gcc/tree-vect-transform.c

   1 /* Transformation Utilities for Loop Vectorization.
   2    Copyright (C) 2003,2004,2005,2006 Free Software Foundation, Inc.
   3    Contributed by Dorit Naishlos <dorit@il.ibm.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  20 02110-1301, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "ggc.h"
  27 #include "tree.h"
  28 #include "target.h"
  29 #include "rtl.h"
  30 #include "basic-block.h"
  31 #include "diagnostic.h"
  32 #include "tree-flow.h"
  33 #include "tree-dump.h"
  34 #include "timevar.h"
  35 #include "cfgloop.h"
  36 #include "expr.h"
  37 #include "optabs.h"
  38 #include "recog.h"
  39 #include "tree-data-ref.h"
  40 #include "tree-chrec.h"
  41 #include "tree-scalar-evolution.h"
  42 #include "tree-vectorizer.h"
  43 #include "langhooks.h"
  44 #include "tree-pass.h"
  45 #include "toplev.h"
  46 #include "real.h"
  47
  48 /* Utility functions for the code transformation.  */
  49 static bool vect_transform_stmt (tree, block_stmt_iterator *, bool *);
  50 static tree vect_create_destination_var (tree, tree);
  51 static tree vect_create_data_ref_ptr
  52   (tree, block_stmt_iterator *, tree, tree *, tree *, bool, tree);
  53 static tree vect_create_addr_base_for_vector_ref (tree, tree *, tree);
  54 static tree vect_setup_realignment (tree, block_stmt_iterator *, tree *);
  55 static tree vect_get_new_vect_var (tree, enum vect_var_kind, const char *);
  56 static tree vect_get_vec_def_for_operand (tree, tree, tree *);
  57 static tree vect_init_vector (tree, tree, tree);
  58 static void vect_finish_stmt_generation
  59   (tree stmt, tree vec_stmt, block_stmt_iterator *bsi);
  60 static bool vect_is_simple_cond (tree, loop_vec_info);
  61 static void update_vuses_to_preheader (tree, struct loop*);
  62 static void vect_create_epilog_for_reduction (tree, tree, enum tree_code, tree);
  63 static tree get_initial_def_for_reduction (tree, tree, tree *);
  64
  65 /* Utility function dealing with loop peeling (not peeling itself).  */
  66 static void vect_generate_tmps_on_preheader
  67   (loop_vec_info, tree *, tree *, tree *);
  68 static tree vect_build_loop_niters (loop_vec_info);
  69 static void vect_update_ivs_after_vectorizer (loop_vec_info, tree, edge);
  70 static tree vect_gen_niters_for_prolog_loop (loop_vec_info, tree);
  71 static void vect_update_init_of_dr (struct data_reference *, tree niters);
  72 static void vect_update_inits_of_drs (loop_vec_info, tree);
  73 static int vect_min_worthwhile_factor (enum tree_code);
  74
  75
  76 /* Function vect_get_new_vect_var.
  77
  78    Returns a name for a new variable. The current naming scheme appends the
  79    prefix "vect_" or "vect_p" (depending on the value of VAR_KIND) to
  80    the name of vectorizer generated variables, and appends that to NAME if
  81    provided.  */
  82
  83 static tree
  84 vect_get_new_vect_var (tree type, enum vect_var_kind var_kind, const char *name)
  85 {
  86   const char *prefix;
  87   tree new_vect_var;
  88
  89   switch (var_kind)
  90   {
  91   case vect_simple_var:
  92     prefix = "vect_";
  93     break;
  94   case vect_scalar_var:
  95     prefix = "stmp_";
  96     break;
  97   case vect_pointer_var:
  98     prefix = "vect_p";
  99     break;
 100   default:
 101     gcc_unreachable ();
 102   }
 103
 104   if (name)
 105     new_vect_var = create_tmp_var (type, concat (prefix, name, NULL));
 106   else
 107     new_vect_var = create_tmp_var (type, prefix);
 108
 109   /* Mark vector typed variable as a gimple register variable.  */
 110   if (TREE_CODE (type) == VECTOR_TYPE)
 111     DECL_GIMPLE_REG_P (new_vect_var) = true;
 112
 113   return new_vect_var;
 114 }
 115
 116
 117 /* Function vect_create_addr_base_for_vector_ref.
 118
 119    Create an expression that computes the address of the first memory location
 120    that will be accessed for a data reference.
 121
 122    Input:
 123    STMT: The statement containing the data reference.
 124    NEW_STMT_LIST: Must be initialized to NULL_TREE or a statement list.
 125    OFFSET: Optional. If supplied, it is be added to the initial address.
 126
 127    Output:
 128    1. Return an SSA_NAME whose value is the address of the memory location of
 129       the first vector of the data reference.
 130    2. If new_stmt_list is not NULL_TREE after return then the caller must insert
 131       these statement(s) which define the returned SSA_NAME.
 132
 133    FORNOW: We are only handling array accesses with step 1.  */
 134
 135 static tree
 136 vect_create_addr_base_for_vector_ref (tree stmt,
 137                                       tree *new_stmt_list,
 138                                       tree offset)
 139 {
 140   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
 141   struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
 142   tree data_ref_base = unshare_expr (DR_BASE_ADDRESS (dr));
 143   tree base_name = build_fold_indirect_ref (data_ref_base);
 144   tree vec_stmt;
 145   tree addr_base, addr_expr;
 146   tree dest, new_stmt;
 147   tree base_offset = unshare_expr (DR_OFFSET (dr));
 148   tree init = unshare_expr (DR_INIT (dr));
 149   tree vect_ptr_type, addr_expr2;
 150
 151   /* Create base_offset */
 152   base_offset = size_binop (PLUS_EXPR, base_offset, init);
 153   dest = create_tmp_var (TREE_TYPE (base_offset), "base_off");
 154   add_referenced_var (dest);
 155   base_offset = force_gimple_operand (base_offset, &new_stmt, false, dest);
 156   append_to_statement_list_force (new_stmt, new_stmt_list);
 157
 158   if (offset)
 159     {
 160       tree tmp = create_tmp_var (TREE_TYPE (base_offset), "offset");
 161       tree step;
 162
 163       /* For interleaved access step we divide STEP by the size of the
 164         interleaving group.  */
 165       if (DR_GROUP_SIZE (stmt_info))
 166         step = fold_build2 (TRUNC_DIV_EXPR, TREE_TYPE (offset), DR_STEP (dr),
 167                             build_int_cst (TREE_TYPE (offset),
 168                                            DR_GROUP_SIZE (stmt_info)));
 169       else
 170         step = DR_STEP (dr);
 171
 172       add_referenced_var (tmp);
 173       offset = fold_build2 (MULT_EXPR, TREE_TYPE (offset), offset, step);
 174       base_offset = fold_build2 (PLUS_EXPR, TREE_TYPE (base_offset),
 175                                  base_offset, offset);
 176       base_offset = force_gimple_operand (base_offset, &new_stmt, false, tmp);
 177       append_to_statement_list_force (new_stmt, new_stmt_list);
 178     }
 179
 180   /* base + base_offset */
 181   addr_base = fold_build2 (PLUS_EXPR, TREE_TYPE (data_ref_base), data_ref_base,
 182                            base_offset);
 183
 184   vect_ptr_type = build_pointer_type (STMT_VINFO_VECTYPE (stmt_info));
 185
 186   /* addr_expr = addr_base */
 187   addr_expr = vect_get_new_vect_var (vect_ptr_type, vect_pointer_var,
 188                                      get_name (base_name));
 189   add_referenced_var (addr_expr);
 190   vec_stmt = fold_convert (vect_ptr_type, addr_base);
 191   addr_expr2 = vect_get_new_vect_var (vect_ptr_type, vect_pointer_var,
 192                                      get_name (base_name));
 193   add_referenced_var (addr_expr2);
 194   vec_stmt = force_gimple_operand (vec_stmt, &new_stmt, false, addr_expr2);
 195   append_to_statement_list_force (new_stmt, new_stmt_list);
 196
 197   if (vect_print_dump_info (REPORT_DETAILS))
 198     {
 199       fprintf (vect_dump, "created ");
 200       print_generic_expr (vect_dump, vec_stmt, TDF_SLIM);
 201     }
 202   return vec_stmt;
 203 }
 204
 205
 206 /* Function vect_create_data_ref_ptr.
 207
 208    Create a new pointer to vector type (vp), that points to the first location
 209    accessed in the loop by STMT, along with the def-use update chain to
 210    appropriately advance the pointer through the loop iterations. Also set
 211    aliasing information for the pointer.  This vector pointer is used by the
 212    callers to this function to create a memory reference expression for vector
 213    load/store access.
 214
 215    Input:
 216    1. STMT: a stmt that references memory. Expected to be of the form
 217          GIMPLE_MODIFY_STMT <name, data-ref> or
 218          GIMPLE_MODIFY_STMT <data-ref, name>.
 219    2. BSI: block_stmt_iterator where new stmts can be added.
 220    3. OFFSET (optional): an offset to be added to the initial address accessed
 221         by the data-ref in STMT.
 222    4. ONLY_INIT: indicate if vp is to be updated in the loop, or remain
 223         pointing to the initial address.
 224    5. TYPE: if not NULL indicates the required type of the data-ref
 225
 226    Output:
 227    1. Declare a new ptr to vector_type, and have it point to the base of the
 228       data reference (initial addressed accessed by the data reference).
 229       For example, for vector of type V8HI, the following code is generated:
 230
 231       v8hi *vp;
 232       vp = (v8hi *)initial_address;
 233
 234       if OFFSET is not supplied:
 235          initial_address = &a[init];
 236       if OFFSET is supplied:
 237          initial_address = &a[init + OFFSET];
 238
 239       Return the initial_address in INITIAL_ADDRESS.
 240
 241    2. If ONLY_INIT is true, just return the initial pointer.  Otherwise, also
 242       update the pointer in each iteration of the loop.
 243
 244       Return the increment stmt that updates the pointer in PTR_INCR.
 245
 246    3. Return the pointer.  */
 247
 248 static tree
 249 vect_create_data_ref_ptr (tree stmt,
 250                           block_stmt_iterator *bsi ATTRIBUTE_UNUSED,
 251                           tree offset, tree *initial_address, tree *ptr_incr,
 252                           bool only_init, tree type)
 253 {
 254   tree base_name;
 255   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
 256   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
 257   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
 258   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
 259   tree vect_ptr_type;
 260   tree vect_ptr;
 261   tree tag;
 262   tree new_temp;
 263   tree vec_stmt;
 264   tree new_stmt_list = NULL_TREE;
 265   edge pe = loop_preheader_edge (loop);
 266   basic_block new_bb;
 267   tree vect_ptr_init;
 268   struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
 269
 270   base_name =  build_fold_indirect_ref (unshare_expr (DR_BASE_ADDRESS (dr)));
 271
 272   if (vect_print_dump_info (REPORT_DETAILS))
 273     {
 274       tree data_ref_base = base_name;
 275       fprintf (vect_dump, "create vector-pointer variable to type: ");
 276       print_generic_expr (vect_dump, vectype, TDF_SLIM);
 277       if (TREE_CODE (data_ref_base) == VAR_DECL)
 278         fprintf (vect_dump, "  vectorizing a one dimensional array ref: ");
 279       else if (TREE_CODE (data_ref_base) == ARRAY_REF)
 280         fprintf (vect_dump, "  vectorizing a multidimensional array ref: ");
 281       else if (TREE_CODE (data_ref_base) == COMPONENT_REF)
 282         fprintf (vect_dump, "  vectorizing a record based array ref: ");
 283       else if (TREE_CODE (data_ref_base) == SSA_NAME)
 284         fprintf (vect_dump, "  vectorizing a pointer ref: ");
 285       print_generic_expr (vect_dump, base_name, TDF_SLIM);
 286     }
 287
 288   /** (1) Create the new vector-pointer variable:  **/
 289   if (type)
 290     vect_ptr_type = build_pointer_type (type);
 291   else
 292     vect_ptr_type = build_pointer_type (vectype);
 293   vect_ptr = vect_get_new_vect_var (vect_ptr_type, vect_pointer_var,
 294                                     get_name (base_name));
 295   add_referenced_var (vect_ptr);
 296
 297   /** (2) Add aliasing information to the new vector-pointer:
 298           (The points-to info (DR_PTR_INFO) may be defined later.)  **/
 299
 300   tag = DR_MEMTAG (dr);
 301   gcc_assert (tag);
 302
 303   /* If tag is a variable (and NOT_A_TAG) than a new symbol memory
 304      tag must be created with tag added to its may alias list.  */
 305   if (!MTAG_P (tag))
 306     new_type_alias (vect_ptr, tag, DR_REF (dr));
 307   else
 308     set_symbol_mem_tag (vect_ptr, tag);
 309
 310   var_ann (vect_ptr)->subvars = DR_SUBVARS (dr);
 311
 312   /** (3) Calculate the initial address the vector-pointer, and set
 313           the vector-pointer to point to it before the loop:  **/
 314
 315   /* Create: (&(base[init_val+offset]) in the loop preheader.  */
 316   new_temp = vect_create_addr_base_for_vector_ref (stmt, &new_stmt_list,
 317                                                    offset);
 318   pe = loop_preheader_edge (loop);
 319   new_bb = bsi_insert_on_edge_immediate (pe, new_stmt_list);
 320   gcc_assert (!new_bb);
 321   *initial_address = new_temp;
 322
 323   /* Create: p = (vectype *) initial_base  */
 324   vec_stmt = fold_convert (vect_ptr_type, new_temp);
 325   vec_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vect_ptr, vec_stmt);
 326   vect_ptr_init = make_ssa_name (vect_ptr, vec_stmt);
 327   GIMPLE_STMT_OPERAND (vec_stmt, 0) = vect_ptr_init;
 328   new_bb = bsi_insert_on_edge_immediate (pe, vec_stmt);
 329   gcc_assert (!new_bb);
 330
 331
 332   /** (4) Handle the updating of the vector-pointer inside the loop: **/
 333
 334   if (only_init) /* No update in loop is required.  */
 335     {
 336       /* Copy the points-to information if it exists. */
 337       if (DR_PTR_INFO (dr))
 338         duplicate_ssa_name_ptr_info (vect_ptr_init, DR_PTR_INFO (dr));
 339       return vect_ptr_init;
 340     }
 341   else
 342     {
 343       block_stmt_iterator incr_bsi;
 344       bool insert_after;
 345       tree indx_before_incr, indx_after_incr;
 346       tree incr;
 347
 348       standard_iv_increment_position (loop, &incr_bsi, &insert_after);
 349       create_iv (vect_ptr_init,
 350                  fold_convert (vect_ptr_type, TYPE_SIZE_UNIT (vectype)),
 351                  NULL_TREE, loop, &incr_bsi, insert_after,
 352                  &indx_before_incr, &indx_after_incr);
 353       incr = bsi_stmt (incr_bsi);
 354       set_stmt_info (stmt_ann (incr),
 355                      new_stmt_vec_info (incr, loop_vinfo));
 356
 357       /* Copy the points-to information if it exists. */
 358       if (DR_PTR_INFO (dr))
 359         {
 360           duplicate_ssa_name_ptr_info (indx_before_incr, DR_PTR_INFO (dr));
 361           duplicate_ssa_name_ptr_info (indx_after_incr, DR_PTR_INFO (dr));
 362         }
 363       merge_alias_info (vect_ptr_init, indx_before_incr);
 364       merge_alias_info (vect_ptr_init, indx_after_incr);
 365       if (ptr_incr)
 366         *ptr_incr = incr;
 367
 368       return indx_before_incr;
 369     }
 370 }
 371
 372
 373 /* Function bump_vector_ptr
 374
 375    Increment a pointer (to a vector type) by vector-size. Connect the new
 376    increment stmt to the existing def-use update-chain of the pointer.
 377
 378    The pointer def-use update-chain before this function:
 379                         DATAREF_PTR = phi (p_0, p_2)
 380                         ....
 381         PTR_INCR:       p_2 = DATAREF_PTR + step
 382
 383    The pointer def-use update-chain after this function:
 384                         DATAREF_PTR = phi (p_0, p_2)
 385                         ....
 386                         NEW_DATAREF_PTR = DATAREF_PTR + vector_size
 387                         ....
 388         PTR_INCR:       p_2 = NEW_DATAREF_PTR + step
 389
 390    Input:
 391    DATAREF_PTR - ssa_name of a pointer (to vector type) that is being updated
 392                  in the loop.
 393    PTR_INCR - the stmt that updates the pointer in each iteration of the loop.
 394               The increment amount across iterations is also expected to be
 395               vector_size.
 396    BSI - location where the new update stmt is to be placed.
 397    STMT - the original scalar memory-access stmt that is being vectorized.
 398
 399    Output: Return NEW_DATAREF_PTR as illustrated above.
 400
 401 */
 402
 403 static tree
 404 bump_vector_ptr (tree dataref_ptr, tree ptr_incr, block_stmt_iterator *bsi,
 405                  tree stmt)
 406 {
 407   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
 408   struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
 409   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
 410   tree vptr_type = TREE_TYPE (dataref_ptr);
 411   tree ptr_var = SSA_NAME_VAR (dataref_ptr);
 412   tree update = fold_convert (vptr_type, TYPE_SIZE_UNIT (vectype));
 413   tree incr_stmt;
 414   ssa_op_iter iter;
 415   use_operand_p use_p;
 416   tree new_dataref_ptr;
 417
 418   incr_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, ptr_var,
 419                 build2 (PLUS_EXPR, vptr_type, dataref_ptr, update));
 420   new_dataref_ptr = make_ssa_name (ptr_var, incr_stmt);
 421   GIMPLE_STMT_OPERAND (incr_stmt, 0) = new_dataref_ptr;
 422   vect_finish_stmt_generation (stmt, incr_stmt, bsi);
 423
 424   /* Update the vector-pointer's cross-iteration increment.  */
 425   FOR_EACH_SSA_USE_OPERAND (use_p, ptr_incr, iter, SSA_OP_USE)
 426     {
 427       tree use = USE_FROM_PTR (use_p);
 428
 429       if (use == dataref_ptr)
 430         SET_USE (use_p, new_dataref_ptr);
 431       else
 432         gcc_assert (tree_int_cst_compare (use, update) == 0);
 433     }
 434
 435   /* Copy the points-to information if it exists. */
 436   if (DR_PTR_INFO (dr))
 437     duplicate_ssa_name_ptr_info (new_dataref_ptr, DR_PTR_INFO (dr));
 438   merge_alias_info (new_dataref_ptr, dataref_ptr);
 439
 440   return new_dataref_ptr;
 441 }
 442
 443
 444 /* Function vect_create_destination_var.
 445
 446    Create a new temporary of type VECTYPE.  */
 447
 448 static tree
 449 vect_create_destination_var (tree scalar_dest, tree vectype)
 450 {
 451   tree vec_dest;
 452   const char *new_name;
 453   tree type;
 454   enum vect_var_kind kind;
 455
 456   kind = vectype ? vect_simple_var : vect_scalar_var;
 457   type = vectype ? vectype : TREE_TYPE (scalar_dest);
 458
 459   gcc_assert (TREE_CODE (scalar_dest) == SSA_NAME);
 460
 461   new_name = get_name (scalar_dest);
 462   if (!new_name)
 463     new_name = "var_";
 464   vec_dest = vect_get_new_vect_var (type, vect_simple_var, new_name);
 465   add_referenced_var (vec_dest);
 466
 467   return vec_dest;
 468 }
 469
 470
 471 /* Function vect_init_vector.
 472
 473    Insert a new stmt (INIT_STMT) that initializes a new vector variable with
 474    the vector elements of VECTOR_VAR. Return the DEF of INIT_STMT. It will be
 475    used in the vectorization of STMT.  */
 476
 477 static tree
 478 vect_init_vector (tree stmt, tree vector_var, tree vector_type)
 479 {
 480   stmt_vec_info stmt_vinfo = vinfo_for_stmt (stmt);
 481   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_vinfo);
 482   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
 483   tree new_var;
 484   tree init_stmt;
 485   tree vec_oprnd;
 486   edge pe;
 487   tree new_temp;
 488   basic_block new_bb;
 489
 490   new_var = vect_get_new_vect_var (vector_type, vect_simple_var, "cst_");
 491   add_referenced_var (new_var);
 492
 493   init_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, new_var, vector_var);
 494   new_temp = make_ssa_name (new_var, init_stmt);
 495   GIMPLE_STMT_OPERAND (init_stmt, 0) = new_temp;
 496
 497   pe = loop_preheader_edge (loop);
 498   new_bb = bsi_insert_on_edge_immediate (pe, init_stmt);
 499   gcc_assert (!new_bb);
 500
 501   if (vect_print_dump_info (REPORT_DETAILS))
 502     {
 503       fprintf (vect_dump, "created new init_stmt: ");
 504       print_generic_expr (vect_dump, init_stmt, TDF_SLIM);
 505     }
 506
 507   vec_oprnd = GIMPLE_STMT_OPERAND (init_stmt, 0);
 508   return vec_oprnd;
 509 }
 510
 511
 512 /* Function vect_get_vec_def_for_operand.
 513
 514    OP is an operand in STMT. This function returns a (vector) def that will be
 515    used in the vectorized stmt for STMT.
 516
 517    In the case that OP is an SSA_NAME which is defined in the loop, then
 518    STMT_VINFO_VEC_STMT of the defining stmt holds the relevant def.
 519
 520    In case OP is an invariant or constant, a new stmt that creates a vector def
 521    needs to be introduced.  */
 522
 523 static tree
 524 vect_get_vec_def_for_operand (tree op, tree stmt, tree *scalar_def)
 525 {
 526   tree vec_oprnd;
 527   tree vec_stmt;
 528   tree def_stmt;
 529   stmt_vec_info def_stmt_info = NULL;
 530   stmt_vec_info stmt_vinfo = vinfo_for_stmt (stmt);
 531   tree vectype = STMT_VINFO_VECTYPE (stmt_vinfo);
 532   int nunits = TYPE_VECTOR_SUBPARTS (vectype);
 533   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_vinfo);
 534   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
 535   tree vec_inv;
 536   tree vec_cst;
 537   tree t = NULL_TREE;
 538   tree def;
 539   int i;
 540   enum vect_def_type dt;
 541   bool is_simple_use;
 542   tree vector_type;
 543
 544   if (vect_print_dump_info (REPORT_DETAILS))
 545     {
 546       fprintf (vect_dump, "vect_get_vec_def_for_operand: ");
 547       print_generic_expr (vect_dump, op, TDF_SLIM);
 548     }
 549
 550   is_simple_use = vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt);
 551   gcc_assert (is_simple_use);
 552   if (vect_print_dump_info (REPORT_DETAILS))
 553     {
 554       if (def)
 555         {
 556           fprintf (vect_dump, "def =  ");
 557           print_generic_expr (vect_dump, def, TDF_SLIM);
 558         }
 559       if (def_stmt)
 560         {
 561           fprintf (vect_dump, "  def_stmt =  ");
 562           print_generic_expr (vect_dump, def_stmt, TDF_SLIM);
 563         }
 564     }
 565
 566   switch (dt)
 567     {
 568     /* Case 1: operand is a constant.  */
 569     case vect_constant_def:
 570       {
 571         if (scalar_def)
 572           *scalar_def = op;
 573
 574         /* Create 'vect_cst_ = {cst,cst,...,cst}'  */
 575         if (vect_print_dump_info (REPORT_DETAILS))
 576           fprintf (vect_dump, "Create vector_cst. nunits = %d", nunits);
 577
 578         for (i = nunits - 1; i >= 0; --i)
 579           {
 580             t = tree_cons (NULL_TREE, op, t);
 581           }
 582         vector_type = get_vectype_for_scalar_type (TREE_TYPE (op));
 583         vec_cst = build_vector (vector_type, t);
 584
 585         return vect_init_vector (stmt, vec_cst, vector_type);
 586       }
 587
 588     /* Case 2: operand is defined outside the loop - loop invariant.  */
 589     case vect_invariant_def:
 590       {
 591         if (scalar_def)
 592           *scalar_def = def;
 593
 594         /* Create 'vec_inv = {inv,inv,..,inv}'  */
 595         if (vect_print_dump_info (REPORT_DETAILS))
 596           fprintf (vect_dump, "Create vector_inv.");
 597
 598         for (i = nunits - 1; i >= 0; --i)
 599           {
 600             t = tree_cons (NULL_TREE, def, t);
 601           }
 602
 603         /* FIXME: use build_constructor directly.  */
 604         vector_type = get_vectype_for_scalar_type (TREE_TYPE (def));
 605         vec_inv = build_constructor_from_list (vector_type, t);
 606         return vect_init_vector (stmt, vec_inv, vector_type);
 607       }
 608
 609     /* Case 3: operand is defined inside the loop.  */
 610     case vect_loop_def:
 611       {
 612         if (scalar_def)
 613           *scalar_def = def_stmt;
 614
 615         /* Get the def from the vectorized stmt.  */
 616         def_stmt_info = vinfo_for_stmt (def_stmt);
 617         vec_stmt = STMT_VINFO_VEC_STMT (def_stmt_info);
 618         gcc_assert (vec_stmt);
 619         vec_oprnd = GIMPLE_STMT_OPERAND (vec_stmt, 0);
 620         return vec_oprnd;
 621       }
 622
 623     /* Case 4: operand is defined by a loop header phi - reduction  */
 624     case vect_reduction_def:
 625       {
 626         gcc_assert (TREE_CODE (def_stmt) == PHI_NODE);
 627
 628         /* Get the def before the loop  */
 629         op = PHI_ARG_DEF_FROM_EDGE (def_stmt, loop_preheader_edge (loop));
 630         return get_initial_def_for_reduction (stmt, op, scalar_def);
 631      }
 632
 633     /* Case 5: operand is defined by loop-header phi - induction.  */
 634     case vect_induction_def:
 635       {
 636         if (vect_print_dump_info (REPORT_DETAILS))
 637           fprintf (vect_dump, "induction - unsupported.");
 638         internal_error ("no support for induction"); /* FORNOW */
 639       }
 640
 641     default:
 642       gcc_unreachable ();
 643     }
 644 }
 645
 646
 647 /* Function vect_get_vec_def_for_stmt_copy
 648
 649    Return a vector-def for an operand. This function is used when the
 650    vectorized stmt to be created (by the caller to this function) is a "copy"
 651    created in case the vectorized result cannot fit in one vector, and several
 652    copies of the vector-stmt are required. In this case the vector-def is
 653    retrieved from the vector stmt recorded in the STMT_VINFO_RELATED_STMT field
 654    of the stmt that defines VEC_OPRND.
