}
#endif
+/* Allocate a PHI node with at least LEN arguments. If the free list
+ happens to contain a PHI node with LEN arguments or more, return
+ that one. */
+
+static inline tree
+allocate_phi_node (int len)
+{
+ tree phi;
+ int bucket = NUM_BUCKETS - 2;
+ int size = (sizeof (struct tree_phi_node)
+ + (len - 1) * sizeof (struct phi_arg_d));
+
+ if (free_phinode_count)
+ for (bucket = len - 2; bucket < NUM_BUCKETS - 2; bucket++)
+ if (free_phinodes[bucket])
+ break;
+
+ /* If our free list has an element, then use it. */
+ if (bucket < NUM_BUCKETS - 2
+ && PHI_ARG_CAPACITY (free_phinodes[bucket]) >= len)
+ {
+ free_phinode_count--;
+ phi = free_phinodes[bucket];
+ free_phinodes[bucket] = PHI_CHAIN (free_phinodes[bucket]);
+#ifdef GATHER_STATISTICS
+ phi_nodes_reused++;
+#endif
+ }
+ else
+ {
+ phi = ggc_alloc (size);
+#ifdef GATHER_STATISTICS
+ phi_nodes_created++;
+ tree_node_counts[(int) phi_kind]++;
+ tree_node_sizes[(int) phi_kind] += size;
+#endif
+ }
+
+ return phi;
+}
+
/* Given LEN, the original number of requested PHI arguments, return
a new, "ideal" length for the PHI node. The "ideal" length rounds
the total size of the PHI node up to the next power of two bytes.
definitions created when a variable is used without a preceding
definition). */
-tree
+static tree
make_phi_node (tree var, int len)
{
tree phi;
- int size;
- int bucket = NUM_BUCKETS - 2;
-
- len = ideal_phi_node_len (len);
+ int capacity;
- size = sizeof (struct tree_phi_node) + (len - 1) * sizeof (struct phi_arg_d);
+ capacity = ideal_phi_node_len (len);
- if (free_phinode_count)
- for (bucket = len - 2; bucket < NUM_BUCKETS - 2; bucket++)
- if (free_phinodes[bucket])
- break;
+ phi = allocate_phi_node (capacity);
- /* If our free list has an element, then use it. */
- if (bucket < NUM_BUCKETS - 2
- && PHI_ARG_CAPACITY (free_phinodes[bucket]) >= len)
- {
- free_phinode_count--;
- phi = free_phinodes[bucket];
- free_phinodes[bucket] = PHI_CHAIN (free_phinodes[bucket]);
-#ifdef GATHER_STATISTICS
- phi_nodes_reused++;
-#endif
- }
- else
- {
- phi = ggc_alloc (size);
-#ifdef GATHER_STATISTICS
- phi_nodes_created++;
- tree_node_counts[(int) phi_kind]++;
- tree_node_sizes[(int) phi_kind] += size;
-#endif
-
- }
-
- memset (phi, 0, size);
+ /* We need to clear the entire PHI node, including the argument
+ portion, because we represent a "missing PHI argument" by placing
+ NULL_TREE in PHI_ARG_DEF. */
+ memset (phi, 0, (sizeof (struct tree_phi_node) - sizeof (struct phi_arg_d)
+ + sizeof (struct phi_arg_d) * len));
TREE_SET_CODE (phi, PHI_NODE);
- PHI_ARG_CAPACITY (phi) = len;
+ PHI_NUM_ARGS (phi) = len;
+ PHI_ARG_CAPACITY (phi) = capacity;
TREE_TYPE (phi) = TREE_TYPE (var);
if (TREE_CODE (var) == SSA_NAME)
SET_PHI_RESULT (phi, var);
static void
resize_phi_node (tree *phi, int len)
{
- int size, old_size;
+ int old_size;
tree new_phi;
- int i, old_len, bucket = NUM_BUCKETS - 2;
- gcc_assert (len >= PHI_ARG_CAPACITY (*phi));
+ gcc_assert (len > PHI_ARG_CAPACITY (*phi));
- /* Note that OLD_SIZE is guaranteed to be smaller than SIZE. */
+ /* The garbage collector will not look at the PHI node beyond the
+ first PHI_NUM_ARGS elements. Therefore, all we have to copy is a
+ portion of the PHI node currently in use. */
old_size = (sizeof (struct tree_phi_node)
- + (PHI_ARG_CAPACITY (*phi) - 1) * sizeof (struct phi_arg_d));
- size = sizeof (struct tree_phi_node) + (len - 1) * sizeof (struct phi_arg_d);
+ + (PHI_NUM_ARGS (*phi) - 1) * sizeof (struct phi_arg_d));
- if (free_phinode_count)
- for (bucket = len - 2; bucket < NUM_BUCKETS - 2; bucket++)
- if (free_phinodes[bucket])
- break;
-
- /* If our free list has an element, then use it. */
- if (bucket < NUM_BUCKETS - 2
- && PHI_ARG_CAPACITY (free_phinodes[bucket]) >= len)
