2009-05-06 Javier Miranda <miranda@adacore.com>

[pf3gnuchains/gcc-fork.git] / gcc / tree-vect-stmts.c

/* Statement Analysis and Transformation for Vectorization
   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software
   Foundation, Inc.
   Contributed by Dorit Naishlos <dorit@il.ibm.com> 
   and Ira Rosen <irar@il.ibm.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 "ggc.h"
#include "tree.h"
#include "target.h"
#include "basic-block.h"
#include "diagnostic.h"
#include "tree-flow.h"
#include "tree-dump.h"
#include "cfgloop.h"
#include "cfglayout.h"
#include "expr.h"
#include "recog.h"
#include "optabs.h"
#include "toplev.h"
#include "tree-vectorizer.h"
#include "langhooks.h"


/* Utility functions used by vect_mark_stmts_to_be_vectorized.  */

/* Function vect_mark_relevant.

   Mark STMT as "relevant for vectorization" and add it to WORKLIST.  */

static void
vect_mark_relevant (VEC(gimple,heap) **worklist, gimple stmt,
                    enum vect_relevant relevant, bool live_p)
{
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  enum vect_relevant save_relevant = STMT_VINFO_RELEVANT (stmt_info);
  bool save_live_p = STMT_VINFO_LIVE_P (stmt_info);

  if (vect_print_dump_info (REPORT_DETAILS))
    fprintf (vect_dump, "mark relevant %d, live %d.", relevant, live_p);

  if (STMT_VINFO_IN_PATTERN_P (stmt_info))
    {
      gimple pattern_stmt;

      /* This is the last stmt in a sequence that was detected as a 
         pattern that can potentially be vectorized.  Don't mark the stmt
         as relevant/live because it's not going to be vectorized.
         Instead mark the pattern-stmt that replaces it.  */

      pattern_stmt = STMT_VINFO_RELATED_STMT (stmt_info);

      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "last stmt in pattern. don't mark relevant/live.");
      stmt_info = vinfo_for_stmt (pattern_stmt);
      gcc_assert (STMT_VINFO_RELATED_STMT (stmt_info) == stmt);
      save_relevant = STMT_VINFO_RELEVANT (stmt_info);
      save_live_p = STMT_VINFO_LIVE_P (stmt_info);
      stmt = pattern_stmt;
    }

  STMT_VINFO_LIVE_P (stmt_info) |= live_p;
  if (relevant > STMT_VINFO_RELEVANT (stmt_info))
    STMT_VINFO_RELEVANT (stmt_info) = relevant;

  if (STMT_VINFO_RELEVANT (stmt_info) == save_relevant
      && STMT_VINFO_LIVE_P (stmt_info) == save_live_p)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "already marked relevant/live.");
      return;
    }

  VEC_safe_push (gimple, heap, *worklist, stmt);
}


/* Function vect_stmt_relevant_p.

   Return true if STMT in loop that is represented by LOOP_VINFO is
   "relevant for vectorization".

   A stmt is considered "relevant for vectorization" if:
   - it has uses outside the loop.
   - it has vdefs (it alters memory).
   - control stmts in the loop (except for the exit condition).

   CHECKME: what other side effects would the vectorizer allow?  */

static bool
vect_stmt_relevant_p (gimple stmt, loop_vec_info loop_vinfo,
                      enum vect_relevant *relevant, bool *live_p)
{
  struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
  ssa_op_iter op_iter;
  imm_use_iterator imm_iter;
  use_operand_p use_p;
  def_operand_p def_p;

  *relevant = vect_unused_in_scope;
  *live_p = false;

  /* cond stmt other than loop exit cond.  */
  if (is_ctrl_stmt (stmt) 
      && STMT_VINFO_TYPE (vinfo_for_stmt (stmt)) 
         != loop_exit_ctrl_vec_info_type) 
    *relevant = vect_used_in_scope;

  /* changing memory.  */
  if (gimple_code (stmt) != GIMPLE_PHI)
    if (gimple_vdef (stmt))
      {
        if (vect_print_dump_info (REPORT_DETAILS))
          fprintf (vect_dump, "vec_stmt_relevant_p: stmt has vdefs.");
        *relevant = vect_used_in_scope;
      }

  /* uses outside the loop.  */
  FOR_EACH_PHI_OR_STMT_DEF (def_p, stmt, op_iter, SSA_OP_DEF)
    {
      FOR_EACH_IMM_USE_FAST (use_p, imm_iter, DEF_FROM_PTR (def_p))
        {
          basic_block bb = gimple_bb (USE_STMT (use_p));
          if (!flow_bb_inside_loop_p (loop, bb))
            {
              if (vect_print_dump_info (REPORT_DETAILS))
                fprintf (vect_dump, "vec_stmt_relevant_p: used out of loop.");

              /* We expect all such uses to be in the loop exit phis
                 (because of loop closed form)   */
              gcc_assert (gimple_code (USE_STMT (use_p)) == GIMPLE_PHI);
              gcc_assert (bb == single_exit (loop)->dest);

              *live_p = true;
            }
        }
    }

  return (*live_p || *relevant);
}


/* Function exist_non_indexing_operands_for_use_p 

   USE is one of the uses attached to STMT. Check if USE is 
   used in STMT for anything other than indexing an array.  */

static bool
exist_non_indexing_operands_for_use_p (tree use, gimple stmt)
{
  tree operand;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
 
  /* USE corresponds to some operand in STMT. If there is no data
     reference in STMT, then any operand that corresponds to USE
     is not indexing an array.  */
  if (!STMT_VINFO_DATA_REF (stmt_info))
    return true;
 
  /* STMT has a data_ref. FORNOW this means that its of one of
     the following forms:
     -1- ARRAY_REF = var
     -2- var = ARRAY_REF
     (This should have been verified in analyze_data_refs).

     'var' in the second case corresponds to a def, not a use,
     so USE cannot correspond to any operands that are not used 
     for array indexing.

     Therefore, all we need to check is if STMT falls into the
     first case, and whether var corresponds to USE.  */
 
  if (TREE_CODE (gimple_assign_lhs (stmt)) == SSA_NAME)
    return false;

  if (!gimple_assign_copy_p (stmt))
    return false;
  operand = gimple_assign_rhs1 (stmt);

  if (TREE_CODE (operand) != SSA_NAME)
    return false;

  if (operand == use)
    return true;

  return false;
}


/* 
   Function process_use.

   Inputs:
   - a USE in STMT in a loop represented by LOOP_VINFO
   - LIVE_P, RELEVANT - enum values to be set in the STMT_VINFO of the stmt 
     that defined USE. This is done by calling mark_relevant and passing it
     the WORKLIST (to add DEF_STMT to the WORKLIST in case it is relevant).

   Outputs:
   Generally, LIVE_P and RELEVANT are used to define the liveness and
   relevance info of the DEF_STMT of this USE:
       STMT_VINFO_LIVE_P (DEF_STMT_info) <-- live_p
       STMT_VINFO_RELEVANT (DEF_STMT_info) <-- relevant
   Exceptions:
   - case 1: If USE is used only for address computations (e.g. array indexing),
   which does not need to be directly vectorized, then the liveness/relevance 
   of the respective DEF_STMT is left unchanged.
   - case 2: If STMT is a reduction phi and DEF_STMT is a reduction stmt, we 
   skip DEF_STMT cause it had already been processed.  
   - case 3: If DEF_STMT and STMT are in different nests, then  "relevant" will
   be modified accordingly.

   Return true if everything is as expected. Return false otherwise.  */

static bool
process_use (gimple stmt, tree use, loop_vec_info loop_vinfo, bool live_p, 
             enum vect_relevant relevant, VEC(gimple,heap) **worklist)
{
  struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
  stmt_vec_info stmt_vinfo = vinfo_for_stmt (stmt);
  stmt_vec_info dstmt_vinfo;
  basic_block bb, def_bb;
  tree def;
  gimple def_stmt;
  enum vect_def_type dt;

  /* case 1: we are only interested in uses that need to be vectorized.  Uses 
     that are used for address computation are not considered relevant.  */
  if (!exist_non_indexing_operands_for_use_p (use, stmt))
     return true;

  if (!vect_is_simple_use (use, loop_vinfo, &def_stmt, &def, &dt))
    { 
      if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
        fprintf (vect_dump, "not vectorized: unsupported use in stmt.");
      return false;
    }

  if (!def_stmt || gimple_nop_p (def_stmt))
    return true;

  def_bb = gimple_bb (def_stmt);
  if (!flow_bb_inside_loop_p (loop, def_bb))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "def_stmt is out of loop.");
      return true;
    }

  /* case 2: A reduction phi (STMT) defined by a reduction stmt (DEF_STMT). 
     DEF_STMT must have already been processed, because this should be the 
     only way that STMT, which is a reduction-phi, was put in the worklist, 
     as there should be no other uses for DEF_STMT in the loop.  So we just 
     check that everything is as expected, and we are done.  */
  dstmt_vinfo = vinfo_for_stmt (def_stmt);
  bb = gimple_bb (stmt);
  if (gimple_code (stmt) == GIMPLE_PHI
      && STMT_VINFO_DEF_TYPE (stmt_vinfo) == vect_reduction_def
      && gimple_code (def_stmt) != GIMPLE_PHI
      && STMT_VINFO_DEF_TYPE (dstmt_vinfo) == vect_reduction_def
      && bb->loop_father == def_bb->loop_father)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "reduc-stmt defining reduc-phi in the same nest.");
      if (STMT_VINFO_IN_PATTERN_P (dstmt_vinfo))
        dstmt_vinfo = vinfo_for_stmt (STMT_VINFO_RELATED_STMT (dstmt_vinfo));
      gcc_assert (STMT_VINFO_RELEVANT (dstmt_vinfo) < vect_used_by_reduction);
      gcc_assert (STMT_VINFO_LIVE_P (dstmt_vinfo) 
                  || STMT_VINFO_RELEVANT (dstmt_vinfo) > vect_unused_in_scope);
      return true;
    }

  /* case 3a: outer-loop stmt defining an inner-loop stmt:
        outer-loop-header-bb:
                d = def_stmt
        inner-loop:
                stmt # use (d)
        outer-loop-tail-bb:
                ...               */
  if (flow_loop_nested_p (def_bb->loop_father, bb->loop_father))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "outer-loop def-stmt defining inner-loop stmt.");
      switch (relevant)
        {
        case vect_unused_in_scope:
          relevant = (STMT_VINFO_DEF_TYPE (stmt_vinfo) == vect_reduction_def) ?
                        vect_used_by_reduction : vect_unused_in_scope;
          break;
        case vect_used_in_outer_by_reduction:
          relevant = vect_used_by_reduction;
          break;
        case vect_used_in_outer:
          relevant = vect_used_in_scope;
          break;
        case vect_used_by_reduction: 
        case vect_used_in_scope:
          break;

        default:
          gcc_unreachable ();
        }   
    }

  /* case 3b: inner-loop stmt defining an outer-loop stmt:
        outer-loop-header-bb:
                ...
        inner-loop:
                d = def_stmt
        outer-loop-tail-bb:
                stmt # use (d)          */
  else if (flow_loop_nested_p (bb->loop_father, def_bb->loop_father))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "inner-loop def-stmt defining outer-loop stmt.");
      switch (relevant)
        {
        case vect_unused_in_scope:
          relevant = (STMT_VINFO_DEF_TYPE (stmt_vinfo) == vect_reduction_def) ?
                        vect_used_in_outer_by_reduction : vect_unused_in_scope;
          break;

        case vect_used_in_outer_by_reduction:
        case vect_used_in_outer:
          break;

        case vect_used_by_reduction:
          relevant = vect_used_in_outer_by_reduction;
          break;

        case vect_used_in_scope:
          relevant = vect_used_in_outer;
          break;

        default:
          gcc_unreachable ();
        }
    }

  vect_mark_relevant (worklist, def_stmt, relevant, live_p);
  return true;
}


/* Function vect_mark_stmts_to_be_vectorized.

   Not all stmts in the loop need to be vectorized. For example:

     for i...
       for j...
   1.    T0 = i + j
   2.    T1 = a[T0]

   3.    j = j + 1

   Stmt 1 and 3 do not need to be vectorized, because loop control and
   addressing of vectorized data-refs are handled differently.

   This pass detects such stmts.  */

bool
vect_mark_stmts_to_be_vectorized (loop_vec_info loop_vinfo)
{
  VEC(gimple,heap) *worklist;
  struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
  basic_block *bbs = LOOP_VINFO_BBS (loop_vinfo);
  unsigned int nbbs = loop->num_nodes;
  gimple_stmt_iterator si;
  gimple stmt;
  unsigned int i;
  stmt_vec_info stmt_vinfo;
  basic_block bb;
  gimple phi;
  bool live_p;
  enum vect_relevant relevant;

  if (vect_print_dump_info (REPORT_DETAILS))
    fprintf (vect_dump, "=== vect_mark_stmts_to_be_vectorized ===");

  worklist = VEC_alloc (gimple, heap, 64);

  /* 1. Init worklist.  */
  for (i = 0; i < nbbs; i++)
    {
      bb = bbs[i];
      for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si))
        { 
          phi = gsi_stmt (si);
          if (vect_print_dump_info (REPORT_DETAILS))
            {
              fprintf (vect_dump, "init: phi relevant? ");
              print_gimple_stmt (vect_dump, phi, 0, TDF_SLIM);
            }

          if (vect_stmt_relevant_p (phi, loop_vinfo, &relevant, &live_p))
            vect_mark_relevant (&worklist, phi, relevant, live_p);
        }
      for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
        {
          stmt = gsi_stmt (si);
          if (vect_print_dump_info (REPORT_DETAILS))
            {
              fprintf (vect_dump, "init: stmt relevant? ");
              print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
            } 

          if (vect_stmt_relevant_p (stmt, loop_vinfo, &relevant, &live_p))
            vect_mark_relevant (&worklist, stmt, relevant, live_p);
        }
    }

  /* 2. Process_worklist */
  while (VEC_length (gimple, worklist) > 0)
    {
      use_operand_p use_p;
      ssa_op_iter iter;

      stmt = VEC_pop (gimple, worklist);
      if (vect_print_dump_info (REPORT_DETAILS))
        {
          fprintf (vect_dump, "worklist: examine stmt: ");
          print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
        }

      /* Examine the USEs of STMT. For each USE, mark the stmt that defines it 
         (DEF_STMT) as relevant/irrelevant and live/dead according to the 
         liveness and relevance properties of STMT.  */
      stmt_vinfo = vinfo_for_stmt (stmt);
      relevant = STMT_VINFO_RELEVANT (stmt_vinfo);
      live_p = STMT_VINFO_LIVE_P (stmt_vinfo);

      /* Generally, the liveness and relevance properties of STMT are
         propagated as is to the DEF_STMTs of its USEs:
          live_p <-- STMT_VINFO_LIVE_P (STMT_VINFO)
          relevant <-- STMT_VINFO_RELEVANT (STMT_VINFO)

         One exception is when STMT has been identified as defining a reduction
         variable; in this case we set the liveness/relevance as follows:
           live_p = false
           relevant = vect_used_by_reduction
         This is because we distinguish between two kinds of relevant stmts -
         those that are used by a reduction computation, and those that are 
         (also) used by a regular computation. This allows us later on to 
         identify stmts that are used solely by a reduction, and therefore the 
         order of the results that they produce does not have to be kept.

         Reduction phis are expected to be used by a reduction stmt, or by
         in an outer loop;  Other reduction stmts are expected to be
         in the loop, and possibly used by a stmt in an outer loop. 
         Here are the expected values of "relevant" for reduction phis/stmts:

         relevance:                             phi     stmt
         vect_unused_in_scope                           ok
         vect_used_in_outer_by_reduction        ok      ok
         vect_used_in_outer                     ok      ok
         vect_used_by_reduction                 ok
         vect_used_in_scope                                           */

      if (STMT_VINFO_DEF_TYPE (stmt_vinfo) == vect_reduction_def)
        {
          enum vect_relevant tmp_relevant = relevant;
          switch (tmp_relevant)
            {
            case vect_unused_in_scope:
              gcc_assert (gimple_code (stmt) != GIMPLE_PHI);
              relevant = vect_used_by_reduction;
              break;

            case vect_used_in_outer_by_reduction:
            case vect_used_in_outer:
              gcc_assert (gimple_code (stmt) != GIMPLE_ASSIGN
                          || (gimple_assign_rhs_code (stmt) != WIDEN_SUM_EXPR
                              && (gimple_assign_rhs_code (stmt)
                                  != DOT_PROD_EXPR)));
              break;

            case vect_used_by_reduction:
              if (gimple_code (stmt) == GIMPLE_PHI)
                break;
              /* fall through */
            case vect_used_in_scope:
            default:
              if (vect_print_dump_info (REPORT_DETAILS))
                fprintf (vect_dump, "unsupported use of reduction.");
              VEC_free (gimple, heap, worklist);
              return false;
            }
          live_p = false;       
        }

      FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_USE)
        {
          tree op = USE_FROM_PTR (use_p);
          if (!process_use (stmt, op, loop_vinfo, live_p, relevant, &worklist))
            {
              VEC_free (gimple, heap, worklist);
              return false;
            }
        }
    } /* while worklist */

  VEC_free (gimple, heap, worklist);
  return true;
}


int
cost_for_stmt (gimple stmt)
{
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);

  switch (STMT_VINFO_TYPE (stmt_info))
  {
  case load_vec_info_type:
    return TARG_SCALAR_LOAD_COST;
  case store_vec_info_type:
    return TARG_SCALAR_STORE_COST;
  case op_vec_info_type:
  case condition_vec_info_type:
  case assignment_vec_info_type:
  case reduc_vec_info_type:
  case induc_vec_info_type:
  case type_promotion_vec_info_type:
  case type_demotion_vec_info_type:
  case type_conversion_vec_info_type:
  case call_vec_info_type:
    return TARG_SCALAR_STMT_COST;
  case undef_vec_info_type:
  default:
    gcc_unreachable ();
  }
}

/* Function vect_model_simple_cost.  