 655    DT is the type of the vector def VEC_OPRND.
 656
 657    Context:
 658         In case the vectorization factor (VF) is bigger than the number
 659    of elements that can fit in a vectype (nunits), we have to generate
 660    more than one vector stmt to vectorize the scalar stmt. This situation
 661    arises when there are multiple data-types operated upon in the loop; the
 662    smallest data-type determines the VF, and as a result, when vectorizing
 663    stmts operating on wider types we need to create 'VF/nunits' "copies" of the
 664    vector stmt (each computing a vector of 'nunits' results, and together
 665    computing 'VF' results in each iteration).  This function is called when
 666    vectorizing such a stmt (e.g. vectorizing S2 in the illustration below, in
 667    which VF=16 and nuniti=4, so the number of copies required is 4):
 668
 669    scalar stmt:         vectorized into:        STMT_VINFO_RELATED_STMT
 670
 671    S1: x = load         VS1.0:  vx.0 = memref0      VS1.1
 672                         VS1.1:  vx.1 = memref1      VS1.2
 673                         VS1.2:  vx.2 = memref2      VS1.3
 674                         VS1.3:  vx.3 = memref3
 675
 676    S2: z = x + ...      VSnew.0:  vz0 = vx.0 + ...  VSnew.1
 677                         VSnew.1:  vz1 = vx.1 + ...  VSnew.2
 678                         VSnew.2:  vz2 = vx.2 + ...  VSnew.3
 679                         VSnew.3:  vz3 = vx.3 + ...
 680
 681    The vectorization of S1 is explained in vectorizable_load.
 682    The vectorization of S2:
 683         To create the first vector-stmt out of the 4 copies - VSnew.0 -
 684    the function 'vect_get_vec_def_for_operand' is called to
 685    get the relevant vector-def for each operand of S2. For operand x it
 686    returns  the vector-def 'vx.0'.
 687
 688         To create the remaining copies of the vector-stmt (VSnew.j), this
 689    function is called to get the relevant vector-def for each operand.  It is
 690    obtained from the respective VS1.j stmt, which is recorded in the
 691    STMT_VINFO_RELATED_STMT field of the stmt that defines VEC_OPRND.
 692
 693         For example, to obtain the vector-def 'vx.1' in order to create the
 694    vector stmt 'VSnew.1', this function is called with VEC_OPRND='vx.0'.
 695    Given 'vx0' we obtain the stmt that defines it ('VS1.0'); from the
 696    STMT_VINFO_RELATED_STMT field of 'VS1.0' we obtain the next copy - 'VS1.1',
 697    and return its def ('vx.1').
 698    Overall, to create the above sequence this function will be called 3 times:
 699         vx.1 = vect_get_vec_def_for_stmt_copy (dt, vx.0);
 700         vx.2 = vect_get_vec_def_for_stmt_copy (dt, vx.1);
 701         vx.3 = vect_get_vec_def_for_stmt_copy (dt, vx.2);  */
 702
 703 static tree
 704 vect_get_vec_def_for_stmt_copy (enum vect_def_type dt, tree vec_oprnd)
 705 {
 706   tree vec_stmt_for_operand;
 707   stmt_vec_info def_stmt_info;
 708
 709   if (dt == vect_invariant_def || dt == vect_constant_def)
 710     {
 711       /* Do nothing; can reuse same def.  */ ;
 712       return vec_oprnd;
 713     }
 714
 715   vec_stmt_for_operand = SSA_NAME_DEF_STMT (vec_oprnd);
 716   def_stmt_info = vinfo_for_stmt (vec_stmt_for_operand);
 717   gcc_assert (def_stmt_info);
 718   vec_stmt_for_operand = STMT_VINFO_RELATED_STMT (def_stmt_info);
 719   gcc_assert (vec_stmt_for_operand);
 720   vec_oprnd = GIMPLE_STMT_OPERAND (vec_stmt_for_operand, 0);
 721
 722   return vec_oprnd;
 723 }
 724
 725
 726 /* Function vect_finish_stmt_generation.
 727
 728    Insert a new stmt.  */
 729
 730 static void
 731 vect_finish_stmt_generation (tree stmt, tree vec_stmt,
 732                              block_stmt_iterator *bsi)
 733 {
 734   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
 735   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
 736
 737   bsi_insert_before (bsi, vec_stmt, BSI_SAME_STMT);
 738   set_stmt_info (get_stmt_ann (vec_stmt),
 739                  new_stmt_vec_info (vec_stmt, loop_vinfo));
 740
 741   if (vect_print_dump_info (REPORT_DETAILS))
 742     {
 743       fprintf (vect_dump, "add new stmt: ");
 744       print_generic_expr (vect_dump, vec_stmt, TDF_SLIM);
 745     }
 746
 747   /* Make sure bsi points to the stmt that is being vectorized.  */
 748   gcc_assert (stmt == bsi_stmt (*bsi));
 749
 750 #ifdef USE_MAPPED_LOCATION
 751   SET_EXPR_LOCATION (vec_stmt, EXPR_LOCATION (stmt));
 752 #else
 753   SET_EXPR_LOCUS (vec_stmt, EXPR_LOCUS (stmt));
 754 #endif
 755 }
 756
 757
 758 #define ADJUST_IN_EPILOG 1
 759
 760 /* Function get_initial_def_for_reduction
 761
 762    Input:
 763    STMT - a stmt that performs a reduction operation in the loop.
 764    INIT_VAL - the initial value of the reduction variable
 765
 766    Output:
 767    SCALAR_DEF - a tree that holds a value to be added to the final result
 768         of the reduction (used for "ADJUST_IN_EPILOG" - see below).
 769    Return a vector variable, initialized according to the operation that STMT
 770         performs. This vector will be used as the initial value of the
 771         vector of partial results.
 772
 773    Option1 ("ADJUST_IN_EPILOG"): Initialize the vector as follows:
 774      add:         [0,0,...,0,0]
 775      mult:        [1,1,...,1,1]
 776      min/max:     [init_val,init_val,..,init_val,init_val]
 777      bit and/or:  [init_val,init_val,..,init_val,init_val]
 778    and when necessary (e.g. add/mult case) let the caller know
 779    that it needs to adjust the result by init_val.
 780
 781    Option2: Initialize the vector as follows:
 782      add:         [0,0,...,0,init_val]
 783      mult:        [1,1,...,1,init_val]
 784      min/max:     [init_val,init_val,...,init_val]
 785      bit and/or:  [init_val,init_val,...,init_val]
 786    and no adjustments are needed.
 787
 788    For example, for the following code:
 789
 790    s = init_val;
 791    for (i=0;i<n;i++)
 792      s = s + a[i];
 793
 794    STMT is 's = s + a[i]', and the reduction variable is 's'.
 795    For a vector of 4 units, we want to return either [0,0,0,init_val],
 796    or [0,0,0,0] and let the caller know that it needs to adjust
 797    the result at the end by 'init_val'.
 798
 799    FORNOW: We use the "ADJUST_IN_EPILOG" scheme.
 800    TODO: Use some cost-model to estimate which scheme is more profitable.
 801 */
 802
 803 static tree
 804 get_initial_def_for_reduction (tree stmt, tree init_val, tree *scalar_def)
 805 {
 806   stmt_vec_info stmt_vinfo = vinfo_for_stmt (stmt);
 807   tree vectype = STMT_VINFO_VECTYPE (stmt_vinfo);
 808   int nunits = GET_MODE_NUNITS (TYPE_MODE (vectype));
 809   int nelements;
 810   enum tree_code code = TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1));
 811   tree type = TREE_TYPE (init_val);
 812   tree def;
 813   tree vec, t = NULL_TREE;
 814   bool need_epilog_adjust;
 815   int i;
 816   tree vector_type;
 817
 818   gcc_assert (INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type));
 819
 820   switch (code)
 821   {
 822   case WIDEN_SUM_EXPR:
 823   case DOT_PROD_EXPR:
 824   case PLUS_EXPR:
 825     if (INTEGRAL_TYPE_P (type))
 826       def = build_int_cst (type, 0);
 827     else
 828       def = build_real (type, dconst0);
 829
 830 #ifdef ADJUST_IN_EPILOG
 831     /* All the 'nunits' elements are set to 0. The final result will be
 832        adjusted by 'init_val' at the loop epilog.  */
 833     nelements = nunits;
 834     need_epilog_adjust = true;
 835 #else
 836     /* 'nunits - 1' elements are set to 0; The last element is set to
 837         'init_val'.  No further adjustments at the epilog are needed.  */
 838     nelements = nunits - 1;
 839     need_epilog_adjust = false;
 840 #endif
 841     break;
 842
 843   case MIN_EXPR:
 844   case MAX_EXPR:
 845     def = init_val;
 846     nelements = nunits;
 847     need_epilog_adjust = false;
 848     break;
 849
 850   default:
 851     gcc_unreachable ();
 852   }
 853
 854   for (i = nelements - 1; i >= 0; --i)
 855     t = tree_cons (NULL_TREE, def, t);
 856
 857   if (nelements == nunits - 1)
 858     {
 859       /* Set the last element of the vector.  */
 860       t = tree_cons (NULL_TREE, init_val, t);
 861       nelements += 1;
 862     }
 863   gcc_assert (nelements == nunits);
 864
 865   vector_type = get_vectype_for_scalar_type (TREE_TYPE (def));
 866   if (TREE_CODE (init_val) == INTEGER_CST || TREE_CODE (init_val) == REAL_CST)
 867     vec = build_vector (vector_type, t);
 868   else
 869     vec = build_constructor_from_list (vector_type, t);
 870
 871   if (!need_epilog_adjust)
 872     *scalar_def = NULL_TREE;
 873   else
 874     *scalar_def = init_val;
 875
 876   return vect_init_vector (stmt, vec, vector_type);
 877 }
 878
 879
 880 /* Function vect_create_epilog_for_reduction
 881
 882    Create code at the loop-epilog to finalize the result of a reduction
 883    computation.
 884
 885    VECT_DEF is a vector of partial results.
 886    REDUC_CODE is the tree-code for the epilog reduction.
 887    STMT is the scalar reduction stmt that is being vectorized.
 888    REDUCTION_PHI is the phi-node that carries the reduction computation.
 889
 890    This function:
 891    1. Creates the reduction def-use cycle: sets the the arguments for
 892       REDUCTION_PHI:
 893       The loop-entry argument is the vectorized initial-value of the reduction.
 894       The loop-latch argument is VECT_DEF - the vector of partial sums.
 895    2. "Reduces" the vector of partial results VECT_DEF into a single result,
 896       by applying the operation specified by REDUC_CODE if available, or by
 897       other means (whole-vector shifts or a scalar loop).
 898       The function also creates a new phi node at the loop exit to preserve
 899       loop-closed form, as illustrated below.
 900
 901      The flow at the entry to this function:
 902
 903         loop:
 904           vec_def = phi <null, null>            # REDUCTION_PHI
 905           VECT_DEF = vector_stmt                # vectorized form of STMT
 906           s_loop = scalar_stmt                  # (scalar) STMT
 907         loop_exit:
 908           s_out0 = phi <s_loop>                 # (scalar) EXIT_PHI
 909           use <s_out0>
 910           use <s_out0>
 911
 912      The above is transformed by this function into:
 913
 914         loop:
 915           vec_def = phi <vec_init, VECT_DEF>    # REDUCTION_PHI
 916           VECT_DEF = vector_stmt                # vectorized form of STMT
 917           s_loop = scalar_stmt                  # (scalar) STMT
 918         loop_exit:
 919           s_out0 = phi <s_loop>                 # (scalar) EXIT_PHI
 920           v_out1 = phi <VECT_DEF>               # NEW_EXIT_PHI
 921           v_out2 = reduce <v_out1>
 922           s_out3 = extract_field <v_out2, 0>
 923           s_out4 = adjust_result <s_out3>
 924           use <s_out4>
 925           use <s_out4>
 926 */
 927
 928 static void
 929 vect_create_epilog_for_reduction (tree vect_def, tree stmt,
 930                                   enum tree_code reduc_code, tree reduction_phi)
 931 {
 932   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
 933   tree vectype;
 934   enum machine_mode mode;
 935   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
 936   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
 937   basic_block exit_bb;
 938   tree scalar_dest;
 939   tree scalar_type;
 940   tree new_phi;
 941   block_stmt_iterator exit_bsi;
 942   tree vec_dest;
 943   tree new_temp;
 944   tree new_name;
 945   tree epilog_stmt;
 946   tree new_scalar_dest, exit_phi;
 947   tree bitsize, bitpos, bytesize;
 948   enum tree_code code = TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1));
 949   tree scalar_initial_def;
 950   tree vec_initial_def;
 951   tree orig_name;
 952   imm_use_iterator imm_iter;
 953   use_operand_p use_p;
 954   bool extract_scalar_result;
 955   tree reduction_op;
 956   tree orig_stmt;
 957   tree use_stmt;
 958   tree operation = GIMPLE_STMT_OPERAND (stmt, 1);
 959   int op_type;
 960
 961   op_type = TREE_CODE_LENGTH (TREE_CODE (operation));
 962   reduction_op = TREE_OPERAND (operation, op_type-1);
 963   vectype = get_vectype_for_scalar_type (TREE_TYPE (reduction_op));
 964   mode = TYPE_MODE (vectype);
 965
 966   /*** 1. Create the reduction def-use cycle  ***/
 967
 968   /* 1.1 set the loop-entry arg of the reduction-phi:  */
 969   /* For the case of reduction, vect_get_vec_def_for_operand returns
 970      the scalar def before the loop, that defines the initial value
 971      of the reduction variable.  */
 972   vec_initial_def = vect_get_vec_def_for_operand (reduction_op, stmt,
 973                                                   &scalar_initial_def);
 974   add_phi_arg (reduction_phi, vec_initial_def, loop_preheader_edge (loop));
 975
 976   /* 1.2 set the loop-latch arg for the reduction-phi:  */
 977   add_phi_arg (reduction_phi, vect_def, loop_latch_edge (loop));
 978
 979   if (vect_print_dump_info (REPORT_DETAILS))
 980     {
 981       fprintf (vect_dump, "transform reduction: created def-use cycle:");
 982       print_generic_expr (vect_dump, reduction_phi, TDF_SLIM);
 983       fprintf (vect_dump, "\n");
 984       print_generic_expr (vect_dump, SSA_NAME_DEF_STMT (vect_def), TDF_SLIM);
 985     }
 986
 987
 988   /*** 2. Create epilog code
 989           The reduction epilog code operates across the elements of the vector
 990           of partial results computed by the vectorized loop.
 991           The reduction epilog code consists of:
 992           step 1: compute the scalar result in a vector (v_out2)
 993           step 2: extract the scalar result (s_out3) from the vector (v_out2)
 994           step 3: adjust the scalar result (s_out3) if needed.
 995
 996           Step 1 can be accomplished using one the following three schemes:
 997           (scheme 1) using reduc_code, if available.
 998           (scheme 2) using whole-vector shifts, if available.
 999           (scheme 3) using a scalar loop. In this case steps 1+2 above are
1000                      combined.
1001
1002           The overall epilog code looks like this:
1003
1004           s_out0 = phi <s_loop>         # original EXIT_PHI
1005           v_out1 = phi <VECT_DEF>       # NEW_EXIT_PHI
1006           v_out2 = reduce <v_out1>              # step 1
1007           s_out3 = extract_field <v_out2, 0>    # step 2
1008           s_out4 = adjust_result <s_out3>       # step 3
1009
1010           (step 3 is optional, and step2 1 and 2 may be combined).
1011           Lastly, the uses of s_out0 are replaced by s_out4.
1012
1013           ***/
1014
1015   /* 2.1 Create new loop-exit-phi to preserve loop-closed form:
1016         v_out1 = phi <v_loop>  */
1017
1018   exit_bb = single_exit (loop)->dest;
1019   new_phi = create_phi_node (SSA_NAME_VAR (vect_def), exit_bb);
1020   SET_PHI_ARG_DEF (new_phi, single_exit (loop)->dest_idx, vect_def);
1021   exit_bsi = bsi_start (exit_bb);
1022
1023   /* 2.2 Get the relevant tree-code to use in the epilog for schemes 2,3
1024          (i.e. when reduc_code is not available) and in the final adjustment code
1025          (if needed).  Also get the original scalar reduction variable as
1026          defined in the loop.  In case STMT is a "pattern-stmt" (i.e. - it
1027          represents a reduction pattern), the tree-code and scalar-def are
1028          taken from the original stmt that the pattern-stmt (STMT) replaces.
1029          Otherwise (it is a regular reduction) - the tree-code and scalar-def
1030          are taken from STMT.  */
1031
1032   orig_stmt = STMT_VINFO_RELATED_STMT (stmt_info);
1033   if (!orig_stmt)
1034     {
1035       /* Regular reduction  */
1036       orig_stmt = stmt;
1037     }
1038   else
1039     {
1040       /* Reduction pattern  */
1041       stmt_vec_info stmt_vinfo = vinfo_for_stmt (orig_stmt);
1042       gcc_assert (STMT_VINFO_IN_PATTERN_P (stmt_vinfo));
1043       gcc_assert (STMT_VINFO_RELATED_STMT (stmt_vinfo) == stmt);
1044     }
1045   code = TREE_CODE (GIMPLE_STMT_OPERAND (orig_stmt, 1));
1046   scalar_dest = GIMPLE_STMT_OPERAND (orig_stmt, 0);
1047   scalar_type = TREE_TYPE (scalar_dest);
1048   new_scalar_dest = vect_create_destination_var (scalar_dest, NULL);
1049   bitsize = TYPE_SIZE (scalar_type);
1050   bytesize = TYPE_SIZE_UNIT (scalar_type);
1051
1052   /* 2.3 Create the reduction code, using one of the three schemes described
1053          above.  */
1054
1055   if (reduc_code < NUM_TREE_CODES)
1056     {
1057       /*** Case 1:  Create:
1058            v_out2 = reduc_expr <v_out1>  */
1059
1060       if (vect_print_dump_info (REPORT_DETAILS))
1061         fprintf (vect_dump, "Reduce using direct vector reduction.");
1062
1063       vec_dest = vect_create_destination_var (scalar_dest, vectype);
1064       epilog_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vec_dest,
1065                         build1 (reduc_code, vectype,  PHI_RESULT (new_phi)));
1066       new_temp = make_ssa_name (vec_dest, epilog_stmt);
1067       GIMPLE_STMT_OPERAND (epilog_stmt, 0) = new_temp;
1068       bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT);
1069
1070       extract_scalar_result = true;
1071     }
1072   else
1073     {
1074       enum tree_code shift_code = 0;
1075       bool have_whole_vector_shift = true;
1076       int bit_offset;
1077       int element_bitsize = tree_low_cst (bitsize, 1);
1078       int vec_size_in_bits = tree_low_cst (TYPE_SIZE (vectype), 1);
1079       tree vec_temp;
1080
1081       if (vec_shr_optab->handlers[mode].insn_code != CODE_FOR_nothing)
1082         shift_code = VEC_RSHIFT_EXPR;
1083       else
1084         have_whole_vector_shift = false;
1085
1086       /* Regardless of whether we have a whole vector shift, if we're
1087          emulating the operation via tree-vect-generic, we don't want
1088          to use it.  Only the first round of the reduction is likely
1089          to still be profitable via emulation.  */
1090       /* ??? It might be better to emit a reduction tree code here, so that
1091          tree-vect-generic can expand the first round via bit tricks.  */
1092       if (!VECTOR_MODE_P (mode))
1093         have_whole_vector_shift = false;
1094       else
1095         {
1096           optab optab = optab_for_tree_code (code, vectype);
1097           if (optab->handlers[mode].insn_code == CODE_FOR_nothing)
1098             have_whole_vector_shift = false;
1099         }
1100
1101       if (have_whole_vector_shift)
1102         {
1103           /*** Case 2: Create:
1104              for (offset = VS/2; offset >= element_size; offset/=2)
1105                 {
1106                   Create:  va' = vec_shift <va, offset>
1107                   Create:  va = vop <va, va'>
1108                 }  */
1109
1110           if (vect_print_dump_info (REPORT_DETAILS))
1111             fprintf (vect_dump, "Reduce using vector shifts");
1112
1113           vec_dest = vect_create_destination_var (scalar_dest, vectype);
1114           new_temp = PHI_RESULT (new_phi);
1115
1116           for (bit_offset = vec_size_in_bits/2;
1117                bit_offset >= element_bitsize;
1118                bit_offset /= 2)
1119             {
1120               tree bitpos = size_int (bit_offset);
1121
1122               epilog_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node,
1123                                     vec_dest,
1124                                     build2 (shift_code, vectype,
1125                                             new_temp, bitpos));
1126               new_name = make_ssa_name (vec_dest, epilog_stmt);
1127               GIMPLE_STMT_OPERAND (epilog_stmt, 0) = new_name;
1128               bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT);
1129
1130               epilog_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node,
1131                                     vec_dest,
1132                                     build2 (code, vectype,
1133                                             new_name, new_temp));
1134               new_temp = make_ssa_name (vec_dest, epilog_stmt);
1135               GIMPLE_STMT_OPERAND (epilog_stmt, 0) = new_temp;
1136               bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT);
1137             }
1138
1139           extract_scalar_result = true;
1140         }
1141       else
1142         {
1143           tree rhs;
1144
1145           /*** Case 3: Create:
1146              s = extract_field <v_out2, 0>
1147              for (offset = element_size;
1148                   offset < vector_size;
1149                   offset += element_size;)
1150                {
1151                  Create:  s' = extract_field <v_out2, offset>
1152                  Create:  s = op <s, s'>
1153                }  */
1154
1155           if (vect_print_dump_info (REPORT_DETAILS))
1156             fprintf (vect_dump, "Reduce using scalar code. ");
1157
1158           vec_temp = PHI_RESULT (new_phi);
1159           vec_size_in_bits = tree_low_cst (TYPE_SIZE (vectype), 1);
1160           rhs = build3 (BIT_FIELD_REF, scalar_type, vec_temp, bitsize,
1161                          bitsize_zero_node);
1162           BIT_FIELD_REF_UNSIGNED (rhs) = TYPE_UNSIGNED (scalar_type);
1163           epilog_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node,
1164                                 new_scalar_dest, rhs);
1165           new_temp = make_ssa_name (new_scalar_dest, epilog_stmt);
1166           GIMPLE_STMT_OPERAND (epilog_stmt, 0) = new_temp;
1167           bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT);
1168
1169           for (bit_offset = element_bitsize;
1170                bit_offset < vec_size_in_bits;
1171                bit_offset += element_bitsize)
1172             {
1173               tree bitpos = bitsize_int (bit_offset);
1174               tree rhs = build3 (BIT_FIELD_REF, scalar_type, vec_temp, bitsize,
1175                                  bitpos);
1176
1177               BIT_FIELD_REF_UNSIGNED (rhs) = TYPE_UNSIGNED (scalar_type);
1178               epilog_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node,
1179                                     new_scalar_dest, rhs);
1180               new_name = make_ssa_name (new_scalar_dest, epilog_stmt);
1181               GIMPLE_STMT_OPERAND (epilog_stmt, 0) = new_name;
1182               bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT);
1183
1184               epilog_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node,
1185                                 new_scalar_dest,
1186                                 build2 (code, scalar_type, new_name, new_temp));
1187               new_temp = make_ssa_name (new_scalar_dest, epilog_stmt);
1188               GIMPLE_STMT_OPERAND (epilog_stmt, 0) = new_temp;
1189               bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT);
1190             }
1191
1192           extract_scalar_result = false;
1193         }
1194     }
1195
1196   /* 2.4  Extract the final scalar result.  Create:
1197          s_out3 = extract_field <v_out2, bitpos>  */
1198
1199   if (extract_scalar_result)
1200     {
1201       tree rhs;
1202
1203       if (vect_print_dump_info (REPORT_DETAILS))
1204         fprintf (vect_dump, "extract scalar result");
1205
1206       if (BYTES_BIG_ENDIAN)
1207         bitpos = size_binop (MULT_EXPR,
1208                        bitsize_int (TYPE_VECTOR_SUBPARTS (vectype) - 1),
1209                        TYPE_SIZE (scalar_type));
1210       else
1211         bitpos = bitsize_zero_node;
1212
1213       rhs = build3 (BIT_FIELD_REF, scalar_type, new_temp, bitsize, bitpos);
1214       BIT_FIELD_REF_UNSIGNED (rhs) = TYPE_UNSIGNED (scalar_type);
1215       epilog_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node,
1216                             new_scalar_dest, rhs);
1217       new_temp = make_ssa_name (new_scalar_dest, epilog_stmt);
1218       GIMPLE_STMT_OPERAND (epilog_stmt, 0) = new_temp;
1219       bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT);
1220     }
1221
1222   /* 2.4 Adjust the final result by the initial value of the reduction
1223          variable. (When such adjustment is not needed, then
1224          'scalar_initial_def' is zero).
