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. Load motion can be performed by value numbering the loads the
- same as we do other expressions. This requires iterative
- hashing the vuses into the values. Right now we simply assign
- a new value every time we see a statement with a vuse.
- 3. Strength reduction can be performed by anticipating expressions
+ 2. Strength reduction can be performed by anticipating expressions
we can repair later on.
- 4. We can do back-substitution or smarter value numbering to catch
+ 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
a given basic block. */
bitmap_set_t avail_out;
- /* The ANTIC_IN set, which represents which values are anticiptable
+ /* The ANTIC_IN set, which represents which values are anticipatable
in a given basic block. */
value_set_t antic_in;
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 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 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
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 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;
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))
+ if (!expressions_equal_p (ve1->e, ve2->e))
+ return false;
+
+ /* Make sure the vuses are equivalent. */
+ if (ve1->vuses == ve2->vuses)
return true;
- return false;
+ 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. Return the translated value, if
- found, NULL otherwise. */
+ 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)
+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.hashcode = vn_compute (e, (unsigned long) pred, NULL);
+ 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)
}
-/* Add the tuple mapping from {expression E, basic block PRED} to
+/* 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)
+phi_trans_add (tree e, tree v, basic_block pred, VEC (tree, gc) *vuses)
{
void **slot;
- expr_pred_trans_t new_pair = xmalloc (sizeof (*new_pair));
+ 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, NULL);
+ 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)
static bitmap_set_t
bitmap_set_new (void)
{
- bitmap_set_t ret = pool_alloc (bitmap_set_pool);
+ 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;
set_new (bool indexed)
{
value_set_t ret;
- ret = pool_alloc (value_set_pool);
+ ret = (value_set_t) pool_alloc (value_set_pool);
ret->head = ret->tail = NULL;
ret->length = 0;
ret->indexed = indexed;
static void
insert_into_set (value_set_t set, tree expr)
{
- value_set_node_t newnode = pool_alloc (value_set_node_pool);
+ value_set_node_t newnode = (value_set_node_t) pool_alloc (value_set_node_pool);
tree val = get_value_handle (expr);
gcc_assert (val);
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);
+ }
+
+}
+
+/* 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);
+ }
+}
+
+/* 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
if (is_gimple_min_invariant (val))
return true;
- if (set->length == 0)
+ if (!set || set->length == 0)
return false;
return value_exists_in_set_bitmap (set, val);
if (list == 0)
return 0;
- head = pool_alloc (list_node_pool);
+ head = (tree) pool_alloc (list_node_pool);
memcpy (head, list, tree_size (list));
prev = head;
next = TREE_CHAIN (list);
while (next)
{
- TREE_CHAIN (prev) = pool_alloc (list_node_pool);
+ 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. */
{
tree phitrans = NULL;
tree oldexpr = expr;
-
if (expr == NULL)
return NULL;
return expr;
/* Phi translations of a given expression don't change. */
- phitrans = phi_trans_lookup (expr, pred);
+ 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;
tree oldwalker;
tree newwalker;
tree newexpr;
+ tree vh = get_value_handle (expr);
bool listchanged = 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
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)
if (listchanged)
vn_lookup_or_add (newarglist, NULL);
- if (listchanged || (newop0 != oldop0) || (oldop2 != newop2))
+ tvuses = translate_vuses_through_block (vuses, pred);
+
+ if (listchanged || (newop0 != oldop0) || (oldop2 != newop2)
+ || vuses != tvuses)
{
- newexpr = pool_alloc (expression_node_pool);
+ 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);
create_tree_ann (newexpr);
- vn_lookup_or_add (newexpr, NULL);
+ vn_lookup_or_add_with_vuses (newexpr, tvuses);
expr = newexpr;
- phi_trans_add (oldexpr, newexpr, pred);
+ 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:
- /* XXX: Until we have PRE of loads working, none will be ANTIC. */
- return NULL;
+ {
+ 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
+ {
+ create_tree_ann (newexpr);
+ 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:
if (newop1 != oldop1 || newop2 != oldop2)
{
tree t;
- newexpr = pool_alloc (binary_node_pool);
+ 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);
vn_lookup_or_add (newexpr, NULL);
}
expr = newexpr;
- phi_trans_add (oldexpr, newexpr, pred);
+ phi_trans_add (oldexpr, newexpr, pred, NULL);
}
}
return expr;
if (newop1 != oldop1)
{
tree t;
- newexpr = pool_alloc (unary_node_pool);
+ 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);
vn_lookup_or_add (newexpr, NULL);
}
expr = newexpr;
- phi_trans_add (oldexpr, newexpr, pred);
+ phi_trans_add (oldexpr, newexpr, pred, NULL);
}
}
return expr;
node = node->next)
{
tree translated;
- translated = phi_translate (node->expr, set, pred, phiblock);
- phi_trans_add (node->expr, translated, pred);
+ 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);
}
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.
