+2011-03-28 Jeff Law <law@redhat.com>
+
+ * tree-ssa-threadupdate.c (redirect_edges): Call
+ create_edge_and_update_destination_phis as needed.
+ (create_edge_and_update_destination_phis): Accept new BB argument.
+ All callers updated.
+ (thread_block): Do not update the profile when threading around
+ intermediate blocks.
+ (thread_single_edge): Likewise.
+ (determine_bb_domination_status): If BB is not a successor of the
+ loop header, return NONDOMINATING.
+ (register_jump_thread): Note when we register a jump thread around
+ an intermediate block.
+ * tree-ssa-threadedge.c (thread_around_empty_block): New function.
+ (thread_across_edge): Use it.
+
2011-03-28 Tristan Gingold <gingold@adacore.com>
* config/ia64/ia64.c (ia64_promote_function_mode): Fix promotion
+2011-03-28 Jeff Law <law@redhat.com>
+
+ * gcc.dg/tree-ssa/ssa-dom-thread-3.c: New test.
+
2011-03-28 Peter Bergner <bergner@vnet.ibm.com>
* gcc.dg/stack-usage-1.c (SIZE): Provide proper values for __PPC64__
--- /dev/null
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-dom1-details" } */
+extern void abort (void) __attribute__ ((__noreturn__));
+union tree_node;
+typedef union tree_node *tree;
+enum tree_code
+{
+ VAR_DECL,
+ SSA_NAME,
+ MAX_TREE_CODES
+};
+extern unsigned char tree_contains_struct[MAX_TREE_CODES][64];
+struct tree_base
+{
+ enum tree_code code:16;
+};
+enum tree_node_structure_enum
+{
+ TS_DECL_COMMON
+};
+struct tree_ssa_name
+{
+ tree var;
+};
+union tree_node
+{
+ struct tree_base base;
+ struct tree_ssa_name ssa_name;
+};
+long
+expand_one_var (tree var, unsigned char toplevel, unsigned char really_expand)
+{
+ tree origvar = var;
+ var = var->ssa_name.var;
+ if (((enum tree_code) (origvar)->base.code) == SSA_NAME
+ && !((var->base.code != VAR_DECL)))
+ abort ();
+ if ((var->base.code) != VAR_DECL && ((origvar)->base.code) != SSA_NAME)
+ ;
+ else if (tree_contains_struct[(var->base.code)][(TS_DECL_COMMON)] != 1)
+ abort ();
+}
+/* We should thread the jump, through an intermediate block. */
+/* { dg-final { scan-tree-dump-times "Threaded" 1 "dom1"} } */
+/* { dg-final { scan-tree-dump-times "one or more intermediate" 1 "dom1"} } */
+/* { dg-final { cleanup-tree-dump "dom1" } } */
+
return cached_lhs;
}
+/* TAKEN_EDGE represents the an edge taken as a result of jump threading.
+ See if we can thread around TAKEN_EDGE->dest as well. If so, return
+ the edge out of TAKEN_EDGE->dest that we can statically compute will be
+ traversed.
+
+ We are much more restrictive as to the contents of TAKEN_EDGE->dest
+ as the path isolation code in tree-ssa-threadupdate.c isn't prepared
+ to handle copying intermediate blocks on a threaded path.
+
+ Long term a more consistent and structured approach to path isolation
+ would be a huge help. */
+static edge
+thread_around_empty_block (edge taken_edge,
+ gimple dummy_cond,
+ bool handle_dominating_asserts,
+ tree (*simplify) (gimple, gimple),
+ bitmap visited)
+{
+ basic_block bb = taken_edge->dest;
+ gimple_stmt_iterator gsi;
+ gimple stmt;
+ tree cond;
+
+ /* This block must have a single predecessor (E->dest). */
+ if (!single_pred_p (bb))
+ return NULL;
+
+ /* This block must have more than one successor. */
+ if (single_succ_p (bb))
+ return NULL;
+
+ /* This block can have no PHI nodes. This is overly conservative. */
+ if (!gsi_end_p (gsi_start_phis (bb)))
+ return NULL;
+
+ /* Skip over DEBUG statements at the start of the block. */
+ gsi = gsi_start_nondebug_bb (bb);
+
+ if (gsi_end_p (gsi))
+ return NULL;
+
+ /* This block can have no statements other than its control altering
+ statement. This is overly conservative. */
+ stmt = gsi_stmt (gsi);
+ if (gimple_code (stmt) != GIMPLE_COND
+ && gimple_code (stmt) != GIMPLE_GOTO
+ && gimple_code (stmt) != GIMPLE_SWITCH)
+ return NULL;
+
+ /* Extract and simplify the condition. */
+ cond = simplify_control_stmt_condition (taken_edge, stmt, dummy_cond,
+ simplify, handle_dominating_asserts);
+
+ /* If the condition can be statically computed and we have not already
+ visited the destination edge, then add the taken edge to our thread
+ path. */
+ if (cond && is_gimple_min_invariant (cond))
+ {
+ edge taken_edge = find_taken_edge (bb, cond);
+
+ if (bitmap_bit_p (visited, taken_edge->dest->index))
+ return NULL;
+ bitmap_set_bit (visited, taken_edge->dest->index);
+ return taken_edge;
+ }
+
+ return NULL;
+}
+
+
/* We are exiting E->src, see if E->dest ends with a conditional
jump which has a known value when reached via E.