1225
1226          Create:
1227          s_out4 = scalar_expr <s_out3, scalar_initial_def>  */
1228
1229   if (scalar_initial_def)
1230     {
1231       epilog_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node,
1232                       new_scalar_dest,
1233                       build2 (code, scalar_type, new_temp, scalar_initial_def));
1234       new_temp = make_ssa_name (new_scalar_dest, epilog_stmt);
1235       GIMPLE_STMT_OPERAND (epilog_stmt, 0) = new_temp;
1236       bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT);
1237     }
1238
1239   /* 2.6 Replace uses of s_out0 with uses of s_out3  */
1240
1241   /* Find the loop-closed-use at the loop exit of the original scalar result.
1242      (The reduction result is expected to have two immediate uses - one at the
1243      latch block, and one at the loop exit).  */
1244   exit_phi = NULL;
1245   FOR_EACH_IMM_USE_FAST (use_p, imm_iter, scalar_dest)
1246     {
1247       if (!flow_bb_inside_loop_p (loop, bb_for_stmt (USE_STMT (use_p))))
1248         {
1249           exit_phi = USE_STMT (use_p);
1250           break;
1251         }
1252     }
1253   /* We expect to have found an exit_phi because of loop-closed-ssa form.  */
1254   gcc_assert (exit_phi);
1255   /* Replace the uses:  */
1256   orig_name = PHI_RESULT (exit_phi);
1257   FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, orig_name)
1258     FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
1259       SET_USE (use_p, new_temp);
1260 }
1261
1262
1263 /* Function vectorizable_reduction.
1264
1265    Check if STMT performs a reduction operation that can be vectorized.
1266    If VEC_STMT is also passed, vectorize the STMT: create a vectorized
1267    stmt to replace it, put it in VEC_STMT, and insert it at BSI.
1268    Return FALSE if not a vectorizable STMT, TRUE otherwise.
1269
1270    This function also handles reduction idioms (patterns) that have been
1271    recognized in advance during vect_pattern_recog. In this case, STMT may be
1272    of this form:
1273      X = pattern_expr (arg0, arg1, ..., X)
1274    and it's STMT_VINFO_RELATED_STMT points to the last stmt in the original
1275    sequence that had been detected and replaced by the pattern-stmt (STMT).
1276
1277    In some cases of reduction patterns, the type of the reduction variable X is
1278    different than the type of the other arguments of STMT.
1279    In such cases, the vectype that is used when transforming STMT into a vector
1280    stmt is different than the vectype that is used to determine the
1281    vectorization factor, because it consists of a different number of elements
1282    than the actual number of elements that are being operated upon in parallel.
1283
1284    For example, consider an accumulation of shorts into an int accumulator.
1285    On some targets it's possible to vectorize this pattern operating on 8
1286    shorts at a time (hence, the vectype for purposes of determining the
1287    vectorization factor should be V8HI); on the other hand, the vectype that
1288    is used to create the vector form is actually V4SI (the type of the result).
1289
1290    Upon entry to this function, STMT_VINFO_VECTYPE records the vectype that
1291    indicates what is the actual level of parallelism (V8HI in the example), so
1292    that the right vectorization factor would be derived. This vectype
1293    corresponds to the type of arguments to the reduction stmt, and should *NOT*
1294    be used to create the vectorized stmt. The right vectype for the vectorized
1295    stmt is obtained from the type of the result X:
1296         get_vectype_for_scalar_type (TREE_TYPE (X))
1297
1298    This means that, contrary to "regular" reductions (or "regular" stmts in
1299    general), the following equation:
1300       STMT_VINFO_VECTYPE == get_vectype_for_scalar_type (TREE_TYPE (X))
1301    does *NOT* necessarily hold for reduction patterns.  */
1302
1303 bool
1304 vectorizable_reduction (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt)
1305 {
1306   tree vec_dest;
1307   tree scalar_dest;
1308   tree op;
1309   tree loop_vec_def0 = NULL_TREE, loop_vec_def1 = NULL_TREE;
1310   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
1311   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
1312   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
1313   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
1314   tree operation;
1315   enum tree_code code, orig_code, epilog_reduc_code = 0;
1316   enum machine_mode vec_mode;
1317   int op_type;
1318   optab optab, reduc_optab;
1319   tree new_temp = NULL_TREE;
1320   tree def, def_stmt;
1321   enum vect_def_type dt;
1322   tree new_phi;
1323   tree scalar_type;
1324   bool is_simple_use;
1325   tree orig_stmt;
1326   stmt_vec_info orig_stmt_info;
1327   tree expr = NULL_TREE;
1328   int i;
1329   int nunits = TYPE_VECTOR_SUBPARTS (vectype);
1330   int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
1331   stmt_vec_info prev_stmt_info;
1332   tree reduc_def;
1333   tree new_stmt = NULL_TREE;
1334   int j;
1335
1336   gcc_assert (ncopies >= 1);
1337
1338   /* 1. Is vectorizable reduction?  */
1339
1340   /* Not supportable if the reduction variable is used in the loop.  */
1341   if (STMT_VINFO_RELEVANT_P (stmt_info))
1342     return false;
1343
1344   if (!STMT_VINFO_LIVE_P (stmt_info))
1345     return false;
1346
1347   /* Make sure it was already recognized as a reduction computation.  */
1348   if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_reduction_def)
1349     return false;
1350
1351   /* 2. Has this been recognized as a reduction pattern?
1352
1353      Check if STMT represents a pattern that has been recognized
1354      in earlier analysis stages.  For stmts that represent a pattern,
1355      the STMT_VINFO_RELATED_STMT field records the last stmt in
1356      the original sequence that constitutes the pattern.  */
1357
1358   orig_stmt = STMT_VINFO_RELATED_STMT (stmt_info);
1359   if (orig_stmt)
1360     {
1361       orig_stmt_info = vinfo_for_stmt (orig_stmt);
1362       gcc_assert (STMT_VINFO_RELATED_STMT (orig_stmt_info) == stmt);
1363       gcc_assert (STMT_VINFO_IN_PATTERN_P (orig_stmt_info));
1364       gcc_assert (!STMT_VINFO_IN_PATTERN_P (stmt_info));
1365     }
1366
1367   /* 3. Check the operands of the operation. The first operands are defined
1368         inside the loop body. The last operand is the reduction variable,
1369         which is defined by the loop-header-phi.  */
1370
1371   gcc_assert (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT);
1372
1373   operation = GIMPLE_STMT_OPERAND (stmt, 1);
1374   code = TREE_CODE (operation);
1375   op_type = TREE_CODE_LENGTH (code);
1376   if (op_type != binary_op && op_type != ternary_op)
1377     return false;
1378   scalar_dest = GIMPLE_STMT_OPERAND (stmt, 0);
1379   scalar_type = TREE_TYPE (scalar_dest);
1380
1381   /* All uses but the last are expected to be defined in the loop.
1382      The last use is the reduction variable.  */
1383   for (i = 0; i < op_type-1; i++)
1384     {
1385       op = TREE_OPERAND (operation, i);
1386       is_simple_use = vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt);
1387       gcc_assert (is_simple_use);
1388       gcc_assert (dt == vect_loop_def || dt == vect_invariant_def ||
1389                   dt == vect_constant_def);
1390     }
1391
1392   op = TREE_OPERAND (operation, i);
1393   is_simple_use = vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt);
1394   gcc_assert (is_simple_use);
1395   gcc_assert (dt == vect_reduction_def);
1396   gcc_assert (TREE_CODE (def_stmt) == PHI_NODE);
1397   if (orig_stmt)
1398     gcc_assert (orig_stmt == vect_is_simple_reduction (loop, def_stmt));
1399   else
1400     gcc_assert (stmt == vect_is_simple_reduction (loop, def_stmt));
1401
1402   if (STMT_VINFO_LIVE_P (vinfo_for_stmt (def_stmt)))
1403     return false;
1404
1405   /* 4. Supportable by target?  */
1406
1407   /* 4.1. check support for the operation in the loop  */
1408   optab = optab_for_tree_code (code, vectype);
1409   if (!optab)
1410     {
1411       if (vect_print_dump_info (REPORT_DETAILS))
1412         fprintf (vect_dump, "no optab.");
1413       return false;
1414     }
1415   vec_mode = TYPE_MODE (vectype);
1416   if (optab->handlers[(int) vec_mode].insn_code == CODE_FOR_nothing)
1417     {
1418       if (vect_print_dump_info (REPORT_DETAILS))
1419         fprintf (vect_dump, "op not supported by target.");
1420       if (GET_MODE_SIZE (vec_mode) != UNITS_PER_WORD
1421           || LOOP_VINFO_VECT_FACTOR (loop_vinfo)
1422              < vect_min_worthwhile_factor (code))
1423         return false;
1424       if (vect_print_dump_info (REPORT_DETAILS))
1425         fprintf (vect_dump, "proceeding using word mode.");
1426     }
1427
1428   /* Worthwhile without SIMD support?  */
1429   if (!VECTOR_MODE_P (TYPE_MODE (vectype))
1430       && LOOP_VINFO_VECT_FACTOR (loop_vinfo)
1431          < vect_min_worthwhile_factor (code))
1432     {
1433       if (vect_print_dump_info (REPORT_DETAILS))
1434         fprintf (vect_dump, "not worthwhile without SIMD support.");
1435       return false;
1436     }
1437
1438   /* 4.2. Check support for the epilog operation.
1439
1440           If STMT represents a reduction pattern, then the type of the
1441           reduction variable may be different than the type of the rest
1442           of the arguments.  For example, consider the case of accumulation
1443           of shorts into an int accumulator; The original code:
1444                         S1: int_a = (int) short_a;
1445           orig_stmt->   S2: int_acc = plus <int_a ,int_acc>;
1446
1447           was replaced with:
1448                         STMT: int_acc = widen_sum <short_a, int_acc>
1449
1450           This means that:
1451           1. The tree-code that is used to create the vector operation in the
1452              epilog code (that reduces the partial results) is not the
1453              tree-code of STMT, but is rather the tree-code of the original
1454              stmt from the pattern that STMT is replacing. I.e, in the example
1455              above we want to use 'widen_sum' in the loop, but 'plus' in the
1456              epilog.
1457           2. The type (mode) we use to check available target support
1458              for the vector operation to be created in the *epilog*, is
1459              determined by the type of the reduction variable (in the example
1460              above we'd check this: plus_optab[vect_int_mode]).
1461              However the type (mode) we use to check available target support
1462              for the vector operation to be created *inside the loop*, is
1463              determined by the type of the other arguments to STMT (in the
1464              example we'd check this: widen_sum_optab[vect_short_mode]).
1465
1466           This is contrary to "regular" reductions, in which the types of all
1467           the arguments are the same as the type of the reduction variable.
1468           For "regular" reductions we can therefore use the same vector type
1469           (and also the same tree-code) when generating the epilog code and
1470           when generating the code inside the loop.  */
1471
1472   if (orig_stmt)
1473     {
1474       /* This is a reduction pattern: get the vectype from the type of the
1475          reduction variable, and get the tree-code from orig_stmt.  */
1476       orig_code = TREE_CODE (GIMPLE_STMT_OPERAND (orig_stmt, 1));
1477       vectype = get_vectype_for_scalar_type (TREE_TYPE (def));
1478       vec_mode = TYPE_MODE (vectype);
1479     }
1480   else
1481     {
1482       /* Regular reduction: use the same vectype and tree-code as used for
1483          the vector code inside the loop can be used for the epilog code. */
1484       orig_code = code;
1485     }
1486
1487   if (!reduction_code_for_scalar_code (orig_code, &epilog_reduc_code))
1488     return false;
1489   reduc_optab = optab_for_tree_code (epilog_reduc_code, vectype);
1490   if (!reduc_optab)
1491     {
1492       if (vect_print_dump_info (REPORT_DETAILS))
1493         fprintf (vect_dump, "no optab for reduction.");
1494       epilog_reduc_code = NUM_TREE_CODES;
1495     }
1496   if (reduc_optab->handlers[(int) vec_mode].insn_code == CODE_FOR_nothing)
1497     {
1498       if (vect_print_dump_info (REPORT_DETAILS))
1499         fprintf (vect_dump, "reduc op not supported by target.");
1500       epilog_reduc_code = NUM_TREE_CODES;
1501     }
1502
1503   if (!vec_stmt) /* transformation not required.  */
1504     {
1505       STMT_VINFO_TYPE (stmt_info) = reduc_vec_info_type;
1506       return true;
1507     }
1508
1509   /** Transform.  **/
1510
1511   if (vect_print_dump_info (REPORT_DETAILS))
1512     fprintf (vect_dump, "transform reduction.");
1513
1514   /* Create the destination vector  */
1515   vec_dest = vect_create_destination_var (scalar_dest, vectype);
1516
1517   /* Create the reduction-phi that defines the reduction-operand.  */
1518   new_phi = create_phi_node (vec_dest, loop->header);
1519
1520   /* In case the vectorization factor (VF) is bigger than the number
1521      of elements that we can fit in a vectype (nunits), we have to generate
1522      more than one vector stmt - i.e - we need to "unroll" the
1523      vector stmt by a factor VF/nunits.  For more details see documentation
1524      in vectorizable_operation.  */
1525
1526   prev_stmt_info = NULL;
1527   for (j = 0; j < ncopies; j++)
1528     {
1529       /* Handle uses.  */
1530       if (j == 0)
1531         {
1532           op = TREE_OPERAND (operation, 0);
1533           loop_vec_def0 = vect_get_vec_def_for_operand (op, stmt, NULL);
1534           if (op_type == ternary_op)
1535             {
1536               op = TREE_OPERAND (operation, 1);
1537               loop_vec_def1 = vect_get_vec_def_for_operand (op, stmt, NULL);
1538             }
1539
1540           /* Get the vector def for the reduction variable from the phi node */
1541           reduc_def = PHI_RESULT (new_phi);
1542         }
1543       else
1544         {
1545           enum vect_def_type dt = vect_unknown_def_type; /* Dummy */
1546           loop_vec_def0 = vect_get_vec_def_for_stmt_copy (dt, loop_vec_def0);
1547           if (op_type == ternary_op)
1548             loop_vec_def1 = vect_get_vec_def_for_stmt_copy (dt, loop_vec_def1);
1549
1550           /* Get the vector def for the reduction variable from the vectorized
1551              reduction operation generated in the previous iteration (j-1)  */
1552           reduc_def = GIMPLE_STMT_OPERAND (new_stmt ,0);
1553         }
1554
1555       /* Arguments are ready. create the new vector stmt.  */
1556
1557       if (op_type == binary_op)
1558         expr = build2 (code, vectype, loop_vec_def0, reduc_def);
1559       else
1560         expr = build3 (code, vectype, loop_vec_def0, loop_vec_def1,
1561                                                                 reduc_def);
1562       new_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vec_dest, expr);
1563       new_temp = make_ssa_name (vec_dest, new_stmt);
1564       GIMPLE_STMT_OPERAND (new_stmt, 0) = new_temp;
1565       vect_finish_stmt_generation (stmt, new_stmt, bsi);
1566
1567       if (j == 0)
1568         STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt = new_stmt;
1569       else
1570         STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;
1571       prev_stmt_info = vinfo_for_stmt (new_stmt);
1572     }
1573
1574   /* Finalize the reduction-phi (set it's arguments) and create the
1575      epilog reduction code.  */
1576   vect_create_epilog_for_reduction (new_temp, stmt, epilog_reduc_code, new_phi);
1577   return true;
1578 }
1579
1580 /* Checks if CALL can be vectorized in type VECTYPE.  Returns
1581    true if the target has a vectorized version of the function,
1582    or false if the function cannot be vectorized.  */
1583
1584 bool
1585 vectorizable_function (tree call, tree vectype)
1586 {
1587   tree fndecl = get_callee_fndecl (call);
1588
1589   /* We only handle functions that do not read or clobber memory -- i.e.
1590      const or novops ones.  */
1591   if (!(call_expr_flags (call) & (ECF_CONST | ECF_NOVOPS)))
1592     return false;
1593
1594   if (!fndecl
1595       || TREE_CODE (fndecl) != FUNCTION_DECL
1596       || !DECL_BUILT_IN (fndecl))
1597     return false;
1598
1599   if (targetm.vectorize.builtin_vectorized_function (DECL_FUNCTION_CODE (fndecl), vectype))
1600     return true;
1601
1602   return false;
1603 }
1604
1605 /* Returns an expression that performs a call to vectorized version
1606    of FNDECL in type VECTYPE, with the arguments given by ARGS.
1607    If extra statements need to be generated, they are inserted
1608    before BSI.  */
1609
1610 static tree
1611 build_vectorized_function_call (tree fndecl,
1612                                 tree vectype, tree args)
1613 {
1614   tree vfndecl;
1615   enum built_in_function code = DECL_FUNCTION_CODE (fndecl);
1616
1617   /* The target specific builtin should be available.  */
1618   vfndecl = targetm.vectorize.builtin_vectorized_function (code, vectype);
1619   gcc_assert (vfndecl != NULL_TREE);
1620
1621   return build_function_call_expr (vfndecl, args);
1622 }
1623
1624 /* Function vectorizable_call.
1625
1626    Check if STMT performs a function call that can be vectorized.
1627    If VEC_STMT is also passed, vectorize the STMT: create a vectorized
1628    stmt to replace it, put it in VEC_STMT, and insert it at BSI.
1629    Return FALSE if not a vectorizable STMT, TRUE otherwise.  */
1630
1631 bool
1632 vectorizable_call (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt)
1633 {
1634   tree vec_dest;
1635   tree scalar_dest;
1636   tree operation;
1637   tree op, args, type;
1638   tree vec_oprnd, vargs, *pvargs_end;
1639   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
1640   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
1641   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
1642   tree fndecl, rhs, new_temp, def, def_stmt;
1643   enum vect_def_type dt;
1644
1645   /* Is STMT a vectorizable call?   */
1646   if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
1647     return false;
1648
1649   if (TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 0)) != SSA_NAME)
1650     return false;
1651
1652   operation = GIMPLE_STMT_OPERAND (stmt, 1);
1653   if (TREE_CODE (operation) != CALL_EXPR)
1654     return false;
1655
1656   /* For now, we only vectorize functions if a target specific builtin
1657      is available.  TODO -- in some cases, it might be profitable to
1658      insert the calls for pieces of the vector, in order to be able
1659      to vectorize other operations in the loop.  */
1660   if (!vectorizable_function (operation, vectype))
1661     {
1662       if (vect_print_dump_info (REPORT_DETAILS))
1663         fprintf (vect_dump, "function is not vectorizable.");
1664
1665       return false;
1666     }
1667   gcc_assert (ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS));
1668
1669   for (args = TREE_OPERAND (operation, 1); args; args = TREE_CHAIN (args))
1670     {
1671       op = TREE_VALUE (args);
1672
1673       if (!vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt))
1674         {
1675           if (vect_print_dump_info (REPORT_DETAILS))
1676             fprintf (vect_dump, "use not simple.");
1677           return false;
1678         }
1679     }
1680
1681   if (!vec_stmt) /* transformation not required.  */
1682     {
1683       STMT_VINFO_TYPE (stmt_info) = call_vec_info_type;
1684       return true;
1685     }
1686
1687   /** Transform.  **/
1688
1689   if (vect_print_dump_info (REPORT_DETAILS))
1690     fprintf (vect_dump, "transform operation.");
1691
1692   /* Handle def.  */
1693   scalar_dest = GIMPLE_STMT_OPERAND (stmt, 0);
1694   vec_dest = vect_create_destination_var (scalar_dest, vectype);
1695
1696   /* Handle uses.  */
1697   vargs = NULL_TREE;
1698   pvargs_end = &vargs;
1699   for (args = TREE_OPERAND (operation, 1); args; args = TREE_CHAIN (args))
1700     {
1701       op = TREE_VALUE (args);
1702       vec_oprnd = vect_get_vec_def_for_operand (op, stmt, NULL);
1703
1704       *pvargs_end = tree_cons (NULL_TREE, vec_oprnd, NULL_TREE);
1705       pvargs_end = &TREE_CHAIN (*pvargs_end);
1706     }
1707
1708   fndecl = get_callee_fndecl (operation);
1709   rhs = build_vectorized_function_call (fndecl, vectype, vargs);
1710   *vec_stmt = build2 (GIMPLE_MODIFY_STMT, vectype, vec_dest, rhs);
1711   new_temp = make_ssa_name (vec_dest, *vec_stmt);
1712   GIMPLE_STMT_OPERAND (*vec_stmt, 0) = new_temp;
1713
1714   vect_finish_stmt_generation (stmt, *vec_stmt, bsi);
1715
1716   /* The call in STMT might prevent it from being removed in dce.  We however
1717      cannot remove it here, due to the way the ssa name it defines is mapped
1718      to the new definition.  So just replace rhs of the statement with something
1719      harmless.  */
1720   type = TREE_TYPE (scalar_dest);
1721   GIMPLE_STMT_OPERAND (stmt, 1) = fold_convert (type, integer_zero_node);
1722
1723   return true;
1724 }
1725
1726
1727 /* Function vectorizable_assignment.
1728
1729    Check if STMT performs an assignment (copy) that can be vectorized.
1730    If VEC_STMT is also passed, vectorize the STMT: create a vectorized
1731    stmt to replace it, put it in VEC_STMT, and insert it at BSI.
