Subversion Repositories openrisc_2011-10-31

/* IRA conflict builder.

   Copyright (C) 2006, 2007, 2008, 2009, 2010

   Free Software Foundation, Inc.

   Contributed by Vladimir Makarov <vmakarov@redhat.com>.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under

the terms of the GNU General Public License as published by the Free

Software Foundation; either version 3, or (at your option) any later

version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY

WARRANTY; without even the implied warranty of MERCHANTABILITY or

FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

for more details.

You should have received a copy of the GNU General Public License

along with GCC; see the file COPYING3.  If not see

<http://www.gnu.org/licenses/>.  */

#include "config.h"

#include "system.h"

#include "coretypes.h"

#include "tm.h"

#include "regs.h"

#include "rtl.h"

#include "tm_p.h"

#include "target.h"

#include "flags.h"

#include "hard-reg-set.h"

#include "basic-block.h"

#include "insn-config.h"

#include "recog.h"

#include "toplev.h"

#include "params.h"

#include "df.h"

#include "sparseset.h"

#include "ira-int.h"

#include "addresses.h"

/* This file contains code responsible for allocno conflict creation,

   allocno copy creation and allocno info accumulation on upper level

   regions.  */

/* ira_allocnos_num array of arrays of bits, recording whether two

   allocno's conflict (can't go in the same hardware register).

   Some arrays will be used as conflict bit vector of the

   corresponding allocnos see function build_allocno_conflicts.  */

static IRA_INT_TYPE **conflicts;

/* Macro to test a conflict of A1 and A2 in `conflicts'.  */

#define CONFLICT_ALLOCNO_P(A1, A2)                                      \

  (ALLOCNO_MIN (A1) <= ALLOCNO_CONFLICT_ID (A2)                         \

   && ALLOCNO_CONFLICT_ID (A2) <= ALLOCNO_MAX (A1)                      \

   && TEST_ALLOCNO_SET_BIT (conflicts[ALLOCNO_NUM (A1)],                \

                            ALLOCNO_CONFLICT_ID (A2),                   \

                            ALLOCNO_MIN (A1),                           \

                            ALLOCNO_MAX (A1)))

/* Build allocno conflict table by processing allocno live ranges.

   Return true if the table was built.  The table is not built if it

   is too big.  */

static bool

build_conflict_bit_table (void)

{

  int i, num, id, allocated_words_num, conflict_bit_vec_words_num;

  unsigned int j;

  enum reg_class cover_class;

  ira_allocno_t allocno, live_a;

  allocno_live_range_t r;

  ira_allocno_iterator ai;

  sparseset allocnos_live;

  int allocno_set_words;

  allocno_set_words = (ira_allocnos_num + IRA_INT_BITS - 1) / IRA_INT_BITS;

  allocated_words_num = 0;

  FOR_EACH_ALLOCNO (allocno, ai)

    {

      if (ALLOCNO_MAX (allocno) < ALLOCNO_MIN (allocno))

          continue;

      conflict_bit_vec_words_num

        = ((ALLOCNO_MAX (allocno) - ALLOCNO_MIN (allocno) + IRA_INT_BITS)

           / IRA_INT_BITS);

      allocated_words_num += conflict_bit_vec_words_num;

      if ((unsigned long long) allocated_words_num * sizeof (IRA_INT_TYPE)

          > (unsigned long long) IRA_MAX_CONFLICT_TABLE_SIZE * 1024 * 1024)

        {

          if (internal_flag_ira_verbose > 0 && ira_dump_file != NULL)

            fprintf

              (ira_dump_file,

               "+++Conflict table will be too big(>%dMB) -- don't use it\n",

               IRA_MAX_CONFLICT_TABLE_SIZE);

          return false;

        }

    }

  allocnos_live = sparseset_alloc (ira_allocnos_num);

  conflicts = (IRA_INT_TYPE **) ira_allocate (sizeof (IRA_INT_TYPE *)

                                              * ira_allocnos_num);

  allocated_words_num = 0;

  FOR_EACH_ALLOCNO (allocno, ai)

    {

      num = ALLOCNO_NUM (allocno);

      if (ALLOCNO_MAX (allocno) < ALLOCNO_MIN (allocno))

        {

          conflicts[num] = NULL;

          continue;

