return false;
}
-/* Update the PHI nodes of NEW_LOOP. NEW_LOOP is a duplicate of
- ORIG_LOOP. */
-
-static void
-update_phis_for_loop_copy (struct loop *orig_loop, struct loop *new_loop)
-{
- tree new_ssa_name;
- gimple_stmt_iterator si_new, si_orig;
- edge orig_loop_latch = loop_latch_edge (orig_loop);
- edge orig_entry_e = loop_preheader_edge (orig_loop);
- edge new_loop_entry_e = loop_preheader_edge (new_loop);
-
- /* Scan the phis in the headers of the old and new loops
- (they are organized in exactly the same order). */
- for (si_new = gsi_start_phis (new_loop->header),
- si_orig = gsi_start_phis (orig_loop->header);
- !gsi_end_p (si_new) && !gsi_end_p (si_orig);
- gsi_next (&si_new), gsi_next (&si_orig))
- {
- tree def;
- source_location locus;
- gimple phi_new = gsi_stmt (si_new);
- gimple phi_orig = gsi_stmt (si_orig);
-
- /* Add the first phi argument for the phi in NEW_LOOP (the one
- associated with the entry of NEW_LOOP) */
- def = PHI_ARG_DEF_FROM_EDGE (phi_orig, orig_entry_e);
- locus = gimple_phi_arg_location_from_edge (phi_orig, orig_entry_e);
- add_phi_arg (phi_new, def, new_loop_entry_e, locus);
-
- /* Add the second phi argument for the phi in NEW_LOOP (the one
- associated with the latch of NEW_LOOP) */
- def = PHI_ARG_DEF_FROM_EDGE (phi_orig, orig_loop_latch);
- locus = gimple_phi_arg_location_from_edge (phi_orig, orig_loop_latch);
-
- if (TREE_CODE (def) == SSA_NAME)
- {
- new_ssa_name = get_current_def (def);
-
- if (!new_ssa_name)
- /* This only happens if there are no definitions inside the
- loop. Use the the invariant in the new loop as is. */
- new_ssa_name = def;
- }
- else
- /* Could be an integer. */
- new_ssa_name = def;
-
- add_phi_arg (phi_new, new_ssa_name, loop_latch_edge (new_loop), locus);
- }
-}
-
/* Return a copy of LOOP placed before LOOP. */
static struct loop *
res = slpeel_tree_duplicate_loop_to_edge_cfg (loop, preheader);
gcc_assert (res != NULL);
free_original_copy_tables ();
-
- update_phis_for_loop_copy (loop, res);
- rename_variables_in_loop (res);
+ delete_update_ssa ();
return res;
}
/* Renames the variables in basic block BB. */
-void
+static void
rename_variables_in_bb (basic_block bb)
{
gimple_stmt_iterator gsi;
rename_use_op (use_p);
}
- FOR_EACH_EDGE (e, ei, bb->succs)
+ FOR_EACH_EDGE (e, ei, bb->preds)
{
- if (!flow_bb_inside_loop_p (loop, e->dest))
+ if (!flow_bb_inside_loop_p (loop, e->src))
continue;
- for (gsi = gsi_start_phis (e->dest); !gsi_end_p (gsi); gsi_next (&gsi))
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
rename_use_op (PHI_ARG_DEF_PTR_FROM_EDGE (gsi_stmt (gsi), e));
}
}
-/* Renames variables in new generated LOOP. */
-
-void
-rename_variables_in_loop (struct loop *loop)
-{
- unsigned i;
- basic_block *bbs;
-
- bbs = get_loop_body (loop);
-
- for (i = 0; i < loop->num_nodes; i++)
- rename_variables_in_bb (bbs[i]);
-
- free (bbs);
-}
-
typedef struct
{
tree from, to;
}
-/* Update the PHI nodes of NEW_LOOP.
-
- NEW_LOOP is a duplicate of ORIG_LOOP.
- AFTER indicates whether NEW_LOOP executes before or after ORIG_LOOP:
- AFTER is true if NEW_LOOP executes after ORIG_LOOP, and false if it
- executes before it. */
-
-static void
-slpeel_update_phis_for_duplicate_loop (struct loop *orig_loop,
- struct loop *new_loop, bool after)
-{
- tree new_ssa_name;
- gimple phi_new, phi_orig;
- tree def;
- edge orig_loop_latch = loop_latch_edge (orig_loop);
- edge orig_entry_e = loop_preheader_edge (orig_loop);
- edge new_loop_exit_e = single_exit (new_loop);
- edge new_loop_entry_e = loop_preheader_edge (new_loop);
- edge entry_arg_e = (after ? orig_loop_latch : orig_entry_e);
- gimple_stmt_iterator gsi_new, gsi_orig;
-
- /*
- step 1. For each loop-header-phi:
- Add the first phi argument for the phi in NEW_LOOP
- (the one associated with the entry of NEW_LOOP)
-
- step 2. For each loop-header-phi:
- Add the second phi argument for the phi in NEW_LOOP
- (the one associated with the latch of NEW_LOOP)
-
- step 3. Update the phis in the successor block of NEW_LOOP.