1732    Return FALSE if not a vectorizable STMT, TRUE otherwise.  */
1733
1734 bool
1735 vectorizable_assignment (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt)
1736 {
1737   tree vec_dest;
1738   tree scalar_dest;
1739   tree op;
1740   tree vec_oprnd;
1741   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
1742   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
1743   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
1744   tree new_temp;
1745   tree def, def_stmt;
1746   enum vect_def_type dt;
1747   int nunits = TYPE_VECTOR_SUBPARTS (vectype);
1748   int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
1749
1750   gcc_assert (ncopies >= 1);
1751   if (ncopies > 1)
1752     return false; /* FORNOW */
1753
1754   /* Is vectorizable assignment?  */
1755   if (!STMT_VINFO_RELEVANT_P (stmt_info))
1756     return false;
1757
1758   gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info) == vect_loop_def);
1759
1760   if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
1761     return false;
1762
1763   scalar_dest = GIMPLE_STMT_OPERAND (stmt, 0);
1764   if (TREE_CODE (scalar_dest) != SSA_NAME)
1765     return false;
1766
1767   op = GIMPLE_STMT_OPERAND (stmt, 1);
1768   if (!vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt))
1769     {
1770       if (vect_print_dump_info (REPORT_DETAILS))
1771         fprintf (vect_dump, "use not simple.");
1772       return false;
1773     }
1774
1775   if (!vec_stmt) /* transformation not required.  */
1776     {
1777       STMT_VINFO_TYPE (stmt_info) = assignment_vec_info_type;
1778       return true;
1779     }
1780
1781   /** Transform.  **/
1782   if (vect_print_dump_info (REPORT_DETAILS))
1783     fprintf (vect_dump, "transform assignment.");
1784
1785   /* Handle def.  */
1786   vec_dest = vect_create_destination_var (scalar_dest, vectype);
1787
1788   /* Handle use.  */
1789   op = GIMPLE_STMT_OPERAND (stmt, 1);
1790   vec_oprnd = vect_get_vec_def_for_operand (op, stmt, NULL);
1791
1792   /* Arguments are ready. create the new vector stmt.  */
1793   *vec_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vec_dest, vec_oprnd);
1794   new_temp = make_ssa_name (vec_dest, *vec_stmt);
1795   GIMPLE_STMT_OPERAND (*vec_stmt, 0) = new_temp;
1796   vect_finish_stmt_generation (stmt, *vec_stmt, bsi);
1797
1798   return true;
1799 }
1800
1801
1802 /* Function vect_min_worthwhile_factor.
1803
1804    For a loop where we could vectorize the operation indicated by CODE,
1805    return the minimum vectorization factor that makes it worthwhile
1806    to use generic vectors.  */
1807 static int
1808 vect_min_worthwhile_factor (enum tree_code code)
1809 {
1810   switch (code)
1811     {
1812     case PLUS_EXPR:
1813     case MINUS_EXPR:
1814     case NEGATE_EXPR:
1815       return 4;
1816
1817     case BIT_AND_EXPR:
1818     case BIT_IOR_EXPR:
1819     case BIT_XOR_EXPR:
1820     case BIT_NOT_EXPR:
1821       return 2;
1822
1823     default:
1824       return INT_MAX;
1825     }
1826 }
1827
1828
1829 /* Function vectorizable_operation.
1830
1831    Check if STMT performs a binary or unary operation that can be vectorized.
1832    If VEC_STMT is also passed, vectorize the STMT: create a vectorized
1833    stmt to replace it, put it in VEC_STMT, and insert it at BSI.
1834    Return FALSE if not a vectorizable STMT, TRUE otherwise.  */
1835
1836 bool
1837 vectorizable_operation (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt)
1838 {
1839   tree vec_dest;
1840   tree scalar_dest;
1841   tree operation;
1842   tree op0, op1 = NULL;
1843   tree vec_oprnd0 = NULL_TREE, vec_oprnd1 = NULL_TREE;
1844   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
1845   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
1846   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
1847   enum tree_code code;
1848   enum machine_mode vec_mode;
1849   tree new_temp;
1850   int op_type;
1851   optab optab;
1852   int icode;
1853   enum machine_mode optab_op2_mode;
1854   tree def, def_stmt;
1855   enum vect_def_type dt0, dt1;
1856   tree new_stmt;
1857   stmt_vec_info prev_stmt_info;
1858   int nunits_in = TYPE_VECTOR_SUBPARTS (vectype);
1859   int nunits_out;
1860   tree vectype_out;
1861   int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_in;
1862   int j;
1863
1864   gcc_assert (ncopies >= 1);
1865
1866   /* Is STMT a vectorizable binary/unary operation?   */
1867   if (!STMT_VINFO_RELEVANT_P (stmt_info))
1868     return false;
1869
1870   gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info) == vect_loop_def);
1871
1872   if (STMT_VINFO_LIVE_P (stmt_info))
1873     {
1874       /* FORNOW: not yet supported.  */
1875       if (vect_print_dump_info (REPORT_DETAILS))
1876         fprintf (vect_dump, "value used after loop.");
1877       return false;
1878     }
1879
1880   if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
1881     return false;
1882
1883   if (TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 0)) != SSA_NAME)
1884     return false;
1885
1886   scalar_dest = GIMPLE_STMT_OPERAND (stmt, 0);
1887   vectype_out = get_vectype_for_scalar_type (TREE_TYPE (scalar_dest));
1888   nunits_out = TYPE_VECTOR_SUBPARTS (vectype_out);
1889   if (nunits_out != nunits_in)
1890     return false;
1891
1892   operation = GIMPLE_STMT_OPERAND (stmt, 1);
1893   code = TREE_CODE (operation);
1894   optab = optab_for_tree_code (code, vectype);
1895
1896   /* Support only unary or binary operations.  */
1897   op_type = TREE_CODE_LENGTH (code);
1898   if (op_type != unary_op && op_type != binary_op)
1899     {
1900       if (vect_print_dump_info (REPORT_DETAILS))
1901         fprintf (vect_dump, "num. args = %d (not unary/binary op).", op_type);
1902       return false;
1903     }
1904
1905   op0 = TREE_OPERAND (operation, 0);
1906   if (!vect_is_simple_use (op0, loop_vinfo, &def_stmt, &def, &dt0))
1907     {
1908       if (vect_print_dump_info (REPORT_DETAILS))
1909         fprintf (vect_dump, "use not simple.");
1910       return false;
1911     }
1912
1913   if (op_type == binary_op)
1914     {
1915       op1 = TREE_OPERAND (operation, 1);
1916       if (!vect_is_simple_use (op1, loop_vinfo, &def_stmt, &def, &dt1))
1917         {
1918           if (vect_print_dump_info (REPORT_DETAILS))
1919             fprintf (vect_dump, "use not simple.");
1920           return false;
1921         }
1922     }
1923
1924   /* Supportable by target?  */
1925   if (!optab)
1926     {
1927       if (vect_print_dump_info (REPORT_DETAILS))
1928         fprintf (vect_dump, "no optab.");
1929       return false;
1930     }
1931   vec_mode = TYPE_MODE (vectype);
1932   icode = (int) optab->handlers[(int) vec_mode].insn_code;
1933   if (icode == CODE_FOR_nothing)
1934     {
1935       if (vect_print_dump_info (REPORT_DETAILS))
1936         fprintf (vect_dump, "op not supported by target.");
1937       if (GET_MODE_SIZE (vec_mode) != UNITS_PER_WORD
1938           || LOOP_VINFO_VECT_FACTOR (loop_vinfo)
1939              < vect_min_worthwhile_factor (code))
1940         return false;
1941       if (vect_print_dump_info (REPORT_DETAILS))
1942         fprintf (vect_dump, "proceeding using word mode.");
1943     }
1944
1945   /* Worthwhile without SIMD support?  */
1946   if (!VECTOR_MODE_P (TYPE_MODE (vectype))
1947       && LOOP_VINFO_VECT_FACTOR (loop_vinfo)
1948          < vect_min_worthwhile_factor (code))
1949     {
1950       if (vect_print_dump_info (REPORT_DETAILS))
1951         fprintf (vect_dump, "not worthwhile without SIMD support.");
1952       return false;
1953     }
1954
1955   if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
1956     {
1957       /* FORNOW: not yet supported.  */
1958       if (!VECTOR_MODE_P (vec_mode))
1959         return false;
1960
1961       /* Invariant argument is needed for a vector shift
1962          by a scalar shift operand.  */
1963       optab_op2_mode = insn_data[icode].operand[2].mode;
1964       if (! (VECTOR_MODE_P (optab_op2_mode)
1965              || dt1 == vect_constant_def
1966              || dt1 == vect_invariant_def))
1967         {
1968           if (vect_print_dump_info (REPORT_DETAILS))
1969             fprintf (vect_dump, "operand mode requires invariant argument.");
1970           return false;
1971         }
1972     }
1973
1974   if (!vec_stmt) /* transformation not required.  */
1975     {
1976       STMT_VINFO_TYPE (stmt_info) = op_vec_info_type;
1977       return true;
1978     }
1979
1980   /** Transform.  **/
1981
1982   if (vect_print_dump_info (REPORT_DETAILS))
1983     fprintf (vect_dump, "transform binary/unary operation.");
1984
1985   /* Handle def.  */
1986   vec_dest = vect_create_destination_var (scalar_dest, vectype);
1987
1988   /* In case the vectorization factor (VF) is bigger than the number
1989      of elements that we can fit in a vectype (nunits), we have to generate
1990      more than one vector stmt - i.e - we need to "unroll" the
1991      vector stmt by a factor VF/nunits. In doing so, we record a pointer
1992      from one copy of the vector stmt to the next, in the field
1993      STMT_VINFO_RELATED_STMT. This is necessary in order to allow following
1994      stages to find the correct vector defs to be used when vectorizing
1995      stmts that use the defs of the current stmt. The example below illustrates
1996      the vectorization process when VF=16 and nunits=4 (i.e - we need to create
1997      4 vectorized stmts):
1998
1999      before vectorization:
2000                                 RELATED_STMT    VEC_STMT
2001         S1:     x = memref      -               -
2002         S2:     z = x + 1       -               -
2003
2004      step 1: vectorize stmt S1 (done in vectorizable_load. See more details
2005              there):
2006                                 RELATED_STMT    VEC_STMT
2007         VS1_0:  vx0 = memref0   VS1_1           -
2008         VS1_1:  vx1 = memref1   VS1_2           -
2009         VS1_2:  vx2 = memref2   VS1_3           -
2010         VS1_3:  vx3 = memref3   -               -
2011         S1:     x = load        -               VS1_0
2012         S2:     z = x + 1       -               -
2013
2014      step2: vectorize stmt S2 (done here):
2015         To vectorize stmt S2 we first need to find the relevant vector
2016         def for the first operand 'x'. This is, as usual, obtained from
2017         the vector stmt recorded in the STMT_VINFO_VEC_STMT of the stmt
2018         that defines 'x' (S1). This way we find the stmt VS1_0, and the
2019         relevant vector def 'vx0'. Having found 'vx0' we can generate
2020         the vector stmt VS2_0, and as usual, record it in the
2021         STMT_VINFO_VEC_STMT of stmt S2.
2022         When creating the second copy (VS2_1), we obtain the relevant vector
2023         def from the vector stmt recorded in the STMT_VINFO_RELATED_STMT of
2024         stmt VS1_0. This way we find the stmt VS1_1 and the relevant
2025         vector def 'vx1'. Using 'vx1' we create stmt VS2_1 and record a
2026         pointer to it in the STMT_VINFO_RELATED_STMT of the vector stmt VS2_0.
2027         Similarly when creating stmts VS2_2 and VS2_3. This is the resulting
2028         chain of stmts and pointers:
2029                                 RELATED_STMT    VEC_STMT
2030         VS1_0:  vx0 = memref0   VS1_1           -
2031         VS1_1:  vx1 = memref1   VS1_2           -
2032         VS1_2:  vx2 = memref2   VS1_3           -
2033         VS1_3:  vx3 = memref3   -               -
2034         S1:     x = load        -               VS1_0
2035         VS2_0:  vz0 = vx0 + v1  VS2_1           -
2036         VS2_1:  vz1 = vx1 + v1  VS2_2           -
2037         VS2_2:  vz2 = vx2 + v1  VS2_3           -
2038         VS2_3:  vz3 = vx3 + v1  -               -
2039         S2:     z = x + 1       -               VS2_0  */
2040
2041   prev_stmt_info = NULL;
2042   for (j = 0; j < ncopies; j++)
2043     {
2044       /* Handle uses.  */
2045       if (j == 0)
2046         {
2047           vec_oprnd0 = vect_get_vec_def_for_operand (op0, stmt, NULL);
2048           if (op_type == binary_op)
2049             {
2050               if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
2051                 {
2052                   /* Vector shl and shr insn patterns can be defined with
2053                      scalar operand 2 (shift operand).  In this case, use
2054                      constant or loop invariant op1 directly, without
2055                      extending it to vector mode first.  */
2056                   optab_op2_mode = insn_data[icode].operand[2].mode;
2057                   if (!VECTOR_MODE_P (optab_op2_mode))
2058                     {
2059                       if (vect_print_dump_info (REPORT_DETAILS))
2060                         fprintf (vect_dump, "operand 1 using scalar mode.");
2061                       vec_oprnd1 = op1;
2062                     }
2063                 }
2064               if (!vec_oprnd1)
2065                 vec_oprnd1 = vect_get_vec_def_for_operand (op1, stmt, NULL);
2066             }
2067         }
2068       else
2069         {
2070           vec_oprnd0 = vect_get_vec_def_for_stmt_copy (dt0, vec_oprnd0);
2071           if (op_type == binary_op)
2072             vec_oprnd1 = vect_get_vec_def_for_stmt_copy (dt1, vec_oprnd1);
2073         }
2074
2075       /* Arguments are ready. create the new vector stmt.  */
2076
2077       if (op_type == binary_op)
2078         new_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vec_dest,
2079                     build2 (code, vectype, vec_oprnd0, vec_oprnd1));
2080       else
2081         new_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vec_dest,
2082                     build1 (code, vectype, vec_oprnd0));
2083       new_temp = make_ssa_name (vec_dest, new_stmt);
2084       GIMPLE_STMT_OPERAND (new_stmt, 0) = new_temp;
2085       vect_finish_stmt_generation (stmt, new_stmt, bsi);
2086
2087       if (j == 0)
2088         STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt = new_stmt;
2089       else
2090         STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;
2091       prev_stmt_info = vinfo_for_stmt (new_stmt);
2092     }
2093
2094   return true;
2095 }
2096
2097
2098 /* Function vectorizable_type_demotion
2099
2100    Check if STMT performs a binary or unary operation that involves
2101    type demotion, and if it can be vectorized.
2102    If VEC_STMT is also passed, vectorize the STMT: create a vectorized
2103    stmt to replace it, put it in VEC_STMT, and insert it at BSI.
2104    Return FALSE if not a vectorizable STMT, TRUE otherwise.  */
2105
2106 bool
2107 vectorizable_type_demotion (tree stmt, block_stmt_iterator *bsi,
2108                              tree *vec_stmt)
2109 {
2110   tree vec_dest;
2111   tree scalar_dest;
2112   tree operation;
2113   tree op0;
2114   tree vec_oprnd0=NULL, vec_oprnd1=NULL;
2115   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
2116   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
2117   enum tree_code code;
2118   tree new_temp;
2119   tree def, def_stmt;
2120   enum vect_def_type dt0;
2121   tree new_stmt;
2122   stmt_vec_info prev_stmt_info;
2123   int nunits_in;
2124   int nunits_out;
2125   tree vectype_out;
2126   int ncopies;
2127   int j;
2128   tree expr;
2129   tree vectype_in;
2130   tree scalar_type;
2131   optab optab;
2132   enum machine_mode vec_mode;
2133
2134   /* Is STMT a vectorizable type-demotion operation?  */
2135
2136   if (!STMT_VINFO_RELEVANT_P (stmt_info))
2137     return false;
2138
2139   gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info) == vect_loop_def);
2140
2141   if (STMT_VINFO_LIVE_P (stmt_info))
2142     {
2143       /* FORNOW: not yet supported.  */
2144       if (vect_print_dump_info (REPORT_DETAILS))
2145         fprintf (vect_dump, "value used after loop.");
2146       return false;
2147     }
2148
2149   if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
2150     return false;
2151
2152   if (TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 0)) != SSA_NAME)
2153     return false;
2154
2155   operation = GIMPLE_STMT_OPERAND (stmt, 1);
2156   code = TREE_CODE (operation);
2157   if (code != NOP_EXPR && code != CONVERT_EXPR)
2158     return false;
2159
2160   op0 = TREE_OPERAND (operation, 0);
2161   vectype_in = get_vectype_for_scalar_type (TREE_TYPE (op0));
2162   nunits_in = TYPE_VECTOR_SUBPARTS (vectype_in);
2163
2164   scalar_dest = GIMPLE_STMT_OPERAND (stmt, 0);
2165   scalar_type = TREE_TYPE (scalar_dest);
2166   vectype_out = get_vectype_for_scalar_type (scalar_type);
2167   nunits_out = TYPE_VECTOR_SUBPARTS (vectype_out);
2168   if (nunits_in != nunits_out / 2) /* FORNOW */
2169     return false;
2170
2171   ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_out;
2172   gcc_assert (ncopies >= 1);
2173
2174   /* Check the operands of the operation.  */
2175   if (!vect_is_simple_use (op0, loop_vinfo, &def_stmt, &def, &dt0))
2176     {
2177       if (vect_print_dump_info (REPORT_DETAILS))
2178         fprintf (vect_dump, "use not simple.");
2179       return false;
2180     }
2181
2182   /* Supportable by target?  */
2183   code = VEC_PACK_MOD_EXPR;
2184   optab = optab_for_tree_code (VEC_PACK_MOD_EXPR, vectype_in);
2185   if (!optab)
2186     return false;
2187
2188   vec_mode = TYPE_MODE (vectype_in);
2189   if (optab->handlers[(int) vec_mode].insn_code == CODE_FOR_nothing)
2190     return false;
2191
2192   STMT_VINFO_VECTYPE (stmt_info) = vectype_in;
2193
2194   if (!vec_stmt) /* transformation not required.  */
2195     {
2196       STMT_VINFO_TYPE (stmt_info) = type_demotion_vec_info_type;
2197       return true;
2198     }
2199
2200   /** Transform.  **/
2201
2202   if (vect_print_dump_info (REPORT_DETAILS))
2203     fprintf (vect_dump, "transform type demotion operation. ncopies = %d.",
2204                         ncopies);
2205
2206   /* Handle def.  */
2207   vec_dest = vect_create_destination_var (scalar_dest, vectype_out);
2208
2209   /* In case the vectorization factor (VF) is bigger than the number
2210      of elements that we can fit in a vectype (nunits), we have to generate
2211      more than one vector stmt - i.e - we need to "unroll" the
2212      vector stmt by a factor VF/nunits.   */
2213   prev_stmt_info = NULL;
2214   for (j = 0; j < ncopies; j++)
2215     {
2216       /* Handle uses.  */
2217       if (j == 0)
2218         {
2219           enum vect_def_type dt = vect_unknown_def_type; /* Dummy */
2220           vec_oprnd0 = vect_get_vec_def_for_operand (op0, stmt, NULL);
2221           vec_oprnd1 = vect_get_vec_def_for_stmt_copy (dt, vec_oprnd0);
2222         }
2223       else
2224         {
2225           vec_oprnd0 = vect_get_vec_def_for_stmt_copy (dt0, vec_oprnd1);
2226           vec_oprnd1 = vect_get_vec_def_for_stmt_copy (dt0, vec_oprnd0);
2227         }
2228
2229       /* Arguments are ready. Create the new vector stmt.  */
2230       expr = build2 (code, vectype_out, vec_oprnd0, vec_oprnd1);
2231       new_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vec_dest, expr);
2232       new_temp = make_ssa_name (vec_dest, new_stmt);
2233       GIMPLE_STMT_OPERAND (new_stmt, 0) = new_temp;
2234       vect_finish_stmt_generation (stmt, new_stmt, bsi);
2235
2236       if (j == 0)
2237         STMT_VINFO_VEC_STMT (stmt_info) = new_stmt;
2238       else
2239         STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;
2240
2241       prev_stmt_info = vinfo_for_stmt (new_stmt);
2242     }
2243
2244   *vec_stmt = STMT_VINFO_VEC_STMT (stmt_info);
2245   return true;
2246 }
2247
2248
2249 /* Function vect_gen_widened_results_half
2250
2251    Create a vector stmt whose code, type, number of arguments, and result
2252    variable are CODE, VECTYPE, OP_TYPE, and VEC_DEST, and its arguments are
2253    VEC_OPRND0 and VEC_OPRND1. The new vector stmt is to be inserted at BSI.
2254    In the case that CODE is a CALL_EXPR, this means that a call to DECL
2255    needs to be created (DECL is a function-decl of a target-builtin).
2256    STMT is the original scalar stmt that we are vectorizing.  */
2257
2258 static tree
2259 vect_gen_widened_results_half (enum tree_code code, tree vectype, tree decl,
2260                                tree vec_oprnd0, tree vec_oprnd1, int op_type,
2261                                tree vec_dest, block_stmt_iterator *bsi,
2262                                tree stmt)
2263 {
2264   tree vec_params;
2265   tree expr;
2266   tree new_stmt;
2267   tree new_temp;
2268   tree sym;
2269   ssa_op_iter iter;
2270
2271   /* Generate half of the widened result:  */
2272   if (code == CALL_EXPR)
2273     {
2274       /* Target specific support  */
2275       vec_params = build_tree_list (NULL_TREE, vec_oprnd0);
2276       if (op_type == binary_op)
2277         vec_params = tree_cons (NULL_TREE, vec_oprnd1, vec_params);
2278       expr = build_function_call_expr (decl, vec_params);
2279     }
2280   else
2281     {
2282       /* Generic support */
2283       gcc_assert (op_type == TREE_CODE_LENGTH (code));
2284       if (op_type == binary_op)
2285         expr = build2 (code, vectype, vec_oprnd0, vec_oprnd1);
2286       else
2287         expr = build1 (code, vectype, vec_oprnd0);
2288     }
2289   new_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vec_dest, expr);
2290   new_temp = make_ssa_name (vec_dest, new_stmt);
2291   GIMPLE_STMT_OPERAND (new_stmt, 0) = new_temp;
2292   vect_finish_stmt_generation (stmt, new_stmt, bsi);
2293
2294   if (code == CALL_EXPR)
2295     {
2296       FOR_EACH_SSA_TREE_OPERAND (sym, new_stmt, iter, SSA_OP_ALL_VIRTUALS)
2297         {
2298           if (TREE_CODE (sym) == SSA_NAME)
2299             sym = SSA_NAME_VAR (sym);
2300           mark_sym_for_renaming (sym);
2301         }
2302     }
2303
2304   return new_stmt;
2305 }
2306
2307
2308 /* Function vectorizable_type_promotion
2309
2310    Check if STMT performs a binary or unary operation that involves
2311    type promotion, and if it can be vectorized.
2312    If VEC_STMT is also passed, vectorize the STMT: create a vectorized
2313    stmt to replace it, put it in VEC_STMT, and insert it at BSI.
