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

   1 /**
   2  * Author:      Daniel Grund
   3  * Date:                25.05.2005
   4  * Copyright:   (c) Universitaet Karlsruhe
   5  * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
   6  *
   7  * Performs SSA-Destruction.
   8  */
   9 #ifdef HAVE_CONFIG_H
  10 #include "config.h"
  11 #endif
  12
  13 #include "debug.h"
  14 #include "set.h"
  15 #include "pmap.h"
  16 #include "irnode.h"
  17 #include "iredges_t.h"
  18 #include "irdump.h"
  19 #include "be_t.h"
  20 #include "beutil.h"
  21 #include "bechordal_t.h"
  22 #include "bearch.h"
  23 #include "benode_t.h"
  24 #include "besched_t.h"
  25
  26 #define get_reg(irn) arch_get_irn_register(chordal_env->arch_env, irn, 0)
  27 #define set_reg(irn, reg) arch_set_irn_register(chordal_env->arch_env, irn, 0, reg)
  28
  29 /**
  30  * Maps blocks to perm nodes inserted during phi destruction.
  31  */
  32 typedef struct _block2perm_t {
  33         ir_node *block, *perm;
  34 } block2perm_t;
  35
  36 static int set_cmp_b2p(const void *x, const void *y, size_t size) {
  37         const block2perm_t *b1 = x;
  38         const block2perm_t *b2 = y;
  39         return b1->block != b2->block;
  40 }
  41
  42 #define is_Branch(irn)          (arch_irn_classify(arch_env, irn) == arch_irn_class_branch)
  43 #define is_Perm(irn)            (arch_irn_classify(arch_env, irn) == arch_irn_class_perm)
  44 #define get_reg_cls(irn)        (arch_get_irn_reg_class(arch_env, irn, arch_pos_make_out(0)))
  45 #define is_curr_reg_class(irn)  (get_reg_cls(p) == chordal_env->cls)
  46
  47 static ir_node *get_perm(be_main_session_env_t *session, be_chordal_env_t *chordal_env, ir_node *block) {
  48         block2perm_t find, *found;
  49         ir_node *p;
  50         set *b2p = chordal_env->data;
  51         const arch_env_t *arch_env = chordal_env->arch_env;
  52
  53         /* iff needed insert perm node */
  54
  55         /* .if the perm is in the pset return it */
  56         find.block = block;
  57         find.perm = NULL;
  58         found = set_insert(b2p, &find, sizeof(find), HASH_PTR(find.block));
  59         if (found->perm)
  60                 return found->perm;
  61
  62         /* .else look for a perm of right register class in the schedule */
  63         p = sched_last(find.block);
  64         while (!is_Block(p) && (is_Branch(p) || (is_Perm(p) && !is_curr_reg_class(p))))
  65                 p = sched_prev(p);
  66
  67         /* if we haven't found a perm of the right register class create a new one */
  68         if (! (is_Perm(p) && is_curr_reg_class(p)))
  69                 p = insert_Perm_after(session, chordal_env->cls, p);
  70
  71         /* insert perm into pset */
  72         found->perm = p;
  73         return p;
  74 }
  75
  76 /**
  77  * Adjusts the register allocation for the phi-operands
  78  * by inserting perm nodes, if necessary.
  79  * @param phi The phi node to adjust operands for
  80  */
  81 static void adjust_arguments(be_main_session_env_t *session, be_chordal_env_t *chordal_env, const ir_node *phi) {
  82         int i, max;
  83         ir_node *arg, *perm, *proj;
  84         const arch_register_t *phi_reg, *arg_reg, *proj_reg;
  85         const ir_edge_t *edge;
  86   ir_node *phi_block = get_nodes_block(phi);
  87
  88         assert(is_Phi(phi) && "Can only handle phi-destruction :)");
  89
  90         phi_reg = get_reg(phi);
  91         /* all arguments of the phi */
  92         for(i=0, max=get_irn_arity(phi); i<max; ++i) {
  93                 arg = get_irn_n(phi, i);
  94                 arg_reg = get_reg(arg);
  95                 /* if registers don't match ...*/
  96                 if (phi_reg != arg_reg) {
  97                         perm = get_perm(session, chordal_env, get_nodes_block(get_irn_n(phi_block, i)));
  98                         /* adjust assigned registers for the projs */
  99                         foreach_out_edge(perm, edge) {
 100                                 proj = get_edge_src_irn(edge);
 101                                 proj_reg = get_reg(proj);
 102                                 if (proj_reg == arg_reg)
 103                                         set_reg(proj, phi_reg);
 104                                 else if (proj_reg == phi_reg)
 105                                         set_reg(proj, arg_reg);
 106                         }
 107                 }
 108         }
 109 }
 110
 111 static void checker(be_chordal_env_t *chordal_env) {
 112         pmap_entry *pme;
 113         int i, max;
 114
 115         /* iterate over all blocks */
 116         pmap_foreach(chordal_env->border_heads, pme) {
 117                 border_t *curr;
 118                 struct list_head *head = pme->value;
 119
 120                 /* iterate over the first ops in the block */
 121                 list_for_each_entry_reverse(border_t, curr, head, list)
 122                         if (curr->is_def && curr->is_real && is_Phi(curr->irn)) {
 123                                 const arch_register_t *phi_reg, *arg_reg;
 124                                 if (!is_Phi(curr->irn))
 125                                         break;
 126
 127                                 phi_reg = get_reg(curr->irn);
 128                                 /* iterate over all args of phi */
 129                                 for(i=0, max=get_irn_arity(curr->irn); i<max; ++i) {
 130                                         arg_reg = get_reg(get_irn_n(curr->irn, i));
 131                                         assert(phi_reg == arg_reg && "WTF? You can do it better!?");
 132                                 }
 133                         }
 134         }
 135 }
 136
 137 void be_ssa_destruction(be_main_session_env_t *session, be_chordal_env_t *chordal_env) {
 138         pmap_entry *pme;
 139         set *b2p;
 140
 141         b2p = new_set(set_cmp_b2p, 32);
 142         chordal_env->data = b2p;
 143         /* iterate over all blocks */
 144         pmap_foreach(chordal_env->border_heads, pme) {
 145                 border_t *curr;
 146                 struct list_head *head = pme->value;
 147
 148                 /* iterate over the first ops in the block until a non-phi is reached */
 149                 list_for_each_entry_reverse(border_t, curr, head, list)
 150                         if (curr->is_def && curr->is_real) {
 151                                 if (!is_Phi(curr->irn))
 152                                         break;
 153                                 adjust_arguments(session, chordal_env, curr->irn);
 154                         }
 155         }
 156     dump_ir_block_graph_sched(session->irg, "-ssa-destr");
 157         del_set(b2p);
 158         checker(chordal_env);
 159 }