-
- case 1: NEW_LOOP was placed before ORIG_LOOP:
- The successor block of NEW_LOOP is the header of ORIG_LOOP.
- Updating the phis in the successor block can therefore be done
- along with the scanning of the loop header phis, because the
- header blocks of ORIG_LOOP and NEW_LOOP have exactly the same
- phi nodes, organized in the same order.
-
- case 2: NEW_LOOP was placed after ORIG_LOOP:
- The successor block of NEW_LOOP is the original exit block of
- ORIG_LOOP - the phis to be updated are the loop-closed-ssa phis.
- We postpone updating these phis to a later stage (when
- loop guards are added).
- */
-
-
- /* Scan the phis in the headers of the old and new loops
- (they are organized in exactly the same order). */
-
- for (gsi_new = gsi_start_phis (new_loop->header),
- gsi_orig = gsi_start_phis (orig_loop->header);
- !gsi_end_p (gsi_new) && !gsi_end_p (gsi_orig);
- gsi_next (&gsi_new), gsi_next (&gsi_orig))
- {
- source_location locus;
- phi_new = gsi_stmt (gsi_new);
- phi_orig = gsi_stmt (gsi_orig);
-
- /* step 1. */
- def = PHI_ARG_DEF_FROM_EDGE (phi_orig, entry_arg_e);
- locus = gimple_phi_arg_location_from_edge (phi_orig, entry_arg_e);
- add_phi_arg (phi_new, def, new_loop_entry_e, locus);
-
- /* step 2. */
- def = PHI_ARG_DEF_FROM_EDGE (phi_orig, orig_loop_latch);
- locus = gimple_phi_arg_location_from_edge (phi_orig, orig_loop_latch);
- if (TREE_CODE (def) != SSA_NAME)
- continue;
-
- new_ssa_name = get_current_def (def);
- if (!new_ssa_name)
- {
- /* This only happens if there are no definitions
- inside the loop. use the phi_result in this case. */
- new_ssa_name = PHI_RESULT (phi_new);
- }
-
- /* An ordinary ssa name defined in the loop. */
- add_phi_arg (phi_new, new_ssa_name, loop_latch_edge (new_loop), locus);
-
- /* Drop any debug references outside the loop, if they would
- become ill-formed SSA. */
- adjust_debug_stmts (def, NULL, single_exit (orig_loop)->dest);
-
- /* step 3 (case 1). */
- if (!after)
- {
- gcc_assert (new_loop_exit_e == orig_entry_e);
- adjust_phi_and_debug_stmts (phi_orig, new_loop_exit_e, new_ssa_name);
- }
- }
-}
-
-
/* Update PHI nodes for a guard of the LOOP.
Input:
bool at_exit;
bool was_imm_dom;
basic_block exit_dest;
- gimple phi;
- tree phi_arg;
edge exit, new_exit;
- gimple_stmt_iterator gsi;
- at_exit = (e == single_exit (loop));
+ exit = single_exit (loop);
+ at_exit = (e == exit);
if (!at_exit && e != loop_preheader_edge (loop))
return NULL;
- bbs = get_loop_body (loop);
+ bbs = XNEWVEC (basic_block, loop->num_nodes + 1);
+ get_loop_body_with_size (loop, bbs, loop->num_nodes);
/* Check whether duplication is possible. */
if (!can_copy_bbs_p (bbs, loop->num_nodes))
/* Generate new loop structure. */
new_loop = duplicate_loop (loop, loop_outer (loop));
- if (!new_loop)
- {
- free (bbs);
- return NULL;
- }
+ duplicate_subloops (loop, new_loop);
- exit_dest = single_exit (loop)->dest;
+ exit_dest = exit->dest;
was_imm_dom = (get_immediate_dominator (CDI_DOMINATORS,
exit_dest) == loop->header ?