2314    Return FALSE if not a vectorizable STMT, TRUE otherwise.  */
2315
2316 bool
2317 vectorizable_type_promotion (tree stmt, block_stmt_iterator *bsi,
2318                              tree *vec_stmt)
2319 {
2320   tree vec_dest;
2321   tree scalar_dest;
2322   tree operation;
2323   tree op0, op1 = NULL;
2324   tree vec_oprnd0=NULL, vec_oprnd1=NULL;
2325   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
2326   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
2327   enum tree_code code, code1 = CODE_FOR_nothing, code2 = CODE_FOR_nothing;
2328   tree decl1 = NULL_TREE, decl2 = NULL_TREE;
2329   int op_type;
2330   tree def, def_stmt;
2331   enum vect_def_type dt0, dt1;
2332   tree new_stmt;
2333   stmt_vec_info prev_stmt_info;
2334   int nunits_in;
2335   int nunits_out;
2336   tree vectype_out;
2337   int ncopies;
2338   int j;
2339   tree vectype_in;
2340
2341   /* Is STMT a vectorizable type-promotion operation?  */
2342
2343   if (!STMT_VINFO_RELEVANT_P (stmt_info))
2344     return false;
2345
2346   gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info) == vect_loop_def);
2347
2348   if (STMT_VINFO_LIVE_P (stmt_info))
2349     {
2350       /* FORNOW: not yet supported.  */
2351       if (vect_print_dump_info (REPORT_DETAILS))
2352         fprintf (vect_dump, "value used after loop.");
2353       return false;
2354     }
2355
2356   if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
2357     return false;
2358
2359   if (TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 0)) != SSA_NAME)
2360     return false;
2361
2362   operation = GIMPLE_STMT_OPERAND (stmt, 1);
2363   code = TREE_CODE (operation);
2364   if (code != NOP_EXPR && code != WIDEN_MULT_EXPR)
2365     return false;
2366
2367   op0 = TREE_OPERAND (operation, 0);
2368   vectype_in = get_vectype_for_scalar_type (TREE_TYPE (op0));
2369   nunits_in = TYPE_VECTOR_SUBPARTS (vectype_in);
2370   ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits_in;
2371   gcc_assert (ncopies >= 1);
2372
2373   scalar_dest = GIMPLE_STMT_OPERAND (stmt, 0);
2374   vectype_out = get_vectype_for_scalar_type (TREE_TYPE (scalar_dest));
2375   nunits_out = TYPE_VECTOR_SUBPARTS (vectype_out);
2376   if (nunits_out != nunits_in / 2) /* FORNOW */
2377     return false;
2378
2379   /* Check the operands of the operation.  */
2380   if (!vect_is_simple_use (op0, loop_vinfo, &def_stmt, &def, &dt0))
2381     {
2382       if (vect_print_dump_info (REPORT_DETAILS))
2383         fprintf (vect_dump, "use not simple.");
2384       return false;
2385     }
2386
2387   op_type = TREE_CODE_LENGTH (code);
2388   if (op_type == binary_op)
2389     {
2390       op1 = TREE_OPERAND (operation, 1);
2391       if (!vect_is_simple_use (op1, loop_vinfo, &def_stmt, &def, &dt1))
2392         {
2393           if (vect_print_dump_info (REPORT_DETAILS))
2394             fprintf (vect_dump, "use not simple.");
2395           return false;
2396         }
2397     }
2398
2399   /* Supportable by target?  */
2400   if (!supportable_widening_operation (code, stmt, vectype_in,
2401                                        &decl1, &decl2, &code1, &code2))
2402     return false;
2403
2404   STMT_VINFO_VECTYPE (stmt_info) = vectype_in;
2405
2406   if (!vec_stmt) /* transformation not required.  */
2407     {
2408       STMT_VINFO_TYPE (stmt_info) = type_promotion_vec_info_type;
2409       return true;
2410     }
2411
2412   /** Transform.  **/
2413
2414   if (vect_print_dump_info (REPORT_DETAILS))
2415     fprintf (vect_dump, "transform type promotion operation. ncopies = %d.",
2416                         ncopies);
2417
2418   /* Handle def.  */
2419   vec_dest = vect_create_destination_var (scalar_dest, vectype_out);
2420
2421   /* In case the vectorization factor (VF) is bigger than the number
2422      of elements that we can fit in a vectype (nunits), we have to generate
2423      more than one vector stmt - i.e - we need to "unroll" the
2424      vector stmt by a factor VF/nunits.   */
2425
2426   prev_stmt_info = NULL;
2427   for (j = 0; j < ncopies; j++)
2428     {
2429       /* Handle uses.  */
2430       if (j == 0)
2431         {
2432           vec_oprnd0 = vect_get_vec_def_for_operand (op0, stmt, NULL);
2433           if (op_type == binary_op)
2434             vec_oprnd1 = vect_get_vec_def_for_operand (op1, stmt, NULL);
2435         }
2436       else
2437         {
2438           vec_oprnd0 = vect_get_vec_def_for_stmt_copy (dt0, vec_oprnd0);
2439           if (op_type == binary_op)
2440             vec_oprnd1 = vect_get_vec_def_for_stmt_copy (dt1, vec_oprnd1);
2441         }
2442
2443       /* Arguments are ready. Create the new vector stmt.  We are creating
2444          two vector defs because the widened result does not fit in one vector.
2445          The vectorized stmt can be expressed as a call to a taregt builtin,
2446          or a using a tree-code.  */
2447       /* Generate first half of the widened result:  */
2448       new_stmt = vect_gen_widened_results_half (code1, vectype_out, decl1,
2449                         vec_oprnd0, vec_oprnd1, op_type, vec_dest, bsi, stmt);
2450       if (j == 0)
2451         STMT_VINFO_VEC_STMT (stmt_info) = new_stmt;
2452       else
2453         STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;
2454       prev_stmt_info = vinfo_for_stmt (new_stmt);
2455
2456       /* Generate second half of the widened result:  */
2457       new_stmt = vect_gen_widened_results_half (code2, vectype_out, decl2,
2458                         vec_oprnd0, vec_oprnd1, op_type, vec_dest, bsi, stmt);
2459       STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;
2460       prev_stmt_info = vinfo_for_stmt (new_stmt);
2461
2462     }
2463
2464   *vec_stmt = STMT_VINFO_VEC_STMT (stmt_info);
2465   return true;
2466 }
2467
2468
2469 /* Function vect_strided_store_supported.
2470
2471    Returns TRUE is INTERLEAVE_HIGH and INTERLEAVE_LOW operations are supported,
2472    and FALSE otherwise.  */
2473
2474 static bool
2475 vect_strided_store_supported (tree vectype)
2476 {
2477   optab interleave_high_optab, interleave_low_optab;
2478   int mode;
2479
2480   mode = (int) TYPE_MODE (vectype);
2481
2482   /* Check that the operation is supported.  */
2483   interleave_high_optab = optab_for_tree_code (VEC_INTERLEAVE_HIGH_EXPR,
2484                                                vectype);
2485   interleave_low_optab = optab_for_tree_code (VEC_INTERLEAVE_LOW_EXPR,
2486                                               vectype);
2487   if (!interleave_high_optab || !interleave_low_optab)
2488     {
2489       if (vect_print_dump_info (REPORT_DETAILS))
2490         fprintf (vect_dump, "no optab for interleave.");
2491       return false;
2492     }
2493
2494   if (interleave_high_optab->handlers[(int) mode].insn_code
2495       == CODE_FOR_nothing
2496       || interleave_low_optab->handlers[(int) mode].insn_code
2497       == CODE_FOR_nothing)
2498     {
2499       if (vect_print_dump_info (REPORT_DETAILS))
2500         fprintf (vect_dump, "interleave op not supported by target.");
2501       return false;
2502     }
2503   return true;
2504 }
2505
2506
2507 /* Function vect_permute_store_chain.
2508
2509    Given a chain of interleaved stores in DR_CHAIN of LENGTH that must be
2510    a power of 2, generate interleave_high/low stmts to reorder the data
2511    correctly for the stores. Return the final references for stores in
2512    RESULT_CHAIN.
2513
2514    E.g., LENGTH is 4 and the scalar type is short, i.e., VF is 8.
2515    The input is 4 vectors each containing 8 elements. We assign a number to each
2516    element, the input sequence is:
2517
2518    1st vec:   0  1  2  3  4  5  6  7
2519    2nd vec:   8  9 10 11 12 13 14 15
2520    3rd vec:  16 17 18 19 20 21 22 23
2521    4th vec:  24 25 26 27 28 29 30 31
2522
2523    The output sequence should be:
2524
2525    1st vec:  0  8 16 24  1  9 17 25
2526    2nd vec:  2 10 18 26  3 11 19 27
2527    3rd vec:  4 12 20 28  5 13 21 30
2528    4th vec:  6 14 22 30  7 15 23 31
2529
2530    i.e., we interleave the contents of the four vectors in their order.
2531
2532    We use interleave_high/low instructions to create such output. The input of
2533    each interleave_high/low operation is two vectors:
2534    1st vec    2nd vec
2535    0 1 2 3    4 5 6 7
2536    the even elements of the result vector are obtained left-to-right from the
2537    high/low elements of the first vector. The odd elements of the result are
2538    obtained left-to-right from the high/low elements of the second vector.
2539    The output of interleave_high will be:   0 4 1 5
2540    and of interleave_low:                   2 6 3 7
2541
2542
2543    The permutation is done in log LENGTH stages. In each stage interleave_high
2544    and interleave_low stmts are created for each pair of vectors in DR_CHAIN,
2545    where the first argument is taken from the first half of DR_CHAIN and the
2546    second argument from it's second half.
2547    In our example,
2548
2549    I1: interleave_high (1st vec, 3rd vec)
2550    I2: interleave_low (1st vec, 3rd vec)
2551    I3: interleave_high (2nd vec, 4th vec)
2552    I4: interleave_low (2nd vec, 4th vec)
2553
2554    The output for the first stage is:
2555
2556    I1:  0 16  1 17  2 18  3 19
2557    I2:  4 20  5 21  6 22  7 23
2558    I3:  8 24  9 25 10 26 11 27
2559    I4: 12 28 13 29 14 30 15 31
2560
2561    The output of the second stage, i.e. the final result is:
2562
2563    I1:  0  8 16 24  1  9 17 25
2564    I2:  2 10 18 26  3 11 19 27
2565    I3:  4 12 20 28  5 13 21 30
2566    I4:  6 14 22 30  7 15 23 31.  */
2567
2568 static bool
2569 vect_permute_store_chain (VEC(tree,heap) *dr_chain,
2570                           unsigned int length,
2571                           tree stmt,
2572                           block_stmt_iterator *bsi,
2573                           VEC(tree,heap) **result_chain)
2574 {
2575   tree perm_dest, perm_stmt, vect1, vect2, high, low;
2576   tree vectype = STMT_VINFO_VECTYPE (vinfo_for_stmt (stmt));
2577   tree scalar_dest;
2578   int i;
2579   unsigned int j;
2580   VEC(tree,heap) *first, *second;
2581
2582   scalar_dest = GIMPLE_STMT_OPERAND (stmt, 0);
2583   first = VEC_alloc (tree, heap, length/2);
2584   second = VEC_alloc (tree, heap, length/2);
2585
2586   /* Check that the operation is supported.  */
2587   if (!vect_strided_store_supported (vectype))
2588     return false;
2589
2590   *result_chain = VEC_copy (tree, heap, dr_chain);
2591
2592   for (i = 0; i < exact_log2 (length); i++)
2593     {
2594       for (j = 0; j < length/2; j++)
2595         {
2596           vect1 = VEC_index (tree, dr_chain, j);
2597           vect2 = VEC_index (tree, dr_chain, j+length/2);
2598
2599           /* Create interleaving stmt:
2600              in the case of big endian:
2601                                 high = interleave_high (vect1, vect2)
2602              and in the case of little endian:
2603                                 high = interleave_low (vect1, vect2).  */
2604           perm_dest = create_tmp_var (vectype, "vect_inter_high");
2605           DECL_GIMPLE_REG_P (perm_dest) = 1;
2606           add_referenced_var (perm_dest);
2607           if (BYTES_BIG_ENDIAN)
2608             perm_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, perm_dest,
2609                                 build2 (VEC_INTERLEAVE_HIGH_EXPR, vectype,
2610                                         vect1, vect2));
2611           else
2612             perm_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, perm_dest,
2613                                 build2 (VEC_INTERLEAVE_LOW_EXPR, vectype,
2614                                         vect1, vect2));
2615           high = make_ssa_name (perm_dest, perm_stmt);
2616           GIMPLE_STMT_OPERAND (perm_stmt, 0) = high;
2617           vect_finish_stmt_generation (stmt, perm_stmt, bsi);
2618           VEC_replace (tree, *result_chain, 2*j, high);
2619
2620           /* Create interleaving stmt:
2621              in the case of big endian:
2622                                low  = interleave_low (vect1, vect2)
2623              and in the case of little endian:
2624                                low  = interleave_high (vect1, vect2).  */
2625           perm_dest = create_tmp_var (vectype, "vect_inter_low");
2626           DECL_GIMPLE_REG_P (perm_dest) = 1;
2627           add_referenced_var (perm_dest);
2628           if (BYTES_BIG_ENDIAN)
2629             perm_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, perm_dest,
2630                                 build2 (VEC_INTERLEAVE_LOW_EXPR, vectype,
2631                                         vect1, vect2));
2632           else
2633             perm_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, perm_dest,
2634                                 build2 (VEC_INTERLEAVE_HIGH_EXPR, vectype,
2635                                         vect1, vect2));
2636           low = make_ssa_name (perm_dest, perm_stmt);
2637           GIMPLE_STMT_OPERAND (perm_stmt, 0) = low;
2638           vect_finish_stmt_generation (stmt, perm_stmt, bsi);
2639           VEC_replace (tree, *result_chain, 2*j+1, low);
2640         }
2641       dr_chain = VEC_copy (tree, heap, *result_chain);
2642     }
2643   return true;
2644 }
2645
2646
2647 /* Function vectorizable_store.
2648
2649    Check if STMT defines a non scalar data-ref (array/pointer/structure) that
2650    can be vectorized.
2651    If VEC_STMT is also passed, vectorize the STMT: create a vectorized
2652    stmt to replace it, put it in VEC_STMT, and insert it at BSI.
2653    Return FALSE if not a vectorizable STMT, TRUE otherwise.  */
2654
2655 bool
2656 vectorizable_store (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt)
2657 {
2658   tree scalar_dest;
2659   tree data_ref;
2660   tree op;
2661   tree vec_oprnd = NULL_TREE;
2662   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
2663   struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info), *first_dr = NULL;
2664   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
2665   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
2666   enum machine_mode vec_mode;
2667   tree dummy;
2668   enum dr_alignment_support alignment_support_cheme;
2669   ssa_op_iter iter;
2670   def_operand_p def_p;
2671   tree def, def_stmt;
2672   enum vect_def_type dt;
2673   stmt_vec_info prev_stmt_info = NULL;
2674   tree dataref_ptr = NULL_TREE;
2675   int nunits = TYPE_VECTOR_SUBPARTS (vectype);
2676   int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
2677   int j;
2678   tree next_stmt, first_stmt;
2679   bool strided_store = false;
2680   unsigned int group_size, i;
2681   VEC(tree,heap) *dr_chain = NULL, *oprnds = NULL, *result_chain = NULL;
2682   gcc_assert (ncopies >= 1);
2683
2684   /* Is vectorizable store? */
2685
2686   if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
2687     return false;
2688
2689   scalar_dest = GIMPLE_STMT_OPERAND (stmt, 0);
2690   if (TREE_CODE (scalar_dest) != ARRAY_REF
2691       && TREE_CODE (scalar_dest) != INDIRECT_REF
2692       && !DR_GROUP_FIRST_DR (stmt_info))
2693     return false;
2694
2695   op = GIMPLE_STMT_OPERAND (stmt, 1);
2696   if (!vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt))
2697     {
2698       if (vect_print_dump_info (REPORT_DETAILS))
2699         fprintf (vect_dump, "use not simple.");
2700       return false;
2701     }
2702
2703   vec_mode = TYPE_MODE (vectype);
2704   /* FORNOW. In some cases can vectorize even if data-type not supported
2705      (e.g. - array initialization with 0).  */
2706   if (mov_optab->handlers[(int)vec_mode].insn_code == CODE_FOR_nothing)
2707     return false;
2708
2709   if (!STMT_VINFO_DATA_REF (stmt_info))
2710     return false;
2711
2712   if (DR_GROUP_FIRST_DR (stmt_info))
2713     {
2714       strided_store = true;
2715       if (!vect_strided_store_supported (vectype))
2716         return false;
2717     }
2718
2719   if (!vec_stmt) /* transformation not required.  */
2720     {
2721       STMT_VINFO_TYPE (stmt_info) = store_vec_info_type;
2722       return true;
2723     }
2724
2725   /** Transform.  **/
2726
2727   if (vect_print_dump_info (REPORT_DETAILS))
2728     fprintf (vect_dump, "transform store. ncopies = %d",ncopies);
2729
2730   if (strided_store)
2731     {
2732       first_stmt = DR_GROUP_FIRST_DR (stmt_info);
2733       first_dr = STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt));
2734       group_size = DR_GROUP_SIZE (vinfo_for_stmt (first_stmt));
2735
2736       DR_GROUP_STORE_COUNT (vinfo_for_stmt (first_stmt))++;
2737
2738       /* We vectorize all the stmts of the interleaving group when we
2739          reach the last stmt in the group.  */
2740       if (DR_GROUP_STORE_COUNT (vinfo_for_stmt (first_stmt))
2741           < DR_GROUP_SIZE (vinfo_for_stmt (first_stmt)))
2742         {
2743           *vec_stmt = NULL_TREE;
2744           return true;
2745         }
2746     }
2747   else
2748     {
2749       first_stmt = stmt;
2750       first_dr = dr;
2751       group_size = 1;
2752     }
2753
2754   dr_chain = VEC_alloc (tree, heap, group_size);
2755   oprnds = VEC_alloc (tree, heap, group_size);
2756
2757   alignment_support_cheme = vect_supportable_dr_alignment (first_dr);
2758   gcc_assert (alignment_support_cheme);
2759   gcc_assert (alignment_support_cheme == dr_aligned);  /* FORNOW */
2760
2761   /* In case the vectorization factor (VF) is bigger than the number
2762      of elements that we can fit in a vectype (nunits), we have to generate
2763      more than one vector stmt - i.e - we need to "unroll" the
2764      vector stmt by a factor VF/nunits.  For more details see documentation in
2765      vect_get_vec_def_for_copy_stmt.  */
2766
2767   /* In case of interleaving (non-unit strided access):
2768
2769         S1:  &base + 2 = x2
2770         S2:  &base = x0
2771         S3:  &base + 1 = x1
2772         S4:  &base + 3 = x3
2773
2774      We create vectorized storess starting from base address (the access of the
2775      first stmt in the chain (S2 in the above example), when the last store stmt
2776      of the chain (S4) is reached:
2777
2778         VS1: &base = vx2
2779         VS2: &base + vec_size*1 = vx0
2780         VS3: &base + vec_size*2 = vx1
2781         VS4: &base + vec_size*3 = vx3
2782
2783      Then permutation statements are generated:
2784
2785         VS5: vx5 = VEC_INTERLEAVE_HIGH_EXPR < vx0, vx3 >
2786         VS6: vx6 = VEC_INTERLEAVE_LOW_EXPR < vx0, vx3 >
2787         ...
2788
2789      And they are put in STMT_VINFO_VEC_STMT of the corresponding scalar stmts
2790      (the order of the data-refs in the output of vect_permute_store_chain
2791      corresponds to the order of scalar stmts in the interleaving chain - see
2792      the documentation of vect_permute_store_chain()).
2793
2794      In case of both multiple types and interleaving, above vector stores and
2795      permutation stmts are created for every copy. The result vector stmts are
2796      put in STMT_VINFO_VEC_STMT for the first copy and in the corresponding
2797      STMT_VINFO_RELATED_STMT for the next copies.
2798   */
2799
2800   prev_stmt_info = NULL;
2801   for (j = 0; j < ncopies; j++)
2802     {
2803       tree new_stmt;
2804       tree ptr_incr;
2805
2806       if (j == 0)
2807         {
2808           /* For interleaved stores we collect vectorized defs for all the
2809              stores in the group in DR_CHAIN and OPRNDS. DR_CHAIN is then used
2810              as an input to vect_permute_store_chain(), and OPRNDS as an input
2811              to vect_get_vec_def_for_stmt_copy() for the next copy.
2812              If the store is not strided, GROUP_SIZE is 1, and DR_CHAIN and
2813              OPRNDS are of size 1.
2814           */
2815           next_stmt = first_stmt;
2816           for (i = 0; i < group_size; i++)
2817             {
2818               /* Since gaps are not supported for interleaved stores, GROUP_SIZE
2819                  is the exact number of stmts in the chain. Therefore, NEXT_STMT
2820                  can't be NULL_TREE.  In case that there is no interleaving,
2821                  GROUP_SIZE is 1, and only one iteration of the loop will be
2822                  executed.
2823               */
2824               gcc_assert (next_stmt);
2825               op = GIMPLE_STMT_OPERAND (next_stmt, 1);
2826               vec_oprnd = vect_get_vec_def_for_operand (op, next_stmt, NULL);
2827               VEC_quick_push(tree, dr_chain, vec_oprnd);
2828               VEC_quick_push(tree, oprnds, vec_oprnd);
2829               next_stmt = DR_GROUP_NEXT_DR (vinfo_for_stmt (next_stmt));
2830             }
2831           dataref_ptr = vect_create_data_ref_ptr (first_stmt, bsi, NULL_TREE,
2832                                                   &dummy, &ptr_incr, false,
2833                                                   TREE_TYPE (vec_oprnd));
2834         }
2835       else
2836         {
2837           /* For interleaved stores we created vectorized defs for all the
2838              defs stored in OPRNDS in the previous iteration (previous copy).
2839              DR_CHAIN is then used as an input to vect_permute_store_chain(),
2840              and OPRNDS as an input to vect_get_vec_def_for_stmt_copy() for the
2841              next copy.
2842              If the store is not strided, GROUP_SIZE is 1, and DR_CHAIN and
2843              OPRNDS are of size 1.
2844           */
2845           for (i = 0; i < group_size; i++)
2846             {
2847               vec_oprnd = vect_get_vec_def_for_stmt_copy (dt,
2848                                                    VEC_index (tree, oprnds, i));
2849               VEC_replace(tree, dr_chain, i, vec_oprnd);
2850               VEC_replace(tree, oprnds, i, vec_oprnd);
2851             }
2852           dataref_ptr = bump_vector_ptr (dataref_ptr, ptr_incr, bsi, stmt);
2853         }
2854
2855       if (strided_store)
2856         {
2857           result_chain = VEC_alloc (tree, heap, group_size);
2858           /* Permute.  */
2859           if (!vect_permute_store_chain (dr_chain, group_size, stmt, bsi,
2860                                          &result_chain))
2861             return false;
2862         }
2863
2864       next_stmt = first_stmt;
2865       for (i = 0; i < group_size; i++)
2866         {
2867           /* For strided stores vectorized defs are interleaved in
2868              vect_permute_store_chain().  */
2869           if (strided_store)
2870             vec_oprnd = VEC_index(tree, result_chain, i);
2871
2872           data_ref = build_fold_indirect_ref (dataref_ptr);
2873           /* Arguments are ready. Create the new vector stmt.  */
2874           new_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, data_ref,
2875                              vec_oprnd);
2876           vect_finish_stmt_generation (stmt, new_stmt, bsi);
2877
2878           /* Set the VDEFs for the vector pointer. If this virtual def
2879              has a use outside the loop and a loop peel is performed
2880              then the def may be renamed by the peel.  Mark it for
2881              renaming so the later use will also be renamed.  */
2882           copy_virtual_operands (new_stmt, next_stmt);
2883           if (j == 0)
2884             {
2885               /* The original store is deleted so the same SSA_NAMEs
2886                  can be used.  */
2887               FOR_EACH_SSA_TREE_OPERAND (def, next_stmt, iter, SSA_OP_VDEF)
2888                 {
2889                   SSA_NAME_DEF_STMT (def) = new_stmt;
2890                   mark_sym_for_renaming (SSA_NAME_VAR (def));
2891                 }
2892
2893               STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt =  new_stmt;
2894             }
2895           else
2896             {
2897               /* Create new names for all the definitions created by COPY and
2898                  add replacement mappings for each new name.  */
2899               FOR_EACH_SSA_DEF_OPERAND (def_p, new_stmt, iter, SSA_OP_VDEF)
2900                 {
2901                   create_new_def_for (DEF_FROM_PTR (def_p), new_stmt, def_p);
2902                   mark_sym_for_renaming (SSA_NAME_VAR (DEF_FROM_PTR (def_p)));
2903                 }
2904
2905               STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;
2906             }
2907
2908           prev_stmt_info = vinfo_for_stmt (new_stmt);
2909                   next_stmt = DR_GROUP_NEXT_DR (vinfo_for_stmt (next_stmt));
2910           if (!next_stmt)
2911             break;
2912           /* Bump the vector pointer.  */
2913           dataref_ptr = bump_vector_ptr (dataref_ptr, ptr_incr, bsi, stmt);
2914         }
2915     }
2916
2917   return true;
2918 }
2919
2920
2921 /* Function vect_setup_realignment
2922
2923    This function is called when vectorizing an unaligned load using
2924    the dr_unaligned_software_pipeline scheme.
2925    This function generates the following code at the loop prolog:
2926
2927       p = initial_addr;
2928       msq_init = *(floor(p));   # prolog load
2929       realignment_token = call target_builtin;
2930     loop:
2931       msq = phi (msq_init, ---)
2932
2933    The code above sets up a new (vector) pointer, pointing to the first
2934    location accessed by STMT, and a "floor-aligned" load using that pointer.
2935    It also generates code to compute the "realignment-token" (if the relevant
2936    target hook was defined), and creates a phi-node at the loop-header bb
2937    whose arguments are the result of the prolog-load (created by this
2938    function) and the result of a load that takes place in the loop (to be
2939    created by the caller to this function).
2940    The caller to this function uses the phi-result (msq) to create the
2941    realignment code inside the loop, and sets up the missing phi argument,
2942    as follows:
2943
2944     loop:
2945       msq = phi (msq_init, lsq)
2946       lsq = *(floor(p'));        # load in loop
2947       result = realign_load (msq, lsq, realignment_token);
2948
2949    Input:
2950    STMT - (scalar) load stmt to be vectorized. This load accesses
2951           a memory location that may be unaligned.