        }

      conflict_bit_vec_words_num

        = ((ALLOCNO_MAX (allocno) - ALLOCNO_MIN (allocno) + IRA_INT_BITS)

           / IRA_INT_BITS);

      allocated_words_num += conflict_bit_vec_words_num;

      conflicts[num]

        = (IRA_INT_TYPE *) ira_allocate (sizeof (IRA_INT_TYPE)

                                         * conflict_bit_vec_words_num);

      memset (conflicts[num], 0,

              sizeof (IRA_INT_TYPE) * conflict_bit_vec_words_num);

    }

  if (internal_flag_ira_verbose > 0 && ira_dump_file != NULL)

    fprintf

      (ira_dump_file,

       "+++Allocating %ld bytes for conflict table (uncompressed size %ld)\n",

       (long) allocated_words_num * sizeof (IRA_INT_TYPE),

       (long) allocno_set_words * ira_allocnos_num * sizeof (IRA_INT_TYPE));

  for (i = 0; i < ira_max_point; i++)

    {

      for (r = ira_start_point_ranges[i]; r != NULL; r = r->start_next)

        {

          allocno = r->allocno;

          num = ALLOCNO_NUM (allocno);

          id = ALLOCNO_CONFLICT_ID (allocno);

          cover_class = ALLOCNO_COVER_CLASS (allocno);

          sparseset_set_bit (allocnos_live, num);

          EXECUTE_IF_SET_IN_SPARSESET (allocnos_live, j)

            {

              live_a = ira_allocnos[j];

              if (ira_reg_classes_intersect_p

                  [cover_class][ALLOCNO_COVER_CLASS (live_a)]

                  /* Don't set up conflict for the allocno with itself.  */

                  && num != (int) j)

                {

                  SET_ALLOCNO_SET_BIT (conflicts[num],

                                       ALLOCNO_CONFLICT_ID (live_a),

                                       ALLOCNO_MIN (allocno),

                                       ALLOCNO_MAX (allocno));

                  SET_ALLOCNO_SET_BIT (conflicts[j], id,

                                       ALLOCNO_MIN (live_a),

                                       ALLOCNO_MAX (live_a));

                }

            }

        }

      for (r = ira_finish_point_ranges[i]; r != NULL; r = r->finish_next)

        sparseset_clear_bit (allocnos_live, ALLOCNO_NUM (r->allocno));

    }

  sparseset_free (allocnos_live);

  return true;

}

/* Return TRUE if the operand constraint STR is commutative.  */

static bool

commutative_constraint_p (const char *str)

{

  bool ignore_p;

  int c;

  for (ignore_p = false;;)

    {

      c = *str;

      if (c == '\0')

        break;

      str += CONSTRAINT_LEN (c, str);

      if (c == '#')

        ignore_p = true;

      else if (c == ',')

        ignore_p = false;

      else if (! ignore_p)

        {

          /* Usually `%' is the first constraint character but the

             documentation does not require this.  */

          if (c == '%')

            return true;

        }

    }

  return false;

}

/* Return the number of the operand which should be the same in any

   case as operand with number OP_NUM (or negative value if there is

   no such operand).  If USE_COMMUT_OP_P is TRUE, the function makes

   temporarily commutative operand exchange before this.  The function

   takes only really possible alternatives into consideration.  */

static int

get_dup_num (int op_num, bool use_commut_op_p)

{

  int curr_alt, c, original, dup;

  bool ignore_p, commut_op_used_p;

  const char *str;

  rtx op;

  if (op_num < 0 || recog_data.n_alternatives == 0)

    return -1;

  op = recog_data.operand[op_num];

  commut_op_used_p = true;

  if (use_commut_op_p)

    {

      if (commutative_constraint_p (recog_data.constraints[op_num]))

        op_num++;

      else if (op_num > 0 && commutative_constraint_p (recog_data.constraints

                                                       [op_num - 1]))

        op_num--;

      else

        commut_op_used_p = false;

    }

  str = recog_data.constraints[op_num];

  for (ignore_p = false, original = -1, curr_alt = 0;;)

    {

      c = *str;

      if (c == '\0')

        break;

      if (c == '#')

        ignore_p = true;

      else if (c == ',')

        {

          curr_alt++;

          ignore_p = false;