- {
- free_phinode_count--;
- new_phi = free_phinodes[bucket];
- free_phinodes[bucket] = PHI_CHAIN (free_phinodes[bucket]);
-#ifdef GATHER_STATISTICS
- phi_nodes_reused++;
-#endif
- }
- else
- {
- new_phi = ggc_alloc (size);
-#ifdef GATHER_STATISTICS
- phi_nodes_created++;
- tree_node_counts[(int) phi_kind]++;
- tree_node_sizes[(int) phi_kind] += size;
-#endif
- }
+ new_phi = allocate_phi_node (len);
memcpy (new_phi, *phi, old_size);
- old_len = PHI_ARG_CAPACITY (new_phi);
PHI_ARG_CAPACITY (new_phi) = len;
- for (i = old_len; i < len; i++)
+ *phi = new_phi;
+}
+
+/* Reserve PHI arguments for a new edge to basic block BB. */
+
+void
+reserve_phi_args_for_new_edge (basic_block bb)
+{
+ tree *loc;
+ int len = EDGE_COUNT (bb->preds);
+ int cap = ideal_phi_node_len (len + 4);
+
+ for (loc = &(bb_ann (bb)->phi_nodes);
+ *loc;
+ loc = &PHI_CHAIN (*loc))
{
- SET_PHI_ARG_DEF (new_phi, i, NULL_TREE);
- PHI_ARG_EDGE (new_phi, i) = NULL;
- PHI_ARG_NONZERO (new_phi, i) = false;
- }
+ if (len > PHI_ARG_CAPACITY (*loc))
+ {
+ tree old_phi = *loc;
- *phi = new_phi;
+ resize_phi_node (loc, cap);
+
+ /* The result of the phi is defined by this phi node. */
+ SSA_NAME_DEF_STMT (PHI_RESULT (*loc)) = *loc;
+
+ release_phi_node (old_phi);
+ }
+
+ /* We represent a "missing PHI argument" by placing NULL_TREE in
+ the corresponding slot. If PHI arguments were added
+ immediately after an edge is created, this zeroing would not
+ be necessary, but unfortunately this is not the case. For
+ example, the loop optimizer duplicates several basic blocks,
+ redirects edges, and then fixes up PHI arguments later in
+ batch. */
+ SET_PHI_ARG_DEF (*loc, len - 1, NULL_TREE);
+
+ PHI_NUM_ARGS (*loc)++;
+ }
}
/* Create a new PHI node for variable VAR at basic block BB. */
phi = make_phi_node (var, EDGE_COUNT (bb->preds));
- /* This is a new phi node, so note that is has not yet been
- rewritten. */
- PHI_REWRITTEN (phi) = 0;
-
/* Add the new PHI node to the list of PHI nodes for block BB. */
PHI_CHAIN (phi) = phi_nodes (bb);
bb_ann (bb)->phi_nodes = phi;
PHI points to the reallocated phi node when we return. */
void
-add_phi_arg (tree *phi, tree def, edge e)
+add_phi_arg (tree phi, tree def, edge e)
{
- int i = PHI_NUM_ARGS (*phi);
+ basic_block bb = e->dest;
- if (i >= PHI_ARG_CAPACITY (*phi))
- {
- tree old_phi = *phi;
+ gcc_assert (bb == bb_for_stmt (phi));
- /* Resize the phi. Unfortunately, this may also relocate it. */
- resize_phi_node (phi, ideal_phi_node_len (i + 4));
+ /* We resize PHI nodes upon edge creation. We should always have
+ enough room at this point. */
+ gcc_assert (PHI_NUM_ARGS (phi) <= PHI_ARG_CAPACITY (phi));
- /* The result of the phi is defined by this phi node. */
- SSA_NAME_DEF_STMT (PHI_RESULT (*phi)) = *phi;
-
- /* If the PHI was relocated, update the PHI chains appropriately and
- release the old PHI node. */
- if (*phi != old_phi)
- {
- /* Extract the basic block for the PHI from the PHI's annotation
- rather than the edge. This works better as the edge's
- destination may not currently be the block with the PHI
- node if we are in the process of threading the edge to
- a new destination. */
- basic_block bb = bb_for_stmt (*phi);
-
- release_phi_node (old_phi);
-
- /* Update the list head if replacing the first listed phi. */
- if (phi_nodes (bb) == old_phi)
- bb_ann (bb)->phi_nodes = *phi;
- else
- {
- /* Traverse the list looking for the phi node to chain to. */
- tree p;
-
- for (p = phi_nodes (bb);
- p && PHI_CHAIN (p) != old_phi;
- p = PHI_CHAIN (p))
- ;
-
- gcc_assert (p);
- PHI_CHAIN (p) = *phi;
- }
- }
- }
+ /* We resize PHI nodes upon edge creation. We should always have
+ enough room at this point. */
+ gcc_assert (e->dest_idx < (unsigned int) PHI_NUM_ARGS (phi));