2952    BSI - place where new code is to be inserted.
2953
2954    Output:
2955    REALIGNMENT_TOKEN - the result of a call to the builtin_mask_for_load
2956                        target hook, if defined.
2957    Return value - the result of the loop-header phi node.  */
2958
2959 static tree
2960 vect_setup_realignment (tree stmt, block_stmt_iterator *bsi,
2961                         tree *realignment_token)
2962 {
2963   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
2964   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
2965   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
2966   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
2967   edge pe = loop_preheader_edge (loop);
2968   tree scalar_dest = GIMPLE_STMT_OPERAND (stmt, 0);
2969   tree vec_dest;
2970   tree init_addr;
2971   tree inc;
2972   tree ptr;
2973   tree data_ref;
2974   tree new_stmt;
2975   basic_block new_bb;
2976   tree msq_init;
2977   tree new_temp;
2978   tree phi_stmt;
2979   tree msq;
2980
2981   /* 1. Create msq_init = *(floor(p1)) in the loop preheader  */
2982   vec_dest = vect_create_destination_var (scalar_dest, vectype);
2983   ptr = vect_create_data_ref_ptr (stmt, bsi, NULL_TREE, &init_addr, &inc, true,
2984                                   NULL_TREE);
2985   data_ref = build1 (ALIGN_INDIRECT_REF, vectype, ptr);
2986   new_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vec_dest, data_ref);
2987   new_temp = make_ssa_name (vec_dest, new_stmt);
2988   GIMPLE_STMT_OPERAND (new_stmt, 0) = new_temp;
2989   new_bb = bsi_insert_on_edge_immediate (pe, new_stmt);
2990   gcc_assert (!new_bb);
2991   msq_init = GIMPLE_STMT_OPERAND (new_stmt, 0);
2992   copy_virtual_operands (new_stmt, stmt);
2993   update_vuses_to_preheader (new_stmt, loop);
2994
2995   /* 2. Create permutation mask, if required, in loop preheader.  */
2996   if (targetm.vectorize.builtin_mask_for_load)
2997     {
2998       tree builtin_decl;
2999       tree params = build_tree_list (NULL_TREE, init_addr);
3000
3001       builtin_decl = targetm.vectorize.builtin_mask_for_load ();
3002       new_stmt = build_function_call_expr (builtin_decl, params);
3003       vec_dest = vect_create_destination_var (scalar_dest,
3004                                               TREE_TYPE (new_stmt));
3005       new_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vec_dest,
3006                          new_stmt);
3007       new_temp = make_ssa_name (vec_dest, new_stmt);
3008       GIMPLE_STMT_OPERAND (new_stmt, 0) = new_temp;
3009       new_bb = bsi_insert_on_edge_immediate (pe, new_stmt);
3010       gcc_assert (!new_bb);
3011       *realignment_token = GIMPLE_STMT_OPERAND (new_stmt, 0);
3012
3013       /* The result of the CALL_EXPR to this builtin is determined from
3014          the value of the parameter and no global variables are touched
3015          which makes the builtin a "const" function.  Requiring the
3016          builtin to have the "const" attribute makes it unnecessary
3017          to call mark_call_clobbered.  */
3018       gcc_assert (TREE_READONLY (builtin_decl));
3019     }
3020
3021   /* 3. Create msq = phi <msq_init, lsq> in loop  */
3022   vec_dest = vect_create_destination_var (scalar_dest, vectype);
3023   msq = make_ssa_name (vec_dest, NULL_TREE);
3024   phi_stmt = create_phi_node (msq, loop->header);
3025   SSA_NAME_DEF_STMT (msq) = phi_stmt;
3026   add_phi_arg (phi_stmt, msq_init, loop_preheader_edge (loop));
3027
3028   return msq;
3029 }
3030
3031
3032 /* Function vect_strided_load_supported.
3033
3034    Returns TRUE is EXTRACT_EVEN and EXTRACT_ODD operations are supported,
3035    and FALSE otherwise.  */
3036
3037 static bool
3038 vect_strided_load_supported (tree vectype)
3039 {
3040   optab perm_even_optab, perm_odd_optab;
3041   int mode;
3042
3043   mode = (int) TYPE_MODE (vectype);
3044
3045   perm_even_optab = optab_for_tree_code (VEC_EXTRACT_EVEN_EXPR, vectype);
3046   if (!perm_even_optab)
3047     {
3048       if (vect_print_dump_info (REPORT_DETAILS))
3049         fprintf (vect_dump, "no optab for perm_even.");
3050       return false;
3051     }
3052
3053   if (perm_even_optab->handlers[mode].insn_code == CODE_FOR_nothing)
3054     {
3055       if (vect_print_dump_info (REPORT_DETAILS))
3056         fprintf (vect_dump, "perm_even op not supported by target.");
3057       return false;
3058     }
3059
3060   perm_odd_optab = optab_for_tree_code (VEC_EXTRACT_ODD_EXPR, vectype);
3061   if (!perm_odd_optab)
3062     {
3063       if (vect_print_dump_info (REPORT_DETAILS))
3064         fprintf (vect_dump, "no optab for perm_odd.");
3065       return false;
3066     }
3067
3068   if (perm_odd_optab->handlers[mode].insn_code == CODE_FOR_nothing)
3069     {
3070       if (vect_print_dump_info (REPORT_DETAILS))
3071         fprintf (vect_dump, "perm_odd op not supported by target.");
3072       return false;
3073     }
3074   return true;
3075 }
3076
3077
3078 /* Function vect_permute_load_chain.
3079
3080    Given a chain of interleaved loads in DR_CHAIN of LENGTH that must be
3081    a power of 2, generate extract_even/odd stmts to reorder the input data
3082    correctly. Return the final references for loads in RESULT_CHAIN.
3083
3084    E.g., LENGTH is 4 and the scalar type is short, i.e., VF is 8.
3085    The input is 4 vectors each containing 8 elements. We assign a number to each
3086    element, the input sequence is:
3087
3088    1st vec:   0  1  2  3  4  5  6  7
3089    2nd vec:   8  9 10 11 12 13 14 15
3090    3rd vec:  16 17 18 19 20 21 22 23
3091    4th vec:  24 25 26 27 28 29 30 31
3092
3093    The output sequence should be:
3094
3095    1st vec:  0 4  8 12 16 20 24 28
3096    2nd vec:  1 5  9 13 17 21 25 29
3097    3rd vec:  2 6 10 14 18 22 26 30
3098    4th vec:  3 7 11 15 19 23 27 31
3099
3100    i.e., the first output vector should contain the first elements of each
3101    interleaving group, etc.
3102
3103    We use extract_even/odd instructions to create such output. The input of each
3104    extract_even/odd operation is two vectors
3105    1st vec    2nd vec
3106    0 1 2 3    4 5 6 7
3107
3108    and the output is the vector of extracted even/odd elements. The output of
3109    extract_even will be:   0 2 4 6
3110    and of extract_odd:     1 3 5 7
3111
3112
3113    The permutation is done in log LENGTH stages. In each stage extract_even and
3114    extract_odd stmts are created for each pair of vectors in DR_CHAIN in their
3115    order. In our example,
3116
3117    E1: extract_even (1st vec, 2nd vec)
3118    E2: extract_odd (1st vec, 2nd vec)
3119    E3: extract_even (3rd vec, 4th vec)
3120    E4: extract_odd (3rd vec, 4th vec)
3121
3122    The output for the first stage will be:
3123
3124    E1:  0  2  4  6  8 10 12 14
3125    E2:  1  3  5  7  9 11 13 15
3126    E3: 16 18 20 22 24 26 28 30
3127    E4: 17 19 21 23 25 27 29 31
3128
3129    In order to proceed and create the correct sequence for the next stage (or
3130    for the correct output, if the second stage is the last one, as in our
3131    example), we first put the output of extract_even operation and then the
3132    output of extract_odd in RESULT_CHAIN (which is then copied to DR_CHAIN).
3133    The input for the second stage is:
3134
3135    1st vec (E1):  0  2  4  6  8 10 12 14
3136    2nd vec (E3): 16 18 20 22 24 26 28 30
3137    3rd vec (E2):  1  3  5  7  9 11 13 15
3138    4th vec (E4): 17 19 21 23 25 27 29 31
3139
3140    The output of the second stage:
3141
3142    E1: 0 4  8 12 16 20 24 28
3143    E2: 2 6 10 14 18 22 26 30
3144    E3: 1 5  9 13 17 21 25 29
3145    E4: 3 7 11 15 19 23 27 31
3146
3147    And RESULT_CHAIN after reordering:
3148
3149    1st vec (E1):  0 4  8 12 16 20 24 28
3150    2nd vec (E3):  1 5  9 13 17 21 25 29
3151    3rd vec (E2):  2 6 10 14 18 22 26 30
3152    4th vec (E4):  3 7 11 15 19 23 27 31.  */
3153
3154 static bool
3155 vect_permute_load_chain (VEC(tree,heap) *dr_chain,
3156                          unsigned int length,
3157                          tree stmt,
3158                          block_stmt_iterator *bsi,
3159                          VEC(tree,heap) **result_chain)
3160 {
3161   tree perm_dest, perm_stmt, data_ref, first_vect, second_vect;
3162   tree vectype = STMT_VINFO_VECTYPE (vinfo_for_stmt (stmt));
3163   int i;
3164   unsigned int j;
3165
3166   /* Check that the operation is supported.  */
3167   if (!vect_strided_load_supported (vectype))
3168     return false;
3169
3170   *result_chain = VEC_copy (tree, heap, dr_chain);
3171   for (i = 0; i < exact_log2 (length); i++)
3172     {
3173       for (j = 0; j < length; j +=2)
3174         {
3175           first_vect = VEC_index (tree, dr_chain, j);
3176           second_vect = VEC_index (tree, dr_chain, j+1);
3177
3178           /* data_ref = permute_even (first_data_ref, second_data_ref);  */
3179           perm_dest = create_tmp_var (vectype, "vect_perm_even");
3180           DECL_GIMPLE_REG_P (perm_dest) = 1;
3181           add_referenced_var (perm_dest);
3182
3183           perm_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, perm_dest,
3184                               build2 (VEC_EXTRACT_EVEN_EXPR, vectype,
3185                                       first_vect, second_vect));
3186
3187           data_ref = make_ssa_name (perm_dest, perm_stmt);
3188           GIMPLE_STMT_OPERAND (perm_stmt, 0) = data_ref;
3189           vect_finish_stmt_generation (stmt, perm_stmt, bsi);
3190           mark_symbols_for_renaming (perm_stmt);
3191
3192           VEC_replace (tree, *result_chain, j/2, data_ref);
3193
3194           /* data_ref = permute_odd (first_data_ref, second_data_ref);  */
3195           perm_dest = create_tmp_var (vectype, "vect_perm_odd");
3196           DECL_GIMPLE_REG_P (perm_dest) = 1;
3197           add_referenced_var (perm_dest);
3198
3199           perm_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, perm_dest,
3200                               build2 (VEC_EXTRACT_ODD_EXPR, vectype,
3201                                       first_vect, second_vect));
3202           data_ref = make_ssa_name (perm_dest, perm_stmt);
3203           GIMPLE_STMT_OPERAND (perm_stmt, 0) = data_ref;
3204           vect_finish_stmt_generation (stmt, perm_stmt, bsi);
3205           mark_symbols_for_renaming (perm_stmt);
3206
3207           VEC_replace (tree, *result_chain, j/2+length/2, data_ref);
3208         }
3209       dr_chain = VEC_copy (tree, heap, *result_chain);
3210     }
3211   return true;
3212 }
3213
3214
3215 /* Function vect_transform_strided_load.
3216
3217    Given a chain of input interleaved data-refs (in DR_CHAIN), build statements
3218    to perform their permutation and ascribe the result vectorized statements to
3219    the scalar statements.
3220 */
3221
3222 static bool
3223 vect_transform_strided_load (tree stmt, VEC(tree,heap) *dr_chain, int size,
3224                              block_stmt_iterator *bsi)
3225 {
3226   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
3227   tree first_stmt = DR_GROUP_FIRST_DR (stmt_info);
3228   tree next_stmt, new_stmt;
3229   VEC(tree,heap) *result_chain = NULL;
3230   unsigned int i, gap_count;
3231   tree tmp_data_ref;
3232
3233   /* DR_CHAIN contains input data-refs that are a part of the interleaving.
3234      RESULT_CHAIN is the output of vect_permute_load_chain, it contains permuted
3235      vectors, that are ready for vector computation.  */
3236   result_chain = VEC_alloc (tree, heap, size);
3237   /* Permute.  */
3238   if (!vect_permute_load_chain (dr_chain, size, stmt, bsi, &result_chain))
3239     return false;
3240
3241   /* Put a permuted data-ref in the VECTORIZED_STMT field.
3242      Since we scan the chain starting from it's first node, their order
3243      corresponds the order of data-refs in RESULT_CHAIN.  */
3244   next_stmt = first_stmt;
3245   gap_count = 1;
3246   for (i = 0; VEC_iterate(tree, result_chain, i, tmp_data_ref); i++)
3247     {
3248       if (!next_stmt)
3249         break;
3250
3251       /* Skip the gaps. Loads created for the gaps will be removed by dead
3252        code elimination pass later.
3253        DR_GROUP_GAP is the number of steps in elements from the previous
3254        access (if there is no gap DR_GROUP_GAP is 1). We skip loads that
3255        correspond to the gaps.
3256       */
3257       if (gap_count < DR_GROUP_GAP (vinfo_for_stmt (next_stmt)))
3258       {
3259         gap_count++;
3260         continue;
3261       }
3262
3263       while (next_stmt)
3264         {
3265           new_stmt = SSA_NAME_DEF_STMT (tmp_data_ref);
3266           /* We assume that if VEC_STMT is not NULL, this is a case of multiple
3267              copies, and we put the new vector statement in the first available
3268              RELATED_STMT.  */
3269           if (!STMT_VINFO_VEC_STMT (vinfo_for_stmt (next_stmt)))
3270             STMT_VINFO_VEC_STMT (vinfo_for_stmt (next_stmt)) = new_stmt;
3271           else
3272             {
3273               tree prev_stmt = STMT_VINFO_VEC_STMT (vinfo_for_stmt (next_stmt));
3274               tree rel_stmt = STMT_VINFO_RELATED_STMT (
3275                                                        vinfo_for_stmt (prev_stmt));
3276               while (rel_stmt)
3277                 {
3278                   prev_stmt = rel_stmt;
3279                   rel_stmt = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (rel_stmt));
3280                 }
3281               STMT_VINFO_RELATED_STMT (vinfo_for_stmt (prev_stmt)) = new_stmt;
3282             }
3283           next_stmt = DR_GROUP_NEXT_DR (vinfo_for_stmt (next_stmt));
3284           gap_count = 1;
3285           /* If NEXT_STMT accesses the same DR as the previous statement,
3286              put the same TMP_DATA_REF as its vectorized statement; otherwise
3287              get the next data-ref from RESULT_CHAIN.  */
3288           if (!next_stmt || !DR_GROUP_SAME_DR_STMT (vinfo_for_stmt (next_stmt)))
3289             break;
3290         }
3291     }
3292   return true;
3293 }
3294
3295
3296 /* vectorizable_load.
3297
3298    Check if STMT reads a non scalar data-ref (array/pointer/structure) that
3299    can be vectorized.
3300    If VEC_STMT is also passed, vectorize the STMT: create a vectorized
3301    stmt to replace it, put it in VEC_STMT, and insert it at BSI.
3302    Return FALSE if not a vectorizable STMT, TRUE otherwise.  */
3303
3304 bool
3305 vectorizable_load (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt)
3306 {
3307   tree scalar_dest;
3308   tree vec_dest = NULL;
3309   tree data_ref = NULL;
3310   tree op;
3311   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
3312   stmt_vec_info prev_stmt_info;
3313   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
3314   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
3315   struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info), *first_dr;
3316   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
3317   tree new_temp;
3318   int mode;
3319   tree new_stmt = NULL_TREE;
3320   tree dummy;
3321   enum dr_alignment_support alignment_support_cheme;
3322   tree dataref_ptr = NULL_TREE;
3323   tree ptr_incr;
3324   int nunits = TYPE_VECTOR_SUBPARTS (vectype);
3325   int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
3326   int i, j, group_size;
3327   tree msq = NULL_TREE, lsq;
3328   tree offset = NULL_TREE;
3329   tree realignment_token = NULL_TREE;
3330   tree phi_stmt = NULL_TREE;
3331   VEC(tree,heap) *dr_chain = NULL;
3332   bool strided_load = false;
3333   tree first_stmt;
3334
3335   /* Is vectorizable load? */
3336   if (!STMT_VINFO_RELEVANT_P (stmt_info))
3337     return false;
3338
3339   gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info) == vect_loop_def);
3340
3341   if (STMT_VINFO_LIVE_P (stmt_info))
3342     {
3343       /* FORNOW: not yet supported.  */
3344       if (vect_print_dump_info (REPORT_DETAILS))
3345         fprintf (vect_dump, "value used after loop.");
3346       return false;
3347     }
3348
3349   if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
3350     return false;
3351
3352   scalar_dest = GIMPLE_STMT_OPERAND (stmt, 0);
3353   if (TREE_CODE (scalar_dest) != SSA_NAME)
3354     return false;
3355
3356   op = GIMPLE_STMT_OPERAND (stmt, 1);
3357   if (TREE_CODE (op) != ARRAY_REF
3358       && TREE_CODE (op) != INDIRECT_REF
3359       && !DR_GROUP_FIRST_DR (stmt_info))
3360     return false;
3361
3362   if (!STMT_VINFO_DATA_REF (stmt_info))
3363     return false;
3364
3365   mode = (int) TYPE_MODE (vectype);
3366
3367   /* FORNOW. In some cases can vectorize even if data-type not supported
3368     (e.g. - data copies).  */
3369   if (mov_optab->handlers[mode].insn_code == CODE_FOR_nothing)
3370     {
3371       if (vect_print_dump_info (REPORT_DETAILS))
3372         fprintf (vect_dump, "Aligned load, but unsupported type.");
3373       return false;
3374     }
3375
3376   /* Check if the load is a part of an interleaving chain.  */
3377   if (DR_GROUP_FIRST_DR (stmt_info))
3378     {
3379       strided_load = true;
3380
3381       /* Check if interleaving is supported.  */
3382       if (!vect_strided_load_supported (vectype))
3383         return false;
3384     }
3385
3386   if (!vec_stmt) /* transformation not required.  */
3387     {
3388       STMT_VINFO_TYPE (stmt_info) = load_vec_info_type;
3389       return true;
3390     }
3391
3392   /** Transform.  **/
3393
3394   if (vect_print_dump_info (REPORT_DETAILS))
3395     fprintf (vect_dump, "transform load.");
3396
3397   if (strided_load)
3398     {
3399       first_stmt = DR_GROUP_FIRST_DR (stmt_info);
3400       /* Check if the chain of loads is already vectorized.  */
3401       if (STMT_VINFO_VEC_STMT (vinfo_for_stmt (first_stmt)))
3402         {
3403           *vec_stmt = STMT_VINFO_VEC_STMT (stmt_info);
3404           return true;
3405         }
3406       first_dr = STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt));
3407       group_size = DR_GROUP_SIZE (vinfo_for_stmt (first_stmt));
3408       dr_chain = VEC_alloc (tree, heap, group_size);
3409     }
3410   else
3411     {
3412       first_stmt = stmt;
3413       first_dr = dr;
3414       group_size = 1;
3415     }
3416
3417   alignment_support_cheme = vect_supportable_dr_alignment (first_dr);
3418   gcc_assert (alignment_support_cheme);
3419
3420
3421   /* In case the vectorization factor (VF) is bigger than the number
3422      of elements that we can fit in a vectype (nunits), we have to generate
3423      more than one vector stmt - i.e - we need to "unroll" the
3424      vector stmt by a factor VF/nunits. In doing so, we record a pointer
3425      from one copy of the vector stmt to the next, in the field
3426      STMT_VINFO_RELATED_STMT. This is necessary in order to allow following
3427      stages to find the correct vector defs to be used when vectorizing
3428      stmts that use the defs of the current stmt. The example below illustrates
3429      the vectorization process when VF=16 and nunits=4 (i.e - we need to create
3430      4 vectorized stmts):
3431
3432      before vectorization:
3433                                 RELATED_STMT    VEC_STMT
3434         S1:     x = memref      -               -
3435         S2:     z = x + 1       -               -
3436
3437      step 1: vectorize stmt S1:
3438         We first create the vector stmt VS1_0, and, as usual, record a
3439         pointer to it in the STMT_VINFO_VEC_STMT of the scalar stmt S1.
3440         Next, we create the vector stmt VS1_1, and record a pointer to
3441         it in the STMT_VINFO_RELATED_STMT of the vector stmt VS1_0.
3442         Similarly, for VS1_2 and VS1_3. This is the resulting chain of
3443         stmts and pointers:
3444                                 RELATED_STMT    VEC_STMT
3445         VS1_0:  vx0 = memref0   VS1_1           -
3446         VS1_1:  vx1 = memref1   VS1_2           -
3447         VS1_2:  vx2 = memref2   VS1_3           -
3448         VS1_3:  vx3 = memref3   -               -
3449         S1:     x = load        -               VS1_0
3450         S2:     z = x + 1       -               -
3451
3452      See in documentation in vect_get_vec_def_for_stmt_copy for how the
3453      information we recorded in RELATED_STMT field is used to vectorize
3454      stmt S2.  */
3455
3456   /* In case of interleaving (non-unit strided access):
3457
3458      S1:  x2 = &base + 2
3459      S2:  x0 = &base
3460      S3:  x1 = &base + 1
3461      S4:  x3 = &base + 3
3462
3463      Vectorized loads are created in the order of memory accesses
3464      starting from the access of the first stmt of the chain:
3465
3466      VS1: vx0 = &base
3467      VS2: vx1 = &base + vec_size*1
3468      VS3: vx3 = &base + vec_size*2
3469      VS4: vx4 = &base + vec_size*3
3470
3471      Then permutation statements are generated:
3472
3473      VS5: vx5 = VEC_EXTRACT_EVEN_EXPR < vx0, vx1 >
3474      VS6: vx6 = VEC_EXTRACT_ODD_EXPR < vx0, vx1 >
3475        ...
3476
3477      And they are put in STMT_VINFO_VEC_STMT of the corresponding scalar stmts
3478      (the order of the data-refs in the output of vect_permute_load_chain
3479      corresponds to the order of scalar stmts in the interleaving chain - see
3480      the documentation of vect_permute_load_chain()).
