, block, stmt);
|
|
if (newt)
|
|
{
|
|
/* If we can combine a conversion expression
|
|
with the expression for its operand just
|
|
record the value number for it. */
|
|
if (try_combine_conversion (&newt))
|
|
vn_add (lhs, newt);
|
|
else
|
|
{
|
|
tree val = vn_lookup_or_add (newt, stmt);
|
|
vn_add (lhs, val);
|
|
value_insert_into_set (EXP_GEN (block), newt);
|
|
}
|
|
bitmap_insert_into_set (TMP_GEN (block), lhs);
|
|
bitmap_value_insert_into_set (AVAIL_OUT (block), lhs);
|
|
continue;
|
|
}
|
|
}
|
|
else if ((TREE_CODE (rhs) == SSA_NAME
|
|
&& !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs))
|
|
|| is_gimple_min_invariant (rhs)
|
|
|| TREE_CODE (rhs) == ADDR_EXPR
|
|
|| TREE_INVARIANT (rhs)
|
|
|| DECL_P (rhs))
|
|
{
|
|
/* Compute a value number for the RHS of the statement
|
|
and add its value to the AVAIL_OUT set for the block.
|
|
Add the LHS to TMP_GEN. */
|
|
add_to_sets (lhs, rhs, stmt, TMP_GEN (block),
|
|
AVAIL_OUT (block));
|
|
|
|
if (TREE_CODE (rhs) == SSA_NAME
|
|
&& !is_undefined_value (rhs))
|
|
value_insert_into_set (EXP_GEN (block), rhs);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/* For any other statement that we don't recognize, simply
|
|
make the names generated by the statement available in
|
|
AVAIL_OUT and TMP_GEN. */
|
|
FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_DEF)
|
|
add_to_sets (op, op, NULL, TMP_GEN (block), AVAIL_OUT (block));
|
|
|
|
FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
|
|
add_to_sets (op, op, NULL, NULL , AVAIL_OUT (block));
|
|
}
|
|
|
|
/* Put the dominator children of BLOCK on the worklist of blocks
|
|
to compute available sets for. */
|
|
for (son = first_dom_son (CDI_DOMINATORS, block);
|
|
son;
|
|
son = next_dom_son (CDI_DOMINATORS, son))
|
|
worklist[sp++] = son;
|
|
}
|
|
|
|
free (worklist);
|
|
}
|
|
|
|
|
|
/* Eliminate fully redundant computations. */
|
|
|
|
static void
|
|
eliminate (void)
|
|
{
|
|
basic_block b;
|
|
|
|
FOR_EACH_BB (b)
|
|
{
|
|
block_stmt_iterator i;
|
|
|
|
for (i = bsi_start (b); !bsi_end_p (i); bsi_next (&i))
|
|
{
|
|
tree stmt = bsi_stmt (i);
|
|
|
|
/* Lookup the RHS of the expression, see if we have an
|
|
available computation for it. If so, replace the RHS with
|
|
the available computation. */
|
|
if (TREE_CODE (stmt) == MODIFY_EXPR
|
|
&& TREE_CODE (TREE_OPERAND (stmt, 0)) == SSA_NAME
|
|
&& TREE_CODE (TREE_OPERAND (stmt ,1)) != SSA_NAME
|
|
&& !is_gimple_min_invariant (TREE_OPERAND (stmt, 1))
|
|
&& !stmt_ann (stmt)->has_volatile_ops)
|
|
{
|
|
tree lhs = TREE_OPERAND (stmt, 0);
|
|
tree *rhs_p = &TREE_OPERAND (stmt, 1);
|
|
tree sprime;
|
|
|
|
sprime = bitmap_find_leader (AVAIL_OUT (b),
|
|
vn_lookup (lhs, NULL));
|
|
if (sprime
|
|
&& sprime != lhs
|
|
&& (TREE_CODE (*rhs_p) != SSA_NAME
|
|
|| may_propagate_copy (*rhs_p, sprime)))
|
|
{
|
|
gcc_assert (sprime != *rhs_p);
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Replaced ");
|
|
print_generic_expr (dump_file, *rhs_p, 0);