        }

      else if (! ignore_p)

        switch (c)

          {

          case 'X':

            return -1;

          case 'm':

          case 'o':

            /* Accept a register which might be placed in memory.  */

            return -1;

            break;

          case 'V':

          case '<':

          case '>':

            break;

          case 'p':

            if (address_operand (op, VOIDmode))

              return -1;

            break;

          case 'g':

            return -1;

          case 'r':

          case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':

          case 'h': case 'j': case 'k': case 'l':

          case 'q': case 't': case 'u':

          case 'v': case 'w': case 'x': case 'y': case 'z':

          case 'A': case 'B': case 'C': case 'D':

          case 'Q': case 'R': case 'S': case 'T': case 'U':

          case 'W': case 'Y': case 'Z':

            {

              enum reg_class cl;

              cl = (c == 'r'

                    ? GENERAL_REGS : REG_CLASS_FROM_CONSTRAINT (c, str));

              if (cl != NO_REGS)

                return -1;

#ifdef EXTRA_CONSTRAINT_STR

              else if (EXTRA_CONSTRAINT_STR (op, c, str))

                return -1;

#endif

              break;

            }

          case '0': case '1': case '2': case '3': case '4':

          case '5': case '6': case '7': case '8': case '9':

            if (original != -1 && original != c)

              return -1;

            original = c;

            break;

          }

      str += CONSTRAINT_LEN (c, str);

    }

  if (original == -1)

    return -1;

  dup = original - '0';

  if (use_commut_op_p)

    {

      if (commutative_constraint_p (recog_data.constraints[dup]))

        dup++;

      else if (dup > 0

               && commutative_constraint_p (recog_data.constraints[dup -1]))

        dup--;

      else if (! commut_op_used_p)

        return -1;

    }

  return dup;

}

/* Check that X is REG or SUBREG of REG.  */

#define REG_SUBREG_P(x)                                                 \

   (REG_P (x) || (GET_CODE (x) == SUBREG && REG_P (SUBREG_REG (x))))

/* Return X if X is a REG, otherwise it should be SUBREG of REG and

   the function returns the reg in this case.  *OFFSET will be set to

static rtx

go_through_subreg (rtx x, int *offset)

{

  rtx reg;

  *offset = 0;

  if (REG_P (x))

    return x;

  ira_assert (GET_CODE (x) == SUBREG);

  reg = SUBREG_REG (x);

  ira_assert (REG_P (reg));

  if (REGNO (reg) < FIRST_PSEUDO_REGISTER)

    *offset = subreg_regno_offset (REGNO (reg), GET_MODE (reg),

                                   SUBREG_BYTE (x), GET_MODE (x));

  else

    *offset = (SUBREG_BYTE (x) / REGMODE_NATURAL_SIZE (GET_MODE (x)));

  return reg;

}

/* Process registers REG1 and REG2 in move INSN with execution

   frequency FREQ.  The function also processes the registers in a

   potential move insn (INSN == NULL in this case) with frequency

   FREQ.  The function can modify hard register costs of the

   corresponding allocnos or create a copy involving the corresponding

   allocnos.  The function does nothing if the both registers are hard

   registers.  When nothing is changed, the function returns

   FALSE.  */

static bool

process_regs_for_copy (rtx reg1, rtx reg2, bool constraint_p,

                       rtx insn, int freq)

{

  int allocno_preferenced_hard_regno, cost, index, offset1, offset2;

  bool only_regs_p;

  ira_allocno_t a;

  enum reg_class rclass, cover_class;

  enum machine_mode mode;

  ira_copy_t cp;

  ira_loop_tree_node_t parent;

  gcc_assert (REG_SUBREG_P (reg1) && REG_SUBREG_P (reg2));

  only_regs_p = REG_P (reg1) && REG_P (reg2);

  reg1 = go_through_subreg (reg1, &offset1);

  reg2 = go_through_subreg (reg2, &offset2);

  /* Set up hard regno preferenced by allocno.  If allocno gets the

     hard regno the copy (or potential move) insn will be removed.  */

  if (HARD_REGISTER_P (reg1))

    {

      if (HARD_REGISTER_P (reg2))

        return false;

      allocno_preferenced_hard_regno = REGNO (reg1) + offset1 - offset2;

      a = ira_curr_regno_allocno_map[REGNO (reg2)];

