#include "irmode.h"
#include "irdom.h"
+#include "beutil.h"
#include "besched_t.h"
#include "belive_t.h"
+static 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(const ir_node *a, const ir_node *b)
{
- int res = 0;
- const ir_node *ba = get_nodes_block(a);
- const ir_node *bb = get_nodes_block(a);
+ 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);
+ /*
+ * 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 = sched_get_time_step(a);
- sched_timestep_t bs = sched_get_time_step(b);
- res = as <= bs;
- }
+ /*
+ * 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;
+ return res;
}
/**
* @param b The second value.
* @return 1, if a and b interfere, 0 if not.
*/
-int values_interfere(const ir_node *a, const ir_node *b)
+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);
-
- /*
- * 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;
- }
+ int a2b = value_dominates(a, b);
+ int b2a = value_dominates(b, a);
- /*
- * If either a dmoninates b or vice versa
- * check if there is usage which is dominated by b.
- *
- * remind, that if a and b are in a dom relation, a always dominates b
- * here due to the if above.
- */
- if(a2b + b2a) {
- const ir_edge_t *edge;
+ /* If there is no dominance relation, they do not interfere. */
+ if((a2b | b2a) > 0) {
+ const ir_edge_t *edge;
+ ir_node *bb;
- /* Look at all usages of a */
- foreach_out_edge(a, edge) {
- const ir_node *user = edge->src;
+ /*
+ * 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;
+ }
- /*
- * If the user is a phi we must check the last instruction in the
- * corresponding phi predecessor block since the phi is not a
- * proper user.
- */
- if(is_Phi(user)) {
- ir_node *phi_block = get_nodes_block(user);
- user = sched_last(get_Block_cfgpred_block(phi_block, edge->pos));
- }
+ bb = get_nodes_block(b);
- /* If b dominates a user of a, we can safely return 1 here. */
- if(value_dominates(b, user))
- return 1;
- }
+ /*
+ * 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;
}