Functions to create, destroy and manipulate an instance of df.
----------------------------------------------------------------------------*/
-struct df *df;
+struct df_d *df;
/* Add PROBLEM (and any dependent problems) to the DF instance. */
rest_of_handle_df_initialize (void)
{
gcc_assert (!df);
- df = XCNEW (struct df);
+ df = XCNEW (struct df_d);
df->changeable_flags = 0;
bitmap_obstack_initialize (&df_bitmap_obstack);
The general data flow analysis engine.
----------------------------------------------------------------------------*/
+/* Return time BB when it was visited for last time. */
+#define BB_LAST_CHANGE_AGE(bb) ((ptrdiff_t)(bb)->aux)
/* Helper function for df_worklist_dataflow.
Propagate the dataflow forward.
Given a BB_INDEX, do the dataflow propagation
and set bits on for successors in PENDING
- if the out set of the dataflow has changed. */
+ if the out set of the dataflow has changed.
-static void
+ AGE specify time when BB was visited last time.
+ AGE of 0 means we are visiting for first time and need to
+ compute transfer function to initialize datastructures.
+ Otherwise we re-do transfer function only if something change
+ while computing confluence functions.
+ We need to compute confluence only of basic block that are younger
+ then last visit of the BB.
+
+ Return true if BB info has changed. This is always the case
+ in the first visit. */
+
+static bool
df_worklist_propagate_forward (struct dataflow *dataflow,
unsigned bb_index,
unsigned *bbindex_to_postorder,
bitmap pending,
- sbitmap considered)
+ sbitmap considered,
+ ptrdiff_t age)
{
edge e;
edge_iterator ei;
basic_block bb = BASIC_BLOCK (bb_index);
+ bool changed = !age;
/* Calculate <conf_op> of incoming edges. */
if (EDGE_COUNT (bb->preds) > 0)
FOR_EACH_EDGE (e, ei, bb->preds)
{
- if (TEST_BIT (considered, e->src->index))
- dataflow->problem->con_fun_n (e);
+ if (age <= BB_LAST_CHANGE_AGE (e->src)
+ && TEST_BIT (considered, e->src->index))
+ changed |= dataflow->problem->con_fun_n (e);
}
else if (dataflow->problem->con_fun_0)
dataflow->problem->con_fun_0 (bb);
- if (dataflow->problem->trans_fun (bb_index))
+ if (changed
+ && dataflow->problem->trans_fun (bb_index))
{
/* The out set of this block has changed.
Propagate to the outgoing blocks. */
if (TEST_BIT (considered, ob_index))
bitmap_set_bit (pending, bbindex_to_postorder[ob_index]);
}
+ return true;
}
+ return false;
}
/* Helper function for df_worklist_dataflow.
Propagate the dataflow backward. */
-static void
+static bool
df_worklist_propagate_backward (struct dataflow *dataflow,
unsigned bb_index,
unsigned *bbindex_to_postorder,
bitmap pending,
- sbitmap considered)
+ sbitmap considered,
+ ptrdiff_t age)
{
edge e;
edge_iterator ei;
basic_block bb = BASIC_BLOCK (bb_index);
+ bool changed = !age;
/* Calculate <conf_op> of incoming edges. */
if (EDGE_COUNT (bb->succs) > 0)
FOR_EACH_EDGE (e, ei, bb->succs)
{
- if (TEST_BIT (considered, e->dest->index))
- dataflow->problem->con_fun_n (e);
+ if (age <= BB_LAST_CHANGE_AGE (e->dest)
+ && TEST_BIT (considered, e->dest->index))
+ changed |= dataflow->problem->con_fun_n (e);
}
else if (dataflow->problem->con_fun_0)
dataflow->problem->con_fun_0 (bb);
- if (dataflow->problem->trans_fun (bb_index))
+ if (changed
+ && dataflow->problem->trans_fun (bb_index))
{
/* The out set of this block has changed.
Propagate to the outgoing blocks. */
if (TEST_BIT (considered, ob_index))
bitmap_set_bit (pending, bbindex_to_postorder[ob_index]);
}
+ return true;
}
+ return false;
}
+/* Main dataflow solver loop.
+
+ DATAFLOW is problem we are solving, PENDING is worklist of basic blocks we
+ need to visit.
+ BLOCK_IN_POSTORDER is array of size N_BLOCKS specifying postorder in BBs and
+ BBINDEX_TO_POSTORDER is array mapping back BB->index to postorder possition.
+ PENDING will be freed.
+
+ The worklists are bitmaps indexed by postorder positions.
+ The function implements standard algorithm for dataflow solving with two
+ worklists (we are processing WORKLIST and storing new BBs to visit in
+ PENDING).
