#include "cfglayout.h"
#include "hashtab.h"
#include "tree-ssa-propagate.h"
+#include "tree-scalar-evolution.h"
/* Remove any fallthru edge from EV. Return true if an edge was removed. */
else
taken_edge = single_succ_edge (bb);
- bsi_remove (&bsi);
+ bsi_remove (&bsi, true);
taken_edge->flags = EDGE_FALLTHRU;
/* We removed some paths from the cfg. */
{
bsi = bsi_last (bb);
+ /* If the last statement of the block could throw and now cannot,
+ we need to prune cfg. */
+ retval |= tree_purge_dead_eh_edges (bb);
+
if (bsi_end_p (bsi))
continue;
stmt = bsi_stmt (bsi);
+
if (TREE_CODE (stmt) == COND_EXPR
|| TREE_CODE (stmt) == SWITCH_EXPR)
retval |= cleanup_control_expr_graph (bb, bsi);
-
/* If we had a computed goto which has a compile-time determinable
destination, then we can eliminate the goto. */
- if (TREE_CODE (stmt) == GOTO_EXPR
- && TREE_CODE (GOTO_DESTINATION (stmt)) == ADDR_EXPR
- && TREE_CODE (TREE_OPERAND (GOTO_DESTINATION (stmt), 0)) == LABEL_DECL)
+ else if (TREE_CODE (stmt) == GOTO_EXPR
+ && TREE_CODE (GOTO_DESTINATION (stmt)) == ADDR_EXPR
+ && (TREE_CODE (TREE_OPERAND (GOTO_DESTINATION (stmt), 0))
+ == LABEL_DECL))
{
edge e;
tree label;
/* Remove the GOTO_EXPR as it is not needed. The CFG has all the
relevant information we need. */
- bsi_remove (&bsi);
+ bsi_remove (&bsi, true);
retval = true;
}
/* Check for indirect calls that have been turned into
noreturn calls. */
- if (noreturn_call_p (stmt) && remove_fallthru_edge (bb->succs))
+ else if (noreturn_call_p (stmt) && remove_fallthru_edge (bb->succs))
{
free_dominance_info (CDI_DOMINATORS);
retval = true;
tree_forwarder_block_p (basic_block bb, bool phi_wanted)
{
block_stmt_iterator bsi;
+ edge_iterator ei;
+ edge e, succ;
+ basic_block dest;
/* BB must have a single outgoing edge. */
if (single_succ_p (bb) != 1
return false;
}
+ /* If we have an EH edge leaving this block, make sure that the
+ destination of this block has only one predecessor. This ensures
+ that we don't get into the situation where we try to remove two
+ forwarders that go to the same basic block but are handlers for
+ different EH regions. */
+ succ = single_succ_edge (bb);
+ dest = succ->dest;
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ {
+ if (e->flags & EDGE_EH)
+ {
+ if (!single_pred_p (dest))
+ return false;
+ }
+ }
+
return true;
}
{
label = bsi_stmt (bsi);
gcc_assert (TREE_CODE (label) == LABEL_EXPR);
- bsi_remove (&bsi);
+ bsi_remove (&bsi, false);
bsi_insert_before (&bsi_to, label, BSI_CONTINUE_LINKING);
}
}
{
basic_block bb;
bool changed = false;
- basic_block *worklist = xmalloc (sizeof (basic_block) * n_basic_blocks);
+ basic_block *worklist = XNEWVEC (basic_block, n_basic_blocks);
basic_block *current = worklist;
FOR_EACH_BB (bb)
void
cleanup_tree_cfg_loop (void)
{
- bitmap changed_bbs = BITMAP_ALLOC (NULL);
-
- cleanup_tree_cfg ();
+ bool changed = cleanup_tree_cfg ();
- fix_loop_structure (current_loops, changed_bbs);
- calculate_dominance_info (CDI_DOMINATORS);
+ if (changed)
+ {
+ bitmap changed_bbs = BITMAP_ALLOC (NULL);
+ fix_loop_structure (current_loops, changed_bbs);
+ calculate_dominance_info (CDI_DOMINATORS);
- /* This usually does nothing. But sometimes parts of cfg that originally
- were inside a loop get out of it due to edge removal (since they
- become unreachable by back edges from latch). */
- rewrite_into_loop_closed_ssa (changed_bbs, TODO_update_ssa);
+ /* This usually does nothing. But sometimes parts of cfg that originally
+ were inside a loop get out of it due to edge removal (since they
+ become unreachable by back edges from latch). */
+ rewrite_into_loop_closed_ssa (changed_bbs, TODO_update_ssa);
- BITMAP_FREE (changed_bbs);
+ BITMAP_FREE (changed_bbs);
#ifdef ENABLE_CHECKING
- verify_loop_structure (current_loops);
+ verify_loop_structure (current_loops);
#endif
+ scev_reset ();
+ }
}
/* Merge the PHI nodes at BB into those at BB's sole successor. */
<L10>:;
*/
-static void
+static unsigned int
merge_phi_nodes (void)
{
- basic_block *worklist = xmalloc (sizeof (basic_block) * n_basic_blocks);
+ basic_block *worklist = XNEWVEC (basic_block, n_basic_blocks);
basic_block *current = worklist;
basic_block bb;
nodes at BB. */
*current++ = bb;
}
+ else
+ {
+ tree phi;
+ unsigned int dest_idx = single_succ_edge (bb)->dest_idx;
+
+ /* BB dominates DEST. There may be many users of the PHI
+ nodes in BB. However, there is still a trivial case we
+ can handle. If the result of every PHI in BB is used
+ only by a PHI in DEST, then we can trivially merge the
+ PHI nodes from BB into DEST. */
+ for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
+ {
+ tree result = PHI_RESULT (phi);
+ use_operand_p imm_use;
+ tree use_stmt;
+
+ /* If the PHI's result is never used, then we can just
+ ignore it. */
+ if (has_zero_uses (result))
+ continue;
+
+ /* Get the single use of the result of this PHI node. */
+ if (!single_imm_use (result, &imm_use, &use_stmt)
+ || TREE_CODE (use_stmt) != PHI_NODE
+ || bb_for_stmt (use_stmt) != dest
+ || PHI_ARG_DEF (use_stmt, dest_idx) != result)
+ break;
+ }
+
+ /* If the loop above iterated through all the PHI nodes
+ in BB, then we can merge the PHIs from BB into DEST. */
+ if (!phi)
+ *current++ = bb;
+ }
}
/* Now let's drain WORKLIST. */
}
free (worklist);
+ return 0;
}
static bool
OSDN Git Service