|
|
fprintf (dump_file, " with ");
|
|
print_generic_expr (dump_file, sprime, 0);
|
|
fprintf (dump_file, " in ");
|
|
print_generic_stmt (dump_file, stmt, 0);
|
|
}
|
|
|
|
if (TREE_CODE (sprime) == SSA_NAME)
|
|
NECESSARY (SSA_NAME_DEF_STMT (sprime)) = 1;
|
|
/* We need to make sure the new and old types actually match,
|
|
which may require adding a simple cast, which fold_convert
|
|
will do for us. */
|
|
if (TREE_CODE (*rhs_p) != SSA_NAME
|
|
&& !tree_ssa_useless_type_conversion_1 (TREE_TYPE (*rhs_p),
|
|
TREE_TYPE (sprime)))
|
|
sprime = fold_convert (TREE_TYPE (*rhs_p), sprime);
|
|
|
|
pre_stats.eliminations++;
|
|
propagate_tree_value (rhs_p, sprime);
|
|
update_stmt (stmt);
|
|
|
|
/* If we removed EH side effects from the statement, clean
|
|
its EH information. */
|
|
if (maybe_clean_or_replace_eh_stmt (stmt, stmt))
|
|
{
|
|
bitmap_set_bit (need_eh_cleanup,
|
|
bb_for_stmt (stmt)->index);
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file, " Removed EH side effects.\n");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Borrow a bit of tree-ssa-dce.c for the moment.
|
|
XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
|
|
this may be a bit faster, and we may want critical edges kept split. */
|
|
|
|
/* If OP's defining statement has not already been determined to be necessary,
|
|
mark that statement necessary. Return the stmt, if it is newly
|
|
necessary. */
|
|
|
|
static inline tree
|
|
mark_operand_necessary (tree op)
|
|
{
|
|
tree stmt;
|
|
|
|
gcc_assert (op);
|
|
|
|
if (TREE_CODE (op) != SSA_NAME)
|
|
return NULL;
|
|
|
|
stmt = SSA_NAME_DEF_STMT (op);
|
|
gcc_assert (stmt);
|
|
|
|
if (NECESSARY (stmt)
|
|
|| IS_EMPTY_STMT (stmt))
|
|
return NULL;
|
|
|
|
NECESSARY (stmt) = 1;
|
|
return stmt;
|
|
}
|
|
|
|
/* Because we don't follow exactly the standard PRE algorithm, and decide not
|
|
to insert PHI nodes sometimes, and because value numbering of casts isn't
|
|
perfect, we sometimes end up inserting dead code. This simple DCE-like
|
|
pass removes any insertions we made that weren't actually used. */
|
|
|
|
static void
|
|
remove_dead_inserted_code (void)
|
|
{
|
|
VEC(tree,heap) *worklist = NULL;
|
|
int i;
|
|
tree t;
|
|
|
|
worklist = VEC_alloc (tree, heap, VEC_length (tree, inserted_exprs));
|
|
for (i = 0; VEC_iterate (tree, inserted_exprs, i, t); i++)
|
|
{
|
|
if (NECESSARY (t))
|
|
VEC_quick_push (tree, worklist, t);
|
|
}
|
|
while (VEC_length (tree, worklist) > 0)
|
|
{
|
|
t = VEC_pop (tree, worklist);
|
|
|
|
/* PHI nodes are somewhat special in that each PHI alternative has
|
|
data and control dependencies. All the statements feeding the
|
|
PHI node's arguments are always necessary. */
|
|
if (TREE_CODE (t) == PHI_NODE)
|
|
{
|
|
int k;
|
|
|
|
VEC_reserve (tree, heap, worklist, PHI_NUM_ARGS (t));
|
|
for (k = 0; k < PHI_NUM_ARGS (t); k++)
|
|
{
|
|
tree arg = PHI_ARG_DEF (t, k);
|
|
if (TREE_CODE (arg) == SSA_NAME)
|
|
{
|
|
arg = mark_operand_necessary (arg);