    }

  else if (HARD_REGISTER_P (reg2))

    {

      allocno_preferenced_hard_regno = REGNO (reg2) + offset2 - offset1;

      a = ira_curr_regno_allocno_map[REGNO (reg1)];

    }

  else if (!CONFLICT_ALLOCNO_P (ira_curr_regno_allocno_map[REGNO (reg1)],

                                ira_curr_regno_allocno_map[REGNO (reg2)])

           && offset1 == offset2)

    {

      cp = ira_add_allocno_copy (ira_curr_regno_allocno_map[REGNO (reg1)],

                                 ira_curr_regno_allocno_map[REGNO (reg2)],

                                 freq, constraint_p, insn,

                                 ira_curr_loop_tree_node);

      bitmap_set_bit (ira_curr_loop_tree_node->local_copies, cp->num);

      return true;

    }

  else

    return false;

  if (! IN_RANGE (allocno_preferenced_hard_regno, 0, FIRST_PSEUDO_REGISTER - 1))

    /* Can not be tied.  */

    return false;

  rclass = REGNO_REG_CLASS (allocno_preferenced_hard_regno);

  mode = ALLOCNO_MODE (a);

  cover_class = ALLOCNO_COVER_CLASS (a);

  if (only_regs_p && insn != NULL_RTX

      && reg_class_size[rclass] <= (unsigned) CLASS_MAX_NREGS (rclass, mode))

    /* It is already taken into account in ira-costs.c.  */

    return false;

  index = ira_class_hard_reg_index[cover_class][allocno_preferenced_hard_regno];

  if (index < 0)

    /* Can not be tied.  It is not in the cover class.  */

    return false;

  if (HARD_REGISTER_P (reg1))

    cost = ira_get_register_move_cost (mode, cover_class, rclass) * freq;

  else

    cost = ira_get_register_move_cost (mode, rclass, cover_class) * freq;

  for (;;)

    {

      ira_allocate_and_set_costs

        (&ALLOCNO_HARD_REG_COSTS (a), cover_class,

         ALLOCNO_COVER_CLASS_COST (a));

      ira_allocate_and_set_costs

        (&ALLOCNO_CONFLICT_HARD_REG_COSTS (a), cover_class, 0);

      ALLOCNO_HARD_REG_COSTS (a)[index] -= cost;

      ALLOCNO_CONFLICT_HARD_REG_COSTS (a)[index] -= cost;

      if (ALLOCNO_HARD_REG_COSTS (a)[index] < ALLOCNO_COVER_CLASS_COST (a))

        ALLOCNO_COVER_CLASS_COST (a) = ALLOCNO_HARD_REG_COSTS (a)[index];

      if (ALLOCNO_CAP (a) != NULL)

        a = ALLOCNO_CAP (a);

      else if ((parent = ALLOCNO_LOOP_TREE_NODE (a)->parent) == NULL

               || (a = parent->regno_allocno_map[ALLOCNO_REGNO (a)]) == NULL)

        break;

    }

  return true;

}

/* Process all of the output registers of the current insn which are

   not bound (BOUND_P) and the input register REG (its operand number

   OP_NUM) which dies in the insn as if there were a move insn between

   them with frequency FREQ.  */

static void

process_reg_shuffles (rtx reg, int op_num, int freq, bool *bound_p)

{

  int i;

  rtx another_reg;

  gcc_assert (REG_SUBREG_P (reg));

  for (i = 0; i < recog_data.n_operands; i++)

    {

      another_reg = recog_data.operand[i];

      if (!REG_SUBREG_P (another_reg) || op_num == i

          || recog_data.operand_type[i] != OP_OUT

          || bound_p[i])

        continue;

      process_regs_for_copy (reg, another_reg, false, NULL_RTX, freq);

    }

}

/* Process INSN and create allocno copies if necessary.  For example,

   it might be because INSN is a pseudo-register move or INSN is two

   operand insn.  */

static void

add_insn_allocno_copies (rtx insn)