true : false);
- new_bbs = XNEWVEC (basic_block, loop->num_nodes);
+ /* Also copy the pre-header, this avoids jumping through hoops to
+ duplicate the loop entry PHI arguments. Create an empty
+ pre-header unconditionally for this. */
+ basic_block preheader = split_edge (loop_preheader_edge (loop));
+ edge entry_e = single_pred_edge (preheader);
+ bbs[loop->num_nodes] = preheader;
+ new_bbs = XNEWVEC (basic_block, loop->num_nodes + 1);
- exit = single_exit (loop);
- copy_bbs (bbs, loop->num_nodes, new_bbs,
+ copy_bbs (bbs, loop->num_nodes + 1, new_bbs,
&exit, 1, &new_exit, NULL,
e->src);
+ basic_block new_preheader = new_bbs[loop->num_nodes];
- /* Duplicating phi args at exit bbs as coming
- also from exit of duplicated loop. */
- for (gsi = gsi_start_phis (exit_dest); !gsi_end_p (gsi); gsi_next (&gsi))
- {
- phi = gsi_stmt (gsi);
- phi_arg = PHI_ARG_DEF_FROM_EDGE (phi, single_exit (loop));
- if (phi_arg)
- {
- edge new_loop_exit_edge;
- source_location locus;
-
- locus = gimple_phi_arg_location_from_edge (phi, single_exit (loop));
- if (EDGE_SUCC (new_loop->header, 0)->dest == new_loop->latch)
- new_loop_exit_edge = EDGE_SUCC (new_loop->header, 1);
- else
- new_loop_exit_edge = EDGE_SUCC (new_loop->header, 0);
-
- add_phi_arg (phi, phi_arg, new_loop_exit_edge, locus);
- }
- }
+ add_phi_args_after_copy (new_bbs, loop->num_nodes + 1, NULL);
if (at_exit) /* Add the loop copy at exit. */
{
- redirect_edge_and_branch_force (e, new_loop->header);
- PENDING_STMT (e) = NULL;
- set_immediate_dominator (CDI_DOMINATORS, new_loop->header, e->src);
+ redirect_edge_and_branch_force (e, new_preheader);
+ flush_pending_stmts (e);
+ set_immediate_dominator (CDI_DOMINATORS, new_preheader, e->src);
if (was_imm_dom)
set_immediate_dominator (CDI_DOMINATORS, exit_dest, new_loop->header);
+
+ /* And remove the non-necessary forwarder again. Keep the other
+ one so we have a proper pre-header for the loop at the exit edge. */
+ redirect_edge_pred (single_succ_edge (preheader), single_pred (preheader));
+ delete_basic_block (preheader);
+ set_immediate_dominator (CDI_DOMINATORS, loop->header,
+ loop_preheader_edge (loop)->src);
}
else /* Add the copy at entry. */
{
- edge new_exit_e;
- edge entry_e = loop_preheader_edge (loop);
- basic_block preheader = entry_e->src;
-
- if (!flow_bb_inside_loop_p (new_loop,
- EDGE_SUCC (new_loop->header, 0)->dest))
- new_exit_e = EDGE_SUCC (new_loop->header, 0);
- else
- new_exit_e = EDGE_SUCC (new_loop->header, 1);
-
- redirect_edge_and_branch_force (new_exit_e, loop->header);
- PENDING_STMT (new_exit_e) = NULL;
- set_immediate_dominator (CDI_DOMINATORS, loop->header,
- new_exit_e->src);
-
- /* We have to add phi args to the loop->header here as coming
- from new_exit_e edge. */
- for (gsi = gsi_start_phis (loop->header);
- !gsi_end_p (gsi);
- gsi_next (&gsi))
- {
- phi = gsi_stmt (gsi);
- phi_arg = PHI_ARG_DEF_FROM_EDGE (phi, entry_e);
- if (phi_arg)
- add_phi_arg (phi, phi_arg, new_exit_e,
- gimple_phi_arg_location_from_edge (phi, entry_e));
- }
-
- redirect_edge_and_branch_force (entry_e, new_loop->header);
- PENDING_STMT (entry_e) = NULL;
- set_immediate_dominator (CDI_DOMINATORS, new_loop->header, preheader);
+ redirect_edge_and_branch_force (entry_e, new_preheader);
+ flush_pending_stmts (entry_e);
+ set_immediate_dominator (CDI_DOMINATORS, new_preheader, entry_e->src);
+
+ redirect_edge_and_branch_force (new_exit, preheader);
+ flush_pending_stmts (new_exit);
+ set_immediate_dominator (CDI_DOMINATORS, preheader, new_exit->src);
+
+ /* And remove the non-necessary forwarder again. Keep the other
+ one so we have a proper pre-header for the loop at the exit edge. */
+ redirect_edge_pred (single_succ_edge (new_preheader), single_pred (new_preheader));
+ delete_basic_block (new_preheader);
+ set_immediate_dominator (CDI_DOMINATORS, new_loop->header,
+ loop_preheader_edge (new_loop)->src);
}
+ for (unsigned i = 0; i < loop->num_nodes+1; i++)
+ rename_variables_in_bb (new_bbs[i]);
+
free (new_bbs);
free (bbs);
+#ifdef ENABLE_CHECKING
+ verify_dominators (CDI_DOMINATORS);
+#endif
+
return new_loop;
}
second_loop = loop;
}
- slpeel_update_phis_for_duplicate_loop (loop, new_loop, e == exit_e);
- rename_variables_in_loop (new_loop);
-
-
/* 2. Add the guard code in one of the following ways:
2.a Add the guard that controls whether the first loop is executed.
*/
bb_before_first_loop = split_edge (loop_preheader_edge (first_loop));
- bb_before_second_loop = split_edge (single_exit (first_loop));
+ /* Loop copying insterted a forwarder block for us here. */
+ bb_before_second_loop = single_exit (first_loop)->dest;
probability_of_second_loop = (inverse_probability (first_guard_probability)
+ combine_probabilities (second_guard_probability,
projects / platform / upstream / gcc.git / commitdiff