3481      The generation of permutation stmts and recording them in
3482      STMT_VINFO_VEC_STMT is done in vect_transform_strided_load().
3483
3484      In case of both multiple types and interleaving, the vector loads and
3485      permutation stmts above are created for every copy. The result vector stmts
3486      are put in STMT_VINFO_VEC_STMT for the first copy and in the corresponding
3487      STMT_VINFO_RELATED_STMT for the next copies.  */
3488
3489   /* If the data reference is aligned (dr_aligned) or potentially unaligned
3490      on a target that supports unaligned accesses (dr_unaligned_supported)
3491      we generate the following code:
3492          p = initial_addr;
3493          indx = 0;
3494          loop {
3495            p = p + indx * vectype_size;
3496            vec_dest = *(p);
3497            indx = indx + 1;
3498          }
3499
3500      Otherwise, the data reference is potentially unaligned on a target that
3501      does not support unaligned accesses (dr_unaligned_software_pipeline) -
3502      then generate the following code, in which the data in each iteration is
3503      obtained by two vector loads, one from the previous iteration, and one
3504      from the current iteration:
3505          p1 = initial_addr;
3506          msq_init = *(floor(p1))
3507          p2 = initial_addr + VS - 1;
3508          realignment_token = call target_builtin;
3509          indx = 0;
3510          loop {
3511            p2 = p2 + indx * vectype_size
3512            lsq = *(floor(p2))
3513            vec_dest = realign_load (msq, lsq, realignment_token)
3514            indx = indx + 1;
3515            msq = lsq;
3516          }   */
3517
3518   if (alignment_support_cheme == dr_unaligned_software_pipeline)
3519     {
3520       msq = vect_setup_realignment (first_stmt, bsi, &realignment_token);
3521       phi_stmt = SSA_NAME_DEF_STMT (msq);
3522       offset = size_int (TYPE_VECTOR_SUBPARTS (vectype) - 1);
3523     }
3524
3525   prev_stmt_info = NULL;
3526   for (j = 0; j < ncopies; j++)
3527     {
3528       /* 1. Create the vector pointer update chain.  */
3529       if (j == 0)
3530         dataref_ptr = vect_create_data_ref_ptr (first_stmt, bsi, offset, &dummy,
3531                                                 &ptr_incr, false, NULL_TREE);
3532       else
3533         dataref_ptr = bump_vector_ptr (dataref_ptr, ptr_incr, bsi, stmt);
3534
3535       for (i = 0; i < group_size; i++)
3536         {
3537           /* 2. Create the vector-load in the loop.  */
3538           switch (alignment_support_cheme)
3539             {
3540             case dr_aligned:
3541               gcc_assert (aligned_access_p (first_dr));
3542               data_ref = build_fold_indirect_ref (dataref_ptr);
3543               break;
3544             case dr_unaligned_supported:
3545               {
3546                 int mis = DR_MISALIGNMENT (first_dr);
3547                 tree tmis = (mis == -1 ? size_zero_node : size_int (mis));
3548
3549                 gcc_assert (!aligned_access_p (first_dr));
3550                 tmis = size_binop (MULT_EXPR, tmis, size_int(BITS_PER_UNIT));
3551                 data_ref =
3552                   build2 (MISALIGNED_INDIRECT_REF, vectype, dataref_ptr, tmis);
3553                 break;
3554               }
3555             case dr_unaligned_software_pipeline:
3556               gcc_assert (!aligned_access_p (first_dr));
3557               data_ref = build1 (ALIGN_INDIRECT_REF, vectype, dataref_ptr);
3558               break;
3559             default:
3560               gcc_unreachable ();
3561             }
3562           vec_dest = vect_create_destination_var (scalar_dest, vectype);
3563           new_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vec_dest,
3564                              data_ref);
3565           new_temp = make_ssa_name (vec_dest, new_stmt);
3566           GIMPLE_STMT_OPERAND (new_stmt, 0) = new_temp;
3567           vect_finish_stmt_generation (stmt, new_stmt, bsi);
3568           copy_virtual_operands (new_stmt, stmt);
3569           mark_symbols_for_renaming (new_stmt);
3570
3571           /* 3. Handle explicit realignment if necessary/supported.  */
3572           if (alignment_support_cheme == dr_unaligned_software_pipeline)
3573             {
3574               /* Create in loop:
3575                  <vec_dest = realign_load (msq, lsq, realignment_token)>  */
3576               lsq = GIMPLE_STMT_OPERAND (new_stmt, 0);
3577               if (!realignment_token)
3578                 realignment_token = dataref_ptr;
3579               vec_dest = vect_create_destination_var (scalar_dest, vectype);
3580               new_stmt =
3581                 build3 (REALIGN_LOAD_EXPR, vectype, msq, lsq, realignment_token);
3582               new_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vec_dest,
3583                                  new_stmt);
3584               new_temp = make_ssa_name (vec_dest, new_stmt);
3585               GIMPLE_STMT_OPERAND (new_stmt, 0) = new_temp;
3586               vect_finish_stmt_generation (stmt, new_stmt, bsi);
3587               if (i == group_size - 1 && j == ncopies - 1)
3588                 add_phi_arg (phi_stmt, lsq, loop_latch_edge (loop));
3589               msq = lsq;
3590             }
3591           if (strided_load)
3592             VEC_quick_push (tree, dr_chain, new_temp);
3593           if (i < group_size - 1)
3594             dataref_ptr = bump_vector_ptr (dataref_ptr, ptr_incr, bsi, stmt);
3595         }
3596
3597       if (strided_load)
3598         {
3599           if (!vect_transform_strided_load (stmt, dr_chain, group_size, bsi))
3600             return false;
3601           *vec_stmt = STMT_VINFO_VEC_STMT (stmt_info);
3602           dr_chain = VEC_alloc (tree, heap, group_size);
3603         }
3604       else
3605         {
3606           if (j == 0)
3607             STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt = new_stmt;
3608           else
3609             STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt;
3610           prev_stmt_info = vinfo_for_stmt (new_stmt);
3611         }
3612     }
3613
3614   return true;
3615 }
3616
3617
3618 /* Function vectorizable_live_operation.
3619
3620    STMT computes a value that is used outside the loop. Check if
3621    it can be supported.  */
3622
3623 bool
3624 vectorizable_live_operation (tree stmt,
3625                              block_stmt_iterator *bsi ATTRIBUTE_UNUSED,
3626                              tree *vec_stmt ATTRIBUTE_UNUSED)
3627 {
3628   tree operation;
3629   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
3630   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
3631   int i;
3632   enum tree_code code;
3633   int op_type;
3634   tree op;
3635   tree def, def_stmt;
3636   enum vect_def_type dt;
3637
3638   if (!STMT_VINFO_LIVE_P (stmt_info))
3639     return false;
3640
3641   if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
3642     return false;
3643
3644   if (TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 0)) != SSA_NAME)
3645     return false;
3646
3647   operation = GIMPLE_STMT_OPERAND (stmt, 1);
3648   code = TREE_CODE (operation);
3649
3650   op_type = TREE_CODE_LENGTH (code);
3651
3652   /* FORNOW: support only if all uses are invariant. This means
3653      that the scalar operations can remain in place, unvectorized.
3654      The original last scalar value that they compute will be used.  */
3655
3656   for (i = 0; i < op_type; i++)
3657     {
3658       op = TREE_OPERAND (operation, i);
3659       if (!vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt))
3660         {
3661           if (vect_print_dump_info (REPORT_DETAILS))
3662             fprintf (vect_dump, "use not simple.");
3663           return false;
3664         }
3665
3666       if (dt != vect_invariant_def && dt != vect_constant_def)
3667         return false;
3668     }
3669
3670   /* No transformation is required for the cases we currently support.  */
3671   return true;
3672 }
3673
3674
3675 /* Function vect_is_simple_cond.
3676
3677    Input:
3678    LOOP - the loop that is being vectorized.
3679    COND - Condition that is checked for simple use.
3680
3681    Returns whether a COND can be vectorized.  Checks whether
3682    condition operands are supportable using vec_is_simple_use.  */
3683
3684 static bool
3685 vect_is_simple_cond (tree cond, loop_vec_info loop_vinfo)
3686 {
3687   tree lhs, rhs;
3688   tree def;
3689   enum vect_def_type dt;
3690
3691   if (!COMPARISON_CLASS_P (cond))
3692     return false;
3693
3694   lhs = TREE_OPERAND (cond, 0);
3695   rhs = TREE_OPERAND (cond, 1);
3696
3697   if (TREE_CODE (lhs) == SSA_NAME)
3698     {
3699       tree lhs_def_stmt = SSA_NAME_DEF_STMT (lhs);
3700       if (!vect_is_simple_use (lhs, loop_vinfo, &lhs_def_stmt, &def, &dt))
3701         return false;
3702     }
3703   else if (TREE_CODE (lhs) != INTEGER_CST && TREE_CODE (lhs) != REAL_CST)
3704     return false;
3705
3706   if (TREE_CODE (rhs) == SSA_NAME)
3707     {
3708       tree rhs_def_stmt = SSA_NAME_DEF_STMT (rhs);
3709       if (!vect_is_simple_use (rhs, loop_vinfo, &rhs_def_stmt, &def, &dt))
3710         return false;
3711     }
3712   else if (TREE_CODE (rhs) != INTEGER_CST  && TREE_CODE (rhs) != REAL_CST)
3713     return false;
3714
3715   return true;
3716 }
3717
3718 /* vectorizable_condition.
3719
3720    Check if STMT is conditional modify expression that can be vectorized.
3721    If VEC_STMT is also passed, vectorize the STMT: create a vectorized
3722    stmt using VEC_COND_EXPR  to replace it, put it in VEC_STMT, and insert it
3723    at BSI.
3724
3725    Return FALSE if not a vectorizable STMT, TRUE otherwise.  */
3726
3727 bool
3728 vectorizable_condition (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt)
3729 {
3730   tree scalar_dest = NULL_TREE;
3731   tree vec_dest = NULL_TREE;
3732   tree op = NULL_TREE;
3733   tree cond_expr, then_clause, else_clause;
3734   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
3735   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
3736   tree vec_cond_lhs, vec_cond_rhs, vec_then_clause, vec_else_clause;
3737   tree vec_compare, vec_cond_expr;
3738   tree new_temp;
3739   loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
3740   enum machine_mode vec_mode;
3741   tree def;
3742   enum vect_def_type dt;
3743   int nunits = TYPE_VECTOR_SUBPARTS (vectype);
3744   int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
3745
3746   gcc_assert (ncopies >= 1);
3747   if (ncopies > 1)
3748     return false; /* FORNOW */
3749
3750   if (!STMT_VINFO_RELEVANT_P (stmt_info))
3751     return false;
3752
3753   gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info) == vect_loop_def);
3754
3755   if (STMT_VINFO_LIVE_P (stmt_info))
3756     {
3757       /* FORNOW: not yet supported.  */
3758       if (vect_print_dump_info (REPORT_DETAILS))
3759         fprintf (vect_dump, "value used after loop.");
3760       return false;
3761     }
3762
3763   if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
3764     return false;
3765
3766   op = GIMPLE_STMT_OPERAND (stmt, 1);
3767
3768   if (TREE_CODE (op) != COND_EXPR)
3769     return false;
3770
3771   cond_expr = TREE_OPERAND (op, 0);
3772   then_clause = TREE_OPERAND (op, 1);
3773   else_clause = TREE_OPERAND (op, 2);
3774
3775   if (!vect_is_simple_cond (cond_expr, loop_vinfo))
3776     return false;
3777
3778   /* We do not handle two different vector types for the condition
3779      and the values.  */
3780   if (TREE_TYPE (TREE_OPERAND (cond_expr, 0)) != TREE_TYPE (vectype))
3781     return false;
3782
3783   if (TREE_CODE (then_clause) == SSA_NAME)
3784     {
3785       tree then_def_stmt = SSA_NAME_DEF_STMT (then_clause);
3786       if (!vect_is_simple_use (then_clause, loop_vinfo,
3787                                &then_def_stmt, &def, &dt))
3788         return false;
3789     }
3790   else if (TREE_CODE (then_clause) != INTEGER_CST
3791            && TREE_CODE (then_clause) != REAL_CST)
3792     return false;
3793
3794   if (TREE_CODE (else_clause) == SSA_NAME)
3795     {
3796       tree else_def_stmt = SSA_NAME_DEF_STMT (else_clause);
3797       if (!vect_is_simple_use (else_clause, loop_vinfo,
3798                                &else_def_stmt, &def, &dt))
3799         return false;
3800     }
3801   else if (TREE_CODE (else_clause) != INTEGER_CST
3802            && TREE_CODE (else_clause) != REAL_CST)
3803     return false;
3804
3805
3806   vec_mode = TYPE_MODE (vectype);
3807
3808   if (!vec_stmt)
3809     {
3810       STMT_VINFO_TYPE (stmt_info) = condition_vec_info_type;
3811       return expand_vec_cond_expr_p (op, vec_mode);
3812     }
3813
3814   /* Transform */
3815
3816   /* Handle def.  */
3817   scalar_dest = GIMPLE_STMT_OPERAND (stmt, 0);
3818   vec_dest = vect_create_destination_var (scalar_dest, vectype);
3819
3820   /* Handle cond expr.  */
3821   vec_cond_lhs =
3822     vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 0), stmt, NULL);
3823   vec_cond_rhs =
3824     vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 1), stmt, NULL);
3825   vec_then_clause = vect_get_vec_def_for_operand (then_clause, stmt, NULL);
3826   vec_else_clause = vect_get_vec_def_for_operand (else_clause, stmt, NULL);
3827
3828   /* Arguments are ready. create the new vector stmt.  */
3829   vec_compare = build2 (TREE_CODE (cond_expr), vectype,
3830                         vec_cond_lhs, vec_cond_rhs);
3831   vec_cond_expr = build3 (VEC_COND_EXPR, vectype,
3832                           vec_compare, vec_then_clause, vec_else_clause);
3833
3834   *vec_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node, vec_dest,
3835                       vec_cond_expr);
3836   new_temp = make_ssa_name (vec_dest, *vec_stmt);
3837   GIMPLE_STMT_OPERAND (*vec_stmt, 0) = new_temp;
3838   vect_finish_stmt_generation (stmt, *vec_stmt, bsi);
3839
3840   return true;
3841 }
3842
3843 /* Function vect_transform_stmt.
3844
3845    Create a vectorized stmt to replace STMT, and insert it at BSI.  */
3846
3847 bool
3848 vect_transform_stmt (tree stmt, block_stmt_iterator *bsi, bool *strided_store)
3849 {
3850   bool is_store = false;
3851   tree vec_stmt = NULL_TREE;
3852   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
3853   tree orig_stmt_in_pattern;
3854   bool done;
3855
3856   if (STMT_VINFO_RELEVANT_P (stmt_info))
3857     {
3858       switch (STMT_VINFO_TYPE (stmt_info))
3859       {
3860       case type_demotion_vec_info_type:
3861         done = vectorizable_type_demotion (stmt, bsi, &vec_stmt);
3862         gcc_assert (done);
3863         break;
3864
3865       case type_promotion_vec_info_type:
3866         done = vectorizable_type_promotion (stmt, bsi, &vec_stmt);
3867         gcc_assert (done);
3868         break;
3869
3870       case op_vec_info_type:
3871         done = vectorizable_operation (stmt, bsi, &vec_stmt);
3872         gcc_assert (done);
3873         break;
3874
3875       case assignment_vec_info_type:
3876         done = vectorizable_assignment (stmt, bsi, &vec_stmt);
3877         gcc_assert (done);
3878         break;
3879
3880       case load_vec_info_type:
3881         done = vectorizable_load (stmt, bsi, &vec_stmt);
3882         gcc_assert (done);
3883         break;
3884
3885       case store_vec_info_type:
3886         done = vectorizable_store (stmt, bsi, &vec_stmt);
3887         gcc_assert (done);
3888         if (DR_GROUP_FIRST_DR (stmt_info))
3889           {
3890             /* In case of interleaving, the whole chain is vectorized when the
3891                last store in the chain is reached. Store stmts before the last
3892                one are skipped, and there vec_stmt_info shouldn't be freed
3893                meanwhile.  */
3894             *strided_store = true;
3895             if (STMT_VINFO_VEC_STMT (stmt_info))
3896               is_store = true;
3897           }
3898         else
3899           is_store = true;
3900         break;
3901
3902       case condition_vec_info_type:
3903         done = vectorizable_condition (stmt, bsi, &vec_stmt);
3904         gcc_assert (done);
3905         break;
3906
3907       case call_vec_info_type:
3908         done = vectorizable_call (stmt, bsi, &vec_stmt);
3909         break;
3910
3911       default:
3912         if (vect_print_dump_info (REPORT_DETAILS))
3913           fprintf (vect_dump, "stmt not supported.");
3914         gcc_unreachable ();
3915       }
3916
3917       gcc_assert (vec_stmt || *strided_store);
3918       if (vec_stmt)
3919         {
3920           STMT_VINFO_VEC_STMT (stmt_info) = vec_stmt;
3921           orig_stmt_in_pattern = STMT_VINFO_RELATED_STMT (stmt_info);
3922           if (orig_stmt_in_pattern)
3923             {
3924               stmt_vec_info stmt_vinfo = vinfo_for_stmt (orig_stmt_in_pattern);
3925               if (STMT_VINFO_IN_PATTERN_P (stmt_vinfo))
3926                 {
3927                   gcc_assert (STMT_VINFO_RELATED_STMT (stmt_vinfo) == stmt);
3928
3929                   /* STMT was inserted by the vectorizer to replace a
3930                      computation idiom.  ORIG_STMT_IN_PATTERN is a stmt in the
3931                      original sequence that computed this idiom.  We need to
3932                      record a pointer to VEC_STMT in the stmt_info of
3933                      ORIG_STMT_IN_PATTERN.  See more details in the
3934                      documentation of vect_pattern_recog.  */
3935
3936                   STMT_VINFO_VEC_STMT (stmt_vinfo) = vec_stmt;
3937                 }
3938             }
3939         }
3940     }
3941
3942   if (STMT_VINFO_LIVE_P (stmt_info))
3943     {
3944       switch (STMT_VINFO_TYPE (stmt_info))
3945       {
3946       case reduc_vec_info_type:
3947         done = vectorizable_reduction (stmt, bsi, &vec_stmt);
3948         gcc_assert (done);
3949         break;
3950
3951       default:
3952         done = vectorizable_live_operation (stmt, bsi, &vec_stmt);
3953         gcc_assert (done);
3954       }
3955     }
3956
3957   return is_store;
3958 }
3959
3960
3961 /* This function builds ni_name = number of iterations loop executes
3962    on the loop preheader.  */
3963
3964 static tree
3965 vect_build_loop_niters (loop_vec_info loop_vinfo)
3966 {
3967   tree ni_name, stmt, var;
3968   edge pe;
3969   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
3970   tree ni = unshare_expr (LOOP_VINFO_NITERS (loop_vinfo));
3971
3972   var = create_tmp_var (TREE_TYPE (ni), "niters");
3973   add_referenced_var (var);
3974   ni_name = force_gimple_operand (ni, &stmt, false, var);
3975
3976   pe = loop_preheader_edge (loop);
3977   if (stmt)
3978     {
3979       basic_block new_bb = bsi_insert_on_edge_immediate (pe, stmt);
3980       gcc_assert (!new_bb);
3981     }
3982
3983   return ni_name;
3984 }
3985
3986
3987 /* This function generates the following statements:
3988
3989  ni_name = number of iterations loop executes
3990  ratio = ni_name / vf
3991  ratio_mult_vf_name = ratio * vf
3992
3993  and places them at the loop preheader edge.  */
3994
3995 static void
3996 vect_generate_tmps_on_preheader (loop_vec_info loop_vinfo,
3997                                  tree *ni_name_ptr,
3998                                  tree *ratio_mult_vf_name_ptr,
3999                                  tree *ratio_name_ptr)
4000 {
4001
4002   edge pe;
4003   basic_block new_bb;
4004   tree stmt, ni_name;
4005   tree var;
4006   tree ratio_name;
4007   tree ratio_mult_vf_name;
4008   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
4009   tree ni = LOOP_VINFO_NITERS (loop_vinfo);
4010   int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
4011   tree log_vf;
4012
4013   pe = loop_preheader_edge (loop);
4014
4015   /* Generate temporary variable that contains
4016      number of iterations loop executes.  */
4017
4018   ni_name = vect_build_loop_niters (loop_vinfo);
4019   log_vf = build_int_cst (TREE_TYPE (ni), exact_log2 (vf));
4020
4021   /* Create: ratio = ni >> log2(vf) */
4022
4023   ratio_name = fold_build2 (RSHIFT_EXPR, TREE_TYPE (ni_name), ni_name, log_vf);
4024   if (!is_gimple_val (ratio_name))
4025     {
4026       var = create_tmp_var (TREE_TYPE (ni), "bnd");
4027       add_referenced_var (var);
4028
4029       ratio_name = force_gimple_operand (ratio_name, &stmt, true, var);
4030       pe = loop_preheader_edge (loop);
4031       new_bb = bsi_insert_on_edge_immediate (pe, stmt);
4032       gcc_assert (!new_bb);
4033     }
4034
4035   /* Create: ratio_mult_vf = ratio << log2 (vf).  */
4036
4037   ratio_mult_vf_name = fold_build2 (LSHIFT_EXPR, TREE_TYPE (ratio_name),
4038                                     ratio_name, log_vf);
4039   if (!is_gimple_val (ratio_mult_vf_name))
4040     {
4041       var = create_tmp_var (TREE_TYPE (ni), "ratio_mult_vf");
4042       add_referenced_var (var);
4043
4044       ratio_mult_vf_name = force_gimple_operand (ratio_mult_vf_name, &stmt,
4045                                                  true, var);
4046       pe = loop_preheader_edge (loop);
4047       new_bb = bsi_insert_on_edge_immediate (pe, stmt);
4048       gcc_assert (!new_bb);
4049     }
4050
4051   *ni_name_ptr = ni_name;
4052   *ratio_mult_vf_name_ptr = ratio_mult_vf_name;
4053   *ratio_name_ptr = ratio_name;
4054
4055   return;
4056 }
4057
4058
4059 /* Function update_vuses_to_preheader.
4060
4061    Input:
4062    STMT - a statement with potential VUSEs.
4063    LOOP - the loop whose preheader will contain STMT.
4064
4065    It's possible to vectorize a loop even though an SSA_NAME from a VUSE
4066    appears to be defined in a VDEF in another statement in a loop.
4067    One such case is when the VUSE is at the dereference of a __restricted__
4068    pointer in a load and the VDEF is at the dereference of a different
4069    __restricted__ pointer in a store.  Vectorization may result in
4070    copy_virtual_uses being called to copy the problematic VUSE to a new
4071    statement that is being inserted in the loop preheader.  This procedure
4072    is called to change the SSA_NAME in the new statement's VUSE from the
4073    SSA_NAME updated in the loop to the related SSA_NAME available on the
4074    path entering the loop.
4075
4076    When this function is called, we have the following situation:
4077
4078         # vuse <name1>
4079         S1: vload
4080     do {
4081         # name1 = phi < name0 , name2>
4082
4083         # vuse <name1>
4084         S2: vload
4085
4086         # name2 = vdef <name1>
4087         S3: vstore
4088
4089     }while...
4090
4091    Stmt S1 was created in the loop preheader block as part of misaligned-load
4092    handling. This function fixes the name of the vuse of S1 from 'name1' to
4093    'name0'.  */
4094
4095 static void
4096 update_vuses_to_preheader (tree stmt, struct loop *loop)
4097 {
4098   basic_block header_bb = loop->header;
4099   edge preheader_e = loop_preheader_edge (loop);
4100   ssa_op_iter iter;
4101   use_operand_p use_p;
4102
4103   FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_VUSE)
4104     {
4105       tree ssa_name = USE_FROM_PTR (use_p);
4106       tree def_stmt = SSA_NAME_DEF_STMT (ssa_name);
4107       tree name_var = SSA_NAME_VAR (ssa_name);
4108       basic_block bb = bb_for_stmt (def_stmt);
4109
4110       /* For a use before any definitions, def_stmt is a NOP_EXPR.  */
4111       if (!IS_EMPTY_STMT (def_stmt)
4112           && flow_bb_inside_loop_p (loop, bb))
4113         {
4114           /* If the block containing the statement defining the SSA_NAME
4115              is in the loop then it's necessary to find the definition
4116              outside the loop using the PHI nodes of the header.  */
4117           tree phi;
4118           bool updated = false;
4119
4120           for (phi = phi_nodes (header_bb); phi; phi = TREE_CHAIN (phi))
4121             {
4122               if (SSA_NAME_VAR (PHI_RESULT (phi)) == name_var)
4123                 {
4124                   SET_USE (use_p, PHI_ARG_DEF (phi, preheader_e->dest_idx));
4125                   updated = true;
4126                   break;
4127                 }
4128             }
4129           gcc_assert (updated);
4130         }
4131     }
4132 }
4133
4134
4135 /*   Function vect_update_ivs_after_vectorizer.
4136
4137      "Advance" the induction variables of LOOP to the value they should take
4138      after the execution of LOOP.  This is currently necessary because the
4139      vectorizer does not handle induction variables that are used after the
4140      loop.  Such a situation occurs when the last iterations of LOOP are
4141      peeled, because:
4142      1. We introduced new uses after LOOP for IVs that were not originally used
4143         after LOOP: the IVs of LOOP are now used by an epilog loop.
4144      2. LOOP is going to be vectorized; this means that it will iterate N/VF
4145         times, whereas the loop IVs should be bumped N times.
4146
4147      Input:
4148      - LOOP - a loop that is going to be vectorized. The last few iterations
4149               of LOOP were peeled.
4150      - NITERS - the number of iterations that LOOP executes (before it is
4151                 vectorized). i.e, the number of times the ivs should be bumped.
4152      - UPDATE_E - a successor edge of LOOP->exit that is on the (only) path
4153                   coming out from LOOP on which there are uses of the LOOP ivs
4154                   (this is the path from LOOP->exit to epilog_loop->preheader).
4155
4156                   The new definitions of the ivs are placed in LOOP->exit.
4157                   The phi args associated with the edge UPDATE_E in the bb
4158                   UPDATE_E->dest are updated accordingly.
4159
4160      Assumption 1: Like the rest of the vectorizer, this function assumes
4161      a single loop exit that has a single predecessor.
4162
4163      Assumption 2: The phi nodes in the LOOP header and in update_bb are
4164      organized in the same order.