   Models cost for simple operations, i.e. those that only emit ncopies of a 
   single op.  Right now, this does not account for multiple insns that could
   be generated for the single vector op.  We will handle that shortly.  */

void
vect_model_simple_cost (stmt_vec_info stmt_info, int ncopies, 
                        enum vect_def_type *dt, slp_tree slp_node)
{
  int i;
  int inside_cost = 0, outside_cost = 0;

  /* The SLP costs were already calculated during SLP tree build.  */
  if (PURE_SLP_STMT (stmt_info))
    return;

  inside_cost = ncopies * TARG_VEC_STMT_COST;

  /* FORNOW: Assuming maximum 2 args per stmts.  */
  for (i = 0; i < 2; i++)
    {
      if (dt[i] == vect_constant_def || dt[i] == vect_external_def)
        outside_cost += TARG_SCALAR_TO_VEC_COST; 
    }
  
  if (vect_print_dump_info (REPORT_COST))
    fprintf (vect_dump, "vect_model_simple_cost: inside_cost = %d, "
             "outside_cost = %d .", inside_cost, outside_cost);

  /* Set the costs either in STMT_INFO or SLP_NODE (if exists).  */
  stmt_vinfo_set_inside_of_loop_cost (stmt_info, slp_node, inside_cost);
  stmt_vinfo_set_outside_of_loop_cost (stmt_info, slp_node, outside_cost);
}


/* Function vect_cost_strided_group_size 
 
   For strided load or store, return the group_size only if it is the first
   load or store of a group, else return 1.  This ensures that group size is
   only returned once per group.  */

static int
vect_cost_strided_group_size (stmt_vec_info stmt_info)
{
  gimple first_stmt = DR_GROUP_FIRST_DR (stmt_info);

  if (first_stmt == STMT_VINFO_STMT (stmt_info))
    return DR_GROUP_SIZE (stmt_info);

  return 1;
}


/* Function vect_model_store_cost

   Models cost for stores.  In the case of strided accesses, one access
   has the overhead of the strided access attributed to it.  */

void
vect_model_store_cost (stmt_vec_info stmt_info, int ncopies, 
                       enum vect_def_type dt, slp_tree slp_node)
{
  int group_size;
  int inside_cost = 0, outside_cost = 0;

  /* The SLP costs were already calculated during SLP tree build.  */
  if (PURE_SLP_STMT (stmt_info))
    return;

  if (dt == vect_constant_def || dt == vect_external_def)
    outside_cost = TARG_SCALAR_TO_VEC_COST;

  /* Strided access?  */
  if (DR_GROUP_FIRST_DR (stmt_info) && !slp_node) 
    group_size = vect_cost_strided_group_size (stmt_info);
  /* Not a strided access.  */
  else
    group_size = 1;

  /* Is this an access in a group of stores, which provide strided access?  
     If so, add in the cost of the permutes.  */
  if (group_size > 1) 
    {
      /* Uses a high and low interleave operation for each needed permute.  */
      inside_cost = ncopies * exact_log2(group_size) * group_size 
             * TARG_VEC_STMT_COST;

      if (vect_print_dump_info (REPORT_COST))
        fprintf (vect_dump, "vect_model_store_cost: strided group_size = %d .",
                 group_size);

    }

  /* Costs of the stores.  */
  inside_cost += ncopies * TARG_VEC_STORE_COST;

  if (vect_print_dump_info (REPORT_COST))
    fprintf (vect_dump, "vect_model_store_cost: inside_cost = %d, "
             "outside_cost = %d .", inside_cost, outside_cost);

  /* Set the costs either in STMT_INFO or SLP_NODE (if exists).  */
  stmt_vinfo_set_inside_of_loop_cost (stmt_info, slp_node, inside_cost);
  stmt_vinfo_set_outside_of_loop_cost (stmt_info, slp_node, outside_cost);
}


/* Function vect_model_load_cost

   Models cost for loads.  In the case of strided accesses, the last access
   has the overhead of the strided access attributed to it.  Since unaligned
   accesses are supported for loads, we also account for the costs of the 
   access scheme chosen.  */

void
vect_model_load_cost (stmt_vec_info stmt_info, int ncopies, slp_tree slp_node)
                 
{
  int group_size;
  int alignment_support_cheme;
  gimple first_stmt;
  struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info), *first_dr;
  int inside_cost = 0, outside_cost = 0;

  /* The SLP costs were already calculated during SLP tree build.  */
  if (PURE_SLP_STMT (stmt_info))
    return;

  /* Strided accesses?  */
  first_stmt = DR_GROUP_FIRST_DR (stmt_info);
  if (first_stmt && !slp_node)
    {
      group_size = vect_cost_strided_group_size (stmt_info);
      first_dr = STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt));
    }
  /* Not a strided access.  */
  else
    {
      group_size = 1;
      first_dr = dr;
    }

  alignment_support_cheme = vect_supportable_dr_alignment (first_dr);

  /* Is this an access in a group of loads providing strided access?  
     If so, add in the cost of the permutes.  */
  if (group_size > 1) 
    {
      /* Uses an even and odd extract operations for each needed permute.  */
      inside_cost = ncopies * exact_log2(group_size) * group_size
        * TARG_VEC_STMT_COST;

      if (vect_print_dump_info (REPORT_COST))
        fprintf (vect_dump, "vect_model_load_cost: strided group_size = %d .",
                 group_size);

    }

  /* The loads themselves.  */
  switch (alignment_support_cheme)
    {
    case dr_aligned:
      {
        inside_cost += ncopies * TARG_VEC_LOAD_COST;

        if (vect_print_dump_info (REPORT_COST))
          fprintf (vect_dump, "vect_model_load_cost: aligned.");

        break;
      }
    case dr_unaligned_supported:
      {
        /* Here, we assign an additional cost for the unaligned load.  */
        inside_cost += ncopies * TARG_VEC_UNALIGNED_LOAD_COST;

        if (vect_print_dump_info (REPORT_COST))
          fprintf (vect_dump, "vect_model_load_cost: unaligned supported by "
                   "hardware.");

        break;
      }
    case dr_explicit_realign:
      {
        inside_cost += ncopies * (2*TARG_VEC_LOAD_COST + TARG_VEC_STMT_COST);

        /* FIXME: If the misalignment remains fixed across the iterations of
           the containing loop, the following cost should be added to the
           outside costs.  */
        if (targetm.vectorize.builtin_mask_for_load)
          inside_cost += TARG_VEC_STMT_COST;

        break;
      }
    case dr_explicit_realign_optimized:
      {
        if (vect_print_dump_info (REPORT_COST))
          fprintf (vect_dump, "vect_model_load_cost: unaligned software "
                   "pipelined.");

        /* Unaligned software pipeline has a load of an address, an initial
           load, and possibly a mask operation to "prime" the loop. However,
           if this is an access in a group of loads, which provide strided
           access, then the above cost should only be considered for one
           access in the group. Inside the loop, there is a load op
           and a realignment op.  */

        if ((!DR_GROUP_FIRST_DR (stmt_info)) || group_size > 1 || slp_node)
          {
            outside_cost = 2*TARG_VEC_STMT_COST;
            if (targetm.vectorize.builtin_mask_for_load)
              outside_cost += TARG_VEC_STMT_COST;
          }

        inside_cost += ncopies * (TARG_VEC_LOAD_COST + TARG_VEC_STMT_COST);

        break;
      }

    default:
      gcc_unreachable ();
    }
  
  if (vect_print_dump_info (REPORT_COST))
    fprintf (vect_dump, "vect_model_load_cost: inside_cost = %d, "
             "outside_cost = %d .", inside_cost, outside_cost);

  /* Set the costs either in STMT_INFO or SLP_NODE (if exists).  */
  stmt_vinfo_set_inside_of_loop_cost (stmt_info, slp_node, inside_cost);
  stmt_vinfo_set_outside_of_loop_cost (stmt_info, slp_node, outside_cost);
}


/* Function vect_init_vector.

   Insert a new stmt (INIT_STMT) that initializes a new vector variable with
   the vector elements of VECTOR_VAR. Place the initialization at BSI if it
   is not NULL. Otherwise, place the initialization at the loop preheader.
   Return the DEF of INIT_STMT. 
   It will be used in the vectorization of STMT.  */

tree
vect_init_vector (gimple stmt, tree vector_var, tree vector_type,
                  gimple_stmt_iterator *gsi)
{
  stmt_vec_info stmt_vinfo = vinfo_for_stmt (stmt);
  tree new_var;
  gimple init_stmt;
  tree vec_oprnd;
  edge pe;
  tree new_temp;
  basic_block new_bb;
 
  new_var = vect_get_new_vect_var (vector_type, vect_simple_var, "cst_");
  add_referenced_var (new_var); 
  init_stmt = gimple_build_assign  (new_var, vector_var);
  new_temp = make_ssa_name (new_var, init_stmt);
  gimple_assign_set_lhs (init_stmt, new_temp);

  if (gsi)
    vect_finish_stmt_generation (stmt, init_stmt, gsi);
  else
    {
      loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_vinfo);
      struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);

      if (nested_in_vect_loop_p (loop, stmt))
        loop = loop->inner;
      pe = loop_preheader_edge (loop);
      new_bb = gsi_insert_on_edge_immediate (pe, init_stmt);
      gcc_assert (!new_bb);
    }

  if (vect_print_dump_info (REPORT_DETAILS))
    {
      fprintf (vect_dump, "created new init_stmt: ");
      print_gimple_stmt (vect_dump, init_stmt, 0, TDF_SLIM);
    }

  vec_oprnd = gimple_assign_lhs (init_stmt);
  return vec_oprnd;
}

/* Function vect_get_vec_def_for_operand.

   OP is an operand in STMT. This function returns a (vector) def that will be
   used in the vectorized stmt for STMT.

   In the case that OP is an SSA_NAME which is defined in the loop, then
   STMT_VINFO_VEC_STMT of the defining stmt holds the relevant def.

   In case OP is an invariant or constant, a new stmt that creates a vector def
   needs to be introduced.  */

tree
vect_get_vec_def_for_operand (tree op, gimple stmt, tree *scalar_def)
{
  tree vec_oprnd;
  gimple vec_stmt;
  gimple def_stmt;
  stmt_vec_info def_stmt_info = NULL;
  stmt_vec_info stmt_vinfo = vinfo_for_stmt (stmt);
  tree vectype = STMT_VINFO_VECTYPE (stmt_vinfo);
  unsigned int nunits = TYPE_VECTOR_SUBPARTS (vectype);
  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_vinfo);
  tree vec_inv;
  tree vec_cst;
  tree t = NULL_TREE;
  tree def;
  int i;
  enum vect_def_type dt;
  bool is_simple_use;
  tree vector_type;

  if (vect_print_dump_info (REPORT_DETAILS))
    {
      fprintf (vect_dump, "vect_get_vec_def_for_operand: ");
      print_generic_expr (vect_dump, op, TDF_SLIM);
    }

  is_simple_use = vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt);
  gcc_assert (is_simple_use);
  if (vect_print_dump_info (REPORT_DETAILS))
    {
      if (def)
        {
          fprintf (vect_dump, "def =  ");
          print_generic_expr (vect_dump, def, TDF_SLIM);
        }
      if (def_stmt)
        {
          fprintf (vect_dump, "  def_stmt =  ");
          print_gimple_stmt (vect_dump, def_stmt, 0, TDF_SLIM);
        }
    }

  switch (dt)
    {
    /* Case 1: operand is a constant.  */
    case vect_constant_def:
      {
        vector_type = get_vectype_for_scalar_type (TREE_TYPE (op));
        gcc_assert (vector_type);

        if (scalar_def) 
          *scalar_def = op;

        /* Create 'vect_cst_ = {cst,cst,...,cst}'  */
        if (vect_print_dump_info (REPORT_DETAILS))
          fprintf (vect_dump, "Create vector_cst. nunits = %d", nunits);

        for (i = nunits - 1; i >= 0; --i)
          {
            t = tree_cons (NULL_TREE, op, t);
          }
        vec_cst = build_vector (vector_type, t);
        return vect_init_vector (stmt, vec_cst, vector_type, NULL);
      }

    /* Case 2: operand is defined outside the loop - loop invariant.  */
    case vect_external_def:
      {
        vector_type = get_vectype_for_scalar_type (TREE_TYPE (def));
        gcc_assert (vector_type);
        nunits = TYPE_VECTOR_SUBPARTS (vector_type);

        if (scalar_def) 
          *scalar_def = def;

        /* Create 'vec_inv = {inv,inv,..,inv}'  */
        if (vect_print_dump_info (REPORT_DETAILS))
          fprintf (vect_dump, "Create vector_inv.");

        for (i = nunits - 1; i >= 0; --i)
          {
            t = tree_cons (NULL_TREE, def, t);
          }

        /* FIXME: use build_constructor directly.  */
        vec_inv = build_constructor_from_list (vector_type, t);
        return vect_init_vector (stmt, vec_inv, vector_type, NULL);
      }

    /* Case 3: operand is defined inside the loop.  */
    case vect_internal_def:
      {
        if (scalar_def) 
          *scalar_def = NULL/* FIXME tuples: def_stmt*/;

        /* Get the def from the vectorized stmt.  */
        def_stmt_info = vinfo_for_stmt (def_stmt);
        vec_stmt = STMT_VINFO_VEC_STMT (def_stmt_info);
        gcc_assert (vec_stmt);
        if (gimple_code (vec_stmt) == GIMPLE_PHI)
          vec_oprnd = PHI_RESULT (vec_stmt);
        else if (is_gimple_call (vec_stmt))
          vec_oprnd = gimple_call_lhs (vec_stmt);
        else
          vec_oprnd = gimple_assign_lhs (vec_stmt);
        return vec_oprnd;
      }

    /* Case 4: operand is defined by a loop header phi - reduction  */
    case vect_reduction_def:
      {
        struct loop *loop;

        gcc_assert (gimple_code (def_stmt) == GIMPLE_PHI);
        loop = (gimple_bb (def_stmt))->loop_father; 

        /* Get the def before the loop  */
        op = PHI_ARG_DEF_FROM_EDGE (def_stmt, loop_preheader_edge (loop));
        return get_initial_def_for_reduction (stmt, op, scalar_def);
     }

    /* Case 5: operand is defined by loop-header phi - induction.  */
    case vect_induction_def:
      {
        gcc_assert (gimple_code (def_stmt) == GIMPLE_PHI);

        /* Get the def from the vectorized stmt.  */
        def_stmt_info = vinfo_for_stmt (def_stmt);
        vec_stmt = STMT_VINFO_VEC_STMT (def_stmt_info);
        gcc_assert (vec_stmt && gimple_code (vec_stmt) == GIMPLE_PHI);
        vec_oprnd = PHI_RESULT (vec_stmt);
        return vec_oprnd;
      }

    default:
      gcc_unreachable ();
    }
}


/* Function vect_get_vec_def_for_stmt_copy

   Return a vector-def for an operand. This function is used when the 
   vectorized stmt to be created (by the caller to this function) is a "copy" 
   created in case the vectorized result cannot fit in one vector, and several 
   copies of the vector-stmt are required. In this case the vector-def is 
   retrieved from the vector stmt recorded in the STMT_VINFO_RELATED_STMT field
   of the stmt that defines VEC_OPRND. 
   DT is the type of the vector def VEC_OPRND.

   Context:
        In case the vectorization factor (VF) is bigger than the number
   of elements that can fit in a vectype (nunits), we have to generate
   more than one vector stmt to vectorize the scalar stmt. This situation
   arises when there are multiple data-types operated upon in the loop; the 
   smallest data-type determines the VF, and as a result, when vectorizing
   stmts operating on wider types we need to create 'VF/nunits' "copies" of the
   vector stmt (each computing a vector of 'nunits' results, and together
   computing 'VF' results in each iteration).  This function is called when 
   vectorizing such a stmt (e.g. vectorizing S2 in the illustration below, in
   which VF=16 and nunits=4, so the number of copies required is 4):

   scalar stmt:         vectorized into:        STMT_VINFO_RELATED_STMT
 
   S1: x = load         VS1.0:  vx.0 = memref0      VS1.1
                        VS1.1:  vx.1 = memref1      VS1.2
                        VS1.2:  vx.2 = memref2      VS1.3
                        VS1.3:  vx.3 = memref3 

   S2: z = x + ...      VSnew.0:  vz0 = vx.0 + ...  VSnew.1
                        VSnew.1:  vz1 = vx.1 + ...  VSnew.2
                        VSnew.2:  vz2 = vx.2 + ...  VSnew.3
                        VSnew.3:  vz3 = vx.3 + ...

   The vectorization of S1 is explained in vectorizable_load.
   The vectorization of S2:
        To create the first vector-stmt out of the 4 copies - VSnew.0 - 
   the function 'vect_get_vec_def_for_operand' is called to 
   get the relevant vector-def for each operand of S2. For operand x it
   returns  the vector-def 'vx.0'.

        To create the remaining copies of the vector-stmt (VSnew.j), this 
   function is called to get the relevant vector-def for each operand.  It is 
   obtained from the respective VS1.j stmt, which is recorded in the 
   STMT_VINFO_RELATED_STMT field of the stmt that defines VEC_OPRND.

        For example, to obtain the vector-def 'vx.1' in order to create the 
   vector stmt 'VSnew.1', this function is called with VEC_OPRND='vx.0'. 
   Given 'vx0' we obtain the stmt that defines it ('VS1.0'); from the 
   STMT_VINFO_RELATED_STMT field of 'VS1.0' we obtain the next copy - 'VS1.1',
   and return its def ('vx.1').
   Overall, to create the above sequence this function will be called 3 times:
        vx.1 = vect_get_vec_def_for_stmt_copy (dt, vx.0);
        vx.2 = vect_get_vec_def_for_stmt_copy (dt, vx.1);
        vx.3 = vect_get_vec_def_for_stmt_copy (dt, vx.2);  */

tree
vect_get_vec_def_for_stmt_copy (enum vect_def_type dt, tree vec_oprnd)
{
  gimple vec_stmt_for_operand;
  stmt_vec_info def_stmt_info;

  /* Do nothing; can reuse same def.  */
  if (dt == vect_external_def || dt == vect_constant_def )
    return vec_oprnd;

  vec_stmt_for_operand = SSA_NAME_DEF_STMT (vec_oprnd);
  def_stmt_info = vinfo_for_stmt (vec_stmt_for_operand);
  gcc_assert (def_stmt_info);
  vec_stmt_for_operand = STMT_VINFO_RELATED_STMT (def_stmt_info);
  gcc_assert (vec_stmt_for_operand);
  vec_oprnd = gimple_get_lhs (vec_stmt_for_operand);
  if (gimple_code (vec_stmt_for_operand) == GIMPLE_PHI)
    vec_oprnd = PHI_RESULT (vec_stmt_for_operand);
  else
    vec_oprnd = gimple_get_lhs (vec_stmt_for_operand);
  return vec_oprnd;
}


/* Get vectorized definitions for the operands to create a copy of an original
   stmt. See vect_get_vec_def_for_stmt_copy() for details.  */

static void
vect_get_vec_defs_for_stmt_copy (enum vect_def_type *dt, 
                                 VEC(tree,heap) **vec_oprnds0, 
                                 VEC(tree,heap) **vec_oprnds1)
{
  tree vec_oprnd = VEC_pop (tree, *vec_oprnds0);

  vec_oprnd = vect_get_vec_def_for_stmt_copy (dt[0], vec_oprnd);
  VEC_quick_push (tree, *vec_oprnds0, vec_oprnd);

  if (vec_oprnds1 && *vec_oprnds1)
    {
      vec_oprnd = VEC_pop (tree, *vec_oprnds1);
      vec_oprnd = vect_get_vec_def_for_stmt_copy (dt[1], vec_oprnd);
      VEC_quick_push (tree, *vec_oprnds1, vec_oprnd);
    }
}


/* Get vectorized definitions for OP0 and OP1, or SLP_NODE if it is not NULL.  */

static void
vect_get_vec_defs (tree op0, tree op1, gimple stmt,
                   VEC(tree,heap) **vec_oprnds0, VEC(tree,heap) **vec_oprnds1,
                   slp_tree slp_node)
{
  if (slp_node)
    vect_get_slp_defs (slp_node, vec_oprnds0, vec_oprnds1);
  else
    {
      tree vec_oprnd;

      *vec_oprnds0 = VEC_alloc (tree, heap, 1); 
      vec_oprnd = vect_get_vec_def_for_operand (op0, stmt, NULL);      
      VEC_quick_push (tree, *vec_oprnds0, vec_oprnd);

      if (op1)
        {
          *vec_oprnds1 = VEC_alloc (tree, heap, 1);     
          vec_oprnd = vect_get_vec_def_for_operand (op1, stmt, NULL);      
          VEC_quick_push (tree, *vec_oprnds1, vec_oprnd);
        }
    }
}


/* Function vect_finish_stmt_generation.

   Insert a new stmt.  */

void
vect_finish_stmt_generation (gimple stmt, gimple vec_stmt,
                             gimple_stmt_iterator *gsi)
{
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);

  gcc_assert (gimple_code (stmt) != GIMPLE_LABEL);

  gsi_insert_before (gsi, vec_stmt, GSI_SAME_STMT);

  set_vinfo_for_stmt (vec_stmt, new_stmt_vec_info (vec_stmt, loop_vinfo));

  if (vect_print_dump_info (REPORT_DETAILS))
    {
      fprintf (vect_dump, "add new stmt: ");
      print_gimple_stmt (vect_dump, vec_stmt, 0, TDF_SLIM);
    }

  gimple_set_location (vec_stmt, gimple_location (gsi_stmt (*gsi)));
}

/* Checks if CALL can be vectorized in type VECTYPE.  Returns
   a function declaration if the target has a vectorized version
   of the function, or NULL_TREE if the function cannot be vectorized.  */

tree
vectorizable_function (gimple call, tree vectype_out, tree vectype_in)
{
  tree fndecl = gimple_call_fndecl (call);
  enum built_in_function code;

  /* We only handle functions that do not read or clobber memory -- i.e.
     const or novops ones.  */
  if (!(gimple_call_flags (call) & (ECF_CONST | ECF_NOVOPS)))
    return NULL_TREE;

  if (!fndecl
      || TREE_CODE (fndecl) != FUNCTION_DECL
      || !DECL_BUILT_IN (fndecl))
    return NULL_TREE;

  code = DECL_FUNCTION_CODE (fndecl);
  return targetm.vectorize.builtin_vectorized_function (code, vectype_out,
                                                        vectype_in);
}

/* Function vectorizable_call.

