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 "bechordal_t.h"
  16 #include "bearch.h"
  17
  18 #define get_reg(irn) arch_get_irn_register(chordal_env->arch_env, irn, arch_pos_make_out(0))
  19 #define set_reg(irn, reg) arch_set_irn_register(chordal_env->arch_env, irn, arch_pos_make_out(0), reg)
  20
  21 /**
  22  * Maps blocks to perm nodes inserted during phi destruction.
  23  */
  24 typedef struct _block2perm_t {
  25         ir_node *block, *perm;
  26 } block2perm_t;
  27
  28 static int set_cmp_b2p(const void *x, const void *y, size_t size) {
  29         const block2perm_t *b1 = x;
  30         const block2perm_t *b2 = y;
  31         return b1->block != b2->block;
  32 }
  33
  34 /**
  35  * Adjusts the register allocation for the phi-operands
  36  * by inserting perm nodes, if necessary.
  37  * @param phi The phi node to adjust operands for
  38  */
  39 static void adjust_arguments(be_chordal_env_t *chordal_env, const ir_node *phi) {
  40         int i, max;
  41         ir_node *arg, *perm, *proj;
  42         const arch_register_t *phi_reg, *arg_reg, *proj_reg;
  43         const ir_edge_t *edge;
  44         set *b2p;
  45         block2perm_t find, *found;
  46
  47         assert(is_Phi(phi) && "Can only handle phi-destruction :)");
  48
  49         b2p = chordal_env->data;
  50         phi_reg = get_reg(phi);
  51         /* all arguments of the phi */
  52         for(i=0, max=get_irn_arity(phi); i<max; ++i) {
  53                 arg = get_irn_n(phi, i);
  54                 arg_reg = get_reg(arg);
  55                 /* if registers don't match ...*/
  56                 if (phi_reg != arg_reg) {
  57                         /* iff needed insert perm node */
  58                         find.block = get_nodes_block(arg);
  59                         find.perm = NULL;
  60                         found = set_insert(b2p, &find, sizeof(find), HASH_PTR(find.block));
  61                         if (!found->perm)
  62                                 found->perm = insert_perm(TODO);
  63
  64                         /* now we have the perm in the predecessor block */
  65                         perm = found->perm;
  66                         /* adjust assigned registers for the projs */
  67                         foreach_out_edge(perm, edge) {
  68                                 proj = get_edge_src_irn(edge);
  69                                 proj_reg = get_reg(proj);
  70                                 if (proj_reg == arg_reg)
  71                                         set_reg(proj, phi_reg);
  72                                 else if (proj_reg == phi_reg)
  73                                         set_reg(proj, arg_reg);
  74                         }
  75                 }
  76         }
  77 }
  78
  79 static void checker(be_chordal_env_t *chordal_env) {
  80         pmap_entry *pme;
  81         int i, max;
  82
  83         /* iterate over all blocks */
  84         pmap_foreach(chordal_env->border_heads, pme) {
  85                 border_t *curr;
  86                 struct list_head *head = pme->value;
  87
  88                 /* iterate over all ops in the block */
  89                 list_for_each_entry_reverse(border_t, curr, head, list)
  90                         if (curr->is_def && curr->is_real && is_Phi(curr->irn)) {
  91                                 const arch_register_t *phi_reg, *arg_reg;
  92                                 phi_reg = get_reg(curr->irn);
  93                                 /* iterate over all args of phi */
  94                                 for(i=0, max=get_irn_arity(phi); i<max; ++i) {
  95                                         arg_reg = get_reg(get_irn_n(curr->irn, i));
  96                                         assert(phi_reg == arg_reg && "WTF? You can do it better!?");
  97                                 }
  98                         }
  99         }
 100 }
 101
 102 void be_ssa_destruction(be_chordal_env_t *chordal_env) {
 103         pmap_entry *pme;
 104         set *b2p;
 105
 106         b2p = new_set(set_cmp_b2p, 32);
 107         chordal_env->data = b2p;
 108         /* iterate over all blocks */
 109         pmap_foreach(chordal_env->border_heads, pme) {
 110                 border_t *curr;
 111                 struct list_head *head = pme->value;
 112
 113                 /* iterate over all ops in the block
 114                  * BETTER: phis are the first ops, so stop iteration on first non-phi-op */
 115                 list_for_each_entry_reverse(border_t, curr, head, list)
 116                         if (curr->is_def && curr->is_real && is_Phi(curr->irn))
 117                                 adjust_arguments(chordal_env, curr->irn);
 118         }
 119         del_set(b2p);
 120         checker(chordal_env);
 121 }