|
|
if (arg)
|
|
VEC_quick_push (tree, worklist, arg);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Propagate through the operands. Examine all the USE, VUSE and
|
|
V_MAY_DEF operands in this statement. Mark all the statements
|
|
which feed this statement's uses as necessary. */
|
|
ssa_op_iter iter;
|
|
tree use;
|
|
|
|
/* The operands of V_MAY_DEF expressions are also needed as they
|
|
represent potential definitions that may reach this
|
|
statement (V_MAY_DEF operands allow us to follow def-def
|
|
links). */
|
|
|
|
FOR_EACH_SSA_TREE_OPERAND (use, t, iter, SSA_OP_ALL_USES)
|
|
{
|
|
tree n = mark_operand_necessary (use);
|
|
if (n)
|
|
VEC_safe_push (tree, heap, worklist, n);
|
|
}
|
|
}
|
|
}
|
|
|
|
for (i = 0; VEC_iterate (tree, inserted_exprs, i, t); i++)
|
|
{
|
|
if (!NECESSARY (t))
|
|
{
|
|
block_stmt_iterator bsi;
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Removing unnecessary insertion:");
|
|
print_generic_stmt (dump_file, t, 0);
|
|
}
|
|
|
|
if (TREE_CODE (t) == PHI_NODE)
|
|
{
|
|
remove_phi_node (t, NULL);
|
|
}
|
|
else
|
|
{
|
|
bsi = bsi_for_stmt (t);
|
|
bsi_remove (&bsi, true);
|
|
release_defs (t);
|
|
}
|
|
}
|
|
}
|
|
VEC_free (tree, heap, worklist);
|
|
}
|
|
|
|
/* Initialize data structures used by PRE. */
|
|
|
|
static void
|
|
init_pre (bool do_fre)
|
|
{
|
|
basic_block bb;
|
|
|
|
in_fre = do_fre;
|
|
|
|
inserted_exprs = NULL;
|
|
need_creation = NULL;
|
|
pretemp = NULL_TREE;
|
|
storetemp = NULL_TREE;
|
|
mergephitemp = NULL_TREE;
|
|
prephitemp = NULL_TREE;
|
|
|
|
vn_init ();
|
|
if (!do_fre)
|
|
current_loops = loop_optimizer_init (LOOPS_NORMAL);
|
|
|
|
connect_infinite_loops_to_exit ();
|
|
memset (&pre_stats, 0, sizeof (pre_stats));
|
|
|
|
/* If block 0 has more than one predecessor, it means that its PHI
|
|
nodes will have arguments coming from block -1. This creates
|
|
problems for several places in PRE that keep local arrays indexed
|
|
by block number. To prevent this, we split the edge coming from
|
|
ENTRY_BLOCK_PTR (FIXME, if ENTRY_BLOCK_PTR had an index number
|
|
different than -1 we wouldn't have to hack this. tree-ssa-dce.c
|
|
needs a similar change). */
|
|
if (!single_pred_p (single_succ (ENTRY_BLOCK_PTR)))
|
|
if (!(single_succ_edge (ENTRY_BLOCK_PTR)->flags & EDGE_ABNORMAL))
|
|
split_edge (single_succ_edge (ENTRY_BLOCK_PTR));
|
|
|
|
FOR_ALL_BB (bb)
|
|
bb->aux = xcalloc (1, sizeof (struct bb_value_sets));
|
|
|
|
bitmap_obstack_initialize (&grand_bitmap_obstack);
|
|
phi_translate_table = htab_create (511, expr_pred_trans_hash,
|
|
expr_pred_trans_eq, free);
|
|
value_set_pool = create_alloc_pool ("Value sets",
|
|
sizeof (struct value_set), 30);
|
|
bitmap_set_pool = create_alloc_pool ("Bitmap sets",
|
|
sizeof (struct bitmap_set), 30);
|
|
value_set_node_pool = create_alloc_pool ("Value set nodes",
|
|
sizeof (struct value_set_node), 30);
|
|
calculate_dominance_info (CDI_POST_DOMINATORS);
|
|