   Check if STMT performs a function call that can be vectorized. 
   If VEC_STMT is also passed, vectorize the STMT: create a vectorized 
   stmt to replace it, put it in VEC_STMT, and insert it at BSI.
   Return FALSE if not a vectorizable STMT, TRUE otherwise.  */

static bool
vectorizable_call (gimple stmt, gimple_stmt_iterator *gsi, gimple *vec_stmt)
{
  tree vec_dest;
  tree scalar_dest;
  tree op, type;
  tree vec_oprnd0 = NULL_TREE, vec_oprnd1 = NULL_TREE;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt), prev_stmt_info;
  tree vectype_out, vectype_in;
  int nunits_in;
  int nunits_out;
  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
  tree fndecl, new_temp, def, rhs_type, lhs_type;
  gimple def_stmt;
  enum vect_def_type dt[2] = {vect_unknown_def_type, vect_unknown_def_type};
  gimple new_stmt;
  int ncopies, j;
  VEC(tree, heap) *vargs = NULL;
  enum { NARROW, NONE, WIDEN } modifier;
  size_t i, nargs;

  if (!STMT_VINFO_RELEVANT_P (stmt_info))
    return false;

  if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def)
    return false;

  /* FORNOW: SLP not supported.  */
  if (STMT_SLP_TYPE (stmt_info))
    return false;

  /* Is STMT a vectorizable call?   */
  if (!is_gimple_call (stmt))
    return false;

  if (TREE_CODE (gimple_call_lhs (stmt)) != SSA_NAME)
    return false;

  /* Process function arguments.  */
  rhs_type = NULL_TREE;
  nargs = gimple_call_num_args (stmt);

  /* Bail out if the function has more than two arguments, we
     do not have interesting builtin functions to vectorize with
     more than two arguments.  No arguments is also not good.  */
  if (nargs == 0 || nargs > 2)
    return false;

  for (i = 0; i < nargs; i++)
    {
      op = gimple_call_arg (stmt, i);

      /* We can only handle calls with arguments of the same type.  */
      if (rhs_type
          && rhs_type != TREE_TYPE (op))
        {
          if (vect_print_dump_info (REPORT_DETAILS))
            fprintf (vect_dump, "argument types differ.");
          return false;
        }
      rhs_type = TREE_TYPE (op);

      if (!vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt[i]))
        {
          if (vect_print_dump_info (REPORT_DETAILS))
            fprintf (vect_dump, "use not simple.");
          return false;
        }
    }

  vectype_in = get_vectype_for_scalar_type (rhs_type);
  if (!vectype_in)
    return false;
  nunits_in = TYPE_VECTOR_SUBPARTS (vectype_in);

  lhs_type = TREE_TYPE (gimple_call_lhs (stmt));
  vectype_out = get_vectype_for_scalar_type (lhs_type);
  if (!vectype_out)
    return false;
  nunits_out = TYPE_VECTOR_SUBPARTS (vectype_out);

  /* FORNOW */
  if (nunits_in == nunits_out / 2)
    modifier = NARROW;
  else if (nunits_out == nunits_in)
    modifier = NONE;
  else if (nunits_out == nunits_in / 2)
    modifier = WIDEN;
  else
    return false;

  /* For now, we only vectorize functions if a target specific builtin
     is available.  TODO -- in some cases, it might be profitable to
     insert the calls for pieces of the vector, in order to be able
     to vectorize other operations in the loop.  */
  fndecl = vectorizable_function (stmt, vectype_out, vectype_in);
  if (fndecl == NULL_TREE)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "function is not vectorizable.");

      return false;
    }

  gcc_assert (!gimple_vuse (stmt));

  if (modifier == NARROW)
    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_out;
  else
    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_in;

  /* Sanity check: make sure that at least one copy of the vectorized stmt
     needs to be generated.  */
  gcc_assert (ncopies >= 1);

  if (!vec_stmt) /* transformation not required.  */
    {
      STMT_VINFO_TYPE (stmt_info) = call_vec_info_type;
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "=== vectorizable_call ===");
      vect_model_simple_cost (stmt_info, ncopies, dt, NULL);
      return true;
    }

  /** Transform.  **/

  if (vect_print_dump_info (REPORT_DETAILS))
    fprintf (vect_dump, "transform operation.");

  /* Handle def.  */
  scalar_dest = gimple_call_lhs (stmt);
  vec_dest = vect_create_destination_var (scalar_dest, vectype_out);

  prev_stmt_info = NULL;
  switch (modifier)
    {
    case NONE:
      for (j = 0; j < ncopies; ++j)
        {
          /* Build argument list for the vectorized call.  */
          if (j == 0)
            vargs = VEC_alloc (tree, heap, nargs);
          else
            VEC_truncate (tree, vargs, 0);

          for (i = 0; i < nargs; i++)
            {
              op = gimple_call_arg (stmt, i);
              if (j == 0)
                vec_oprnd0
                  = vect_get_vec_def_for_operand (op, stmt, NULL);
              else
                vec_oprnd0
                  = vect_get_vec_def_for_stmt_copy (dt[nargs], vec_oprnd0);

              VEC_quick_push (tree, vargs, vec_oprnd0);
            }

          new_stmt = gimple_build_call_vec (fndecl, vargs);
          new_temp = make_ssa_name (vec_dest, new_stmt);
          gimple_call_set_lhs (new_stmt, new_temp);

          vect_finish_stmt_generation (stmt, new_stmt, gsi);

          if (j == 0)
            STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt = new_stmt;
          else
            STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;

          prev_stmt_info = vinfo_for_stmt (new_stmt);
        }

      break;

    case NARROW:
      for (j = 0; j < ncopies; ++j)
        {
          /* Build argument list for the vectorized call.  */
          if (j == 0)
            vargs = VEC_alloc (tree, heap, nargs * 2);
          else
            VEC_truncate (tree, vargs, 0);

          for (i = 0; i < nargs; i++)
            {
              op = gimple_call_arg (stmt, i);
              if (j == 0)
                {
                  vec_oprnd0
                    = vect_get_vec_def_for_operand (op, stmt, NULL);
                  vec_oprnd1
                    = vect_get_vec_def_for_stmt_copy (dt[nargs], vec_oprnd0);
                }
              else
                {
                  vec_oprnd0
                    = vect_get_vec_def_for_stmt_copy (dt[nargs], vec_oprnd1);
                  vec_oprnd1
                    = vect_get_vec_def_for_stmt_copy (dt[nargs], vec_oprnd0);
                }

              VEC_quick_push (tree, vargs, vec_oprnd0);
              VEC_quick_push (tree, vargs, vec_oprnd1);
            }

          new_stmt = gimple_build_call_vec (fndecl, vargs);
          new_temp = make_ssa_name (vec_dest, new_stmt);
          gimple_call_set_lhs (new_stmt, new_temp);

          vect_finish_stmt_generation (stmt, new_stmt, gsi);

          if (j == 0)
            STMT_VINFO_VEC_STMT (stmt_info) = new_stmt;
          else
            STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;

          prev_stmt_info = vinfo_for_stmt (new_stmt);
        }

      *vec_stmt = STMT_VINFO_VEC_STMT (stmt_info);

      break;

    case WIDEN:
      /* No current target implements this case.  */
      return false;
    }

  VEC_free (tree, heap, vargs);

  /* Update the exception handling table with the vector stmt if necessary.  */
  if (maybe_clean_or_replace_eh_stmt (stmt, *vec_stmt))
    gimple_purge_dead_eh_edges (gimple_bb (stmt));

  /* The call in STMT might prevent it from being removed in dce.
     We however cannot remove it here, due to the way the ssa name
     it defines is mapped to the new definition.  So just replace
     rhs of the statement with something harmless.  */

  type = TREE_TYPE (scalar_dest);
  new_stmt = gimple_build_assign (gimple_call_lhs (stmt),
                                  fold_convert (type, integer_zero_node));
  set_vinfo_for_stmt (new_stmt, stmt_info);
  set_vinfo_for_stmt (stmt, NULL);
  STMT_VINFO_STMT (stmt_info) = new_stmt;
  gsi_replace (gsi, new_stmt, false);
  SSA_NAME_DEF_STMT (gimple_assign_lhs (new_stmt)) = new_stmt;

  return true;
}


/* Function vect_gen_widened_results_half

   Create a vector stmt whose code, type, number of arguments, and result
   variable are CODE, OP_TYPE, and VEC_DEST, and its arguments are 
   VEC_OPRND0 and VEC_OPRND1. The new vector stmt is to be inserted at BSI.
   In the case that CODE is a CALL_EXPR, this means that a call to DECL
   needs to be created (DECL is a function-decl of a target-builtin).
   STMT is the original scalar stmt that we are vectorizing.  */

static gimple
vect_gen_widened_results_half (enum tree_code code,
                               tree decl,
                               tree vec_oprnd0, tree vec_oprnd1, int op_type,
                               tree vec_dest, gimple_stmt_iterator *gsi,
                               gimple stmt)
{ 
  gimple new_stmt;
  tree new_temp; 
 
  /* Generate half of the widened result:  */ 
  if (code == CALL_EXPR) 
    {  
      /* Target specific support  */ 
      if (op_type == binary_op)
        new_stmt = gimple_build_call (decl, 2, vec_oprnd0, vec_oprnd1);
      else
        new_stmt = gimple_build_call (decl, 1, vec_oprnd0);
      new_temp = make_ssa_name (vec_dest, new_stmt);
      gimple_call_set_lhs (new_stmt, new_temp);
    } 
  else 
    {
      /* Generic support */ 
      gcc_assert (op_type == TREE_CODE_LENGTH (code)); 
      if (op_type != binary_op)
        vec_oprnd1 = NULL;
      new_stmt = gimple_build_assign_with_ops (code, vec_dest, vec_oprnd0,
                                               vec_oprnd1);
      new_temp = make_ssa_name (vec_dest, new_stmt);
      gimple_assign_set_lhs (new_stmt, new_temp);
    } 
  vect_finish_stmt_generation (stmt, new_stmt, gsi);

  return new_stmt;
}


/* Check if STMT performs a conversion operation, that can be vectorized. 
   If VEC_STMT is also passed, vectorize the STMT: create a vectorized 
   stmt to replace it, put it in VEC_STMT, and insert it at BSI.
   Return FALSE if not a vectorizable STMT, TRUE otherwise.  */

static bool
vectorizable_conversion (gimple stmt, gimple_stmt_iterator *gsi,
                         gimple *vec_stmt, slp_tree slp_node)
{
  tree vec_dest;
  tree scalar_dest;
  tree op0;
  tree vec_oprnd0 = NULL_TREE, vec_oprnd1 = NULL_TREE;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
  enum tree_code code, code1 = ERROR_MARK, code2 = ERROR_MARK;
  tree decl1 = NULL_TREE, decl2 = NULL_TREE;
  tree new_temp;
  tree def;
  gimple def_stmt;
  enum vect_def_type dt[2] = {vect_unknown_def_type, vect_unknown_def_type};
  gimple new_stmt = NULL;
  stmt_vec_info prev_stmt_info;
  int nunits_in;
  int nunits_out;
  tree vectype_out, vectype_in;
  int ncopies, j;
  tree expr;
  tree rhs_type, lhs_type;
  tree builtin_decl;
  enum { NARROW, NONE, WIDEN } modifier;
  int i;
  VEC(tree,heap) *vec_oprnds0 = NULL;
  tree vop0;
  tree integral_type;
  VEC(tree,heap) *dummy = NULL;
  int dummy_int;

  /* Is STMT a vectorizable conversion?   */

  if (!STMT_VINFO_RELEVANT_P (stmt_info))
    return false;

  if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def)
    return false;

  if (!is_gimple_assign (stmt))
    return false;

  if (TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME)
    return false;

  code = gimple_assign_rhs_code (stmt);
  if (code != FIX_TRUNC_EXPR && code != FLOAT_EXPR)
    return false;

  /* Check types of lhs and rhs.  */
  op0 = gimple_assign_rhs1 (stmt);
  rhs_type = TREE_TYPE (op0);
  vectype_in = get_vectype_for_scalar_type (rhs_type);
  if (!vectype_in)
    return false;
  nunits_in = TYPE_VECTOR_SUBPARTS (vectype_in);

  scalar_dest = gimple_assign_lhs (stmt);
  lhs_type = TREE_TYPE (scalar_dest);
  vectype_out = get_vectype_for_scalar_type (lhs_type);
  if (!vectype_out)
    return false;
  nunits_out = TYPE_VECTOR_SUBPARTS (vectype_out);

  /* FORNOW */
  if (nunits_in == nunits_out / 2)
    modifier = NARROW;
  else if (nunits_out == nunits_in)
    modifier = NONE;
  else if (nunits_out == nunits_in / 2)
    modifier = WIDEN;
  else
    return false;

  if (modifier == NONE)
    gcc_assert (STMT_VINFO_VECTYPE (stmt_info) == vectype_out);

  /* Bail out if the types are both integral or non-integral.  */
  if ((INTEGRAL_TYPE_P (rhs_type) && INTEGRAL_TYPE_P (lhs_type))
      || (!INTEGRAL_TYPE_P (rhs_type) && !INTEGRAL_TYPE_P (lhs_type)))
    return false;

  integral_type = INTEGRAL_TYPE_P (rhs_type) ? vectype_in : vectype_out;

  if (modifier == NARROW)
    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_out;
  else
    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_in;

  /* FORNOW: SLP with multiple types is not supported. The SLP analysis verifies
     this, so we can safely override NCOPIES with 1 here.  */
  if (slp_node)
    ncopies = 1;
  
  /* Sanity check: make sure that at least one copy of the vectorized stmt
     needs to be generated.  */
  gcc_assert (ncopies >= 1);

  /* Check the operands of the operation.  */
  if (!vect_is_simple_use (op0, loop_vinfo, &def_stmt, &def, &dt[0]))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "use not simple.");
      return false;
    }

  /* Supportable by target?  */
  if ((modifier == NONE
       && !targetm.vectorize.builtin_conversion (code, integral_type))
      || (modifier == WIDEN
          && !supportable_widening_operation (code, stmt, vectype_in,
                                              &decl1, &decl2,
                                              &code1, &code2,
                                              &dummy_int, &dummy))
      || (modifier == NARROW
          && !supportable_narrowing_operation (code, stmt, vectype_in,
                                               &code1, &dummy_int, &dummy)))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "conversion not supported by target.");
      return false;
    }

  if (modifier != NONE)
    {
      STMT_VINFO_VECTYPE (stmt_info) = vectype_in;
      /* FORNOW: SLP not supported.  */
      if (STMT_SLP_TYPE (stmt_info))
        return false;      
    }

  if (!vec_stmt)                /* transformation not required.  */
    {
      STMT_VINFO_TYPE (stmt_info) = type_conversion_vec_info_type;
      return true;
    }

  /** Transform.  **/
  if (vect_print_dump_info (REPORT_DETAILS))
    fprintf (vect_dump, "transform conversion.");

  /* Handle def.  */
  vec_dest = vect_create_destination_var (scalar_dest, vectype_out);

  if (modifier == NONE && !slp_node)
    vec_oprnds0 = VEC_alloc (tree, heap, 1);

  prev_stmt_info = NULL;
  switch (modifier)
    {
    case NONE:
      for (j = 0; j < ncopies; j++)
        {
          if (j == 0)
            vect_get_vec_defs (op0, NULL, stmt, &vec_oprnds0, NULL, slp_node); 
          else
            vect_get_vec_defs_for_stmt_copy (dt, &vec_oprnds0, NULL);

          builtin_decl =
            targetm.vectorize.builtin_conversion (code, integral_type);
          for (i = 0; VEC_iterate (tree, vec_oprnds0, i, vop0); i++)
            { 
              /* Arguments are ready. create the new vector stmt.  */
              new_stmt = gimple_build_call (builtin_decl, 1, vop0);
              new_temp = make_ssa_name (vec_dest, new_stmt);
              gimple_call_set_lhs (new_stmt, new_temp);
              vect_finish_stmt_generation (stmt, new_stmt, gsi);
              if (slp_node)
                VEC_quick_push (gimple, SLP_TREE_VEC_STMTS (slp_node), new_stmt);
            }

          if (j == 0)
            STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt = new_stmt;
          else
            STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;
          prev_stmt_info = vinfo_for_stmt (new_stmt);
        }
      break;

    case WIDEN:
      /* In case the vectorization factor (VF) is bigger than the number
         of elements that we can fit in a vectype (nunits), we have to
         generate more than one vector stmt - i.e - we need to "unroll"
         the vector stmt by a factor VF/nunits.  */
      for (j = 0; j < ncopies; j++)
        {
          if (j == 0)
            vec_oprnd0 = vect_get_vec_def_for_operand (op0, stmt, NULL);
          else
            vec_oprnd0 = vect_get_vec_def_for_stmt_copy (dt[0], vec_oprnd0);

          STMT_VINFO_VECTYPE (stmt_info) = vectype_in;

          /* Generate first half of the widened result:  */
          new_stmt
            = vect_gen_widened_results_half (code1, decl1, 
                                             vec_oprnd0, vec_oprnd1,
                                             unary_op, vec_dest, gsi, stmt);
          if (j == 0)
            STMT_VINFO_VEC_STMT (stmt_info) = new_stmt;
          else
            STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;
          prev_stmt_info = vinfo_for_stmt (new_stmt);

          /* Generate second half of the widened result:  */
          new_stmt
            = vect_gen_widened_results_half (code2, decl2,
                                             vec_oprnd0, vec_oprnd1,
                                             unary_op, vec_dest, gsi, stmt);
          STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;
          prev_stmt_info = vinfo_for_stmt (new_stmt);
        }
      break;

    case NARROW:
      /* In case the vectorization factor (VF) is bigger than the number
         of elements that we can fit in a vectype (nunits), we have to
         generate more than one vector stmt - i.e - we need to "unroll"
         the vector stmt by a factor VF/nunits.  */
      for (j = 0; j < ncopies; j++)
        {
          /* Handle uses.  */
          if (j == 0)
            {
              vec_oprnd0 = vect_get_vec_def_for_operand (op0, stmt, NULL);
              vec_oprnd1 = vect_get_vec_def_for_stmt_copy (dt[0], vec_oprnd0);
            }
          else
            {
              vec_oprnd0 = vect_get_vec_def_for_stmt_copy (dt[0], vec_oprnd1);
              vec_oprnd1 = vect_get_vec_def_for_stmt_copy (dt[0], vec_oprnd0);
            }

          /* Arguments are ready. Create the new vector stmt.  */
          expr = build2 (code1, vectype_out, vec_oprnd0, vec_oprnd1);
          new_stmt = gimple_build_assign_with_ops (code1, vec_dest, vec_oprnd0,
                                                   vec_oprnd1);
          new_temp = make_ssa_name (vec_dest, new_stmt);
          gimple_assign_set_lhs (new_stmt, new_temp);
          vect_finish_stmt_generation (stmt, new_stmt, gsi);

          if (j == 0)
            STMT_VINFO_VEC_STMT (stmt_info) = new_stmt;
          else
            STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;

          prev_stmt_info = vinfo_for_stmt (new_stmt);
        }

      *vec_stmt = STMT_VINFO_VEC_STMT (stmt_info);
    }

  if (vec_oprnds0)
    VEC_free (tree, heap, vec_oprnds0); 

  return true;
}
/* Function vectorizable_assignment.

   Check if STMT performs an assignment (copy) that can be vectorized. 
   If VEC_STMT is also passed, vectorize the STMT: create a vectorized 
   stmt to replace it, put it in VEC_STMT, and insert it at BSI.
   Return FALSE if not a vectorizable STMT, TRUE otherwise.  */

static bool
vectorizable_assignment (gimple stmt, gimple_stmt_iterator *gsi,
                         gimple *vec_stmt, slp_tree slp_node)
{
  tree vec_dest;
  tree scalar_dest;
  tree op;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  tree vectype = STMT_VINFO_VECTYPE (stmt_info);
  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
  tree new_temp;
  tree def;
  gimple def_stmt;
  enum vect_def_type dt[2] = {vect_unknown_def_type, vect_unknown_def_type};
  int nunits = TYPE_VECTOR_SUBPARTS (vectype);
  int ncopies;
  int i;
  VEC(tree,heap) *vec_oprnds = NULL;
  tree vop;

  /* Multiple types in SLP are handled by creating the appropriate number of
     vectorized stmts for each SLP node. Hence, NCOPIES is always 1 in
     case of SLP.  */
  if (slp_node)
    ncopies = 1;
  else
    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;

  gcc_assert (ncopies >= 1);
  if (ncopies > 1)
    return false; /* FORNOW */

  if (!STMT_VINFO_RELEVANT_P (stmt_info))
    return false;

  if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def)
    return false;

  /* Is vectorizable assignment?  */
  if (!is_gimple_assign (stmt))
    return false;

  scalar_dest = gimple_assign_lhs (stmt);
  if (TREE_CODE (scalar_dest) != SSA_NAME)
    return false;

  if (gimple_assign_single_p (stmt)
      || gimple_assign_rhs_code (stmt) == PAREN_EXPR)
    op = gimple_assign_rhs1 (stmt);
  else
    return false;

  if (!vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt[0]))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "use not simple.");
      return false;
    }

  if (!vec_stmt) /* transformation not required.  */
    {
      STMT_VINFO_TYPE (stmt_info) = assignment_vec_info_type;
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "=== vectorizable_assignment ===");
      vect_model_simple_cost (stmt_info, ncopies, dt, NULL);
      return true;
    }

  /** Transform.  **/
  if (vect_print_dump_info (REPORT_DETAILS))
    fprintf (vect_dump, "transform assignment.");

  /* Handle def.  */
  vec_dest = vect_create_destination_var (scalar_dest, vectype);

  /* Handle use.  */
  vect_get_vec_defs (op, NULL, stmt, &vec_oprnds, NULL, slp_node);

  /* Arguments are ready. create the new vector stmt.  */
  for (i = 0; VEC_iterate (tree, vec_oprnds, i, vop); i++)
    {
      *vec_stmt = gimple_build_assign (vec_dest, vop);
      new_temp = make_ssa_name (vec_dest, *vec_stmt);
      gimple_assign_set_lhs (*vec_stmt, new_temp);
      vect_finish_stmt_generation (stmt, *vec_stmt, gsi);
      STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt;

      if (slp_node)
        VEC_quick_push (gimple, SLP_TREE_VEC_STMTS (slp_node), *vec_stmt);
   }
  
  VEC_free (tree, heap, vec_oprnds);       
  return true;
}

/* Function vectorizable_operation.