-/* This will free "pending". */
+ As an optimization we maintain ages when BB was changed (stored in bb->aux)
+ and when it was last visited (stored in last_visit_age). This avoids need
+ to re-do confluence function for edges to basic blocks whose source
+ did not change since destination was visited last time. */
static void
df_worklist_dataflow_doublequeue (struct dataflow *dataflow,
bitmap pending,
sbitmap considered,
int *blocks_in_postorder,
- unsigned *bbindex_to_postorder)
+ unsigned *bbindex_to_postorder,
+ int n_blocks)
{
enum df_flow_dir dir = dataflow->problem->dir;
int dcount = 0;
bitmap worklist = BITMAP_ALLOC (&df_bitmap_obstack);
+ int age = 0;
+ bool changed;
+ VEC(int, heap) *last_visit_age = NULL;
+ int prev_age;
+ basic_block bb;
+ int i;
+
+ VEC_safe_grow_cleared (int, heap, last_visit_age, n_blocks);
/* Double-queueing. Worklist is for the current iteration,
and pending is for the next. */
while (!bitmap_empty_p (pending))
{
+ bitmap_iterator bi;
+ unsigned int index;
+
/* Swap pending and worklist. */
bitmap temp = worklist;
worklist = pending;
pending = temp;
- do
+ EXECUTE_IF_SET_IN_BITMAP (worklist, 0, index, bi)
{
- int index;
unsigned bb_index;
dcount++;
- index = bitmap_first_set_bit (worklist);
- bitmap_clear_bit (worklist, index);
-
+ bitmap_clear_bit (pending, index);
bb_index = blocks_in_postorder[index];
-
+ bb = BASIC_BLOCK (bb_index);
+ prev_age = VEC_index (int, last_visit_age, index);
if (dir == DF_FORWARD)
- df_worklist_propagate_forward (dataflow, bb_index,
- bbindex_to_postorder,
- pending, considered);
+ changed = df_worklist_propagate_forward (dataflow, bb_index,
+ bbindex_to_postorder,
+ pending, considered,
+ prev_age);
else
- df_worklist_propagate_backward (dataflow, bb_index,
- bbindex_to_postorder,
- pending, considered);
+ changed = df_worklist_propagate_backward (dataflow, bb_index,
+ bbindex_to_postorder,
+ pending, considered,
+ prev_age);
+ VEC_replace (int, last_visit_age, index, ++age);
+ if (changed)
+ bb->aux = (void *)(ptrdiff_t)age;
}
- while (!bitmap_empty_p (worklist));
+ bitmap_clear (worklist);
}
+ for (i = 0; i < n_blocks; i++)
+ BASIC_BLOCK (blocks_in_postorder[i])->aux = NULL;
BITMAP_FREE (worklist);
BITMAP_FREE (pending);
+ VEC_free (int, heap, last_visit_age);
/* Dump statistics. */
if (dump_file)
/* Solve it. */
df_worklist_dataflow_doublequeue (dataflow, pending, considered,
blocks_in_postorder,
- bbindex_to_postorder);
-
+ bbindex_to_postorder,
+ n_blocks);
sbitmap_free (considered);
free (bbindex_to_postorder);
}
void
df_set_bb_dirty (basic_block bb)
{
+ bb->flags |= BB_MODIFIED;
if (df)
{
int p;
+ i * dflow->problem->block_info_elt_size, 0,
(last_basic_block - i)
* dflow->problem->block_info_elt_size);
+ free (problem_temps);
}
}
debugging dump. */
void
-df_print_byte_regset (FILE *file, bitmap r)
+df_print_word_regset (FILE *file, bitmap r)
{
unsigned int max_reg = max_reg_num ();
- bitmap_iterator bi;
if (r == NULL)
fputs (" (nil)", file);
else
{
unsigned int i;
- for (i = 0; i < max_reg; i++)
+ for (i = FIRST_PSEUDO_REGISTER; i < max_reg; i++)
{
- unsigned int first = df_byte_lr_get_regno_start (i);
- unsigned int len = df_byte_lr_get_regno_len (i);
-
- if (len > 1)
- {
- bool found = false;
- unsigned int j;
-
- EXECUTE_IF_SET_IN_BITMAP (r, first, j, bi)
- {
- found = j < first + len;
- break;
- }
- if (found)
- {
- const char * sep = "";
- fprintf (file, " %d", i);
- if (i < FIRST_PSEUDO_REGISTER)
- fprintf (file, " [%s]", reg_names[i]);
- fprintf (file, "(");
- EXECUTE_IF_SET_IN_BITMAP (r, first, j, bi)
- {
- if (j > first + len - 1)
- break;
- fprintf (file, "%s%d", sep, j-first);
- sep = ", ";
- }
- fprintf (file, ")");
- }
- }
- else
+ bool found = (bitmap_bit_p (r, 2 * i)
+ || bitmap_bit_p (r, 2 * i + 1));
+ if (found)
{
- if (bitmap_bit_p (r, first))
- {
- fprintf (file, " %d", i);
- if (i < FIRST_PSEUDO_REGISTER)
- fprintf (file, " [%s]", reg_names[i]);
- }
+ int word;
+ const char * sep = "";
+ fprintf (file, " %d", i);
+ fprintf (file, "(");
+ for (word = 0; word < 2; word++)
+ if (bitmap_bit_p (r, 2 * i + word))
+ {
+ fprintf (file, "%s%d", sep, word);
+ sep = ", ";
+ }
+ fprintf (file, ")");
}
-
}
}
fprintf (file, "\n");
OSDN Git Service