(IE VALUE1 + VALUE2, *VALUE1, VALUE1 < VALUE2) */
static bool
-valid_in_set (value_set_t set, tree expr)
+valid_in_set (value_set_t set, tree expr, basic_block block)
{
- switch (TREE_CODE_CLASS (TREE_CODE (expr)))
+ tree vh = get_value_handle (expr);
+ switch (TREE_CODE_CLASS (TREE_CODE (expr)))
{
case tcc_binary:
case tcc_comparison:
if (!set_contains_value (set, TREE_VALUE (arglist)))
return false;
}
- return true;
+ return !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh), block);
}
return false;
}
case tcc_reference:
- /* XXX: Until PRE of loads works, no reference nodes are ANTIC. */
+ {
+ 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:
return true;
case tcc_declaration:
- /* VAR_DECL and PARM_DECL are never anticipatable. */
- return false;
+ return !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh), block);
default:
/* No other cases should be encountered. */
in SET. */
static void
-clean (value_set_t set)
+clean (value_set_t set, basic_block block)
{
value_set_node_t node;
value_set_node_t next;
while (node)
{
next = node->next;
- if (!valid_in_set (set, node->expr))
+ if (!valid_in_set (set, node->expr, block))
set_remove (set, node->expr);
node = next;
}
}
-DEF_VEC_P (basic_block);
-DEF_VEC_ALLOC_P (basic_block, heap);
static sbitmap has_abnormal_preds;
/* Compute the ANTIC set for BLOCK.
{
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);
for (node = S->head; node; node = node->next)
value_insert_into_set (ANTIC_IN (block), node->expr);
- clean (ANTIC_IN (block));
+ clean (ANTIC_IN (block), block);
if (!set_equal (old, ANTIC_IN (block)))
changed = true;
{
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);
}
fprintf (dump_file, "compute_antic required %d iterations\n", num_iterations);
}
-static VEC(tree,heap) *inserted_exprs;
-/* 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)
+/* Print the names represented by the bitmap NAMES, to the file OUT. */
+static void
+dump_bitmap_of_names (FILE *out, bitmap names)
{
- tree genop = bitmap_find_leader (AVAIL_OUT (block), expr);
+ bitmap_iterator bi;
+ unsigned int i;
- /* If it's still NULL, it must be a complex expression, so generate
- it recursively. */
- if (genop == NULL)
+ fprintf (out, " { ");
+ EXECUTE_IF_SET_IN_BITMAP (names, 0, i, bi)
{
- genop = VALUE_HANDLE_EXPR_SET (expr)->head->expr;
- gcc_assert (UNARY_CLASS_P (genop)
- || BINARY_CLASS_P (genop)
- || COMPARISON_CLASS_P (genop)
- || REFERENCE_CLASS_P (genop)
- || TREE_CODE (genop) == CALL_EXPR);
- genop = create_expression_by_pieces (block, genop, stmts);
+ print_generic_expr (out, ssa_name (i), 0);
+ fprintf (out, " ");
}
- return genop;
+ fprintf (out, "}\n");
}
-#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.
+ /* 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.