   Check if STMT performs a binary or unary operation that can be vectorized. 
   If VEC_STMT is also passed, vectorize the STMT: create a vectorized 
   stmt to replace it, put it in VEC_STMT, and insert it at BSI.
   Return FALSE if not a vectorizable STMT, TRUE otherwise.  */

static bool
vectorizable_operation (gimple stmt, gimple_stmt_iterator *gsi,
                        gimple *vec_stmt, slp_tree slp_node)
{
  tree vec_dest;
  tree scalar_dest;
  tree op0, op1 = NULL;
  tree vec_oprnd1 = NULL_TREE;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  tree vectype = STMT_VINFO_VECTYPE (stmt_info);
  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
  enum tree_code code;
  enum machine_mode vec_mode;
  tree new_temp;
  int op_type;
  optab optab;
  int icode;
  enum machine_mode optab_op2_mode;
  tree def;
  gimple def_stmt;
  enum vect_def_type dt[2] = {vect_unknown_def_type, vect_unknown_def_type};
  gimple new_stmt = NULL;
  stmt_vec_info prev_stmt_info;
  int nunits_in = TYPE_VECTOR_SUBPARTS (vectype);
  int nunits_out;
  tree vectype_out;
  int ncopies;
  int j, i;
  VEC(tree,heap) *vec_oprnds0 = NULL, *vec_oprnds1 = NULL;
  tree vop0, vop1;
  unsigned int k;
  bool shift_p = false;
  bool scalar_shift_arg = false;

  /* Multiple types in SLP are handled by creating the appropriate number of
     vectorized stmts for each SLP node. Hence, NCOPIES is always 1 in
     case of SLP.  */
  if (slp_node)
    ncopies = 1;
  else
    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_in;

  gcc_assert (ncopies >= 1);

  if (!STMT_VINFO_RELEVANT_P (stmt_info))
    return false;

  if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def)
    return false;

  /* Is STMT a vectorizable binary/unary operation?   */
  if (!is_gimple_assign (stmt))
    return false;

  if (TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME)
    return false;

  scalar_dest = gimple_assign_lhs (stmt);
  vectype_out = get_vectype_for_scalar_type (TREE_TYPE (scalar_dest));
  if (!vectype_out)
    return false;
  nunits_out = TYPE_VECTOR_SUBPARTS (vectype_out);
  if (nunits_out != nunits_in)
    return false;

  code = gimple_assign_rhs_code (stmt);

  /* For pointer addition, we should use the normal plus for
     the vector addition.  */
  if (code == POINTER_PLUS_EXPR)
    code = PLUS_EXPR;

  /* Support only unary or binary operations.  */
  op_type = TREE_CODE_LENGTH (code);
  if (op_type != unary_op && op_type != binary_op)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "num. args = %d (not unary/binary op).", op_type);
      return false;
    }

  op0 = gimple_assign_rhs1 (stmt);
  if (!vect_is_simple_use (op0, loop_vinfo, &def_stmt, &def, &dt[0]))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "use not simple.");
      return false;
    }

  if (op_type == binary_op)
    {
      op1 = gimple_assign_rhs2 (stmt);
      if (!vect_is_simple_use (op1, loop_vinfo, &def_stmt, &def, &dt[1]))
        {
          if (vect_print_dump_info (REPORT_DETAILS))
            fprintf (vect_dump, "use not simple.");
          return false;
        }
    }

  /* If this is a shift/rotate, determine whether the shift amount is a vector,
     or scalar.  If the shift/rotate amount is a vector, use the vector/vector
     shift optabs.  */
  if (code == LSHIFT_EXPR || code == RSHIFT_EXPR || code == LROTATE_EXPR
      || code == RROTATE_EXPR)
    {
      shift_p = true;

      /* vector shifted by vector */
      if (dt[1] == vect_internal_def)
        {
          optab = optab_for_tree_code (code, vectype, optab_vector);
          if (vect_print_dump_info (REPORT_DETAILS))
            fprintf (vect_dump, "vector/vector shift/rotate found.");
        }

      /* See if the machine has a vector shifted by scalar insn and if not
         then see if it has a vector shifted by vector insn */
      else if (dt[1] == vect_constant_def || dt[1] == vect_external_def)
        {
          optab = optab_for_tree_code (code, vectype, optab_scalar);
          if (optab
              && (optab_handler (optab, TYPE_MODE (vectype))->insn_code
                  != CODE_FOR_nothing))
            {
              scalar_shift_arg = true;
              if (vect_print_dump_info (REPORT_DETAILS))
                fprintf (vect_dump, "vector/scalar shift/rotate found.");
            }
          else
            {
              optab = optab_for_tree_code (code, vectype, optab_vector);
              if (vect_print_dump_info (REPORT_DETAILS)
                  && optab
                  && (optab_handler (optab, TYPE_MODE (vectype))->insn_code
                      != CODE_FOR_nothing))
                fprintf (vect_dump, "vector/vector shift/rotate found.");
            }
        }

      else
        {
          if (vect_print_dump_info (REPORT_DETAILS))
            fprintf (vect_dump, "operand mode requires invariant argument.");
          return false;
        }
    }
  else
    optab = optab_for_tree_code (code, vectype, optab_default);

  /* Supportable by target?  */
  if (!optab)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "no optab.");
      return false;
    }
  vec_mode = TYPE_MODE (vectype);
  icode = (int) optab_handler (optab, vec_mode)->insn_code;
  if (icode == CODE_FOR_nothing)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "op not supported by target.");
      /* Check only during analysis.  */
      if (GET_MODE_SIZE (vec_mode) != UNITS_PER_WORD
          || (LOOP_VINFO_VECT_FACTOR (loop_vinfo)
              < vect_min_worthwhile_factor (code)
              && !vec_stmt))
        return false;
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "proceeding using word mode.");
    }

  /* Worthwhile without SIMD support? Check only during analysis.  */
  if (!VECTOR_MODE_P (TYPE_MODE (vectype))
      && LOOP_VINFO_VECT_FACTOR (loop_vinfo)
         < vect_min_worthwhile_factor (code)
      && !vec_stmt)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "not worthwhile without SIMD support.");
      return false;
    }

  if (!vec_stmt) /* transformation not required.  */
    {
      STMT_VINFO_TYPE (stmt_info) = op_vec_info_type;
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "=== vectorizable_operation ===");
      vect_model_simple_cost (stmt_info, ncopies, dt, NULL);
      return true;
    }

  /** Transform.  **/

  if (vect_print_dump_info (REPORT_DETAILS))
    fprintf (vect_dump, "transform binary/unary operation.");

  /* Handle def.  */
  vec_dest = vect_create_destination_var (scalar_dest, vectype);

  /* Allocate VECs for vector operands. In case of SLP, vector operands are 
     created in the previous stages of the recursion, so no allocation is
     needed, except for the case of shift with scalar shift argument. In that
     case we store the scalar operand in VEC_OPRNDS1 for every vector stmt to
     be created to vectorize the SLP group, i.e., SLP_NODE->VEC_STMTS_SIZE.
     In case of loop-based vectorization we allocate VECs of size 1. We 
     allocate VEC_OPRNDS1 only in case of binary operation.  */ 
  if (!slp_node)
    {
      vec_oprnds0 = VEC_alloc (tree, heap, 1);
      if (op_type == binary_op)
        vec_oprnds1 = VEC_alloc (tree, heap, 1);
    }
  else if (scalar_shift_arg)
    vec_oprnds1 = VEC_alloc (tree, heap, slp_node->vec_stmts_size);  

  /* In case the vectorization factor (VF) is bigger than the number
     of elements that we can fit in a vectype (nunits), we have to generate
     more than one vector stmt - i.e - we need to "unroll" the
     vector stmt by a factor VF/nunits. In doing so, we record a pointer
     from one copy of the vector stmt to the next, in the field
     STMT_VINFO_RELATED_STMT. This is necessary in order to allow following
     stages to find the correct vector defs to be used when vectorizing
     stmts that use the defs of the current stmt. The example below illustrates
     the vectorization process when VF=16 and nunits=4 (i.e - we need to create
     4 vectorized stmts):

     before vectorization:
                                RELATED_STMT    VEC_STMT
        S1:     x = memref      -               -
        S2:     z = x + 1       -               -

     step 1: vectorize stmt S1 (done in vectorizable_load. See more details
             there):
                                RELATED_STMT    VEC_STMT
        VS1_0:  vx0 = memref0   VS1_1           -
        VS1_1:  vx1 = memref1   VS1_2           -
        VS1_2:  vx2 = memref2   VS1_3           -
        VS1_3:  vx3 = memref3   -               -
        S1:     x = load        -               VS1_0
        S2:     z = x + 1       -               -

     step2: vectorize stmt S2 (done here):
        To vectorize stmt S2 we first need to find the relevant vector
        def for the first operand 'x'. This is, as usual, obtained from
        the vector stmt recorded in the STMT_VINFO_VEC_STMT of the stmt
        that defines 'x' (S1). This way we find the stmt VS1_0, and the
        relevant vector def 'vx0'. Having found 'vx0' we can generate
        the vector stmt VS2_0, and as usual, record it in the
        STMT_VINFO_VEC_STMT of stmt S2.
        When creating the second copy (VS2_1), we obtain the relevant vector
        def from the vector stmt recorded in the STMT_VINFO_RELATED_STMT of
        stmt VS1_0. This way we find the stmt VS1_1 and the relevant
        vector def 'vx1'. Using 'vx1' we create stmt VS2_1 and record a
        pointer to it in the STMT_VINFO_RELATED_STMT of the vector stmt VS2_0.
        Similarly when creating stmts VS2_2 and VS2_3. This is the resulting
        chain of stmts and pointers:
                                RELATED_STMT    VEC_STMT
        VS1_0:  vx0 = memref0   VS1_1           -
        VS1_1:  vx1 = memref1   VS1_2           -
        VS1_2:  vx2 = memref2   VS1_3           -
        VS1_3:  vx3 = memref3   -               -
        S1:     x = load        -               VS1_0
        VS2_0:  vz0 = vx0 + v1  VS2_1           -
        VS2_1:  vz1 = vx1 + v1  VS2_2           -
        VS2_2:  vz2 = vx2 + v1  VS2_3           -
        VS2_3:  vz3 = vx3 + v1  -               -
        S2:     z = x + 1       -               VS2_0  */

  prev_stmt_info = NULL;
  for (j = 0; j < ncopies; j++)
    {
      /* Handle uses.  */
      if (j == 0)
        {
          if (op_type == binary_op && scalar_shift_arg)
            {
              /* Vector shl and shr insn patterns can be defined with scalar 
                 operand 2 (shift operand). In this case, use constant or loop 
                 invariant op1 directly, without extending it to vector mode 
                 first.  */
              optab_op2_mode = insn_data[icode].operand[2].mode;
              if (!VECTOR_MODE_P (optab_op2_mode))
                {
                  if (vect_print_dump_info (REPORT_DETAILS))
                    fprintf (vect_dump, "operand 1 using scalar mode.");
                  vec_oprnd1 = op1;
                  VEC_quick_push (tree, vec_oprnds1, vec_oprnd1);
                  if (slp_node)
                    {
                      /* Store vec_oprnd1 for every vector stmt to be created
                         for SLP_NODE. We check during the analysis that all the
                         shift arguments are the same.  
                         TODO: Allow different constants for different vector 
                         stmts generated for an SLP instance.  */          
                      for (k = 0; k < slp_node->vec_stmts_size - 1; k++)
                        VEC_quick_push (tree, vec_oprnds1, vec_oprnd1);
                    }
                }
            }
         
          /* vec_oprnd1 is available if operand 1 should be of a scalar-type 
             (a special case for certain kind of vector shifts); otherwise, 
             operand 1 should be of a vector type (the usual case).  */
          if (op_type == binary_op && !vec_oprnd1)
            vect_get_vec_defs (op0, op1, stmt, &vec_oprnds0, &vec_oprnds1, 
                               slp_node);
          else
            vect_get_vec_defs (op0, NULL_TREE, stmt, &vec_oprnds0, NULL, 
                               slp_node);
        }
      else
        vect_get_vec_defs_for_stmt_copy (dt, &vec_oprnds0, &vec_oprnds1);

      /* Arguments are ready. Create the new vector stmt.  */
      for (i = 0; VEC_iterate (tree, vec_oprnds0, i, vop0); i++)
        {
          vop1 = ((op_type == binary_op)
                  ? VEC_index (tree, vec_oprnds1, i) : NULL);
          new_stmt = gimple_build_assign_with_ops (code, vec_dest, vop0, vop1);
          new_temp = make_ssa_name (vec_dest, new_stmt);
          gimple_assign_set_lhs (new_stmt, new_temp);
          vect_finish_stmt_generation (stmt, new_stmt, gsi);
          if (slp_node)
            VEC_quick_push (gimple, SLP_TREE_VEC_STMTS (slp_node), new_stmt);
        }

      if (slp_node)
        continue;

      if (j == 0)
        STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt = new_stmt;
      else
        STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;
      prev_stmt_info = vinfo_for_stmt (new_stmt);
    }

  VEC_free (tree, heap, vec_oprnds0);
  if (vec_oprnds1)
    VEC_free (tree, heap, vec_oprnds1);

  return true;
}


/* Get vectorized definitions for loop-based vectorization. For the first
   operand we call vect_get_vec_def_for_operand() (with OPRND containing 
   scalar operand), and for the rest we get a copy with 
   vect_get_vec_def_for_stmt_copy() using the previous vector definition
   (stored in OPRND). See vect_get_vec_def_for_stmt_copy() for details.
   The vectors are collected into VEC_OPRNDS.  */

static void
vect_get_loop_based_defs (tree *oprnd, gimple stmt, enum vect_def_type dt, 
                          VEC (tree, heap) **vec_oprnds, int multi_step_cvt)
{
  tree vec_oprnd;

  /* Get first vector operand.  */
  /* All the vector operands except the very first one (that is scalar oprnd)
     are stmt copies.  */
  if (TREE_CODE (TREE_TYPE (*oprnd)) != VECTOR_TYPE)  
    vec_oprnd = vect_get_vec_def_for_operand (*oprnd, stmt, NULL);
  else
    vec_oprnd = vect_get_vec_def_for_stmt_copy (dt, *oprnd);

  VEC_quick_push (tree, *vec_oprnds, vec_oprnd);

  /* Get second vector operand.  */
  vec_oprnd = vect_get_vec_def_for_stmt_copy (dt, vec_oprnd);
  VEC_quick_push (tree, *vec_oprnds, vec_oprnd);
    
  *oprnd = vec_oprnd;

  /* For conversion in multiple steps, continue to get operands 
     recursively.  */
  if (multi_step_cvt)
    vect_get_loop_based_defs (oprnd, stmt, dt, vec_oprnds,  multi_step_cvt - 1); 
}


/* Create vectorized demotion statements for vector operands from VEC_OPRNDS.
   For multi-step conversions store the resulting vectors and call the function 
   recursively.  */

static void
vect_create_vectorized_demotion_stmts (VEC (tree, heap) **vec_oprnds,
                                       int multi_step_cvt, gimple stmt,
                                       VEC (tree, heap) *vec_dsts,
                                       gimple_stmt_iterator *gsi,
                                       slp_tree slp_node, enum tree_code code,
                                       stmt_vec_info *prev_stmt_info)
{
  unsigned int i;
  tree vop0, vop1, new_tmp, vec_dest;
  gimple new_stmt;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);

  vec_dest = VEC_pop (tree, vec_dsts); 

  for (i = 0; i < VEC_length (tree, *vec_oprnds); i += 2)
    {
      /* Create demotion operation.  */
      vop0 = VEC_index (tree, *vec_oprnds, i);
      vop1 = VEC_index (tree, *vec_oprnds, i + 1);
      new_stmt = gimple_build_assign_with_ops (code, vec_dest, vop0, vop1);
      new_tmp = make_ssa_name (vec_dest, new_stmt);
      gimple_assign_set_lhs (new_stmt, new_tmp);
      vect_finish_stmt_generation (stmt, new_stmt, gsi);

      if (multi_step_cvt)
        /* Store the resulting vector for next recursive call.  */
        VEC_replace (tree, *vec_oprnds, i/2, new_tmp);      
      else
        {
          /* This is the last step of the conversion sequence. Store the 
             vectors in SLP_NODE or in vector info of the scalar statement
             (or in STMT_VINFO_RELATED_STMT chain).  */
          if (slp_node)
            VEC_quick_push (gimple, SLP_TREE_VEC_STMTS (slp_node), new_stmt);
          else
            {
              if (!*prev_stmt_info)
                STMT_VINFO_VEC_STMT (stmt_info) = new_stmt;
              else
                STMT_VINFO_RELATED_STMT (*prev_stmt_info) = new_stmt;

              *prev_stmt_info = vinfo_for_stmt (new_stmt);
            }
        }
    }

  /* For multi-step demotion operations we first generate demotion operations
     from the source type to the intermediate types, and then combine the 
     results (stored in VEC_OPRNDS) in demotion operation to the destination
     type.  */
  if (multi_step_cvt)
    {
      /* At each level of recursion we have have of the operands we had at the
         previous level.  */
      VEC_truncate (tree, *vec_oprnds, (i+1)/2);
      vect_create_vectorized_demotion_stmts (vec_oprnds, multi_step_cvt - 1, 
                                             stmt, vec_dsts, gsi, slp_node,
                                             code, prev_stmt_info);
    }
}


/* Function vectorizable_type_demotion

   Check if STMT performs a binary or unary operation that involves
   type demotion, and if it can be vectorized.
   If VEC_STMT is also passed, vectorize the STMT: create a vectorized
   stmt to replace it, put it in VEC_STMT, and insert it at BSI.
   Return FALSE if not a vectorizable STMT, TRUE otherwise.  */

static bool
vectorizable_type_demotion (gimple stmt, gimple_stmt_iterator *gsi,
                            gimple *vec_stmt, slp_tree slp_node)
{
  tree vec_dest;
  tree scalar_dest;
  tree op0;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
  enum tree_code code, code1 = ERROR_MARK;
  tree def;
  gimple def_stmt;
  enum vect_def_type dt[2] = {vect_unknown_def_type, vect_unknown_def_type};
  stmt_vec_info prev_stmt_info;
  int nunits_in;
  int nunits_out;
  tree vectype_out;
  int ncopies;
  int j, i;
  tree vectype_in;
  int multi_step_cvt = 0;
  VEC (tree, heap) *vec_oprnds0 = NULL;
  VEC (tree, heap) *vec_dsts = NULL, *interm_types = NULL, *tmp_vec_dsts = NULL;
  tree last_oprnd, intermediate_type;

  if (!STMT_VINFO_RELEVANT_P (stmt_info))
    return false;

  if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def)
    return false;

  /* Is STMT a vectorizable type-demotion operation?  */
  if (!is_gimple_assign (stmt))
    return false;

  if (TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME)
    return false;

  code = gimple_assign_rhs_code (stmt);
  if (!CONVERT_EXPR_CODE_P (code))
    return false;

  op0 = gimple_assign_rhs1 (stmt);
  vectype_in = get_vectype_for_scalar_type (TREE_TYPE (op0));
  if (!vectype_in)
    return false;
  nunits_in = TYPE_VECTOR_SUBPARTS (vectype_in);

  scalar_dest = gimple_assign_lhs (stmt);
  vectype_out = get_vectype_for_scalar_type (TREE_TYPE (scalar_dest));
  if (!vectype_out)
    return false;
  nunits_out = TYPE_VECTOR_SUBPARTS (vectype_out);
  if (nunits_in >= nunits_out)
    return false;

  /* Multiple types in SLP are handled by creating the appropriate number of
     vectorized stmts for each SLP node. Hence, NCOPIES is always 1 in
     case of SLP.  */
  if (slp_node)
    ncopies = 1;
  else
    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_out;

  gcc_assert (ncopies >= 1);

  if (! ((INTEGRAL_TYPE_P (TREE_TYPE (scalar_dest))
          && INTEGRAL_TYPE_P (TREE_TYPE (op0)))
         || (SCALAR_FLOAT_TYPE_P (TREE_TYPE (scalar_dest))
             && SCALAR_FLOAT_TYPE_P (TREE_TYPE (op0))
             && CONVERT_EXPR_CODE_P (code))))
    return false;

