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 /**
  38  * Adjusts the register allocation for the phi-operands
  39  * by inserting perm nodes, if necessary.
  40  * @param phi The phi node to adjust operands for
  41  */
  42 static void adjust_arguments(be_main_session_env_t *session, be_chordal_env_t *chordal_env, const ir_node *phi) {
  43         int i, max;
  44         ir_node *arg, *perm, *proj;
  45         const arch_register_t *phi_reg, *arg_reg, *proj_reg;
  46         const ir_edge_t *edge;
  47         set *b2p;
  48         block2perm_t find, *found;
  49
  50         assert(is_Phi(phi) && "Can only handle phi-destruction :)");
  51
  52         b2p = chordal_env->data;
  53         phi_reg = get_reg(phi);
  54         /* all arguments of the phi */
  55         for(i=0, max=get_irn_arity(phi); i<max; ++i) {
  56                 arg = get_irn_n(phi, i);
  57                 arg_reg = get_reg(arg);
  58                 /* if registers don't match ...*/
  59                 if (phi_reg != arg_reg) {
  60                         /* iff needed insert perm node */
  61                         find.block = get_nodes_block(arg);
  62                         find.perm = NULL;
  63                         found = set_insert(b2p, &find, sizeof(find), HASH_PTR(find.block));
  64                         if (!found->perm)
  65                                 found->perm = insert_Perm_after(session, chordal_env->cls, sched_last(find.block));
  66
  67                         /* now we have the perm in the predecessor block */
  68                         perm = found->perm;
  69                         /* adjust assigned registers for the projs */
  70                         foreach_out_edge(perm, edge) {
  71                                 proj = get_edge_src_irn(edge);
  72                                 proj_reg = get_reg(proj);
  73                                 if (proj_reg == arg_reg)
  74                                         set_reg(proj, phi_reg);
  75                                 else if (proj_reg == phi_reg)
  76                                         set_reg(proj, arg_reg);
  77                         }
  78                 }
  79         }
  80 }
  81
  82 static void checker(be_chordal_env_t *chordal_env) {
  83         pmap_entry *pme;
  84         int i, max;
  85
  86         /* iterate over all blocks */
  87         pmap_foreach(chordal_env->border_heads, pme) {
  88                 border_t *curr;
  89                 struct list_head *head = pme->value;
  90
  91                 /* iterate over all ops in the block */
  92                 list_for_each_entry_reverse(border_t, curr, head, list)
  93                         if (curr->is_def && curr->is_real && is_Phi(curr->irn)) {
  94                                 const arch_register_t *phi_reg, *arg_reg;
  95                                 phi_reg = get_reg(curr->irn);
  96                                 /* iterate over all args of phi */
  97                                 for(i=0, max=get_irn_arity(curr->irn); i<max; ++i) {
  98                                         arg_reg = get_reg(get_irn_n(curr->irn, i));
  99                                         assert(phi_reg == arg_reg && "WTF? You can do it better!?");
 100                                 }
 101                         }
 102         }
 103 }
 104
 105 void be_ssa_destruction(be_main_session_env_t *session, be_chordal_env_t *chordal_env) {
 106         pmap_entry *pme;
 107         set *b2p;
 108
 109         b2p = new_set(set_cmp_b2p, 32);
 110         chordal_env->data = b2p;
 111         /* iterate over all blocks */
 112         pmap_foreach(chordal_env->border_heads, pme) {
 113                 border_t *curr;
 114                 struct list_head *head = pme->value;
 115
 116                 /* iterate over all ops in the block
 117                  * BETTER: phis are the first ops, so stop iteration on first non-phi-op */
 118                 list_for_each_entry_reverse(border_t, curr, head, list)
 119                         if (curr->is_def && curr->is_real && is_Phi(curr->irn))
 120                                 adjust_arguments(session, chordal_env, curr->irn);
 121         }
 122         del_set(b2p);
 123         checker(chordal_env);
 124 }