* @author Sebastian Hack
* @date 22.11.2004
*/
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
#include "pset.h"
#include "impl.h"
#include "irnode.h"
#include "irmode.h"
-#include "besched.h"
+#include "irdom.h"
-#include "bera_t.h"
+#include "beutil.h"
+#include "besched_t.h"
+#include "belive_t.h"
-FIRM_IMPL1(is_allocatable_irn, int, const ir_node *)
+static sched_timestep_t get_time_step(const ir_node *irn)
+{
+ if(is_Phi(irn))
+ return 0;
-size_t ra_irn_data_offset = 0;
-size_t ra_irg_data_offset = 0;
+ return sched_get_time_step(irn);
+}
-void be_ra_init(void)
+int value_dominates(const ir_node *a, const ir_node *b)
{
- ra_irn_data_offset = register_additional_node_data(sizeof(ra_info_t));
- ra_irg_data_offset = register_additional_graph_data(sizeof(void *));
+ int res = 0;
+ const ir_node *ba = get_block(a);
+ const ir_node *bb = get_block(b);
+
+ /*
+ * a and b are not in the same block,
+ * so dominance is determined by the dominance of the blocks.
+ */
+ if(ba != bb) {
+ res = block_dominates(ba, bb);
+
+ /*
+ * Dominance is determined by the time steps of the schedule.
+ */
+ } else {
+ sched_timestep_t as = get_time_step(a);
+ sched_timestep_t bs = get_time_step(b);
+ res = as <= bs;
+ }
+
+ return res;
+}
+
+/**
+ * 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;
}