  /* Check the operands of the operation.  */
  if (!vect_is_simple_use (op0, loop_vinfo, &def_stmt, &def, &dt[0]))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "use not simple.");
      return false;
    }

  /* Supportable by target?  */
  if (!supportable_narrowing_operation (code, stmt, vectype_in, &code1,
                                        &multi_step_cvt, &interm_types))
    return false;

  STMT_VINFO_VECTYPE (stmt_info) = vectype_in;

  if (!vec_stmt) /* transformation not required.  */
    {
      STMT_VINFO_TYPE (stmt_info) = type_demotion_vec_info_type;
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "=== vectorizable_demotion ===");
      vect_model_simple_cost (stmt_info, ncopies, dt, NULL);
      return true;
    }

  /** Transform.  **/
  if (vect_print_dump_info (REPORT_DETAILS))
    fprintf (vect_dump, "transform type demotion operation. ncopies = %d.",
             ncopies);

  /* In case of multi-step demotion, we first generate demotion operations to 
     the intermediate types, and then from that types to the final one. 
     We create vector destinations for the intermediate type (TYPES) received
     from supportable_narrowing_operation, and store them in the correct order 
     for future use in vect_create_vectorized_demotion_stmts().  */
  if (multi_step_cvt)
    vec_dsts = VEC_alloc (tree, heap, multi_step_cvt + 1);
  else
    vec_dsts = VEC_alloc (tree, heap, 1);
 
  vec_dest = vect_create_destination_var (scalar_dest, vectype_out);
  VEC_quick_push (tree, vec_dsts, vec_dest);

  if (multi_step_cvt)
    {
      for (i = VEC_length (tree, interm_types) - 1; 
           VEC_iterate (tree, interm_types, i, intermediate_type); i--)
        {
          vec_dest = vect_create_destination_var (scalar_dest, 
                                                  intermediate_type);
          VEC_quick_push (tree, vec_dsts, vec_dest);
        }
    }

  /* In case the vectorization factor (VF) is bigger than the number
     of elements that we can fit in a vectype (nunits), we have to generate
     more than one vector stmt - i.e - we need to "unroll" the
     vector stmt by a factor VF/nunits.   */
  last_oprnd = op0;
  prev_stmt_info = NULL;
  for (j = 0; j < ncopies; j++)
    {
      /* Handle uses.  */
      if (slp_node)
        vect_get_slp_defs (slp_node, &vec_oprnds0, NULL); 
      else
        {
          VEC_free (tree, heap, vec_oprnds0);
          vec_oprnds0 = VEC_alloc (tree, heap,
                        (multi_step_cvt ? vect_pow2 (multi_step_cvt) * 2 : 2));
          vect_get_loop_based_defs (&last_oprnd, stmt, dt[0], &vec_oprnds0,  
                                    vect_pow2 (multi_step_cvt) - 1);
        }

      /* Arguments are ready. Create the new vector stmts.  */
      tmp_vec_dsts = VEC_copy (tree, heap, vec_dsts);
      vect_create_vectorized_demotion_stmts (&vec_oprnds0,  
                                             multi_step_cvt, stmt, tmp_vec_dsts,
                                             gsi, slp_node, code1, 
                                             &prev_stmt_info);
    }

  VEC_free (tree, heap, vec_oprnds0);
  VEC_free (tree, heap, vec_dsts);
  VEC_free (tree, heap, tmp_vec_dsts);
  VEC_free (tree, heap, interm_types);

  *vec_stmt = STMT_VINFO_VEC_STMT (stmt_info);
  return true;
}


/* Create vectorized promotion statements for vector operands from VEC_OPRNDS0
   and VEC_OPRNDS1 (for binary operations). For multi-step conversions store 
   the resulting vectors and call the function recursively.  */

static void
vect_create_vectorized_promotion_stmts (VEC (tree, heap) **vec_oprnds0,
                                        VEC (tree, heap) **vec_oprnds1,
                                        int multi_step_cvt, gimple stmt,
                                        VEC (tree, heap) *vec_dsts,
                                        gimple_stmt_iterator *gsi,
                                        slp_tree slp_node, enum tree_code code1,
                                        enum tree_code code2, tree decl1, 
                                        tree decl2, int op_type,
                                        stmt_vec_info *prev_stmt_info)
{
  int i;
  tree vop0, vop1, new_tmp1, new_tmp2, vec_dest;
  gimple new_stmt1, new_stmt2;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  VEC (tree, heap) *vec_tmp;

  vec_dest = VEC_pop (tree, vec_dsts);
  vec_tmp = VEC_alloc (tree, heap, VEC_length (tree, *vec_oprnds0) * 2);

  for (i = 0; VEC_iterate (tree, *vec_oprnds0, i, vop0); i++)
    {
      if (op_type == binary_op)
        vop1 = VEC_index (tree, *vec_oprnds1, i);
      else
        vop1 = NULL_TREE;

      /* Generate the two halves of promotion operation.  */
      new_stmt1 = vect_gen_widened_results_half (code1, decl1, vop0, vop1,  
                                                 op_type, vec_dest, gsi, stmt);
      new_stmt2 = vect_gen_widened_results_half (code2, decl2, vop0, vop1,
                                                 op_type, vec_dest, gsi, stmt);
      if (is_gimple_call (new_stmt1))
        {
          new_tmp1 = gimple_call_lhs (new_stmt1);
          new_tmp2 = gimple_call_lhs (new_stmt2);
        }
      else
        {
          new_tmp1 = gimple_assign_lhs (new_stmt1);
          new_tmp2 = gimple_assign_lhs (new_stmt2);
        }

      if (multi_step_cvt)
        {
          /* Store the results for the recursive call.  */
          VEC_quick_push (tree, vec_tmp, new_tmp1);
          VEC_quick_push (tree, vec_tmp, new_tmp2);
        }
      else
        {
          /* Last step of promotion sequience - store the results.  */
          if (slp_node)
            {
              VEC_quick_push (gimple, SLP_TREE_VEC_STMTS (slp_node), new_stmt1);
              VEC_quick_push (gimple, SLP_TREE_VEC_STMTS (slp_node), new_stmt2);
            }
          else
            {
              if (!*prev_stmt_info)
                STMT_VINFO_VEC_STMT (stmt_info) = new_stmt1;
              else
                STMT_VINFO_RELATED_STMT (*prev_stmt_info) = new_stmt1;

              *prev_stmt_info = vinfo_for_stmt (new_stmt1);
              STMT_VINFO_RELATED_STMT (*prev_stmt_info) = new_stmt2;
              *prev_stmt_info = vinfo_for_stmt (new_stmt2);
            }
        }
    }

  if (multi_step_cvt)
    {
      /* For multi-step promotion operation we first generate we call the 
         function recurcively for every stage. We start from the input type,
         create promotion operations to the intermediate types, and then
         create promotions to the output type.  */
      *vec_oprnds0 = VEC_copy (tree, heap, vec_tmp);
      VEC_free (tree, heap, vec_tmp);
      vect_create_vectorized_promotion_stmts (vec_oprnds0, vec_oprnds1,
                                              multi_step_cvt - 1, stmt,
                                              vec_dsts, gsi, slp_node, code1,
                                              code2, decl2, decl2, op_type,
                                              prev_stmt_info);
    }
}


/* Function vectorizable_type_promotion

   Check if STMT performs a binary or unary operation that involves
   type promotion, and if it can be vectorized.
   If VEC_STMT is also passed, vectorize the STMT: create a vectorized
   stmt to replace it, put it in VEC_STMT, and insert it at BSI.
   Return FALSE if not a vectorizable STMT, TRUE otherwise.  */

static bool
vectorizable_type_promotion (gimple stmt, gimple_stmt_iterator *gsi,
                             gimple *vec_stmt, slp_tree slp_node)
{
  tree vec_dest;
  tree scalar_dest;
  tree op0, op1 = NULL;
  tree vec_oprnd0=NULL, vec_oprnd1=NULL;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
  enum tree_code code, code1 = ERROR_MARK, code2 = ERROR_MARK;
  tree decl1 = NULL_TREE, decl2 = NULL_TREE;
  int op_type; 
  tree def;
  gimple def_stmt;
  enum vect_def_type dt[2] = {vect_unknown_def_type, vect_unknown_def_type};
  stmt_vec_info prev_stmt_info;
  int nunits_in;
  int nunits_out;
  tree vectype_out;
  int ncopies;
  int j, i;
  tree vectype_in;
  tree intermediate_type = NULL_TREE;
  int multi_step_cvt = 0;
  VEC (tree, heap) *vec_oprnds0 = NULL, *vec_oprnds1 = NULL;
  VEC (tree, heap) *vec_dsts = NULL, *interm_types = NULL, *tmp_vec_dsts = NULL;
  
  if (!STMT_VINFO_RELEVANT_P (stmt_info))
    return false;

  if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def)
    return false;

  /* Is STMT a vectorizable type-promotion operation?  */
  if (!is_gimple_assign (stmt))
    return false;

  if (TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME)
    return false;

  code = gimple_assign_rhs_code (stmt);
  if (!CONVERT_EXPR_CODE_P (code)
      && code != WIDEN_MULT_EXPR)
    return false;

  op0 = gimple_assign_rhs1 (stmt);
  vectype_in = get_vectype_for_scalar_type (TREE_TYPE (op0));
  if (!vectype_in)
    return false;
  nunits_in = TYPE_VECTOR_SUBPARTS (vectype_in);

  scalar_dest = gimple_assign_lhs (stmt);
  vectype_out = get_vectype_for_scalar_type (TREE_TYPE (scalar_dest));
  if (!vectype_out)
    return false;
  nunits_out = TYPE_VECTOR_SUBPARTS (vectype_out);
  if (nunits_in <= nunits_out)
    return false;

  /* Multiple types in SLP are handled by creating the appropriate number of
     vectorized stmts for each SLP node. Hence, NCOPIES is always 1 in
     case of SLP.  */
  if (slp_node)
    ncopies = 1;
  else
    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_in;

  gcc_assert (ncopies >= 1);

  if (! ((INTEGRAL_TYPE_P (TREE_TYPE (scalar_dest))
          && INTEGRAL_TYPE_P (TREE_TYPE (op0)))
         || (SCALAR_FLOAT_TYPE_P (TREE_TYPE (scalar_dest))
             && SCALAR_FLOAT_TYPE_P (TREE_TYPE (op0))
             && CONVERT_EXPR_CODE_P (code))))
    return false;

  /* Check the operands of the operation.  */
  if (!vect_is_simple_use (op0, loop_vinfo, &def_stmt, &def, &dt[0]))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "use not simple.");
      return false;
    }

  op_type = TREE_CODE_LENGTH (code);
  if (op_type == binary_op)
    {
      op1 = gimple_assign_rhs2 (stmt);
      if (!vect_is_simple_use (op1, loop_vinfo, &def_stmt, &def, &dt[1]))
        {
          if (vect_print_dump_info (REPORT_DETAILS))
            fprintf (vect_dump, "use not simple.");
          return false;
        }
    }

  /* Supportable by target?  */
  if (!supportable_widening_operation (code, stmt, vectype_in,
                                       &decl1, &decl2, &code1, &code2,
                                       &multi_step_cvt, &interm_types))
    return false;

  /* Binary widening operation can only be supported directly by the
     architecture.  */
  gcc_assert (!(multi_step_cvt && op_type == binary_op));

  STMT_VINFO_VECTYPE (stmt_info) = vectype_in;

  if (!vec_stmt) /* transformation not required.  */
    {
      STMT_VINFO_TYPE (stmt_info) = type_promotion_vec_info_type;
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "=== vectorizable_promotion ===");
      vect_model_simple_cost (stmt_info, 2*ncopies, dt, NULL);
      return true;
    }

  /** Transform.  **/

  if (vect_print_dump_info (REPORT_DETAILS))
    fprintf (vect_dump, "transform type promotion operation. ncopies = %d.",
                        ncopies);

  /* Handle def.  */
  /* In case of multi-step promotion, we first generate promotion operations 
     to the intermediate types, and then from that types to the final one.
     We store vector destination in VEC_DSTS in the correct order for 
     recursive creation of promotion operations in 
     vect_create_vectorized_promotion_stmts(). Vector destinations are created
     according to TYPES recieved from supportable_widening_operation().   */
  if (multi_step_cvt)
    vec_dsts = VEC_alloc (tree, heap, multi_step_cvt + 1);
  else
    vec_dsts = VEC_alloc (tree, heap, 1);

  vec_dest = vect_create_destination_var (scalar_dest, vectype_out);
  VEC_quick_push (tree, vec_dsts, vec_dest);

  if (multi_step_cvt)
    {
      for (i = VEC_length (tree, interm_types) - 1;
           VEC_iterate (tree, interm_types, i, intermediate_type); i--)
        {
          vec_dest = vect_create_destination_var (scalar_dest,
                                                  intermediate_type);
          VEC_quick_push (tree, vec_dsts, vec_dest);
        }
    }
  
  if (!slp_node)
    {
      vec_oprnds0 = VEC_alloc (tree, heap, 
                            (multi_step_cvt ? vect_pow2 (multi_step_cvt) : 1));
      if (op_type == binary_op)
        vec_oprnds1 = VEC_alloc (tree, heap, 1);
    }

  /* In case the vectorization factor (VF) is bigger than the number
     of elements that we can fit in a vectype (nunits), we have to generate
     more than one vector stmt - i.e - we need to "unroll" the
     vector stmt by a factor VF/nunits.   */

  prev_stmt_info = NULL;
  for (j = 0; j < ncopies; j++)
    {
      /* Handle uses.  */
      if (j == 0)
        {
          if (slp_node)
              vect_get_slp_defs (slp_node, &vec_oprnds0, &vec_oprnds1);
          else
            {
              vec_oprnd0 = vect_get_vec_def_for_operand (op0, stmt, NULL);
              VEC_quick_push (tree, vec_oprnds0, vec_oprnd0);
              if (op_type == binary_op)
                {
                  vec_oprnd1 = vect_get_vec_def_for_operand (op1, stmt, NULL);
                  VEC_quick_push (tree, vec_oprnds1, vec_oprnd1);
                }
            }
        }
      else
        {
          vec_oprnd0 = vect_get_vec_def_for_stmt_copy (dt[0], vec_oprnd0);
          VEC_replace (tree, vec_oprnds0, 0, vec_oprnd0);
          if (op_type == binary_op)
            {
              vec_oprnd1 = vect_get_vec_def_for_stmt_copy (dt[1], vec_oprnd1);
              VEC_replace (tree, vec_oprnds1, 0, vec_oprnd1);
            }
        }

      /* Arguments are ready. Create the new vector stmts.  */
      tmp_vec_dsts = VEC_copy (tree, heap, vec_dsts);
      vect_create_vectorized_promotion_stmts (&vec_oprnds0, &vec_oprnds1,
                                              multi_step_cvt, stmt, 
                                              tmp_vec_dsts,
                                              gsi, slp_node, code1, code2,
                                              decl1, decl2, op_type,
                                              &prev_stmt_info);
    }

  VEC_free (tree, heap, vec_dsts);
  VEC_free (tree, heap, tmp_vec_dsts);
  VEC_free (tree, heap, interm_types);
  VEC_free (tree, heap, vec_oprnds0);
  VEC_free (tree, heap, vec_oprnds1);

  *vec_stmt = STMT_VINFO_VEC_STMT (stmt_info);
  return true;
}


/* Function vectorizable_store.

   Check if STMT defines a non scalar data-ref (array/pointer/structure) that 
   can be vectorized. 
   If VEC_STMT is also passed, vectorize the STMT: create a vectorized 
   stmt to replace it, put it in VEC_STMT, and insert it at BSI.
   Return FALSE if not a vectorizable STMT, TRUE otherwise.  */

static bool
vectorizable_store (gimple stmt, gimple_stmt_iterator *gsi, gimple *vec_stmt,
                    slp_tree slp_node)
{
  tree scalar_dest;
  tree data_ref;
  tree op;
  tree vec_oprnd = NULL_TREE;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info), *first_dr = NULL;
  tree vectype = STMT_VINFO_VECTYPE (stmt_info);
  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
  struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
  enum machine_mode vec_mode;
  tree dummy;
  enum dr_alignment_support alignment_support_scheme;
  tree def;
  gimple def_stmt;
  enum vect_def_type dt;
  stmt_vec_info prev_stmt_info = NULL;
  tree dataref_ptr = NULL_TREE;
  int nunits = TYPE_VECTOR_SUBPARTS (vectype);
  int ncopies;
  int j;
  gimple next_stmt, first_stmt = NULL;
  bool strided_store = false;
  unsigned int group_size, i;
  VEC(tree,heap) *dr_chain = NULL, *oprnds = NULL, *result_chain = NULL;
  bool inv_p;
  VEC(tree,heap) *vec_oprnds = NULL;
  bool slp = (slp_node != NULL);
  stmt_vec_info first_stmt_vinfo;
  unsigned int vec_num;

  /* Multiple types in SLP are handled by creating the appropriate number of
     vectorized stmts for each SLP node. Hence, NCOPIES is always 1 in
     case of SLP.  */
  if (slp)
    ncopies = 1;
  else
    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;

  gcc_assert (ncopies >= 1);

  /* FORNOW. This restriction should be relaxed.  */
  if (nested_in_vect_loop_p (loop, stmt) && ncopies > 1)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "multiple types in nested loop.");
      return false;
    }

  if (!STMT_VINFO_RELEVANT_P (stmt_info))
    return false;

  if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def)
    return false;

  /* Is vectorizable store? */

  if (!is_gimple_assign (stmt))
    return false;

  scalar_dest = gimple_assign_lhs (stmt);
  if (TREE_CODE (scalar_dest) != ARRAY_REF
      && TREE_CODE (scalar_dest) != INDIRECT_REF
      && !STMT_VINFO_STRIDED_ACCESS (stmt_info))
    return false;

  gcc_assert (gimple_assign_single_p (stmt));
  op = gimple_assign_rhs1 (stmt);
  if (!vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "use not simple.");
      return false;
    }

  /* The scalar rhs type needs to be trivially convertible to the vector
     component type.  This should always be the case.  */
  if (!useless_type_conversion_p (TREE_TYPE (vectype), TREE_TYPE (op)))
    {      
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "???  operands of different types");
      return false;
    }

  vec_mode = TYPE_MODE (vectype);
  /* FORNOW. In some cases can vectorize even if data-type not supported
     (e.g. - array initialization with 0).  */
  if (optab_handler (mov_optab, (int)vec_mode)->insn_code == CODE_FOR_nothing)
    return false;

  if (!STMT_VINFO_DATA_REF (stmt_info))
    return false;

  if (STMT_VINFO_STRIDED_ACCESS (stmt_info))
    {
      strided_store = true;
      first_stmt = DR_GROUP_FIRST_DR (stmt_info);
      if (!vect_strided_store_supported (vectype)
          && !PURE_SLP_STMT (stmt_info) && !slp)
        return false;
     
      if (first_stmt == stmt)
        {
          /* STMT is the leader of the group. Check the operands of all the
             stmts of the group.  */
          next_stmt = DR_GROUP_NEXT_DR (stmt_info);
          while (next_stmt)
            {
              gcc_assert (gimple_assign_single_p (next_stmt));
              op = gimple_assign_rhs1 (next_stmt);
              if (!vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt))
                {
                  if (vect_print_dump_info (REPORT_DETAILS))
                    fprintf (vect_dump, "use not simple.");
                  return false;
                }
              next_stmt = DR_GROUP_NEXT_DR (vinfo_for_stmt (next_stmt));
            }
        }
    }

  if (!vec_stmt) /* transformation not required.  */
    {
      STMT_VINFO_TYPE (stmt_info) = store_vec_info_type;
      vect_model_store_cost (stmt_info, ncopies, dt, NULL);
      return true;
    }

  /** Transform.  **/

  if (strided_store)
    {
      first_dr = STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt));
      group_size = DR_GROUP_SIZE (vinfo_for_stmt (first_stmt));

      DR_GROUP_STORE_COUNT (vinfo_for_stmt (first_stmt))++;

      /* FORNOW */
      gcc_assert (!nested_in_vect_loop_p (loop, stmt));

      /* We vectorize all the stmts of the interleaving group when we
         reach the last stmt in the group.  */
      if (DR_GROUP_STORE_COUNT (vinfo_for_stmt (first_stmt)) 
          < DR_GROUP_SIZE (vinfo_for_stmt (first_stmt))
          && !slp)
        {
          *vec_stmt = NULL;
          return true;
        }

      if (slp)
        strided_store = false;

      /* VEC_NUM is the number of vect stmts to be created for this group.  */
      if (slp)
        vec_num = SLP_TREE_NUMBER_OF_VEC_STMTS (slp_node);
      else
        vec_num = group_size;
    }
  else 
    {
      first_stmt = stmt;
      first_dr = dr;
      group_size = vec_num = 1;
      first_stmt_vinfo = stmt_info;
    }
  
  if (vect_print_dump_info (REPORT_DETAILS))
    fprintf (vect_dump, "transform store. ncopies = %d",ncopies);

  dr_chain = VEC_alloc (tree, heap, group_size);
  oprnds = VEC_alloc (tree, heap, group_size);

  alignment_support_scheme = vect_supportable_dr_alignment (first_dr);
  gcc_assert (alignment_support_scheme);
  gcc_assert (alignment_support_scheme == dr_aligned);  /* FORNOW */

  /* In case the vectorization factor (VF) is bigger than the number
     of elements that we can fit in a vectype (nunits), we have to generate
     more than one vector stmt - i.e - we need to "unroll" the
     vector stmt by a factor VF/nunits.  For more details see documentation in 
     vect_get_vec_def_for_copy_stmt.  */

  /* In case of interleaving (non-unit strided access):

        S1:  &base + 2 = x2
        S2:  &base = x0
        S3:  &base + 1 = x1
        S4:  &base + 3 = x3

     We create vectorized stores starting from base address (the access of the
     first stmt in the chain (S2 in the above example), when the last store stmt
     of the chain (S4) is reached:

        VS1: &base = vx2
        VS2: &base + vec_size*1 = vx0
        VS3: &base + vec_size*2 = vx1
        VS4: &base + vec_size*3 = vx3

     Then permutation statements are generated:

        VS5: vx5 = VEC_INTERLEAVE_HIGH_EXPR < vx0, vx3 >
        VS6: vx6 = VEC_INTERLEAVE_LOW_EXPR < vx0, vx3 >
        ...
        