calculate_dominance_info (CDI_DOMINATORS);
|
|
binary_node_pool = create_alloc_pool ("Binary tree nodes",
|
|
tree_code_size (PLUS_EXPR), 30);
|
|
unary_node_pool = create_alloc_pool ("Unary tree nodes",
|
|
tree_code_size (NEGATE_EXPR), 30);
|
|
reference_node_pool = create_alloc_pool ("Reference tree nodes",
|
|
tree_code_size (ARRAY_REF), 30);
|
|
expression_node_pool = create_alloc_pool ("Expression tree nodes",
|
|
tree_code_size (CALL_EXPR), 30);
|
|
list_node_pool = create_alloc_pool ("List tree nodes",
|
|
tree_code_size (TREE_LIST), 30);
|
|
comparison_node_pool = create_alloc_pool ("Comparison tree nodes",
|
|
tree_code_size (EQ_EXPR), 30);
|
|
modify_expr_node_pool = create_alloc_pool ("MODIFY_EXPR nodes",
|
|
tree_code_size (MODIFY_EXPR),
|
|
30);
|
|
modify_expr_template = NULL;
|
|
|
|
FOR_ALL_BB (bb)
|
|
{
|
|
EXP_GEN (bb) = set_new (true);
|
|
PHI_GEN (bb) = bitmap_set_new ();
|
|
TMP_GEN (bb) = bitmap_set_new ();
|
|
AVAIL_OUT (bb) = bitmap_set_new ();
|
|
}
|
|
|
|
need_eh_cleanup = BITMAP_ALLOC (NULL);
|
|
}
|
|
|
|
|
|
/* Deallocate data structures used by PRE. */
|
|
|
|
static void
|
|
fini_pre (bool do_fre)
|
|
{
|
|
basic_block bb;
|
|
unsigned int i;
|
|
|
|
VEC_free (tree, heap, inserted_exprs);
|
|
VEC_free (tree, heap, need_creation);
|
|
bitmap_obstack_release (&grand_bitmap_obstack);
|
|
free_alloc_pool (value_set_pool);
|
|
free_alloc_pool (bitmap_set_pool);
|
|
free_alloc_pool (value_set_node_pool);
|
|
free_alloc_pool (binary_node_pool);
|
|
free_alloc_pool (reference_node_pool);
|
|
free_alloc_pool (unary_node_pool);
|
|
free_alloc_pool (list_node_pool);
|
|
free_alloc_pool (expression_node_pool);
|
|
free_alloc_pool (comparison_node_pool);
|
|
free_alloc_pool (modify_expr_node_pool);
|
|
htab_delete (phi_translate_table);
|
|
remove_fake_exit_edges ();
|
|
|
|
FOR_ALL_BB (bb)
|
|
{
|
|
free (bb->aux);
|
|
bb->aux = NULL;
|
|
}
|
|
|
|
free_dominance_info (CDI_POST_DOMINATORS);
|
|
vn_delete ();
|
|
|
|
if (!bitmap_empty_p (need_eh_cleanup))
|
|
{
|
|
tree_purge_all_dead_eh_edges (need_eh_cleanup);
|
|
cleanup_tree_cfg ();
|
|
}
|
|
|
|
BITMAP_FREE (need_eh_cleanup);
|
|
|
|
/* Wipe out pointers to VALUE_HANDLEs. In the not terribly distant
|
|
future we will want them to be persistent though. */
|
|
for (i = 0; i < num_ssa_names; i++)
|
|
{
|
|
tree name = ssa_name (i);
|
|
|
|
if (!name)
|
|
continue;
|
|
|
|
if (SSA_NAME_VALUE (name)
|
|
&& TREE_CODE (SSA_NAME_VALUE (name)) == VALUE_HANDLE)
|
|
SSA_NAME_VALUE (name) = NULL;
|
|
}
|
|
if (!do_fre && current_loops)
|
|
{
|
|
loop_optimizer_finalize (current_loops);
|
|
current_loops = NULL;
|
|
}
|
|
}
|
|
|
|
/* Main entry point to the SSA-PRE pass. DO_FRE is true if the caller
|
|
only wants to do full redundancy elimination. */
|
|
|
|
static void
|
|
execute_pre (bool do_fre)
|
|
{
|
|
init_pre (do_fre);
|
|
|
|
if (!do_fre)
|
|
insert_fake_stores ();
|
|
|
|
/* Collect and value number expressions computed in each basic block. */
|
|
compute_avail ();