/* Copy propagation needs to know what object occur in abnormal
PHI nodes. This is a convenient place to record such information. */
if (e->flags & EDGE_ABNORMAL)
{
SSA_NAME_OCCURS_IN_ABNORMAL_PHI (def) = 1;
- SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (*phi)) = 1;
+ SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi)) = 1;
}
- SET_PHI_ARG_DEF (*phi, i, def);
- PHI_ARG_EDGE (*phi, i) = e;
- PHI_ARG_NONZERO (*phi, i) = false;
- PHI_NUM_ARGS (*phi)++;
-}
-
-/* Remove a PHI argument from PHI. BLOCK is the predecessor block where
- the PHI argument is coming from. */
-
-void
-remove_phi_arg (tree phi, basic_block block)
-{
- int i, num_elem = PHI_NUM_ARGS (phi);
-
- for (i = 0; i < num_elem; i++)
- {
- basic_block src_bb;
-
- src_bb = PHI_ARG_EDGE (phi, i)->src;
-
- if (src_bb == block)
- {
- remove_phi_arg_num (phi, i);
- return;
- }
- }
+ SET_PHI_ARG_DEF (phi, e->dest_idx, def);
+ PHI_ARG_NONZERO (phi, e->dest_idx) = false;
}
+/* Remove the Ith argument from PHI's argument list. This routine
+ implements removal by swapping the last alternative with the
+ alternative we want to delete and then shrinking the vector, which
+ is consistent with how we remove an edge from the edge vector. */
-/* Remove the Ith argument from PHI's argument list. This routine assumes
- ordering of alternatives in the vector is not important and implements
- removal by swapping the last alternative with the alternative we want to
- delete, then shrinking the vector. */
-
-void
+static void
remove_phi_arg_num (tree phi, int i)
{
int num_elem = PHI_NUM_ARGS (phi);
if (i != num_elem - 1)
{
SET_PHI_ARG_DEF (phi, i, PHI_ARG_DEF (phi, num_elem - 1));
- PHI_ARG_EDGE (phi, i) = PHI_ARG_EDGE (phi, num_elem - 1);
PHI_ARG_NONZERO (phi, i) = PHI_ARG_NONZERO (phi, num_elem - 1);
}
- /* Shrink the vector and return. */
- SET_PHI_ARG_DEF (phi, num_elem - 1, NULL_TREE);
- PHI_ARG_EDGE (phi, num_elem - 1) = NULL;
- PHI_ARG_NONZERO (phi, num_elem - 1) = false;
+ /* Shrink the vector and return. Note that we do not have to clear
+ PHI_ARG_DEF or PHI_ARG_NONZERO because the garbage collector will
+ not look at those elements beyond the first PHI_NUM_ARGS elements
+ of the array. */
PHI_NUM_ARGS (phi)--;
}
+/* Remove all PHI arguments associated with edge E. */
+
+void
+remove_phi_args (edge e)
+{
+ tree phi;
+
+ for (phi = phi_nodes (e->dest); phi; phi = PHI_CHAIN (phi))
+ remove_phi_arg_num (phi, e->dest_idx);
+}
+
/* Remove PHI node PHI from basic block BB. If PREV is non-NULL, it is
used as the node immediately before PHI in the linked list. */
FOR_EACH_BB (bb)
{
/* Build a new PHI list for BB without variables in VARS. */
- tree phi, new_phi_list, last_phi, next;
+ tree phi, new_phi_list, next;
+ tree *lastp = &new_phi_list;
- last_phi = new_phi_list = NULL_TREE;
- for (phi = phi_nodes (bb), next = NULL; phi; phi = next)
+ for (phi = phi_nodes (bb); phi; phi = next)
{
tree var = SSA_NAME_VAR (PHI_RESULT (phi));
Note that fact in PHI_REWRITTEN. */
PHI_REWRITTEN (phi) = 1;
- if (new_phi_list == NULL_TREE)
- new_phi_list = last_phi = phi;
- else
- {
- PHI_CHAIN (last_phi) = phi;
- last_phi = phi;
- }
+ *lastp = phi;
+ lastp = &PHI_CHAIN (phi);
}
else
{
}
/* Make sure the last node in the new list has no successors. */
- if (last_phi)
- PHI_CHAIN (last_phi) = NULL_TREE;
+ *lastp = NULL;
bb_ann (bb)->phi_nodes = new_phi_list;
#if defined ENABLE_CHECKING
}
}
+/* Reverse the order of PHI nodes in the chain PHI.
+ Return the new head of the chain (old last PHI node). */
+
+tree
+phi_reverse (tree phi)
+{
+ tree prev = NULL_TREE, next;
+ for (; phi; phi = next)
+ {
+ next = PHI_CHAIN (phi);
+ PHI_CHAIN (phi) = prev;
+ prev = phi;
+ }
+ return prev;
+}
#include "gt-tree-phinodes.h"
OSDN Git Service