     And they are put in STMT_VINFO_VEC_STMT of the corresponding scalar stmts
     (the order of the data-refs in the output of vect_permute_store_chain
     corresponds to the order of scalar stmts in the interleaving chain - see
     the documentation of vect_permute_store_chain()).

     In case of both multiple types and interleaving, above vector stores and
     permutation stmts are created for every copy. The result vector stmts are
     put in STMT_VINFO_VEC_STMT for the first copy and in the corresponding
     STMT_VINFO_RELATED_STMT for the next copies.     
  */

  prev_stmt_info = NULL;
  for (j = 0; j < ncopies; j++)
    {
      gimple new_stmt;
      gimple ptr_incr;

      if (j == 0)
        {
          if (slp)
            {
              /* Get vectorized arguments for SLP_NODE.  */
              vect_get_slp_defs (slp_node, &vec_oprnds, NULL);

              vec_oprnd = VEC_index (tree, vec_oprnds, 0);
            }
          else
            {
              /* For interleaved stores we collect vectorized defs for all the 
                 stores in the group in DR_CHAIN and OPRNDS. DR_CHAIN is then 
                 used as an input to vect_permute_store_chain(), and OPRNDS as 
                 an input to vect_get_vec_def_for_stmt_copy() for the next copy.

                 If the store is not strided, GROUP_SIZE is 1, and DR_CHAIN and
                 OPRNDS are of size 1.  */
              next_stmt = first_stmt;     
              for (i = 0; i < group_size; i++)
                {
                  /* Since gaps are not supported for interleaved stores, 
                     GROUP_SIZE is the exact number of stmts in the chain. 
                     Therefore, NEXT_STMT can't be NULL_TREE.  In case that 
                     there is no interleaving, GROUP_SIZE is 1, and only one 
                     iteration of the loop will be executed.  */
                  gcc_assert (next_stmt
                              && gimple_assign_single_p (next_stmt));
                  op = gimple_assign_rhs1 (next_stmt);

                  vec_oprnd = vect_get_vec_def_for_operand (op, next_stmt, 
                                                            NULL);
                  VEC_quick_push(tree, dr_chain, vec_oprnd); 
                  VEC_quick_push(tree, oprnds, vec_oprnd); 
                  next_stmt = DR_GROUP_NEXT_DR (vinfo_for_stmt (next_stmt));
                }
            }

          /* We should have catched mismatched types earlier.  */
          gcc_assert (useless_type_conversion_p (vectype,
                                                 TREE_TYPE (vec_oprnd)));
          dataref_ptr = vect_create_data_ref_ptr (first_stmt, NULL, NULL_TREE, 
                                                  &dummy, &ptr_incr, false, 
                                                  &inv_p);
          gcc_assert (!inv_p);
        }
      else 
        {
          /* For interleaved stores we created vectorized defs for all the 
             defs stored in OPRNDS in the previous iteration (previous copy). 
             DR_CHAIN is then used as an input to vect_permute_store_chain(), 
             and OPRNDS as an input to vect_get_vec_def_for_stmt_copy() for the
             next copy.
             If the store is not strided, GROUP_SIZE is 1, and DR_CHAIN and
             OPRNDS are of size 1.  */
          for (i = 0; i < group_size; i++)
            {
              op = VEC_index (tree, oprnds, i);
              vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt);
              vec_oprnd = vect_get_vec_def_for_stmt_copy (dt, op); 
              VEC_replace(tree, dr_chain, i, vec_oprnd);
              VEC_replace(tree, oprnds, i, vec_oprnd);
            }
          dataref_ptr = 
                bump_vector_ptr (dataref_ptr, ptr_incr, gsi, stmt, NULL_TREE);
        }

      if (strided_store)
        {
          result_chain = VEC_alloc (tree, heap, group_size);     
          /* Permute.  */
          if (!vect_permute_store_chain (dr_chain, group_size, stmt, gsi,
                                         &result_chain))
            return false;
        }

      next_stmt = first_stmt;
      for (i = 0; i < vec_num; i++)
        {
          if (i > 0)
            /* Bump the vector pointer.  */
            dataref_ptr = bump_vector_ptr (dataref_ptr, ptr_incr, gsi, stmt,
                                           NULL_TREE);

          if (slp)
            vec_oprnd = VEC_index (tree, vec_oprnds, i);
          else if (strided_store)
            /* For strided stores vectorized defs are interleaved in 
               vect_permute_store_chain().  */
            vec_oprnd = VEC_index (tree, result_chain, i);

          data_ref = build_fold_indirect_ref (dataref_ptr);
          /* If accesses through a pointer to vectype do not alias the original
             memory reference we have a problem.  This should never happen.  */
          gcc_assert (alias_sets_conflict_p (get_alias_set (data_ref),
                      get_alias_set (gimple_assign_lhs (stmt))));

          /* Arguments are ready. Create the new vector stmt.  */
          new_stmt = gimple_build_assign (data_ref, vec_oprnd);
          vect_finish_stmt_generation (stmt, new_stmt, gsi);
          mark_symbols_for_renaming (new_stmt);

          if (slp)
            continue;
          
          if (j == 0)
            STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt =  new_stmt;
          else
            STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;

          prev_stmt_info = vinfo_for_stmt (new_stmt);
          next_stmt = DR_GROUP_NEXT_DR (vinfo_for_stmt (next_stmt));
          if (!next_stmt)
            break;
        }
    }

  VEC_free (tree, heap, dr_chain);  
  VEC_free (tree, heap, oprnds);  
  if (result_chain)
    VEC_free (tree, heap, result_chain);  

  return true;
}

/* vectorizable_load.

   Check if STMT reads a non scalar data-ref (array/pointer/structure) that 
   can be vectorized. 
   If VEC_STMT is also passed, vectorize the STMT: create a vectorized 
   stmt to replace it, put it in VEC_STMT, and insert it at BSI.
   Return FALSE if not a vectorizable STMT, TRUE otherwise.  */

static bool
vectorizable_load (gimple stmt, gimple_stmt_iterator *gsi, gimple *vec_stmt,
                   slp_tree slp_node, slp_instance slp_node_instance)
{
  tree scalar_dest;
  tree vec_dest = NULL;
  tree data_ref = NULL;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  stmt_vec_info prev_stmt_info; 
  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
  struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
  struct loop *containing_loop = (gimple_bb (stmt))->loop_father;
  bool nested_in_vect_loop = nested_in_vect_loop_p (loop, stmt);
  struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info), *first_dr;
  tree vectype = STMT_VINFO_VECTYPE (stmt_info);
  tree new_temp;
  int mode;
  gimple new_stmt = NULL;
  tree dummy;
  enum dr_alignment_support alignment_support_scheme;
  tree dataref_ptr = NULL_TREE;
  gimple ptr_incr;
  int nunits = TYPE_VECTOR_SUBPARTS (vectype);
  int ncopies;
  int i, j, group_size;
  tree msq = NULL_TREE, lsq;
  tree offset = NULL_TREE;
  tree realignment_token = NULL_TREE;
  gimple phi = NULL;
  VEC(tree,heap) *dr_chain = NULL;
  bool strided_load = false;
  gimple first_stmt;
  tree scalar_type;
  bool inv_p;
  bool compute_in_loop = false;
  struct loop *at_loop;
  int vec_num;
  bool slp = (slp_node != NULL);
  bool slp_perm = false;
  enum tree_code code;

  /* Multiple types in SLP are handled by creating the appropriate number of
     vectorized stmts for each SLP node. Hence, NCOPIES is always 1 in
     case of SLP.  */
  if (slp)
    ncopies = 1;
  else
    ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;

  gcc_assert (ncopies >= 1);

  /* FORNOW. This restriction should be relaxed.  */
  if (nested_in_vect_loop && ncopies > 1)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "multiple types in nested loop.");
      return false;
    }

  if (slp && SLP_INSTANCE_LOAD_PERMUTATION (slp_node_instance))
    slp_perm = true;
 
  if (!STMT_VINFO_RELEVANT_P (stmt_info))
    return false;

  if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def)
    return false;

  /* Is vectorizable load? */
  if (!is_gimple_assign (stmt))
    return false;

  scalar_dest = gimple_assign_lhs (stmt);
  if (TREE_CODE (scalar_dest) != SSA_NAME)
    return false;

  code = gimple_assign_rhs_code (stmt);
  if (code != ARRAY_REF
      && code != INDIRECT_REF
      && !STMT_VINFO_STRIDED_ACCESS (stmt_info))
    return false;

  if (!STMT_VINFO_DATA_REF (stmt_info))
    return false;

  scalar_type = TREE_TYPE (DR_REF (dr));
  mode = (int) TYPE_MODE (vectype);

  /* FORNOW. In some cases can vectorize even if data-type not supported
    (e.g. - data copies).  */
  if (optab_handler (mov_optab, mode)->insn_code == CODE_FOR_nothing)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "Aligned load, but unsupported type.");
      return false;
    }

  /* The vector component type needs to be trivially convertible to the
     scalar lhs.  This should always be the case.  */
  if (!useless_type_conversion_p (TREE_TYPE (scalar_dest), TREE_TYPE (vectype)))
    {      
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "???  operands of different types");
      return false;
    }

  /* Check if the load is a part of an interleaving chain.  */
  if (STMT_VINFO_STRIDED_ACCESS (stmt_info))
    {
      strided_load = true;
      /* FORNOW */
      gcc_assert (! nested_in_vect_loop);

      /* Check if interleaving is supported.  */
      if (!vect_strided_load_supported (vectype)
          && !PURE_SLP_STMT (stmt_info) && !slp)
        return false;
    }

  if (!vec_stmt) /* transformation not required.  */
    {
      STMT_VINFO_TYPE (stmt_info) = load_vec_info_type;
      vect_model_load_cost (stmt_info, ncopies, NULL);
      return true;
    }

  if (vect_print_dump_info (REPORT_DETAILS))
    fprintf (vect_dump, "transform load.");

  /** Transform.  **/

  if (strided_load)
    {
      first_stmt = DR_GROUP_FIRST_DR (stmt_info);
      /* Check if the chain of loads is already vectorized.  */
      if (STMT_VINFO_VEC_STMT (vinfo_for_stmt (first_stmt)))
        {
          *vec_stmt = STMT_VINFO_VEC_STMT (stmt_info);
          return true;
        }
      first_dr = STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt));
      group_size = DR_GROUP_SIZE (vinfo_for_stmt (first_stmt));

      /* VEC_NUM is the number of vect stmts to be created for this group.  */
      if (slp)
        {
          strided_load = false;
          vec_num = SLP_TREE_NUMBER_OF_VEC_STMTS (slp_node);
        }
      else
        vec_num = group_size;

      dr_chain = VEC_alloc (tree, heap, vec_num);
    }
  else
    {
      first_stmt = stmt;
      first_dr = dr;
      group_size = vec_num = 1;
    }

  alignment_support_scheme = vect_supportable_dr_alignment (first_dr);
  gcc_assert (alignment_support_scheme);

  /* In case the vectorization factor (VF) is bigger than the number
     of elements that we can fit in a vectype (nunits), we have to generate
     more than one vector stmt - i.e - we need to "unroll" the
     vector stmt by a factor VF/nunits. In doing so, we record a pointer
     from one copy of the vector stmt to the next, in the field
     STMT_VINFO_RELATED_STMT. This is necessary in order to allow following
     stages to find the correct vector defs to be used when vectorizing
     stmts that use the defs of the current stmt. The example below illustrates
     the vectorization process when VF=16 and nunits=4 (i.e - we need to create
     4 vectorized stmts):

     before vectorization:
                                RELATED_STMT    VEC_STMT
        S1:     x = memref      -               -
        S2:     z = x + 1       -               -

     step 1: vectorize stmt S1:
        We first create the vector stmt VS1_0, and, as usual, record a
        pointer to it in the STMT_VINFO_VEC_STMT of the scalar stmt S1.
        Next, we create the vector stmt VS1_1, and record a pointer to
        it in the STMT_VINFO_RELATED_STMT of the vector stmt VS1_0.
        Similarly, for VS1_2 and VS1_3. This is the resulting chain of
        stmts and pointers:
                                RELATED_STMT    VEC_STMT
        VS1_0:  vx0 = memref0   VS1_1           -
        VS1_1:  vx1 = memref1   VS1_2           -
        VS1_2:  vx2 = memref2   VS1_3           -
        VS1_3:  vx3 = memref3   -               -
        S1:     x = load        -               VS1_0
        S2:     z = x + 1       -               -

     See in documentation in vect_get_vec_def_for_stmt_copy for how the 
     information we recorded in RELATED_STMT field is used to vectorize 
     stmt S2.  */

  /* In case of interleaving (non-unit strided access):

     S1:  x2 = &base + 2
     S2:  x0 = &base
     S3:  x1 = &base + 1
     S4:  x3 = &base + 3

     Vectorized loads are created in the order of memory accesses 
     starting from the access of the first stmt of the chain:

     VS1: vx0 = &base
     VS2: vx1 = &base + vec_size*1
     VS3: vx3 = &base + vec_size*2
     VS4: vx4 = &base + vec_size*3

     Then permutation statements are generated:

     VS5: vx5 = VEC_EXTRACT_EVEN_EXPR < vx0, vx1 >
     VS6: vx6 = VEC_EXTRACT_ODD_EXPR < vx0, vx1 >
       ...

     And they are put in STMT_VINFO_VEC_STMT of the corresponding scalar stmts
     (the order of the data-refs in the output of vect_permute_load_chain
     corresponds to the order of scalar stmts in the interleaving chain - see
     the documentation of vect_permute_load_chain()).
     The generation of permutation stmts and recording them in
     STMT_VINFO_VEC_STMT is done in vect_transform_strided_load().

     In case of both multiple types and interleaving, the vector loads and 
     permutation stmts above are created for every copy. The result vector stmts
     are put in STMT_VINFO_VEC_STMT for the first copy and in the corresponding
     STMT_VINFO_RELATED_STMT for the next copies.  */

  /* If the data reference is aligned (dr_aligned) or potentially unaligned
     on a target that supports unaligned accesses (dr_unaligned_supported)
     we generate the following code:
         p = initial_addr;
         indx = 0;
         loop {
           p = p + indx * vectype_size;
           vec_dest = *(p);
           indx = indx + 1;
         }

     Otherwise, the data reference is potentially unaligned on a target that
     does not support unaligned accesses (dr_explicit_realign_optimized) - 
     then generate the following code, in which the data in each iteration is
     obtained by two vector loads, one from the previous iteration, and one
     from the current iteration:
         p1 = initial_addr;
         msq_init = *(floor(p1))
         p2 = initial_addr + VS - 1;
         realignment_token = call target_builtin;
         indx = 0;
         loop {
           p2 = p2 + indx * vectype_size
           lsq = *(floor(p2))
           vec_dest = realign_load (msq, lsq, realignment_token)
           indx = indx + 1;
           msq = lsq;
         }   */

  /* If the misalignment remains the same throughout the execution of the
     loop, we can create the init_addr and permutation mask at the loop
     preheader. Otherwise, it needs to be created inside the loop.
     This can only occur when vectorizing memory accesses in the inner-loop
     nested within an outer-loop that is being vectorized.  */

  if (nested_in_vect_loop_p (loop, stmt)
      && (TREE_INT_CST_LOW (DR_STEP (dr))
          % GET_MODE_SIZE (TYPE_MODE (vectype)) != 0))
    {
      gcc_assert (alignment_support_scheme != dr_explicit_realign_optimized);
      compute_in_loop = true;
    }

  if ((alignment_support_scheme == dr_explicit_realign_optimized
       || alignment_support_scheme == dr_explicit_realign)
      && !compute_in_loop)
    {
      msq = vect_setup_realignment (first_stmt, gsi, &realignment_token,
                                    alignment_support_scheme, NULL_TREE,
                                    &at_loop);
      if (alignment_support_scheme == dr_explicit_realign_optimized)
        {
          phi = SSA_NAME_DEF_STMT (msq);
          offset = size_int (TYPE_VECTOR_SUBPARTS (vectype) - 1);
        }
    }
  else
    at_loop = loop;

  prev_stmt_info = NULL;
  for (j = 0; j < ncopies; j++)
    { 
      /* 1. Create the vector pointer update chain.  */
      if (j == 0)
        dataref_ptr = vect_create_data_ref_ptr (first_stmt,
                                                at_loop, offset, 
                                                &dummy, &ptr_incr, false, 
                                                &inv_p);
      else
        dataref_ptr = 
                bump_vector_ptr (dataref_ptr, ptr_incr, gsi, stmt, NULL_TREE);

      for (i = 0; i < vec_num; i++)
        {
          if (i > 0)
            dataref_ptr = bump_vector_ptr (dataref_ptr, ptr_incr, gsi, stmt,
                                           NULL_TREE);

          /* 2. Create the vector-load in the loop.  */
          switch (alignment_support_scheme)
            {
            case dr_aligned:
              gcc_assert (aligned_access_p (first_dr));
              data_ref = build_fold_indirect_ref (dataref_ptr);
              break;
            case dr_unaligned_supported:
              {
                int mis = DR_MISALIGNMENT (first_dr);
                tree tmis = (mis == -1 ? size_zero_node : size_int (mis));

                tmis = size_binop (MULT_EXPR, tmis, size_int(BITS_PER_UNIT));
                data_ref =
                  build2 (MISALIGNED_INDIRECT_REF, vectype, dataref_ptr, tmis);
                break;
              }
            case dr_explicit_realign:
              {
                tree ptr, bump;
                tree vs_minus_1 = size_int (TYPE_VECTOR_SUBPARTS (vectype) - 1);

                if (compute_in_loop)
                  msq = vect_setup_realignment (first_stmt, gsi,
                                                &realignment_token,
                                                dr_explicit_realign, 
                                                dataref_ptr, NULL);

                data_ref = build1 (ALIGN_INDIRECT_REF, vectype, dataref_ptr);
                vec_dest = vect_create_destination_var (scalar_dest, vectype);
                new_stmt = gimple_build_assign (vec_dest, data_ref);
                new_temp = make_ssa_name (vec_dest, new_stmt);
                gimple_assign_set_lhs (new_stmt, new_temp);
                gimple_set_vdef (new_stmt, gimple_vdef (stmt));
                gimple_set_vuse (new_stmt, gimple_vuse (stmt));
                vect_finish_stmt_generation (stmt, new_stmt, gsi);
                msq = new_temp;

                bump = size_binop (MULT_EXPR, vs_minus_1,
                                   TYPE_SIZE_UNIT (scalar_type));
                ptr = bump_vector_ptr (dataref_ptr, NULL, gsi, stmt, bump);
                data_ref = build1 (ALIGN_INDIRECT_REF, vectype, ptr);
                break;
              }
            case dr_explicit_realign_optimized:
              data_ref = build1 (ALIGN_INDIRECT_REF, vectype, dataref_ptr);
              break;
            default:
              gcc_unreachable ();
            }
          /* If accesses through a pointer to vectype do not alias the original
             memory reference we have a problem.  This should never happen. */
          gcc_assert (alias_sets_conflict_p (get_alias_set (data_ref),
                      get_alias_set (gimple_assign_rhs1 (stmt))));
          vec_dest = vect_create_destination_var (scalar_dest, vectype);
          new_stmt = gimple_build_assign (vec_dest, data_ref);
          new_temp = make_ssa_name (vec_dest, new_stmt);
          gimple_assign_set_lhs (new_stmt, new_temp);
          vect_finish_stmt_generation (stmt, new_stmt, gsi);
          mark_symbols_for_renaming (new_stmt);

