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

   1 /**
   2  * Author:      Daniel Grund, Sebastian Hack
   3  * Date:                15.12.2005
   4  * Copyright:   (c) Universitaet Karlsruhe
   5  * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
   6  *
   7  */
   8 #ifdef HAVE_CONFIG_H
   9 #include "config.h"
  10 #endif
  11
  12 #include "irgraph_t.h"
  13 #include "irnode_t.h"
  14 #include "irgwalk.h"
  15
  16 #include "bearch.h"
  17 #include "belive_t.h"
  18 #include "benode_t.h"
  19 #include "besched_t.h"
  20 #include "beconstrperm.h"
  21
  22 static void check_constraints(const be_chordal_env_t *cenv, ir_node *base, ir_node *irn, ir_node **perm)
  23 {
  24         const arch_env_t *aenv    = cenv->main_env->arch_env;
  25         const be_main_env_t *menv = cenv->main_env;
  26         arch_register_req_t req;
  27         int pos, n;
  28
  29         assert(is_Proj(irn) || (base == irn));
  30
  31         for(pos = -1, n = get_irn_arity(irn); pos < n; ++pos) {
  32                 arch_get_register_req(aenv, &req, irn, pos);
  33
  34                 if(arch_irn_has_reg_class(aenv, irn, pos, cenv->cls)
  35                         && arch_register_req_is(&req, limited)
  36                         && !arch_irn_is_ignore(aenv, irn)) {
  37
  38                 /*
  39                 * If we inserted a perm,
  40                 * we have to recompute liveness analysis since inserting
  41                 * a Perm changes the liveness situation at the end
  42                 * of the block.
  43                 * (its needed by successive calls to insert_Perm_after)
  44                 * Perhaps thinking about an online liveness analysis
  45                 * would help.
  46                         */
  47                         if(*perm == NULL) {
  48                                 *perm = insert_Perm_after(aenv, cenv->cls, cenv->dom_front, sched_prev(base));
  49                                 be_liveness(cenv->irg);
  50                         }
  51
  52                         /*
  53                         * Turn an input constraint into an output constraint:
  54                         * The Proj of the Perm which corresponds to the input
  55                         * constraint will have the input constraint of the node
  56                         * as an output constraint
  57                         */
  58                         if(pos >= 0) {
  59                                 ir_node *op = get_irn_n(irn, pos);
  60
  61                                 /*
  62                                 * The operand must be a proj now, since a perm cut
  63                                 * all live ranges.
  64                                 */
  65                                 assert(is_Proj(op));
  66                                 be_set_Perm_out_req(*perm, get_Proj_proj(op), &req);
  67                         }
  68                 }
  69         }
  70 }
  71
  72 static void walker_insert_constr_perms(ir_node *bl, void *env) {
  73         be_chordal_env_t *cenv    = env;
  74         ir_node *irn;
  75
  76         for(irn = sched_first(bl); !sched_is_end(irn); irn = sched_next(irn)) {
  77                 ir_node *perm = NULL;
  78
  79                 if(get_irn_mode(irn) == mode_T) {
  80                         ir_node *proj;
  81
  82                         for(proj = sched_next(irn); is_Proj(proj); proj = sched_next(proj))
  83                                 check_constraints(cenv, irn, proj, &perm);
  84
  85                         irn = sched_prev(proj);
  86                 }
  87
  88                 else
  89                         check_constraints(cenv, irn, irn, &perm);
  90         }
  91 }
  92
  93 void be_insert_constr_perms(be_chordal_env_t *cenv) {
  94         irg_block_walk_graph(cenv->irg, walker_insert_constr_perms, NULL, cenv);
  95 }