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
basic_block bb;
|
|
|
|
FOR_ALL_BB (bb)
|
|
{
|
|
print_value_set (dump_file, EXP_GEN (bb), "exp_gen", bb->index);
|
|
bitmap_print_value_set (dump_file, TMP_GEN (bb), "tmp_gen",
|
|
bb->index);
|
|
bitmap_print_value_set (dump_file, AVAIL_OUT (bb), "avail_out",
|
|
bb->index);
|
|
}
|
|
}
|
|
|
|
/* Insert can get quite slow on an incredibly large number of basic
|
|
blocks due to some quadratic behavior. Until this behavior is
|
|
fixed, don't run it when he have an incredibly large number of
|
|
bb's. If we aren't going to run insert, there is no point in
|
|
computing ANTIC, either, even though it's plenty fast. */
|
|
if (!do_fre && n_basic_blocks < 4000)
|
|
{
|
|
vuse_names = XCNEWVEC (bitmap, num_ssa_names);
|
|
compute_rvuse_and_antic_safe ();
|
|
compute_antic ();
|
|
insert ();
|
|
free (vuse_names);
|
|
}
|
|
|
|
/* Remove all the redundant expressions. */
|
|
eliminate ();
|
|
|
|
|
|
if (dump_file && (dump_flags & TDF_STATS))
|
|
{
|
|
fprintf (dump_file, "Insertions: %d\n", pre_stats.insertions);
|
|
fprintf (dump_file, "New PHIs: %d\n", pre_stats.phis);
|
|
fprintf (dump_file, "Eliminated: %d\n", pre_stats.eliminations);
|
|
fprintf (dump_file, "Constified: %d\n", pre_stats.constified);
|
|
}
|
|
|
|
bsi_commit_edge_inserts ();
|
|
|
|
if (!do_fre)
|
|
{
|
|
remove_dead_inserted_code ();
|
|
realify_fake_stores ();
|
|
}
|
|
|
|
fini_pre (do_fre);
|
|
|
|
}
|
|
|
|
/* Gate and execute functions for PRE. */
|
|
|
|
static unsigned int
|
|
do_pre (void)
|
|
{
|
|
execute_pre (false);
|
|
return 0;
|
|
}
|
|
|
|
static bool
|
|
gate_pre (void)
|
|
{
|
|
return flag_tree_pre != 0;
|
|
}
|
|
|
|
struct tree_opt_pass pass_pre =
|
|
{
|
|
"pre", /* name */
|
|
gate_pre, /* gate */
|
|
do_pre, /* execute */
|
|
NULL, /* sub */
|
|
NULL, /* next */
|
|
0, /* static_pass_number */
|
|
TV_TREE_PRE, /* tv_id */
|
|
PROP_no_crit_edges | PROP_cfg
|
|
| PROP_ssa | PROP_alias, /* properties_required */
|
|
0, /* properties_provided */
|
|
0, /* properties_destroyed */
|
|
0, /* todo_flags_start */
|
|
TODO_update_ssa_only_virtuals | TODO_dump_func | TODO_ggc_collect
|
|
| TODO_verify_ssa, /* todo_flags_finish */
|
|
0 /* letter */
|
|
};
|
|
|
|
|
|
/* Gate and execute functions for FRE. */
|
|
|
|
static unsigned int
|
|
execute_fre (void)
|
|
{
|
|
execute_pre (true);
|
|
return 0;
|
|
}
|
|
|
|
static bool
|
|
gate_fre (void)
|
|
{
|
|
return flag_tree_fre != 0;
|
|
}
|
|
|
|
struct tree_opt_pass pass_fre =
|
|
{
|
|
"fre", /* name */
|
|
gate_fre, /* gate */
|
|
execute_fre, /* execute */
|
|
NULL, /* sub */
|
|
NULL, /* next */
|
|
0, /* static_pass_number */
|
|
TV_TREE_FRE, /* tv_id */
|
|
PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */
|
|
0, /* properties_provided */
|
|
0, /* properties_destroyed */
|
|
0, /* todo_flags_start */
|
|
TODO_dump_func | TODO_ggc_collect | TODO_verify_ssa, /* todo_flags_finish */
|
|
0 /* letter */
|
|
};
|