- 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). */
+ 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 tree
-create_expression_by_pieces (basic_block block, tree expr, tree stmts)
+static bitmap *vuse_names;
+static void
+compute_vuse_representatives (void)
{
- tree temp, name;
- tree folded, forced_stmts, newexpr;
- tree v;
- tree_stmt_iterator tsi;
+ tree phi;
+ basic_block bb;
+ VEC (tree, heap) *phis = NULL;
+ bool changed = true;
+ size_t i;
- switch (TREE_CODE_CLASS (TREE_CODE (expr)))
+ FOR_EACH_BB (bb)
{
- case tcc_expression:
+ 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++)
{
- 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))
+ bitmap reps = get_representative (vuse_names,
+ SSA_NAME_VERSION (PHI_RESULT (phi)));
+ if (reps)
{
- TREE_VALUE (genwalker) = find_or_generate_expression (block,
- TREE_VALUE (walker),
- stmts);
+ 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);
+}
- if (op2)
- genop2 = find_or_generate_expression (block, op2, stmts);
- folded = fold_build3 (TREE_CODE (expr), TREE_TYPE (expr),
+/* 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 val = vn_lookup_or_add (forcedexpr, NULL);
VEC_safe_push (tree, heap, inserted_exprs, stmt);
- vn_add (forcedname, val, NULL);
+ 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. */
- temp = create_tmp_var (TREE_TYPE (expr), "pretmp");
- add_referenced_tmp_var (temp);
+ 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 = build (MODIFY_EXPR, TREE_TYPE (expr), temp, newexpr);
+
+ 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
the expression may have been represented. There is no harm in replacing
here. */
v = get_value_handle (expr);
- vn_add (name, v, NULL);
+ vn_add (name, v);
bitmap_value_replace_in_set (NEW_SETS (block), name);
bitmap_value_replace_in_set (AVAIL_OUT (block), name);
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. The prefix of the phi node is
- given with TMPNAME. Return true if we have inserted new stuff. */
+/* 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, const char *tmpname)
+ tree *avail)
{
tree val = get_value_handle (node->expr);
edge pred;
{
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)
+ 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;
tree builtexpr;
bprime = pred->src;
eprime = avail[bprime->index];
- if (BINARY_CLASS_P (eprime)
- || COMPARISON_CLASS_P (eprime)
- || UNARY_CLASS_P (eprime)
- || TREE_CODE (eprime) == CALL_EXPR)
+
+ 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);
return false;
/* Now build a phi for the new variable. */
- temp = create_tmp_var (type, tmpname);
- add_referenced_tmp_var (temp);
+ 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, NULL);
+ 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
node;
node = node->next)
{
- if (BINARY_CLASS_P (node->expr)
- || COMPARISON_CLASS_P (node->expr)
- || UNARY_CLASS_P (node->expr)
- || TREE_CODE (node->expr) == CALL_EXPR)
+ if (can_PRE_operation (node->expr)
+ && !AGGREGATE_TYPE_P (TREE_TYPE (node->expr)))
{
tree *avail;
tree val;
continue;
}
- avail = xcalloc (last_basic_block, sizeof (tree));
+ avail = XCNEWVEC (tree, last_basic_block);
FOR_EACH_EDGE (pred, ei, block->preds)
{
tree vprime;
partially redundant. */
if (!cant_insert && !all_same && by_some)
{
- if (insert_into_preds_of_block (block, node, avail,
- "prephitmp"))
+ if (insert_into_preds_of_block (block, node, avail))
new_stuff = true;
}
/* If all edges produce the same value and that value is
{
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, NULL);
+ vn_add (node->expr, eprime);
pre_stats.constified++;
}
}
S1 and its value handle to S2.
VUSES represent the virtual use operands associated with EXPR (if
- any). They are used when computing the hash value for EXPR. */
+ any). */
static inline void
add_to_sets (tree var, tree expr, tree stmt, bitmap_set_t s1,
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, NULL_TREE);
+ vn_add (var, val);
if (s1)
bitmap_insert_into_set (s1, var);
replaced with the value handles of each of the operands of EXPR.
VUSES represent the virtual use operands associated with EXPR (if
- any). They are used when computing the hash value for EXPR.
