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 #ifdef HAVE_CONFIG_H
   8 #include <config.h>
   9 #endif
  10
  11 #include <stdlib.h>
  12
  13 #include "besched_t.h"
  14 #include "belistsched.h"
  15
  16 /**
  17  * The trivial selector:
  18  * Just assure that branches are executed last, otherwise select
  19  * the first node ready.
  20  */
  21 static ir_node *trivial_select(void *block_env, ir_nodeset_t *ready_set, ir_nodeset_t *live_set)
  22 {
  23         const arch_env_t *arch_env = block_env;
  24         ir_node          *irn      = NULL;
  25         ir_nodeset_iterator_t iter;
  26
  27         /* assure that branches and constants are executed last */
  28         foreach_ir_nodeset(ready_set, irn, iter) {
  29                 if (! arch_irn_class_is(arch_env, irn, branch)) {
  30                         return irn;
  31                 }
  32         }
  33
  34         /* at last: schedule branches */
  35         ir_nodeset_iterator_init(&iter, ready_set);
  36         irn = ir_nodeset_iterator_next(&iter);
  37
  38         return irn;
  39 }
  40
  41 static void *trivial_init_graph(const list_sched_selector_t *vtab, const arch_env_t *arch_env, ir_graph *irg)
  42 {
  43         return (void *)arch_env;
  44 }
  45
  46 static void *trivial_init_block(void *graph_env, ir_node *bl)
  47 {
  48         return graph_env;
  49 }
  50
  51 static const list_sched_selector_t trivial_selector_struct = {
  52         trivial_init_graph,
  53         trivial_init_block,
  54         trivial_select,
  55         NULL,                /* to_appear_in_schedule */
  56         NULL,                /* node_ready */
  57         NULL,                /* node_selected */
  58         NULL,                /* exectime */
  59         NULL,                /* latency */
  60         NULL,                /* finish_block */
  61         NULL                 /* finish_graph */
  62 };
  63
  64 const list_sched_selector_t *trivial_selector = &trivial_selector_struct;