better treatment of costs

[r15476]

diff --git a/ir/be/bespillbelady2.c b/ir/be/bespillbelady2.c
index 1ae5f18..e6e0bb8 100644 (file)
--- a/ir/be/bespillbelady2.c
+++ b/ir/be/bespillbelady2.c
@@ -679,9 +679,9 @@ static block_end_state_t *get_block_end_state(global_end_state_t *state, ir_node
        }
 }
 
-static double can_bring_in(global_end_state_t *ges, ir_node *bl, ir_node *irn, int level);
+static double can_bring_in(global_end_state_t *ges, ir_node *bl, ir_node *irn, double limit, int level);
 
-static double can_make_available_at_end(global_end_state_t *ges, ir_node *bl, ir_node *irn, int level)
+static double can_make_available_at_end(global_end_state_t *ges, ir_node *bl, ir_node *irn, double limit, int level)
 {
        block_end_state_t *bes = get_block_end_state(ges, bl, irn);
        workset_t *end         = bes->end_state;
@@ -790,7 +790,8 @@ static double can_make_available_at_end(global_end_state_t *ges, ir_node *bl, ir
                        rollback_info_t rb  = trans_begin(ges);
                        ir_node *ins_before = block_info_get_last_ins(bi);
                        double reload_here  = be_get_reload_costs(bi->bel->senv, irn, ins_before);
-                       double bring_in     = bi->pressure < n_regs ? can_bring_in(ges, bl, irn, level + 1) : HUGE_VAL;
+                       double new_limit    = MIN(reload_here, limit);
+                       double bring_in     = bi->pressure < n_regs ? can_bring_in(ges, bl, irn, new_limit, level + 1) : HUGE_VAL;
 
                        DBG((dbg, DBG_GLOBAL, "\t%2Dthere is a free slot. capacity=%d, reload here=%f, bring in=%f\n",
                                                level, n_regs - bi->pressure, reload_here, bring_in));
@@ -820,7 +821,7 @@ end:
        return bes->costs;
 }
 
-static double can_bring_in(global_end_state_t *ges, ir_node *bl, ir_node *irn, int level)
+static double can_bring_in(global_end_state_t *ges, ir_node *bl, ir_node *irn, double limit, int level)
 {
        double glob_costs = HUGE_VAL;
 
@@ -836,15 +837,15 @@ static double can_bring_in(global_end_state_t *ges, ir_node *bl, ir_node *irn, i
                for (i = 0; i < n; ++i) {
                        ir_node *pr = get_Block_cfgpred_block(bl, i);
                        ir_node *op = is_local_phi(bl, irn) ? get_irn_n(irn, i) : irn;
-                       double c    = can_make_available_at_end(ges, pr, op, level + 1);
+                       double c    = can_make_available_at_end(ges, pr, op, limit, level + 1);
 
-                       if (c >= HUGE_VAL) {
-                               trans_rollback(ges, &rb);
+                       glob_costs += c;
+
+                       if (glob_costs >= limit) {
                                glob_costs = HUGE_VAL;
+                               trans_rollback(ges, &rb);
                                goto end;
                        }
-
-                       glob_costs += c;
                }
        }
 
@@ -936,7 +937,7 @@ static void fix_block_borders(global_end_state_t *ges, ir_node *block) {
 
                DBG((dbg, DBG_GLOBAL, "\ttrans in var %+F, version %x\n", irn, ges->version));
 
-               bring_in_costs = can_bring_in(ges, block, irn, 1);
+               bring_in_costs = can_bring_in(ges, block, irn, local_costs, 1);
 
                DBG((dbg, DBG_GLOBAL, "\tbring in: %f, local: %f", bring_in_costs, local_costs));
 
@@ -945,8 +946,7 @@ static void fix_block_borders(global_end_state_t *ges, ir_node *block) {
                 * in a register at the entrance of the block
                 * or it is too costly, so we have to do the reload locally
                 */
-               if (bring_in_costs > local_costs) {
-
+               if (bring_in_costs >= local_costs) {
                        DBG((dbg, DBG_GLOBAL, " -> do local reload\n"));
                        be_add_reload(env->senv, irn, bi->first_non_in, env->cls, 1);
                } else {