          /* 3. Handle explicit realignment if necessary/supported. Create in
                loop: vec_dest = realign_load (msq, lsq, realignment_token)  */
          if (alignment_support_scheme == dr_explicit_realign_optimized
              || alignment_support_scheme == dr_explicit_realign)
            {
              tree tmp;

              lsq = gimple_assign_lhs (new_stmt);
              if (!realignment_token)
                realignment_token = dataref_ptr;
              vec_dest = vect_create_destination_var (scalar_dest, vectype);
              tmp = build3 (REALIGN_LOAD_EXPR, vectype, msq, lsq,
                            realignment_token);
              new_stmt = gimple_build_assign (vec_dest, tmp);
              new_temp = make_ssa_name (vec_dest, new_stmt);
              gimple_assign_set_lhs (new_stmt, new_temp);
              vect_finish_stmt_generation (stmt, new_stmt, gsi);

              if (alignment_support_scheme == dr_explicit_realign_optimized)
                {
                  gcc_assert (phi);
                  if (i == vec_num - 1 && j == ncopies - 1)
                    add_phi_arg (phi, lsq, loop_latch_edge (containing_loop));
                  msq = lsq;
                }
            }

          /* 4. Handle invariant-load.  */
          if (inv_p)
            {
              gcc_assert (!strided_load);
              gcc_assert (nested_in_vect_loop_p (loop, stmt));
              if (j == 0)
                {
                  int k;
                  tree t = NULL_TREE;
                  tree vec_inv, bitpos, bitsize = TYPE_SIZE (scalar_type);

                  /* CHECKME: bitpos depends on endianess?  */
                  bitpos = bitsize_zero_node;
                  vec_inv = build3 (BIT_FIELD_REF, scalar_type, new_temp, 
                                    bitsize, bitpos);
                  vec_dest = 
                        vect_create_destination_var (scalar_dest, NULL_TREE);
                  new_stmt = gimple_build_assign (vec_dest, vec_inv);
                  new_temp = make_ssa_name (vec_dest, new_stmt);
                  gimple_assign_set_lhs (new_stmt, new_temp);
                  vect_finish_stmt_generation (stmt, new_stmt, gsi);

                  for (k = nunits - 1; k >= 0; --k)
                    t = tree_cons (NULL_TREE, new_temp, t);
                  /* FIXME: use build_constructor directly.  */
                  vec_inv = build_constructor_from_list (vectype, t);
                  new_temp = vect_init_vector (stmt, vec_inv, vectype, gsi);
                  new_stmt = SSA_NAME_DEF_STMT (new_temp);
                }
              else
                gcc_unreachable (); /* FORNOW. */
            }

          /* Collect vector loads and later create their permutation in
             vect_transform_strided_load ().  */
          if (strided_load || slp_perm)
            VEC_quick_push (tree, dr_chain, new_temp);

         /* Store vector loads in the corresponding SLP_NODE.  */
          if (slp && !slp_perm)
            VEC_quick_push (gimple, SLP_TREE_VEC_STMTS (slp_node), new_stmt);
        }

      if (slp && !slp_perm)
        continue;

      if (slp_perm)
        {
          if (!vect_transform_slp_perm_load (stmt, dr_chain, gsi,
                                   LOOP_VINFO_VECT_FACTOR (loop_vinfo),
                                             slp_node_instance, false))
            {
              VEC_free (tree, heap, dr_chain);
              return false;
            }
        }
      else
        {
          if (strided_load)
            {
              if (!vect_transform_strided_load (stmt, dr_chain, group_size, gsi))
                return false;     

              *vec_stmt = STMT_VINFO_VEC_STMT (stmt_info);
              VEC_free (tree, heap, dr_chain);
              dr_chain = VEC_alloc (tree, heap, group_size);
            }
          else
            {
              if (j == 0)
                STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt = new_stmt;
              else
                STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;
              prev_stmt_info = vinfo_for_stmt (new_stmt);
            }
        }
    }

  if (dr_chain)
    VEC_free (tree, heap, dr_chain);

  return true;
}

/* Function vect_is_simple_cond.
  
   Input:
   LOOP - the loop that is being vectorized.
   COND - Condition that is checked for simple use.

   Returns whether a COND can be vectorized.  Checks whether
   condition operands are supportable using vec_is_simple_use.  */

static bool
vect_is_simple_cond (tree cond, loop_vec_info loop_vinfo)
{
  tree lhs, rhs;
  tree def;
  enum vect_def_type dt;

  if (!COMPARISON_CLASS_P (cond))
    return false;

  lhs = TREE_OPERAND (cond, 0);
  rhs = TREE_OPERAND (cond, 1);

  if (TREE_CODE (lhs) == SSA_NAME)
    {
      gimple lhs_def_stmt = SSA_NAME_DEF_STMT (lhs);
      if (!vect_is_simple_use (lhs, loop_vinfo, &lhs_def_stmt, &def, &dt))
        return false;
    }
  else if (TREE_CODE (lhs) != INTEGER_CST && TREE_CODE (lhs) != REAL_CST
           && TREE_CODE (lhs) != FIXED_CST)
    return false;

  if (TREE_CODE (rhs) == SSA_NAME)
    {
      gimple rhs_def_stmt = SSA_NAME_DEF_STMT (rhs);
      if (!vect_is_simple_use (rhs, loop_vinfo, &rhs_def_stmt, &def, &dt))
        return false;
    }
  else if (TREE_CODE (rhs) != INTEGER_CST  && TREE_CODE (rhs) != REAL_CST
           && TREE_CODE (rhs) != FIXED_CST)
    return false;

  return true;
}

/* vectorizable_condition.

   Check if STMT is conditional modify expression that can be vectorized. 
   If VEC_STMT is also passed, vectorize the STMT: create a vectorized 
   stmt using VEC_COND_EXPR  to replace it, put it in VEC_STMT, and insert it 
   at BSI.

   Return FALSE if not a vectorizable STMT, TRUE otherwise.  */

static bool
vectorizable_condition (gimple stmt, gimple_stmt_iterator *gsi,
                        gimple *vec_stmt)
{
  tree scalar_dest = NULL_TREE;
  tree vec_dest = NULL_TREE;
  tree op = NULL_TREE;
  tree cond_expr, then_clause, else_clause;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  tree vectype = STMT_VINFO_VECTYPE (stmt_info);
  tree vec_cond_lhs, vec_cond_rhs, vec_then_clause, vec_else_clause;
  tree vec_compare, vec_cond_expr;
  tree new_temp;
  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
  enum machine_mode vec_mode;
  tree def;
  enum vect_def_type dt;
  int nunits = TYPE_VECTOR_SUBPARTS (vectype);
  int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
  enum tree_code code;

  gcc_assert (ncopies >= 1);
  if (ncopies > 1)
    return false; /* FORNOW */

  if (!STMT_VINFO_RELEVANT_P (stmt_info))
    return false;

  if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def)
    return false;

  /* FORNOW: SLP not supported.  */
  if (STMT_SLP_TYPE (stmt_info))
    return false;

  /* FORNOW: not yet supported.  */
  if (STMT_VINFO_LIVE_P (stmt_info))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "value used after loop.");
      return false;
    }

  /* Is vectorizable conditional operation?  */
  if (!is_gimple_assign (stmt))
    return false;

  code = gimple_assign_rhs_code (stmt);

  if (code != COND_EXPR)
    return false;

  gcc_assert (gimple_assign_single_p (stmt));
  op = gimple_assign_rhs1 (stmt);
  cond_expr = TREE_OPERAND (op, 0);
  then_clause = TREE_OPERAND (op, 1);
  else_clause = TREE_OPERAND (op, 2);

  if (!vect_is_simple_cond (cond_expr, loop_vinfo))
    return false;

  /* We do not handle two different vector types for the condition
     and the values.  */
  if (TREE_TYPE (TREE_OPERAND (cond_expr, 0)) != TREE_TYPE (vectype))
    return false;

  if (TREE_CODE (then_clause) == SSA_NAME)
    {
      gimple then_def_stmt = SSA_NAME_DEF_STMT (then_clause);
      if (!vect_is_simple_use (then_clause, loop_vinfo, 
                               &then_def_stmt, &def, &dt))
        return false;
    }
  else if (TREE_CODE (then_clause) != INTEGER_CST 
           && TREE_CODE (then_clause) != REAL_CST
           && TREE_CODE (then_clause) != FIXED_CST)
    return false;

  if (TREE_CODE (else_clause) == SSA_NAME)
    {
      gimple else_def_stmt = SSA_NAME_DEF_STMT (else_clause);
      if (!vect_is_simple_use (else_clause, loop_vinfo, 
                               &else_def_stmt, &def, &dt))
        return false;
    }
  else if (TREE_CODE (else_clause) != INTEGER_CST 
           && TREE_CODE (else_clause) != REAL_CST
           && TREE_CODE (else_clause) != FIXED_CST)
    return false;


  vec_mode = TYPE_MODE (vectype);

  if (!vec_stmt) 
    {
      STMT_VINFO_TYPE (stmt_info) = condition_vec_info_type;
      return expand_vec_cond_expr_p (op, vec_mode);
    }

  /* Transform */

  /* Handle def.  */
  scalar_dest = gimple_assign_lhs (stmt);
  vec_dest = vect_create_destination_var (scalar_dest, vectype);

  /* Handle cond expr.  */
  vec_cond_lhs = 
    vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 0), stmt, NULL);
  vec_cond_rhs = 
    vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 1), stmt, NULL);
  vec_then_clause = vect_get_vec_def_for_operand (then_clause, stmt, NULL);
  vec_else_clause = vect_get_vec_def_for_operand (else_clause, stmt, NULL);

  /* Arguments are ready. Create the new vector stmt.  */
  vec_compare = build2 (TREE_CODE (cond_expr), vectype, 
                        vec_cond_lhs, vec_cond_rhs);
  vec_cond_expr = build3 (VEC_COND_EXPR, vectype, 
                          vec_compare, vec_then_clause, vec_else_clause);

  *vec_stmt = gimple_build_assign (vec_dest, vec_cond_expr);
  new_temp = make_ssa_name (vec_dest, *vec_stmt);
  gimple_assign_set_lhs (*vec_stmt, new_temp);
  vect_finish_stmt_generation (stmt, *vec_stmt, gsi);
  
  return true;
}


/* Make sure the statement is vectorizable.  */

bool
vect_analyze_stmt (gimple stmt, bool *need_to_vectorize)
{
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  enum vect_relevant relevance = STMT_VINFO_RELEVANT (stmt_info);
  bool ok;

  if (vect_print_dump_info (REPORT_DETAILS))
    {
      fprintf (vect_dump, "==> examining statement: ");
      print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
    }

  /* Skip stmts that do not need to be vectorized. In loops this is expected
     to include:
     - the COND_EXPR which is the loop exit condition
     - any LABEL_EXPRs in the loop
     - computations that are used only for array indexing or loop control.
     In basic blocks we only analyze statements that are a part of some SLP
     instance, therefore, all the statements are relevant.  */

  if (!STMT_VINFO_RELEVANT_P (stmt_info)
      && !STMT_VINFO_LIVE_P (stmt_info))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "irrelevant.");

      return true;
    }

  switch (STMT_VINFO_DEF_TYPE (stmt_info))
    {
      case vect_internal_def:
        break;

      case vect_reduction_def:
         gcc_assert (relevance == vect_used_in_outer
                     || relevance == vect_used_in_outer_by_reduction
                     || relevance == vect_unused_in_scope);
         break;

      case vect_induction_def:
      case vect_constant_def:
      case vect_external_def:
      case vect_unknown_def_type:
      default:
        gcc_unreachable ();
    }

  if (STMT_VINFO_RELEVANT_P (stmt_info))
    {
      gcc_assert (!VECTOR_MODE_P (TYPE_MODE (gimple_expr_type (stmt))));
      gcc_assert (STMT_VINFO_VECTYPE (stmt_info));
      *need_to_vectorize = true;
    }

   ok = true;
   if (STMT_VINFO_RELEVANT_P (stmt_info)
       || STMT_VINFO_DEF_TYPE (stmt_info) == vect_reduction_def)
      ok = (vectorizable_type_promotion (stmt, NULL, NULL, NULL)
            || vectorizable_type_demotion (stmt, NULL, NULL, NULL)
            || vectorizable_conversion (stmt, NULL, NULL, NULL)
            || vectorizable_operation (stmt, NULL, NULL, NULL)
            || vectorizable_assignment (stmt, NULL, NULL, NULL)
            || vectorizable_load (stmt, NULL, NULL, NULL, NULL)
            || vectorizable_call (stmt, NULL, NULL)
            || vectorizable_store (stmt, NULL, NULL, NULL)
            || vectorizable_condition (stmt, NULL, NULL)
            || vectorizable_reduction (stmt, NULL, NULL));

  if (!ok)
    {
      if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
        {
          fprintf (vect_dump, "not vectorized: relevant stmt not ");
          fprintf (vect_dump, "supported: ");
          print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
        }

      return false;
    }

  /* Stmts that are (also) "live" (i.e. - that are used out of the loop)
      need extra handling, except for vectorizable reductions.  */
  if (STMT_VINFO_LIVE_P (stmt_info)
      && STMT_VINFO_TYPE (stmt_info) != reduc_vec_info_type)
    ok = vectorizable_live_operation (stmt, NULL, NULL);

  if (!ok)
    {
      if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
        {
          fprintf (vect_dump, "not vectorized: live stmt not ");
          fprintf (vect_dump, "supported: ");
          print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
        }

       return false;
    }

  if (!PURE_SLP_STMT (stmt_info))
    {
      /* Groups of strided accesses whose size is not a power of 2 are not
         vectorizable yet using loop-vectorization. Therefore, if this stmt
         feeds non-SLP-able stmts (i.e., this stmt has to be both SLPed and
         loop-based vectorized), the loop cannot be vectorized.  */
      if (STMT_VINFO_STRIDED_ACCESS (stmt_info)
          && exact_log2 (DR_GROUP_SIZE (vinfo_for_stmt (
                                        DR_GROUP_FIRST_DR (stmt_info)))) == -1)
        {
          if (vect_print_dump_info (REPORT_DETAILS))
            {
              fprintf (vect_dump, "not vectorized: the size of group "
                                  "of strided accesses is not a power of 2");
              print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
            }

          return false;
        }
    }

  return true;
}


/* Function vect_transform_stmt.

   Create a vectorized stmt to replace STMT, and insert it at BSI.  */

bool
vect_transform_stmt (gimple stmt, gimple_stmt_iterator *gsi,
                     bool *strided_store, slp_tree slp_node, 
                     slp_instance slp_node_instance)
{
  bool is_store = false;
  gimple vec_stmt = NULL;
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  gimple orig_stmt_in_pattern;
  bool done;
  loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
  struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);

  switch (STMT_VINFO_TYPE (stmt_info))
    {
    case type_demotion_vec_info_type:
      done = vectorizable_type_demotion (stmt, gsi, &vec_stmt, slp_node);
      gcc_assert (done);
      break;

    case type_promotion_vec_info_type:
      done = vectorizable_type_promotion (stmt, gsi, &vec_stmt, slp_node);
      gcc_assert (done);
      break;

    case type_conversion_vec_info_type:
      done = vectorizable_conversion (stmt, gsi, &vec_stmt, slp_node);
      gcc_assert (done);
      break;

    case induc_vec_info_type:
      gcc_assert (!slp_node);
      done = vectorizable_induction (stmt, gsi, &vec_stmt);
      gcc_assert (done);
      break;

    case op_vec_info_type:
      done = vectorizable_operation (stmt, gsi, &vec_stmt, slp_node);
      gcc_assert (done);
      break;

    case assignment_vec_info_type:
      done = vectorizable_assignment (stmt, gsi, &vec_stmt, slp_node);
      gcc_assert (done);
      break;

    case load_vec_info_type:
      done = vectorizable_load (stmt, gsi, &vec_stmt, slp_node, 
                                slp_node_instance);
      gcc_assert (done);
      break;

    case store_vec_info_type:
      done = vectorizable_store (stmt, gsi, &vec_stmt, slp_node);
      gcc_assert (done);
      if (STMT_VINFO_STRIDED_ACCESS (stmt_info) && !slp_node)
        {
          /* In case of interleaving, the whole chain is vectorized when the
             last store in the chain is reached. Store stmts before the last
             one are skipped, and there vec_stmt_info shouldn't be freed
             meanwhile.  */
          *strided_store = true;
          if (STMT_VINFO_VEC_STMT (stmt_info))
            is_store = true;
          }
      else
        is_store = true;
      break;

    case condition_vec_info_type:
      gcc_assert (!slp_node);
      done = vectorizable_condition (stmt, gsi, &vec_stmt);
      gcc_assert (done);
      break;

    case call_vec_info_type:
      gcc_assert (!slp_node);
      done = vectorizable_call (stmt, gsi, &vec_stmt);
      break;

    case reduc_vec_info_type:
      gcc_assert (!slp_node);
      done = vectorizable_reduction (stmt, gsi, &vec_stmt);
      gcc_assert (done);
      break;

    default:
      if (!STMT_VINFO_LIVE_P (stmt_info))
        {
          if (vect_print_dump_info (REPORT_DETAILS))
            fprintf (vect_dump, "stmt not supported.");
          gcc_unreachable ();
        }
    }

  /* Handle inner-loop stmts whose DEF is used in the loop-nest that
     is being vectorized, but outside the immediately enclosing loop.  */
  if (vec_stmt
      && nested_in_vect_loop_p (loop, stmt)
      && STMT_VINFO_TYPE (stmt_info) != reduc_vec_info_type
      && (STMT_VINFO_RELEVANT (stmt_info) == vect_used_in_outer
          || STMT_VINFO_RELEVANT (stmt_info) == vect_used_in_outer_by_reduction))
    {
      struct loop *innerloop = loop->inner;
      imm_use_iterator imm_iter;
      use_operand_p use_p;
      tree scalar_dest;
      gimple exit_phi;

      if (vect_print_dump_info (REPORT_DETAILS))
       fprintf (vect_dump, "Record the vdef for outer-loop vectorization.");

      /* Find the relevant loop-exit phi-node, and reord the vec_stmt there
        (to be used when vectorizing outer-loop stmts that use the DEF of
        STMT).  */
      if (gimple_code (stmt) == GIMPLE_PHI)
        scalar_dest = PHI_RESULT (stmt);
      else
        scalar_dest = gimple_assign_lhs (stmt);

      FOR_EACH_IMM_USE_FAST (use_p, imm_iter, scalar_dest)
       {
         if (!flow_bb_inside_loop_p (innerloop, gimple_bb (USE_STMT (use_p))))
           {
             exit_phi = USE_STMT (use_p);
             STMT_VINFO_VEC_STMT (vinfo_for_stmt (exit_phi)) = vec_stmt;
           }
       }
    }

  /* Handle stmts whose DEF is used outside the loop-nest that is
     being vectorized.  */
  if (STMT_VINFO_LIVE_P (stmt_info)
      && STMT_VINFO_TYPE (stmt_info) != reduc_vec_info_type)
    {
      done = vectorizable_live_operation (stmt, gsi, &vec_stmt);
      gcc_assert (done);
    }

  if (vec_stmt)
    {
      STMT_VINFO_VEC_STMT (stmt_info) = vec_stmt;
      orig_stmt_in_pattern = STMT_VINFO_RELATED_STMT (stmt_info);
      if (orig_stmt_in_pattern)
        {
          stmt_vec_info stmt_vinfo = vinfo_for_stmt (orig_stmt_in_pattern);
          /* STMT was inserted by the vectorizer to replace a computation idiom.
             ORIG_STMT_IN_PATTERN is a stmt in the original sequence that 
             computed this idiom.  We need to record a pointer to VEC_STMT in 
             the stmt_info of ORIG_STMT_IN_PATTERN.  See more details in the 
             documentation of vect_pattern_recog.  */
          if (STMT_VINFO_IN_PATTERN_P (stmt_vinfo))
            {
              gcc_assert (STMT_VINFO_RELATED_STMT (stmt_vinfo) == stmt);
              STMT_VINFO_VEC_STMT (stmt_vinfo) = vec_stmt;
            }
        }
    }

  return is_store; 
}


/* Remove a group of stores (for SLP or interleaving), free their 
   stmt_vec_info.  */

void
vect_remove_stores (gimple first_stmt)
{
  gimple next = first_stmt;
  gimple tmp;
  gimple_stmt_iterator next_si;

  while (next)
    {
      /* Free the attached stmt_vec_info and remove the stmt.  */
      next_si = gsi_for_stmt (next);
      gsi_remove (&next_si, true);
      tmp = DR_GROUP_NEXT_DR (vinfo_for_stmt (next));
      free_stmt_vec_info (next);
      next = tmp;
    }
}


/* Function new_stmt_vec_info.

