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