+/*
+ * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
/**
- * Base routines for register allocation.
- * @author Sebastian Hack
- * @date 22.11.2004
+ * @file
+ * @brief Base routines for register allocation.
+ * @author Sebastian Hack
+ * @date 22.11.2004
+ * @version $Id$
*/
-#ifdef HAVE_CONFIG_H
#include "config.h"
-#endif
#include <stdlib.h>
#include "irnode.h"
#include "irmode.h"
#include "irdom.h"
+#include "iredges.h"
#include "bera.h"
#include "beutil.h"
#include "belive_t.h"
#include "bemodule.h"
-be_ra_timer_t *global_ra_timer = NULL;
-
-static INLINE
-sched_timestep_t get_time_step(const ir_node *irn)
-{
- if(is_Phi(irn))
- return 0;
-
- return sched_get_time_step(irn);
-}
-
-int value_dominates_intrablock(const ir_node *a, const ir_node *b)
-{
- sched_timestep_t as = get_time_step(a);
- sched_timestep_t bs = get_time_step(b);
-
- return as <= bs;
-}
-
-int value_dominates(const ir_node *a, const ir_node *b)
-{
- const ir_node *block_a = get_block(a);
- const ir_node *block_b = get_block(b);
-
- /*
- * a and b are not in the same block,
- * so dominance is determined by the dominance of the blocks.
- */
- if(block_a != block_b) {
- return block_dominates(block_a, block_b);
- }
-
- /*
- * Dominance is determined by the time steps of the schedule.
- */
- return value_dominates_intrablock(a, b);
-}
-
-/**
- * Check, if two values interfere.
- * @param a The first value.
- * @param b The second value.
- * @return 1, if a and b interfere, 0 if not.
- */
-int values_interfere(const be_lv_t *lv, const ir_node *a, const ir_node *b)
-{
- int a2b = value_dominates(a, b);
- int b2a = value_dominates(b, a);
-
- /* If there is no dominance relation, they do not interfere. */
- if((a2b | b2a) > 0) {
- const ir_edge_t *edge;
- ir_node *bb;
-
- /*
- * Adjust a and b so, that a dominates b if
- * a dominates b or vice versa.
- */
- if(b2a) {
- const ir_node *t = a;
- a = b;
- b = t;
- }
-
- bb = get_nodes_block(b);
-
- /*
- * If a is live end in b's block it is
- * live at b's definition (a dominates b)
- */
- if(be_is_live_end(lv, bb, a))
- return 1;
-
- /*
- * Look at all usages of a.
- * If there's one usage of a in the block of b, then
- * we check, if this use is dominated by b, if that's true
- * a and b interfere. Note that b must strictly dominate the user,
- * since if b is the last user of in the block, b and a do not
- * interfere.
- * Uses of a not in b's block can be disobeyed, because the
- * check for a being live at the end of b's block is already
- * performed.
- */
- foreach_out_edge(a, edge) {
- const ir_node *user = get_edge_src_irn(edge);
- if(get_nodes_block(user) == bb && !is_Phi(user) && b != user && value_dominates(b, user))
- return 1;
- }
- }
-
- return 0;
-}
-
/** The list of register allocators */
static be_module_list_entry_t *register_allocators = NULL;
static be_ra_t *selected_allocator = NULL;
projects / libfirm / blobdiff