tree cond;
/* Extract and simplify the condition. */
- cond = simplify_control_stmt_condition (e, stmt, dummy_cond, simplify, handle_dominating_asserts);
+ cond = simplify_control_stmt_condition (e, stmt, dummy_cond, simplify,
+ handle_dominating_asserts);
if (cond && is_gimple_min_invariant (cond))
{
edge taken_edge = find_taken_edge (e->dest, cond);
basic_block dest = (taken_edge ? taken_edge->dest : NULL);
+ bitmap visited;
+ edge e2;
if (dest == e->dest)
goto fail;
+ /* DEST could be null for a computed jump to an absolute
+ address. If DEST is not null, then see if we can thread
+ through it as well, this helps capture secondary effects
+ of threading without having to re-run DOM or VRP. */
+ if (dest)
+ {
+ /* We don't want to thread back to a block we have already
+ visited. This may be overly conservative. */
+ visited = BITMAP_ALLOC (NULL);
+ bitmap_set_bit (visited, dest->index);
+ bitmap_set_bit (visited, e->dest->index);
+ do
+ {
+ e2 = thread_around_empty_block (taken_edge,
+ dummy_cond,
+ handle_dominating_asserts,
+ simplify,
+ visited);
+ if (e2)
+ taken_edge = e2;
+ }
+ while (e2);
+ BITMAP_FREE (visited);
+ }
+
remove_temporary_equivalences (stack);
register_jump_thread (e, taken_edge);
}
destination. */
static void
-create_edge_and_update_destination_phis (struct redirection_data *rd)
+create_edge_and_update_destination_phis (struct redirection_data *rd,
+ basic_block bb)
{
- edge e = make_edge (rd->dup_block, rd->outgoing_edge->dest, EDGE_FALLTHRU);
+ edge e = make_edge (bb, rd->outgoing_edge->dest, EDGE_FALLTHRU);
gimple_stmt_iterator gsi;
rescan_loop_exit (e, true, false);
e->probability = REG_BR_PROB_BASE;
- e->count = rd->dup_block->count;
+ e->count = bb->count;
e->aux = rd->outgoing_edge->aux;
/* If there are any PHI nodes at the destination of the outgoing edge
/* Go ahead and wire up outgoing edges and update PHIs for the duplicate
block. */
- create_edge_and_update_destination_phis (rd);
+ create_edge_and_update_destination_phis (rd, rd->dup_block);
}
/* Keep walking the hash table. */
and halt the hash table traversal. */
if (rd->dup_block && rd->dup_block == local_info->template_block)
{
- create_edge_and_update_destination_phis (rd);
+ create_edge_and_update_destination_phis (rd, rd->dup_block);
return 0;
}
remove_ctrl_stmt_and_useless_edges (local_info->bb,
rd->outgoing_edge->dest);
+ /* If we are threading beyond the immediate successors of
+ the duplicate, then BB will have no edges, create one. */
+ if (EDGE_COUNT (local_info->bb->succs) == 0)
+ create_edge_and_update_destination_phis (rd, local_info->bb);
+
/* Fixup the flags on the single remaining edge. */
single_succ_edge (local_info->bb)->flags
&= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE | EDGE_ABNORMAL);
continue;
}
- update_bb_profile_for_threading (e->dest, EDGE_FREQUENCY (e),
- e->count, (edge) e->aux);
+ if (e->dest == e2->src)
+ update_bb_profile_for_threading (e->dest, EDGE_FREQUENCY (e),
+ e->count, (edge) e->aux);
/* Insert the outgoing edge into the hash table if it is not
already in the hash table. */
}
/* Otherwise, we need to create a copy. */
- update_bb_profile_for_threading (bb, EDGE_FREQUENCY (e), e->count, eto);
+ if (e->dest == eto->src)
+ update_bb_profile_for_threading (bb, EDGE_FREQUENCY (e), e->count, eto);
rd.outgoing_edge = eto;
create_block_for_threading (bb, &rd);
- create_edge_and_update_destination_phis (&rd);
+ create_edge_and_update_destination_phis (&rd, rd.dup_block);
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, " Threaded jump %d --> %d to %d\n",
edge e;
#ifdef ENABLE_CHECKING
- /* This function assumes BB is a successor of LOOP->header. */
+ /* This function assumes BB is a successor of LOOP->header.
+ If that is not the case return DOMST_NONDOMINATING which
+ is always safe. */
{
bool ok = false;
}
}
- gcc_assert (ok);
+ if (!ok)
+ return DOMST_NONDOMINATING;
}
#endif
if (threaded_edges == NULL)
threaded_edges = VEC_alloc (edge, heap, 10);
+ if (dump_file && (dump_flags & TDF_DETAILS)
+ && e->dest != e2->src)
+ fprintf (dump_file,
+ " Registering jump thread around one or more intermediate blocks\n");
+
VEC_safe_push (edge, heap, threaded_edges, e);
VEC_safe_push (edge, heap, threaded_edges, e2);
}
projects / gcc.git / commitdiff