- Insert EXPR's operands into the EXP_GEN set for BLOCK. */
+ 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)
|| 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_exceptional
+ || TREE_CODE_CLASS (code) == tcc_declaration);
if (TREE_CODE_CLASS (code) == tcc_unary)
pool = unary_node_pool;
pool = expression_node_pool;
}
- vexpr = pool_alloc (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
if (op == NULL_TREE)
continue;
- /* If OP is a constant that has overflowed, do not value number
- this expression. */
- if (CONSTANT_CLASS_P (op)
- && TREE_OVERFLOW (op))
- {
- pool_free (pool, vexpr);
- return NULL;
- }
-
/* Recursively value-numberize reference ops and tree lists. */
if (REFERENCE_CLASS_P (op))
{
}
-/* Return true if we can value number a call. This is true if we have
- a pure or constant call. */
+
+/* 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
-can_value_number_call (tree stmt)
+try_look_through_load (tree lhs, tree mem_ref, tree stmt, basic_block block)
{
- tree call = get_call_expr_in (stmt);
+ 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;
+ }
- /* This is a temporary restriction until we translate vuses through
- phi nodes. This is only needed for PRE, of course. */
- if (!in_fre && !ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
- return false;
- if (call_expr_flags (call) & (ECF_PURE | ECF_CONST))
- 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);
+
+ /* Disallow value expressions we have no value number for already, as
+ we would miss a leader for it here. */
+ if (t
+ && !(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;
}
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);
}
}
+ /* 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 = xmalloc (sizeof (basic_block) * n_basic_blocks);
+ worklist = XNEWVEC (basic_block, n_basic_blocks);
/* Seed the algorithm by putting the dominator children of the entry
block on the worklist. */
block_stmt_iterator bsi;
tree stmt, phi;
basic_block dom;
+ unsigned int stmt_uid = 1;
/* Pick a block from the worklist. */
block = worklist[--sp];
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
stmt = bsi_stmt (bsi);
ann = stmt_ann (stmt);
+
+ ann->uid = stmt_uid++;
- /* 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. */
+ /* 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
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 (UNARY_CLASS_P (rhs)
- || BINARY_CLASS_P (rhs)
- || COMPARISON_CLASS_P (rhs)
- || REFERENCE_CLASS_P (rhs)
- || (TREE_CODE (rhs) == CALL_EXPR
- && can_value_number_call (stmt)))
+ if (can_value_number_operation (rhs))
{
- /* For binary, unary, and reference expressions,
- create a duplicate expression with the operands
- replaced with the value handles of the original
- 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)
{
- add_to_sets (lhs, newt, stmt, TMP_GEN (block),
- AVAIL_OUT (block));
- value_insert_into_set (EXP_GEN (block), 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
+ 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)
gcc_assert (op);
+ if (TREE_CODE (op) != SSA_NAME)
+ return NULL;
+
stmt = SSA_NAME_DEF_STMT (op);
gcc_assert (stmt);
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)
{
- /* 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. In aggressive mode,
- we also consider the control dependent edges leading to the
- predecessor block associated with each PHI alternative as
- necessary. */
int k;
VEC_reserve (tree, heap, worklist, PHI_NUM_ARGS (t));
}
}
}
+
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);
+ bsi_remove (&bsi, true);
+ release_defs (t);
}
}
}
VEC_free (tree, heap, worklist);
}
+
/* Initialize data structures used by PRE. */
static void
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 (dump_file);
+ current_loops = loop_optimizer_init (LOOPS_NORMAL);
+
connect_infinite_loops_to_exit ();
memset (&pre_stats, 0, sizeof (pre_stats));
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);
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 (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 ();
}
if (!do_fre && current_loops)
{
- loop_optimizer_finalize (current_loops, dump_file);
+ 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. */
{
init_pre (do_fre);
+ if (!do_fre)
+ insert_fake_stores ();
+
/* Collect and value number expressions computed in each basic block. */
compute_avail ();
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. */
}
bsi_commit_edge_inserts ();
+
if (!do_fre)
- remove_dead_inserted_code ();
+ {
+ remove_dead_inserted_code ();
+ realify_fake_stores ();
+ }
+
fini_pre (do_fre);
}
-
/* Gate and execute functions for PRE. */
-static void
+static unsigned int
do_pre (void)
{
execute_pre (false);
+ return 0;
}
static bool
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_update_ssa | TODO_dump_func | TODO_ggc_collect
+ 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 void
+static unsigned int
execute_fre (void)
{
execute_pre (true);
+ return 0;
}
static bool
0 /* letter */
};
-/* Return true if T is a copy statement between two ssa names. */
-
-static bool
-is_copy_stmt (tree t)
-{
- if (!t || TREE_CODE (t) != MODIFY_EXPR)
- return false;
- if (TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME
- && TREE_CODE (TREE_OPERAND (t, 1)) == SSA_NAME)
- return true;
- return false;
-}
-
-/* Starting from START, walk copy statements till we hit a statement with a
- VUSE or a non-copy statement. */
-
-static tree
-follow_copies_till_vuse (tree start)
-{
- if (is_copy_stmt (start) && ZERO_SSA_OPERANDS (start, SSA_OP_VIRTUAL_USES))
- {
- tree rhs, defstmt;
-
- rhs = TREE_OPERAND (start, 1);
- defstmt = SSA_NAME_DEF_STMT (rhs);
- return follow_copies_till_vuse (defstmt);
- }
- return start;
-}
-
-/* Gate and execute functions for eliminate useless stores.
