[libfirm] / ir / be / bessadestr.c

/**
 * Author:      Daniel Grund
 * Date:                25.05.2005
 * Copyright:   (c) Universitaet Karlsruhe
 * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
 *
 * Performs SSA-Destruction.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "debug.h"
#include "set.h"
#include "pmap.h"
#include "irnode.h"
#include "iredges_t.h"
#include "irdump.h"
#include "irprintf.h"

#include "be_t.h"
#include "beutil.h"
#include "bechordal_t.h"
#include "bearch.h"
#include "benode_t.h"
#include "besched_t.h"

#define get_reg(irn) arch_get_irn_register(chordal_env->arch_env, irn, 0)
#define set_reg(irn, reg) arch_set_irn_register(chordal_env->arch_env, irn, 0, reg)

/**
 * Maps blocks to perm nodes inserted during phi destruction.
 */
typedef struct _block2perm_t {
  ir_node *block, *perm;
} block2perm_t;

static int set_cmp_b2p(const void *x, const void *y, size_t size) {
  const block2perm_t *b1 = x;
  const block2perm_t *b2 = y;
  return b1->block != b2->block;
}

#define is_Branch(irn)          (arch_irn_classify(arch_env, irn) == arch_irn_class_branch)
#define is_Perm(irn)            (arch_irn_classify(arch_env, irn) == arch_irn_class_perm)
#define get_reg_cls(irn)        (arch_get_irn_reg_class(arch_env, irn, arch_pos_make_out(0)))
#define is_curr_reg_class(irn)  (get_reg_cls(p) == chordal_env->cls)

static ir_node *get_perm(be_main_session_env_t *session, be_chordal_env_t *chordal_env, ir_node *block) {
  block2perm_t find, *found;
  ir_node *p;
  set *b2p = chordal_env->data;
  const arch_env_t *arch_env = chordal_env->arch_env;

  /* iff needed insert perm node */

  /* .if the perm is in the pset return it */
  find.block = block;
  find.perm = NULL;
  found = set_insert(b2p, &find, sizeof(find), HASH_PTR(find.block));
  if (found->perm)
    return found->perm;

  /* .else look for a perm of right register class in the schedule */
  p = sched_last(find.block);
  while (!is_Block(p) && (is_Branch(p) || (is_Perm(p) && !is_curr_reg_class(p))))
    p = sched_prev(p);

  /* if we haven't found a perm of the right register class create a new one */
  if (! (is_Perm(p) && is_curr_reg_class(p)))
                p = insert_Perm_after(session, chordal_env->cls, p);

        /* insert perm into pset */
        found->perm = p;
        return p;
}

/**
 * Adjusts the register allocation for the phi-operands
 * by inserting perm nodes, if necessary.
 * @param phi The phi node to adjust operands for
 */
static void adjust_arguments(be_main_session_env_t *session, be_chordal_env_t *chordal_env, const ir_node *phi) {
        int i, max;
        ir_node *arg;
        const arch_register_t *phi_reg, *arg_reg, *proj_reg;
        const ir_edge_t *edge;
  ir_node *phi_block = get_nodes_block(phi);

        assert(is_Phi(phi) && "Can only handle phi-destruction :)");

        phi_reg = get_reg(phi);
        /* all arguments of the phi */
        for(i=0, max=get_irn_arity(phi); i<max; ++i) {
                arg = get_irn_n(phi, i);
                arg_reg = get_reg(arg);
                /* if registers don't match ...*/
                if (phi_reg != arg_reg) {
      ir_node *perm;

                        perm = get_perm(session, chordal_env, get_nodes_block(get_irn_n(phi_block, i)));

                        /*
       * Look at the projs of the perm.
       * Find the one which corresponds to the phi argument
       * This is done via the proj number: If
       * the i-th argument of the perm is the old Phi
       * argument, then the Proj with number i is the
       * one we want.
       */
                        foreach_out_edge(perm, edge) {
                                ir_node *proj = get_edge_src_irn(edge);
        int proj_nr = get_Proj_proj(proj);

        if(get_irn_n(perm, proj_nr) == arg) {
          assert(get_reg(proj) == NULL);
          set_reg(proj, phi_reg);
        }
                        }
                }
        }
}

static void checker(be_chordal_env_t *chordal_env) {
  pmap_entry *pme;
  int i, max;

  /* iterate over all blocks */
  pmap_foreach(chordal_env->border_heads, pme) {
    border_t *curr;
    struct list_head *head = pme->value;

    /* iterate over the first ops in the block */
    list_for_each_entry_reverse(border_t, curr, head, list)
      if (curr->is_def && curr->is_real && is_Phi(curr->irn)) {
        const arch_register_t *phi_reg, *arg_reg;
        if (!is_Phi(curr->irn))
          break;

        phi_reg = get_reg(curr->irn);
        /* iterate over all args of phi */
        for(i=0, max=get_irn_arity(curr->irn); i<max; ++i) {
          arg_reg = get_reg(get_irn_n(curr->irn, i));
          if(phi_reg != arg_reg)
            ir_printf("register differ: %s %s\n", phi_reg->name, arg_reg->name);
        }
      }
  }
}

void be_ssa_destruction(be_main_session_env_t *session, be_chordal_env_t *chordal_env) {
        pmap_entry *pme;
        set *b2p;

        b2p = new_set(set_cmp_b2p, 32);
        chordal_env->data = b2p;
        /* iterate over all blocks */
        pmap_foreach(chordal_env->border_heads, pme) {
                border_t *curr;
                struct list_head *head = pme->value;

                /* iterate over the first ops in the block until a non-phi is reached */
                list_for_each_entry_reverse(border_t, curr, head, list)
                        if (curr->is_def && curr->is_real) {
                                if (!is_Phi(curr->irn))
                                        break;
                                adjust_arguments(session, chordal_env, curr->irn);
                        }
        }
    dump_ir_block_graph_sched(session->irg, "-ssa-destr");
        del_set(b2p);
        checker(chordal_env);
}