nsz Git - libfirm/blob - ir/be/beschedtrivial.c

   1 /**
   2  * Trivial node selector.
   3  * @author Christian Wuerdig
   4  * @date   29.08.2006
   5  * @cvs-id $Id$
   6  */
   7
   8 #include <stdlib.h>
   9
  10 #include "besched_t.h"
  11 #include "belistsched.h"
  12
  13 /**
  14  * The trivial selector:
  15  * Just assure that branches are executed last, otherwise select
  16  * the first node ready.
  17  */
  18 static ir_node *trivial_select(void *block_env, nodeset *ready_set, nodeset *live_set)
  19 {
  20         const arch_env_t *arch_env = block_env;
  21         ir_node          *irn      = NULL;
  22
  23         /* assure that branches and constants are executed last */
  24         for (irn = nodeset_first(ready_set); irn; irn = nodeset_next(ready_set)) {
  25                 if (! arch_irn_class_is(arch_env, irn, branch)) {
  26                         nodeset_break(ready_set);
  27                         return irn;
  28                 }
  29         }
  30
  31         /* at last: schedule branches */
  32         irn = nodeset_first(ready_set);
  33         nodeset_break(ready_set);
  34
  35         return irn;
  36 }
  37
  38 static void *trivial_init_graph(const list_sched_selector_t *vtab, const arch_env_t *arch_env, ir_graph *irg)
  39 {
  40         return (void *)arch_env;
  41 }
  42
  43 static void *trivial_init_block(void *graph_env, ir_node *bl)
  44 {
  45         return graph_env;
  46 }
  47
  48 static const list_sched_selector_t trivial_selector_struct = {
  49         trivial_init_graph,
  50         trivial_init_block,
  51         trivial_select,
  52         NULL,                /* to_appear_in_schedule */
  53         NULL,                /* node_ready */
  54         NULL,                /* node_selected */
  55         NULL,                /* exectime */
  56         NULL,                /* latency */
  57         NULL,                /* finish_block */
  58         NULL                 /* finish_graph */
  59 };
  60
  61 const list_sched_selector_t *trivial_selector = &trivial_selector_struct;