- The goal here is to recognize the pattern *x = ... *x, and eliminate the
- store because the value hasn't changed. Store copy/const prop won't
- do this because making *more* loads (IE propagating *x) is not a win, so it
- ignores them.
- This pass is currently geared completely towards static variable store
- elimination. */
-
-static void
-do_eustores (void)
-{
- basic_block bb;
- /* For each basic block
- For each statement (STMT) in the block
- if STMT is a stores of the pattern *x = y
- follow the chain of definitions for y, until we hit a non-copy
- statement or a statement with a vuse.
- if the statement we arrive at is a vuse of the operand we killed,
- accessed through the same memory operation, then we have a
- useless store (because it is *x = ... = *x). */
-
- FOR_EACH_BB (bb)
- {
- block_stmt_iterator bsi;
-
- for (bsi = bsi_start (bb);
- !bsi_end_p (bsi);)
- {
- tree stmt = bsi_stmt (bsi);
- tree startat;
- tree kill;
- tree found;
-
- if (NUM_SSA_OPERANDS (stmt, SSA_OP_VMUSTDEF) != 1
- || TREE_CODE (stmt) != MODIFY_EXPR
- || TREE_CODE (TREE_OPERAND (stmt, 1)) != SSA_NAME)
- {
- bsi_next (&bsi);
- continue;
- }
-
- kill = MUSTDEF_KILL (MUSTDEF_OPS (stmt));
- startat = TREE_OPERAND (stmt, 1);
- startat = SSA_NAME_DEF_STMT (startat);
- found = follow_copies_till_vuse (startat);
-
- if (found && TREE_CODE (found) == MODIFY_EXPR)
- {
-
- /* We want exactly one virtual use, and it should match up with
- the use being killed. */
-
- if (NUM_SSA_OPERANDS (found, SSA_OP_VUSE) != 1
- || VUSE_OP (VUSE_OPS (found)) != kill
- || !DECL_P (TREE_OPERAND (stmt, 0))
- || !operand_equal_p (TREE_OPERAND (found, 1),
- TREE_OPERAND (stmt, 0), 0))
- {
- bsi_next (&bsi);
- continue;
- }
-
- if (dump_file)
- {
- fprintf (dump_file, "Eliminating useless store ");
- print_generic_stmt (dump_file, stmt, 0);
- }
- mark_sym_for_renaming (TREE_OPERAND (stmt, 0));
- bsi_remove (&bsi);
- }
- else
- {
- bsi_next (&bsi);
- continue;
- }
- }
- }
-}
-
-static bool
-gate_eustores(void)
-{
- return flag_unit_at_a_time != 0;
-}
-
-struct tree_opt_pass pass_eliminate_useless_stores =
-{
- "eustores", /* name */
- gate_eustores, /* gate */
- do_eustores, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- 0, /* tv_id */
- PROP_cfg | PROP_ssa | PROP_alias, /* properties_required */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- TODO_update_ssa | TODO_dump_func
- | TODO_ggc_collect | TODO_verify_ssa, /* todo_flags_finish */
- 0 /* letter */
-};