{

  rtx set, operand, dup;

  const char *str;

  bool commut_p, bound_p[MAX_RECOG_OPERANDS];

  int i, j, n, freq;

  freq = REG_FREQ_FROM_BB (BLOCK_FOR_INSN (insn));

  if (freq == 0)

    freq = 1;

  if ((set = single_set (insn)) != NULL_RTX

      && REG_SUBREG_P (SET_DEST (set)) && REG_SUBREG_P (SET_SRC (set))

      && ! side_effects_p (set)

      && find_reg_note (insn, REG_DEAD,

                        REG_P (SET_SRC (set))

                        ? SET_SRC (set)

                        : SUBREG_REG (SET_SRC (set))) != NULL_RTX)

    {

      process_regs_for_copy (SET_DEST (set), SET_SRC (set), false, insn, freq);

      return;

    }

  /* Fast check of possibility of constraint or shuffle copies.  If

     there are no dead registers, there will be no such copies.  */

  if (! find_reg_note (insn, REG_DEAD, NULL_RTX))

    return;

  extract_insn (insn);

  for (i = 0; i < recog_data.n_operands; i++)

    bound_p[i] = false;

  for (i = 0; i < recog_data.n_operands; i++)

    {

      operand = recog_data.operand[i];

      if (! REG_SUBREG_P (operand))

        continue;

      str = recog_data.constraints[i];

      while (*str == ' ' || *str == '\t')

        str++;

      for (j = 0, commut_p = false; j < 2; j++, commut_p = true)

        if ((n = get_dup_num (i, commut_p)) >= 0)

          {

            bound_p[n] = true;

            dup = recog_data.operand[n];

            if (REG_SUBREG_P (dup)

                && find_reg_note (insn, REG_DEAD,

                                  REG_P (operand)

                                  ? operand

                                  : SUBREG_REG (operand)) != NULL_RTX)

              process_regs_for_copy (operand, dup, true, NULL_RTX, freq);

          }

    }

  for (i = 0; i < recog_data.n_operands; i++)

    {

      operand = recog_data.operand[i];

      if (REG_SUBREG_P (operand)

          && find_reg_note (insn, REG_DEAD,

                            REG_P (operand)

                            ? operand : SUBREG_REG (operand)) != NULL_RTX)

        /* If an operand dies, prefer its hard register for the output

           operands by decreasing the hard register cost or creating

           the corresponding allocno copies.  The cost will not

           correspond to a real move insn cost, so make the frequency

           smaller.  */

        process_reg_shuffles (operand, i, freq < 8 ? 1 : freq / 8, bound_p);

    }

}

/* Add copies originated from BB given by LOOP_TREE_NODE.  */

static void

add_copies (ira_loop_tree_node_t loop_tree_node)

{

  basic_block bb;

  rtx insn;

  bb = loop_tree_node->bb;

  if (bb == NULL)

    return;

  FOR_BB_INSNS (bb, insn)

    if (NONDEBUG_INSN_P (insn))

      add_insn_allocno_copies (insn);

}

/* Propagate copies the corresponding allocnos on upper loop tree

   level.  */

static void

propagate_copies (void)

{

  ira_copy_t cp;

  ira_copy_iterator ci;

  ira_allocno_t a1, a2, parent_a1, parent_a2;

  ira_loop_tree_node_t parent;

  FOR_EACH_COPY (cp, ci)

    {

      a1 = cp->first;

      a2 = cp->second;

      if (ALLOCNO_LOOP_TREE_NODE (a1) == ira_loop_tree_root)

        continue;

      ira_assert ((ALLOCNO_LOOP_TREE_NODE (a2) != ira_loop_tree_root));

      parent = ALLOCNO_LOOP_TREE_NODE (a1)->parent;

      if ((parent_a1 = ALLOCNO_CAP (a1)) == NULL)

        parent_a1 = parent->regno_allocno_map[ALLOCNO_REGNO (a1)];

      if ((parent_a2 = ALLOCNO_CAP (a2)) == NULL)

        parent_a2 = parent->regno_allocno_map[ALLOCNO_REGNO (a2)];

      ira_assert (parent_a1 != NULL && parent_a2 != NULL);

      if (! CONFLICT_ALLOCNO_P (parent_a1, parent_a2))

        ira_add_allocno_copy (parent_a1, parent_a2, cp->freq,

                              cp->constraint_p, cp->insn, cp->loop_tree_node);