   Create and initialize a new stmt_vec_info struct for STMT.  */

stmt_vec_info
new_stmt_vec_info (gimple stmt, loop_vec_info loop_vinfo)
{
  stmt_vec_info res;
  res = (stmt_vec_info) xcalloc (1, sizeof (struct _stmt_vec_info));

  STMT_VINFO_TYPE (res) = undef_vec_info_type;
  STMT_VINFO_STMT (res) = stmt;
  STMT_VINFO_LOOP_VINFO (res) = loop_vinfo;
  STMT_VINFO_RELEVANT (res) = vect_unused_in_scope;
  STMT_VINFO_LIVE_P (res) = false;
  STMT_VINFO_VECTYPE (res) = NULL;
  STMT_VINFO_VEC_STMT (res) = NULL;
  STMT_VINFO_IN_PATTERN_P (res) = false;
  STMT_VINFO_RELATED_STMT (res) = NULL;
  STMT_VINFO_DATA_REF (res) = NULL;

  STMT_VINFO_DR_BASE_ADDRESS (res) = NULL;
  STMT_VINFO_DR_OFFSET (res) = NULL;
  STMT_VINFO_DR_INIT (res) = NULL;
  STMT_VINFO_DR_STEP (res) = NULL;
  STMT_VINFO_DR_ALIGNED_TO (res) = NULL;

  if (gimple_code (stmt) == GIMPLE_PHI
      && is_loop_header_bb_p (gimple_bb (stmt)))
    STMT_VINFO_DEF_TYPE (res) = vect_unknown_def_type;
  else
    STMT_VINFO_DEF_TYPE (res) = vect_internal_def;

  STMT_VINFO_SAME_ALIGN_REFS (res) = VEC_alloc (dr_p, heap, 5);
  STMT_VINFO_INSIDE_OF_LOOP_COST (res) = 0;
  STMT_VINFO_OUTSIDE_OF_LOOP_COST (res) = 0;
  STMT_SLP_TYPE (res) = loop_vect;
  DR_GROUP_FIRST_DR (res) = NULL;
  DR_GROUP_NEXT_DR (res) = NULL;
  DR_GROUP_SIZE (res) = 0;
  DR_GROUP_STORE_COUNT (res) = 0;
  DR_GROUP_GAP (res) = 0;
  DR_GROUP_SAME_DR_STMT (res) = NULL;
  DR_GROUP_READ_WRITE_DEPENDENCE (res) = false;

  return res;
}


/* Create a hash table for stmt_vec_info. */

void
init_stmt_vec_info_vec (void)
{
  gcc_assert (!stmt_vec_info_vec);
  stmt_vec_info_vec = VEC_alloc (vec_void_p, heap, 50);
}


/* Free hash table for stmt_vec_info. */

void
free_stmt_vec_info_vec (void)
{
  gcc_assert (stmt_vec_info_vec);
  VEC_free (vec_void_p, heap, stmt_vec_info_vec);
}


/* Free stmt vectorization related info.  */

void
free_stmt_vec_info (gimple stmt)
{
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);

  if (!stmt_info)
    return;

  VEC_free (dr_p, heap, STMT_VINFO_SAME_ALIGN_REFS (stmt_info));
  set_vinfo_for_stmt (stmt, NULL);
  free (stmt_info);
}


/* Function get_vectype_for_scalar_type.

   Returns the vector type corresponding to SCALAR_TYPE as supported
   by the target.  */

tree
get_vectype_for_scalar_type (tree scalar_type)
{
  enum machine_mode inner_mode = TYPE_MODE (scalar_type);
  int nbytes = GET_MODE_SIZE (inner_mode);
  int nunits;
  tree vectype;

  if (nbytes == 0 || nbytes >= UNITS_PER_SIMD_WORD (inner_mode))
    return NULL_TREE;

  /* FORNOW: Only a single vector size per mode (UNITS_PER_SIMD_WORD)
     is expected.  */
  nunits = UNITS_PER_SIMD_WORD (inner_mode) / nbytes;

  vectype = build_vector_type (scalar_type, nunits);
  if (vect_print_dump_info (REPORT_DETAILS))
    {
      fprintf (vect_dump, "get vectype with %d units of type ", nunits);
      print_generic_expr (vect_dump, scalar_type, TDF_SLIM);
    }

  if (!vectype)
    return NULL_TREE;

  if (vect_print_dump_info (REPORT_DETAILS))
    {
      fprintf (vect_dump, "vectype: ");
      print_generic_expr (vect_dump, vectype, TDF_SLIM);
    }

  if (!VECTOR_MODE_P (TYPE_MODE (vectype))
      && !INTEGRAL_MODE_P (TYPE_MODE (vectype)))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "mode not supported by target.");
      return NULL_TREE;
    }

  return vectype;
}

/* Function vect_is_simple_use.

   Input:
   LOOP - the loop that is being vectorized.
   OPERAND - operand of a stmt in LOOP.
   DEF - the defining stmt in case OPERAND is an SSA_NAME.

   Returns whether a stmt with OPERAND can be vectorized.
   Supportable operands are constants, loop invariants, and operands that are
   defined by the current iteration of the loop. Unsupportable operands are 
   those that are defined by a previous iteration of the loop (as is the case
   in reduction/induction computations).  */

bool
vect_is_simple_use (tree operand, loop_vec_info loop_vinfo, gimple *def_stmt,
                    tree *def, enum vect_def_type *dt)
{ 
  basic_block bb;
  stmt_vec_info stmt_vinfo;
  struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);

  *def_stmt = NULL;
  *def = NULL_TREE;
  
  if (vect_print_dump_info (REPORT_DETAILS))
    {
      fprintf (vect_dump, "vect_is_simple_use: operand ");
      print_generic_expr (vect_dump, operand, TDF_SLIM);
    }
    
  if (TREE_CODE (operand) == INTEGER_CST || TREE_CODE (operand) == REAL_CST)
    {
      *dt = vect_constant_def;
      return true;
    }
  if (is_gimple_min_invariant (operand))
    {
      *def = operand;
      *dt = vect_external_def;
      return true;
    }

  if (TREE_CODE (operand) == PAREN_EXPR)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "non-associatable copy.");
      operand = TREE_OPERAND (operand, 0);
    }
  if (TREE_CODE (operand) != SSA_NAME)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "not ssa-name.");
      return false;
    }
    
  *def_stmt = SSA_NAME_DEF_STMT (operand);
  if (*def_stmt == NULL)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "no def_stmt.");
      return false;
    }

  if (vect_print_dump_info (REPORT_DETAILS))
    {
      fprintf (vect_dump, "def_stmt: ");
      print_gimple_stmt (vect_dump, *def_stmt, 0, TDF_SLIM);
    }

  /* Empty stmt is expected only in case of a function argument.
     (Otherwise - we expect a phi_node or a GIMPLE_ASSIGN).  */
  if (gimple_nop_p (*def_stmt))
    {
      *def = operand;
      *dt = vect_external_def;
      return true;
    }

  bb = gimple_bb (*def_stmt);
  if (!flow_bb_inside_loop_p (loop, bb))
    *dt = vect_external_def;
  else
    {
      stmt_vinfo = vinfo_for_stmt (*def_stmt);
      *dt = STMT_VINFO_DEF_TYPE (stmt_vinfo);
    }

  if (*dt == vect_unknown_def_type)
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "Unsupported pattern.");
      return false;
    }

  if (vect_print_dump_info (REPORT_DETAILS))
    fprintf (vect_dump, "type of def: %d.",*dt);

  switch (gimple_code (*def_stmt))
    {
    case GIMPLE_PHI:
      *def = gimple_phi_result (*def_stmt);
      break;

    case GIMPLE_ASSIGN:
      *def = gimple_assign_lhs (*def_stmt);
      break;

    case GIMPLE_CALL:
      *def = gimple_call_lhs (*def_stmt);
      if (*def != NULL)
        break;
      /* FALLTHRU */
    default:
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "unsupported defining stmt: ");
      return false;
    }

  return true;
}


/* Function supportable_widening_operation

   Check whether an operation represented by the code CODE is a 
   widening operation that is supported by the target platform in 
   vector form (i.e., when operating on arguments of type VECTYPE).
    
   Widening operations we currently support are NOP (CONVERT), FLOAT
   and WIDEN_MULT.  This function checks if these operations are supported
   by the target platform either directly (via vector tree-codes), or via
   target builtins.

   Output:
   - CODE1 and CODE2 are codes of vector operations to be used when 
   vectorizing the operation, if available. 
   - DECL1 and DECL2 are decls of target builtin functions to be used
   when vectorizing the operation, if available. In this case,
   CODE1 and CODE2 are CALL_EXPR.  
   - MULTI_STEP_CVT determines the number of required intermediate steps in
   case of multi-step conversion (like char->short->int - in that case
   MULTI_STEP_CVT will be 1).
   - INTERM_TYPES contains the intermediate type required to perform the 
   widening operation (short in the above example).  */   

bool
supportable_widening_operation (enum tree_code code, gimple stmt, tree vectype,
                                tree *decl1, tree *decl2,
                                enum tree_code *code1, enum tree_code *code2,
                                int *multi_step_cvt,
                                VEC (tree, heap) **interm_types)
{
  stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
  loop_vec_info loop_info = STMT_VINFO_LOOP_VINFO (stmt_info);
  struct loop *vect_loop = LOOP_VINFO_LOOP (loop_info);
  bool ordered_p;
  enum machine_mode vec_mode;
  enum insn_code icode1, icode2;
  optab optab1, optab2;
  tree type = gimple_expr_type (stmt);
  tree wide_vectype = get_vectype_for_scalar_type (type);
  enum tree_code c1, c2;

  /* The result of a vectorized widening operation usually requires two vectors
     (because the widened results do not fit int one vector). The generated 
     vector results would normally be expected to be generated in the same 
     order as in the original scalar computation, i.e. if 8 results are
     generated in each vector iteration, they are to be organized as follows:
        vect1: [res1,res2,res3,res4], vect2: [res5,res6,res7,res8]. 

     However, in the special case that the result of the widening operation is 
     used in a reduction computation only, the order doesn't matter (because
     when vectorizing a reduction we change the order of the computation). 
     Some targets can take advantage of this and generate more efficient code.
     For example, targets like Altivec, that support widen_mult using a sequence
     of {mult_even,mult_odd} generate the following vectors:
        vect1: [res1,res3,res5,res7], vect2: [res2,res4,res6,res8].

     When vectorizing outer-loops, we execute the inner-loop sequentially
     (each vectorized inner-loop iteration contributes to VF outer-loop 
     iterations in parallel). We therefore don't allow to change the order 
     of the computation in the inner-loop during outer-loop vectorization.  */

   if (STMT_VINFO_RELEVANT (stmt_info) == vect_used_by_reduction
       && !nested_in_vect_loop_p (vect_loop, stmt))
     ordered_p = false;
   else
     ordered_p = true;

  if (!ordered_p
      && code == WIDEN_MULT_EXPR
      && targetm.vectorize.builtin_mul_widen_even
      && targetm.vectorize.builtin_mul_widen_even (vectype)
      && targetm.vectorize.builtin_mul_widen_odd
      && targetm.vectorize.builtin_mul_widen_odd (vectype))
    {
      if (vect_print_dump_info (REPORT_DETAILS))
        fprintf (vect_dump, "Unordered widening operation detected.");

      *code1 = *code2 = CALL_EXPR;
      *decl1 = targetm.vectorize.builtin_mul_widen_even (vectype);
      *decl2 = targetm.vectorize.builtin_mul_widen_odd (vectype);
      return true;
    }

  switch (code)
    {
    case WIDEN_MULT_EXPR:
      if (BYTES_BIG_ENDIAN)
        {
          c1 = VEC_WIDEN_MULT_HI_EXPR;
          c2 = VEC_WIDEN_MULT_LO_EXPR;
        }
      else
        {
          c2 = VEC_WIDEN_MULT_HI_EXPR;
          c1 = VEC_WIDEN_MULT_LO_EXPR;
        }
      break;

    CASE_CONVERT:
      if (BYTES_BIG_ENDIAN)
        {
          c1 = VEC_UNPACK_HI_EXPR;
          c2 = VEC_UNPACK_LO_EXPR;
        }
      else
        {
          c2 = VEC_UNPACK_HI_EXPR;
          c1 = VEC_UNPACK_LO_EXPR;
        }
      break;

    case FLOAT_EXPR:
      if (BYTES_BIG_ENDIAN)
        {
          c1 = VEC_UNPACK_FLOAT_HI_EXPR;
          c2 = VEC_UNPACK_FLOAT_LO_EXPR;
        }
      else
        {
          c2 = VEC_UNPACK_FLOAT_HI_EXPR;
          c1 = VEC_UNPACK_FLOAT_LO_EXPR;
        }
      break;

    case FIX_TRUNC_EXPR:
      /* ??? Not yet implemented due to missing VEC_UNPACK_FIX_TRUNC_HI_EXPR/
         VEC_UNPACK_FIX_TRUNC_LO_EXPR tree codes and optabs used for
         computing the operation.  */
      return false;

    default:
      gcc_unreachable ();
    }

  if (code == FIX_TRUNC_EXPR)
    {
      /* The signedness is determined from output operand.  */
      optab1 = optab_for_tree_code (c1, type, optab_default);
      optab2 = optab_for_tree_code (c2, type, optab_default);
    }
  else
    {
      optab1 = optab_for_tree_code (c1, vectype, optab_default);
      optab2 = optab_for_tree_code (c2, vectype, optab_default);
    }

  if (!optab1 || !optab2)
    return false;

  vec_mode = TYPE_MODE (vectype);
  if ((icode1 = optab_handler (optab1, vec_mode)->insn_code) == CODE_FOR_nothing
       || (icode2 = optab_handler (optab2, vec_mode)->insn_code)
                                                       == CODE_FOR_nothing)
    return false;

  /* Check if it's a multi-step conversion that can be done using intermediate 
     types.  */
  if (insn_data[icode1].operand[0].mode != TYPE_MODE (wide_vectype)
       || insn_data[icode2].operand[0].mode != TYPE_MODE (wide_vectype))
    {
      int i;
      tree prev_type = vectype, intermediate_type;
      enum machine_mode intermediate_mode, prev_mode = vec_mode;
      optab optab3, optab4;

      if (!CONVERT_EXPR_CODE_P (code))
        return false;
      
      *code1 = c1;
      *code2 = c2;
    
      /* We assume here that there will not be more than MAX_INTERM_CVT_STEPS
         intermediate  steps in promotion sequence. We try MAX_INTERM_CVT_STEPS
         to get to NARROW_VECTYPE, and fail if we do not.  */
      *interm_types = VEC_alloc (tree, heap, MAX_INTERM_CVT_STEPS);
      for (i = 0; i < 3; i++)
        {
          intermediate_mode = insn_data[icode1].operand[0].mode;
          intermediate_type = lang_hooks.types.type_for_mode (intermediate_mode,
                                                     TYPE_UNSIGNED (prev_type));
          optab3 = optab_for_tree_code (c1, intermediate_type, optab_default);
          optab4 = optab_for_tree_code (c2, intermediate_type, optab_default);

          if (!optab3 || !optab4
              || (icode1 = optab1->handlers[(int) prev_mode].insn_code)
                                                        == CODE_FOR_nothing
              || insn_data[icode1].operand[0].mode != intermediate_mode
              || (icode2 = optab2->handlers[(int) prev_mode].insn_code)
                                                        == CODE_FOR_nothing
              || insn_data[icode2].operand[0].mode != intermediate_mode
              || (icode1 = optab3->handlers[(int) intermediate_mode].insn_code) 
                                                        == CODE_FOR_nothing
              || (icode2 = optab4->handlers[(int) intermediate_mode].insn_code)
                                                        == CODE_FOR_nothing)
            return false;

          VEC_quick_push (tree, *interm_types, intermediate_type);
          (*multi_step_cvt)++;

          if (insn_data[icode1].operand[0].mode == TYPE_MODE (wide_vectype)
              && insn_data[icode2].operand[0].mode == TYPE_MODE (wide_vectype))
            return true;

          prev_type = intermediate_type;
          prev_mode = intermediate_mode;
        }

       return false;
    }

  *code1 = c1;
  *code2 = c2;
  return true;
}


/* Function supportable_narrowing_operation

   Check whether an operation represented by the code CODE is a 
   narrowing operation that is supported by the target platform in 
   vector form (i.e., when operating on arguments of type VECTYPE).
    
   Narrowing operations we currently support are NOP (CONVERT) and
   FIX_TRUNC. This function checks if these operations are supported by
   the target platform directly via vector tree-codes.

   Output:
   - CODE1 is the code of a vector operation to be used when 
   vectorizing the operation, if available. 
   - MULTI_STEP_CVT determines the number of required intermediate steps in
   case of multi-step conversion (like int->short->char - in that case
   MULTI_STEP_CVT will be 1).
   - INTERM_TYPES contains the intermediate type required to perform the
   narrowing operation (short in the above example).   */ 

bool
supportable_narrowing_operation (enum tree_code code,
                                 const_gimple stmt, tree vectype,
                                 enum tree_code *code1, int *multi_step_cvt,
                                 VEC (tree, heap) **interm_types)
{
  enum machine_mode vec_mode;
  enum insn_code icode1;
  optab optab1, interm_optab;
  tree type = gimple_expr_type (stmt);
  tree narrow_vectype = get_vectype_for_scalar_type (type);
  enum tree_code c1;
  tree intermediate_type, prev_type;
  int i;

  switch (code)
    {
    CASE_CONVERT:
      c1 = VEC_PACK_TRUNC_EXPR;
      break;

    case FIX_TRUNC_EXPR:
      c1 = VEC_PACK_FIX_TRUNC_EXPR;
      break;

    case FLOAT_EXPR:
      /* ??? Not yet implemented due to missing VEC_PACK_FLOAT_EXPR
         tree code and optabs used for computing the operation.  */
      return false;

    default:
      gcc_unreachable ();
    }

  if (code == FIX_TRUNC_EXPR)
    /* The signedness is determined from output operand.  */
    optab1 = optab_for_tree_code (c1, type, optab_default);
  else
    optab1 = optab_for_tree_code (c1, vectype, optab_default);

  if (!optab1)
    return false;

  vec_mode = TYPE_MODE (vectype);
  if ((icode1 = optab_handler (optab1, vec_mode)->insn_code) 
       == CODE_FOR_nothing)
    return false;

  /* Check if it's a multi-step conversion that can be done using intermediate
     types.  */
  if (insn_data[icode1].operand[0].mode != TYPE_MODE (narrow_vectype))
    {
      enum machine_mode intermediate_mode, prev_mode = vec_mode;

      *code1 = c1;
      prev_type = vectype;
      /* We assume here that there will not be more than MAX_INTERM_CVT_STEPS
         intermediate  steps in promotion sequence. We try MAX_INTERM_CVT_STEPS
         to get to NARROW_VECTYPE, and fail if we do not.  */
      *interm_types = VEC_alloc (tree, heap, MAX_INTERM_CVT_STEPS);
      for (i = 0; i < 3; i++)
        {
          intermediate_mode = insn_data[icode1].operand[0].mode;
          intermediate_type = lang_hooks.types.type_for_mode (intermediate_mode,
                                                     TYPE_UNSIGNED (prev_type));
          interm_optab = optab_for_tree_code (c1, intermediate_type, 
                                              optab_default);
          if (!interm_optab  
              || (icode1 = optab1->handlers[(int) prev_mode].insn_code)
                                                        == CODE_FOR_nothing
              || insn_data[icode1].operand[0].mode != intermediate_mode
              || (icode1 
                  = interm_optab->handlers[(int) intermediate_mode].insn_code)
                 == CODE_FOR_nothing)
            return false;

          VEC_quick_push (tree, *interm_types, intermediate_type);
          (*multi_step_cvt)++;

          if (insn_data[icode1].operand[0].mode == TYPE_MODE (narrow_vectype))
            return true;

          prev_type = intermediate_type;
          prev_mode = intermediate_mode;
        }

      return false;
    }

  *code1 = c1;
  return true;
}