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