    }

}

/* Array used to collect all conflict allocnos for given allocno.  */

static ira_allocno_t *collected_conflict_allocnos;

/* Build conflict vectors or bit conflict vectors (whatever is more

   profitable) for allocno A from the conflict table and propagate the

   conflicts to upper level allocno.  */

static void

build_allocno_conflicts (ira_allocno_t a)

{

  int i, px, parent_num;

  int conflict_bit_vec_words_num;

  ira_loop_tree_node_t parent;

  ira_allocno_t parent_a, another_a, another_parent_a;

  ira_allocno_t *vec;

  IRA_INT_TYPE *allocno_conflicts;

  ira_allocno_set_iterator asi;

  allocno_conflicts = conflicts[ALLOCNO_NUM (a)];

  px = 0;

  FOR_EACH_ALLOCNO_IN_SET (allocno_conflicts,

                           ALLOCNO_MIN (a), ALLOCNO_MAX (a), i, asi)

    {

      another_a = ira_conflict_id_allocno_map[i];

      ira_assert (ira_reg_classes_intersect_p

                  [ALLOCNO_COVER_CLASS (a)][ALLOCNO_COVER_CLASS (another_a)]);

      collected_conflict_allocnos[px++] = another_a;

    }

  if (ira_conflict_vector_profitable_p (a, px))

    {

      ira_allocate_allocno_conflict_vec (a, px);

      vec = (ira_allocno_t*) ALLOCNO_CONFLICT_ALLOCNO_ARRAY (a);

      memcpy (vec, collected_conflict_allocnos, sizeof (ira_allocno_t) * px);

      vec[px] = NULL;

      ALLOCNO_CONFLICT_ALLOCNOS_NUM (a) = px;

    }

  else

    {

      ALLOCNO_CONFLICT_ALLOCNO_ARRAY (a) = conflicts[ALLOCNO_NUM (a)];

      if (ALLOCNO_MAX (a) < ALLOCNO_MIN (a))

        conflict_bit_vec_words_num = 0;

      else

        conflict_bit_vec_words_num

          = ((ALLOCNO_MAX (a) - ALLOCNO_MIN (a) + IRA_INT_BITS)

             / IRA_INT_BITS);

      ALLOCNO_CONFLICT_ALLOCNO_ARRAY_SIZE (a)

        = conflict_bit_vec_words_num * sizeof (IRA_INT_TYPE);

    }

  parent = ALLOCNO_LOOP_TREE_NODE (a)->parent;

  if ((parent_a = ALLOCNO_CAP (a)) == NULL

      && (parent == NULL

          || (parent_a = parent->regno_allocno_map[ALLOCNO_REGNO (a)])

          == NULL))

    return;

  ira_assert (parent != NULL);

  ira_assert (ALLOCNO_COVER_CLASS (a) == ALLOCNO_COVER_CLASS (parent_a));

  parent_num = ALLOCNO_NUM (parent_a);

  FOR_EACH_ALLOCNO_IN_SET (allocno_conflicts,

                           ALLOCNO_MIN (a), ALLOCNO_MAX (a), i, asi)

    {

      another_a = ira_conflict_id_allocno_map[i];

      ira_assert (ira_reg_classes_intersect_p

                  [ALLOCNO_COVER_CLASS (a)][ALLOCNO_COVER_CLASS (another_a)]);

      if ((another_parent_a = ALLOCNO_CAP (another_a)) == NULL

          && (another_parent_a = (parent->regno_allocno_map

                                  [ALLOCNO_REGNO (another_a)])) == NULL)

        continue;

      ira_assert (ALLOCNO_NUM (another_parent_a) >= 0);

      ira_assert (ALLOCNO_COVER_CLASS (another_a)

                  == ALLOCNO_COVER_CLASS (another_parent_a));

      SET_ALLOCNO_SET_BIT (conflicts[parent_num],

                           ALLOCNO_CONFLICT_ID (another_parent_a),

                           ALLOCNO_MIN (parent_a),

                           ALLOCNO_MAX (parent_a));

    }

}

/* Build conflict vectors or bit conflict vectors (whatever is more

   profitable) of all allocnos from the conflict table.  */

static void

build_conflicts (void)

{

  int i;

  ira_allocno_t a, cap;

  collected_conflict_allocnos