4165
4166      Assumption 3: The access function of the ivs is simple enough (see
4167      vect_can_advance_ivs_p).  This assumption will be relaxed in the future.
4168
4169      Assumption 4: Exactly one of the successors of LOOP exit-bb is on a path
4170      coming out of LOOP on which the ivs of LOOP are used (this is the path
4171      that leads to the epilog loop; other paths skip the epilog loop).  This
4172      path starts with the edge UPDATE_E, and its destination (denoted update_bb)
4173      needs to have its phis updated.
4174  */
4175
4176 static void
4177 vect_update_ivs_after_vectorizer (loop_vec_info loop_vinfo, tree niters,
4178                                   edge update_e)
4179 {
4180   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
4181   basic_block exit_bb = single_exit (loop)->dest;
4182   tree phi, phi1;
4183   basic_block update_bb = update_e->dest;
4184
4185   /* gcc_assert (vect_can_advance_ivs_p (loop_vinfo)); */
4186
4187   /* Make sure there exists a single-predecessor exit bb:  */
4188   gcc_assert (single_pred_p (exit_bb));
4189
4190   for (phi = phi_nodes (loop->header), phi1 = phi_nodes (update_bb);
4191        phi && phi1;
4192        phi = PHI_CHAIN (phi), phi1 = PHI_CHAIN (phi1))
4193     {
4194       tree access_fn = NULL;
4195       tree evolution_part;
4196       tree init_expr;
4197       tree step_expr;
4198       tree var, stmt, ni, ni_name;
4199       block_stmt_iterator last_bsi;
4200
4201       if (vect_print_dump_info (REPORT_DETAILS))
4202         {
4203           fprintf (vect_dump, "vect_update_ivs_after_vectorizer: phi: ");
4204           print_generic_expr (vect_dump, phi, TDF_SLIM);
4205         }
4206
4207       /* Skip virtual phi's.  */
4208       if (!is_gimple_reg (SSA_NAME_VAR (PHI_RESULT (phi))))
4209         {
4210           if (vect_print_dump_info (REPORT_DETAILS))
4211             fprintf (vect_dump, "virtual phi. skip.");
4212           continue;
4213         }
4214
4215       /* Skip reduction phis.  */
4216       if (STMT_VINFO_DEF_TYPE (vinfo_for_stmt (phi)) == vect_reduction_def)
4217         {
4218           if (vect_print_dump_info (REPORT_DETAILS))
4219             fprintf (vect_dump, "reduc phi. skip.");
4220           continue;
4221         }
4222
4223       access_fn = analyze_scalar_evolution (loop, PHI_RESULT (phi));
4224       gcc_assert (access_fn);
4225       evolution_part =
4226          unshare_expr (evolution_part_in_loop_num (access_fn, loop->num));
4227       gcc_assert (evolution_part != NULL_TREE);
4228
4229       /* FORNOW: We do not support IVs whose evolution function is a polynomial
4230          of degree >= 2 or exponential.  */
4231       gcc_assert (!tree_is_chrec (evolution_part));
4232
4233       step_expr = evolution_part;
4234       init_expr = unshare_expr (initial_condition_in_loop_num (access_fn,
4235                                                                loop->num));
4236
4237       ni = fold_build2 (PLUS_EXPR, TREE_TYPE (init_expr),
4238                         fold_build2 (MULT_EXPR, TREE_TYPE (init_expr),
4239                                      fold_convert (TREE_TYPE (init_expr),
4240                                                    niters),
4241                                      step_expr),
4242                         init_expr);
4243
4244       var = create_tmp_var (TREE_TYPE (init_expr), "tmp");
4245       add_referenced_var (var);
4246
4247       ni_name = force_gimple_operand (ni, &stmt, false, var);
4248
4249       /* Insert stmt into exit_bb.  */
4250       last_bsi = bsi_last (exit_bb);
4251       if (stmt)
4252         bsi_insert_before (&last_bsi, stmt, BSI_SAME_STMT);
4253
4254       /* Fix phi expressions in the successor bb.  */
4255       SET_PHI_ARG_DEF (phi1, update_e->dest_idx, ni_name);
4256     }
4257 }
4258
4259
4260 /* Function vect_do_peeling_for_loop_bound
4261
4262    Peel the last iterations of the loop represented by LOOP_VINFO.
4263    The peeled iterations form a new epilog loop.  Given that the loop now
4264    iterates NITERS times, the new epilog loop iterates
4265    NITERS % VECTORIZATION_FACTOR times.
4266
4267    The original loop will later be made to iterate
4268    NITERS / VECTORIZATION_FACTOR times (this value is placed into RATIO).  */
4269
4270 static void
4271 vect_do_peeling_for_loop_bound (loop_vec_info loop_vinfo, tree *ratio)
4272 {
4273   tree ni_name, ratio_mult_vf_name;
4274   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
4275   struct loop *new_loop;
4276   edge update_e;
4277   basic_block preheader;
4278   int loop_num;
4279
4280   if (vect_print_dump_info (REPORT_DETAILS))
4281     fprintf (vect_dump, "=== vect_do_peeling_for_loop_bound ===");
4282
4283   initialize_original_copy_tables ();
4284
4285   /* Generate the following variables on the preheader of original loop:
4286
4287      ni_name = number of iteration the original loop executes
4288      ratio = ni_name / vf
4289      ratio_mult_vf_name = ratio * vf  */
4290   vect_generate_tmps_on_preheader (loop_vinfo, &ni_name,
4291                                    &ratio_mult_vf_name, ratio);
4292
4293   loop_num  = loop->num;
4294   new_loop = slpeel_tree_peel_loop_to_edge (loop, single_exit (loop),
4295                                             ratio_mult_vf_name, ni_name, false);
4296   gcc_assert (new_loop);
4297   gcc_assert (loop_num == loop->num);
4298 #ifdef ENABLE_CHECKING
4299   slpeel_verify_cfg_after_peeling (loop, new_loop);
4300 #endif
4301
4302   /* A guard that controls whether the new_loop is to be executed or skipped
4303      is placed in LOOP->exit.  LOOP->exit therefore has two successors - one
4304      is the preheader of NEW_LOOP, where the IVs from LOOP are used.  The other
4305      is a bb after NEW_LOOP, where these IVs are not used.  Find the edge that
4306      is on the path where the LOOP IVs are used and need to be updated.  */
4307
4308   preheader = loop_preheader_edge (new_loop)->src;
4309   if (EDGE_PRED (preheader, 0)->src == single_exit (loop)->dest)
4310     update_e = EDGE_PRED (preheader, 0);
4311   else
4312     update_e = EDGE_PRED (preheader, 1);
4313
4314   /* Update IVs of original loop as if they were advanced
4315      by ratio_mult_vf_name steps.  */
4316   vect_update_ivs_after_vectorizer (loop_vinfo, ratio_mult_vf_name, update_e);
4317
4318   /* After peeling we have to reset scalar evolution analyzer.  */
4319   scev_reset ();
4320
4321   free_original_copy_tables ();
4322 }
4323
4324
4325 /* Function vect_gen_niters_for_prolog_loop
4326
4327    Set the number of iterations for the loop represented by LOOP_VINFO
4328    to the minimum between LOOP_NITERS (the original iteration count of the loop)
4329    and the misalignment of DR - the data reference recorded in
4330    LOOP_VINFO_UNALIGNED_DR (LOOP_VINFO).  As a result, after the execution of
4331    this loop, the data reference DR will refer to an aligned location.
4332
4333    The following computation is generated:
4334
4335    If the misalignment of DR is known at compile time:
4336      addr_mis = int mis = DR_MISALIGNMENT (dr);
4337    Else, compute address misalignment in bytes:
4338      addr_mis = addr & (vectype_size - 1)
4339
4340    prolog_niters = min ( LOOP_NITERS , (VF - addr_mis/elem_size)&(VF-1) )
4341
4342    (elem_size = element type size; an element is the scalar element
4343         whose type is the inner type of the vectype)
4344
4345    For interleaving,
4346
4347    prolog_niters = min ( LOOP_NITERS ,
4348                         (VF/group_size - addr_mis/elem_size)&(VF/group_size-1) )
4349          where group_size is the size of the interleaved group.
4350 */
4351
4352 static tree
4353 vect_gen_niters_for_prolog_loop (loop_vec_info loop_vinfo, tree loop_niters)
4354 {
4355   struct data_reference *dr = LOOP_VINFO_UNALIGNED_DR (loop_vinfo);
4356   int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
4357   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
4358   tree var, stmt;
4359   tree iters, iters_name;
4360   edge pe;
4361   basic_block new_bb;
4362   tree dr_stmt = DR_STMT (dr);
4363   stmt_vec_info stmt_info = vinfo_for_stmt (dr_stmt);
4364   tree vectype = STMT_VINFO_VECTYPE (stmt_info);
4365   int vectype_align = TYPE_ALIGN (vectype) / BITS_PER_UNIT;
4366   tree niters_type = TREE_TYPE (loop_niters);
4367   int group_size = 1;
4368   int element_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (dr))));
4369
4370   if (DR_GROUP_FIRST_DR (stmt_info))
4371     {
4372       /* For interleaved access element size must be multiplied by the size of
4373          the interleaved group.  */
4374       group_size = DR_GROUP_SIZE (vinfo_for_stmt (
4375                                                DR_GROUP_FIRST_DR (stmt_info)));
4376       element_size *= group_size;
4377     }
4378
4379   pe = loop_preheader_edge (loop);
4380
4381   if (LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo) > 0)
4382     {
4383       int byte_misalign = LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo);
4384       int elem_misalign = byte_misalign / element_size;
4385
4386       if (vect_print_dump_info (REPORT_DETAILS))
4387         fprintf (vect_dump, "known alignment = %d.", byte_misalign);
4388       iters = build_int_cst (niters_type,
4389                              (vf - elem_misalign)&(vf/group_size-1));
4390     }
4391   else
4392     {
4393       tree new_stmts = NULL_TREE;
4394       tree start_addr =
4395         vect_create_addr_base_for_vector_ref (dr_stmt, &new_stmts, NULL_TREE);
4396       tree ptr_type = TREE_TYPE (start_addr);
4397       tree size = TYPE_SIZE (ptr_type);
4398       tree type = lang_hooks.types.type_for_size (tree_low_cst (size, 1), 1);
4399       tree vectype_size_minus_1 = build_int_cst (type, vectype_align - 1);
4400       tree elem_size_log =
4401         build_int_cst (type, exact_log2 (vectype_align/vf));
4402       tree vf_minus_1 = build_int_cst (type, vf - 1);
4403       tree vf_tree = build_int_cst (type, vf);
4404       tree byte_misalign;
4405       tree elem_misalign;
4406
4407       new_bb = bsi_insert_on_edge_immediate (pe, new_stmts);
4408       gcc_assert (!new_bb);
4409
4410       /* Create:  byte_misalign = addr & (vectype_size - 1)  */
4411       byte_misalign =
4412         fold_build2 (BIT_AND_EXPR, type, start_addr, vectype_size_minus_1);
4413
4414       /* Create:  elem_misalign = byte_misalign / element_size  */
4415       elem_misalign =
4416         fold_build2 (RSHIFT_EXPR, type, byte_misalign, elem_size_log);
4417
4418       /* Create:  (niters_type) (VF - elem_misalign)&(VF - 1)  */
4419       iters = fold_build2 (MINUS_EXPR, type, vf_tree, elem_misalign);
4420       iters = fold_build2 (BIT_AND_EXPR, type, iters, vf_minus_1);
4421       iters = fold_convert (niters_type, iters);
4422     }
4423
4424   /* Create:  prolog_loop_niters = min (iters, loop_niters) */
4425   /* If the loop bound is known at compile time we already verified that it is
4426      greater than vf; since the misalignment ('iters') is at most vf, there's
4427      no need to generate the MIN_EXPR in this case.  */
4428   if (TREE_CODE (loop_niters) != INTEGER_CST)
4429     iters = fold_build2 (MIN_EXPR, niters_type, iters, loop_niters);
4430
4431   if (vect_print_dump_info (REPORT_DETAILS))
4432     {
4433       fprintf (vect_dump, "niters for prolog loop: ");
4434       print_generic_expr (vect_dump, iters, TDF_SLIM);
4435     }
4436
4437   var = create_tmp_var (niters_type, "prolog_loop_niters");
4438   add_referenced_var (var);
4439   iters_name = force_gimple_operand (iters, &stmt, false, var);
4440
4441   /* Insert stmt on loop preheader edge.  */
4442   if (stmt)
4443     {
4444       basic_block new_bb = bsi_insert_on_edge_immediate (pe, stmt);
4445       gcc_assert (!new_bb);
4446     }
4447
4448   return iters_name;
4449 }
4450
4451
4452 /* Function vect_update_init_of_dr
4453
4454    NITERS iterations were peeled from LOOP.  DR represents a data reference
4455    in LOOP.  This function updates the information recorded in DR to
4456    account for the fact that the first NITERS iterations had already been
4457    executed.  Specifically, it updates the OFFSET field of DR.  */
4458
4459 static void
4460 vect_update_init_of_dr (struct data_reference *dr, tree niters)
4461 {
4462   tree offset = DR_OFFSET (dr);
4463
4464   niters = fold_build2 (MULT_EXPR, TREE_TYPE (niters), niters, DR_STEP (dr));
4465   offset = fold_build2 (PLUS_EXPR, TREE_TYPE (offset), offset, niters);
4466   DR_OFFSET (dr) = offset;
4467 }
4468
4469
4470 /* Function vect_update_inits_of_drs
4471
4472    NITERS iterations were peeled from the loop represented by LOOP_VINFO.
4473    This function updates the information recorded for the data references in
4474    the loop to account for the fact that the first NITERS iterations had
4475    already been executed.  Specifically, it updates the initial_condition of the
4476    access_function of all the data_references in the loop.  */
4477
4478 static void
4479 vect_update_inits_of_drs (loop_vec_info loop_vinfo, tree niters)
4480 {
4481   unsigned int i;
4482   VEC (data_reference_p, heap) *datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
4483   struct data_reference *dr;
4484
4485   if (vect_dump && (dump_flags & TDF_DETAILS))
4486     fprintf (vect_dump, "=== vect_update_inits_of_dr ===");
4487
4488   for (i = 0; VEC_iterate (data_reference_p, datarefs, i, dr); i++)
4489     vect_update_init_of_dr (dr, niters);
4490 }
4491
4492
4493 /* Function vect_do_peeling_for_alignment
4494
4495    Peel the first 'niters' iterations of the loop represented by LOOP_VINFO.
4496    'niters' is set to the misalignment of one of the data references in the
4497    loop, thereby forcing it to refer to an aligned location at the beginning
4498    of the execution of this loop.  The data reference for which we are
4499    peeling is recorded in LOOP_VINFO_UNALIGNED_DR.  */
4500
4501 static void
4502 vect_do_peeling_for_alignment (loop_vec_info loop_vinfo)
4503 {
4504   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
4505   tree niters_of_prolog_loop, ni_name;
4506   tree n_iters;
4507   struct loop *new_loop;
4508
4509   if (vect_print_dump_info (REPORT_DETAILS))
4510     fprintf (vect_dump, "=== vect_do_peeling_for_alignment ===");
4511
4512   initialize_original_copy_tables ();
4513
4514   ni_name = vect_build_loop_niters (loop_vinfo);
4515   niters_of_prolog_loop = vect_gen_niters_for_prolog_loop (loop_vinfo, ni_name);
4516
4517   /* Peel the prolog loop and iterate it niters_of_prolog_loop.  */
4518   new_loop =
4519         slpeel_tree_peel_loop_to_edge (loop, loop_preheader_edge (loop),
4520                                        niters_of_prolog_loop, ni_name, true);
4521   gcc_assert (new_loop);
4522 #ifdef ENABLE_CHECKING
4523   slpeel_verify_cfg_after_peeling (new_loop, loop);
4524 #endif
4525
4526   /* Update number of times loop executes.  */
4527   n_iters = LOOP_VINFO_NITERS (loop_vinfo);
4528   LOOP_VINFO_NITERS (loop_vinfo) = fold_build2 (MINUS_EXPR,
4529                 TREE_TYPE (n_iters), n_iters, niters_of_prolog_loop);
4530
4531   /* Update the init conditions of the access functions of all data refs.  */
4532   vect_update_inits_of_drs (loop_vinfo, niters_of_prolog_loop);
4533
4534   /* After peeling we have to reset scalar evolution analyzer.  */
4535   scev_reset ();
4536
4537   free_original_copy_tables ();
4538 }
4539
4540
4541 /* Function vect_create_cond_for_align_checks.
4542
4543    Create a conditional expression that represents the alignment checks for
4544    all of data references (array element references) whose alignment must be
4545    checked at runtime.
4546
4547    Input:
4548    LOOP_VINFO - two fields of the loop information are used.
4549                 LOOP_VINFO_PTR_MASK is the mask used to check the alignment.
4550                 LOOP_VINFO_MAY_MISALIGN_STMTS contains the refs to be checked.
4551
4552    Output:
4553    COND_EXPR_STMT_LIST - statements needed to construct the conditional
4554                          expression.
4555    The returned value is the conditional expression to be used in the if
4556    statement that controls which version of the loop gets executed at runtime.
4557
4558    The algorithm makes two assumptions:
4559      1) The number of bytes "n" in a vector is a power of 2.
4560      2) An address "a" is aligned if a%n is zero and that this
4561         test can be done as a&(n-1) == 0.  For example, for 16
4562         byte vectors the test is a&0xf == 0.  */
4563
4564 static tree
4565 vect_create_cond_for_align_checks (loop_vec_info loop_vinfo,
4566                                    tree *cond_expr_stmt_list)
4567 {
4568   VEC(tree,heap) *may_misalign_stmts
4569     = LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo);
4570   tree ref_stmt;
4571   int mask = LOOP_VINFO_PTR_MASK (loop_vinfo);
4572   tree mask_cst;
4573   unsigned int i;
4574   tree psize;
4575   tree int_ptrsize_type;
4576   char tmp_name[20];
4577   tree or_tmp_name = NULL_TREE;
4578   tree and_tmp, and_tmp_name, and_stmt;
4579   tree ptrsize_zero;
4580
4581   /* Check that mask is one less than a power of 2, i.e., mask is
4582      all zeros followed by all ones.  */
4583   gcc_assert ((mask != 0) && ((mask & (mask+1)) == 0));
4584
4585   /* CHECKME: what is the best integer or unsigned type to use to hold a
4586      cast from a pointer value?  */
4587   psize = TYPE_SIZE (ptr_type_node);
4588   int_ptrsize_type
4589     = lang_hooks.types.type_for_size (tree_low_cst (psize, 1), 0);
4590
4591   /* Create expression (mask & (dr_1 || ... || dr_n)) where dr_i is the address
4592      of the first vector of the i'th data reference. */
4593
4594   for (i = 0; VEC_iterate (tree, may_misalign_stmts, i, ref_stmt); i++)
4595     {
4596       tree new_stmt_list = NULL_TREE;
4597       tree addr_base;
4598       tree addr_tmp, addr_tmp_name, addr_stmt;
4599       tree or_tmp, new_or_tmp_name, or_stmt;
4600
4601       /* create: addr_tmp = (int)(address_of_first_vector) */
4602       addr_base = vect_create_addr_base_for_vector_ref (ref_stmt,
4603                                                         &new_stmt_list,
4604                                                         NULL_TREE);
4605
4606       if (new_stmt_list != NULL_TREE)
4607         append_to_statement_list_force (new_stmt_list, cond_expr_stmt_list);
4608
4609       sprintf (tmp_name, "%s%d", "addr2int", i);
4610       addr_tmp = create_tmp_var (int_ptrsize_type, tmp_name);
4611       add_referenced_var (addr_tmp);
4612       addr_tmp_name = make_ssa_name (addr_tmp, NULL_TREE);
4613       addr_stmt = fold_convert (int_ptrsize_type, addr_base);
4614       addr_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node,
4615                           addr_tmp_name, addr_stmt);
4616       SSA_NAME_DEF_STMT (addr_tmp_name) = addr_stmt;
4617       append_to_statement_list_force (addr_stmt, cond_expr_stmt_list);
4618
4619       /* The addresses are OR together.  */
4620
4621       if (or_tmp_name != NULL_TREE)
4622         {
4623           /* create: or_tmp = or_tmp | addr_tmp */
4624           sprintf (tmp_name, "%s%d", "orptrs", i);
4625           or_tmp = create_tmp_var (int_ptrsize_type, tmp_name);
4626           add_referenced_var (or_tmp);
4627           new_or_tmp_name = make_ssa_name (or_tmp, NULL_TREE);
4628           or_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node,
4629                             new_or_tmp_name,
4630                             build2 (BIT_IOR_EXPR, int_ptrsize_type,
4631                                     or_tmp_name,
4632                                     addr_tmp_name));
4633           SSA_NAME_DEF_STMT (new_or_tmp_name) = or_stmt;
4634           append_to_statement_list_force (or_stmt, cond_expr_stmt_list);
4635           or_tmp_name = new_or_tmp_name;
4636         }
4637       else
4638         or_tmp_name = addr_tmp_name;
4639
4640     } /* end for i */
4641
4642   mask_cst = build_int_cst (int_ptrsize_type, mask);
4643
4644   /* create: and_tmp = or_tmp & mask  */
4645   and_tmp = create_tmp_var (int_ptrsize_type, "andmask" );
4646   add_referenced_var (and_tmp);
4647   and_tmp_name = make_ssa_name (and_tmp, NULL_TREE);
4648
4649   and_stmt = build2 (GIMPLE_MODIFY_STMT, void_type_node,
4650                      and_tmp_name,
4651                      build2 (BIT_AND_EXPR, int_ptrsize_type,
4652                              or_tmp_name, mask_cst));
4653   SSA_NAME_DEF_STMT (and_tmp_name) = and_stmt;
4654   append_to_statement_list_force (and_stmt, cond_expr_stmt_list);
4655
4656   /* Make and_tmp the left operand of the conditional test against zero.
4657      if and_tmp has a nonzero bit then some address is unaligned.  */
4658   ptrsize_zero = build_int_cst (int_ptrsize_type, 0);
4659   return build2 (EQ_EXPR, boolean_type_node,
4660                  and_tmp_name, ptrsize_zero);
4661 }
4662
4663
4664 /* Function vect_transform_loop.
4665
4666    The analysis phase has determined that the loop is vectorizable.
4667    Vectorize the loop - created vectorized stmts to replace the scalar
4668    stmts in the loop, and update the loop exit condition.  */
4669
4670 void
4671 vect_transform_loop (loop_vec_info loop_vinfo)
4672 {
4673   struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
4674   basic_block *bbs = LOOP_VINFO_BBS (loop_vinfo);
4675   int nbbs = loop->num_nodes;
4676   block_stmt_iterator si;
4677   int i;
4678   tree ratio = NULL;
4679   int vectorization_factor = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
4680   bool strided_store;
4681
4682   if (vect_print_dump_info (REPORT_DETAILS))
4683     fprintf (vect_dump, "=== vec_transform_loop ===");
4684
4685   /* If the loop has data references that may or may not be aligned then
4686      two versions of the loop need to be generated, one which is vectorized
4687      and one which isn't.  A test is then generated to control which of the
4688      loops is executed.  The test checks for the alignment of all of the
4689      data references that may or may not be aligned. */
4690
4691   if (VEC_length (tree, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo)))
4692     {
4693       struct loop *nloop;
4694       tree cond_expr;
4695       tree cond_expr_stmt_list = NULL_TREE;
4696       basic_block condition_bb;
4697       block_stmt_iterator cond_exp_bsi;
4698       basic_block merge_bb;
4699       basic_block new_exit_bb;
4700       edge new_exit_e, e;
4701       tree orig_phi, new_phi, arg;
4702
4703       cond_expr = vect_create_cond_for_align_checks (loop_vinfo,
4704                                                      &cond_expr_stmt_list);
4705       initialize_original_copy_tables ();
4706       nloop = loop_version (loop, cond_expr, &condition_bb, true);
4707       free_original_copy_tables();
4708
4709       /** Loop versioning violates an assumption we try to maintain during
4710          vectorization - that the loop exit block has a single predecessor.
4711          After versioning, the exit block of both loop versions is the same
4712          basic block (i.e. it has two predecessors). Just in order to simplify
4713          following transformations in the vectorizer, we fix this situation
4714          here by adding a new (empty) block on the exit-edge of the loop,
4715          with the proper loop-exit phis to maintain loop-closed-form.  **/
4716
4717       merge_bb = single_exit (loop)->dest;
4718       gcc_assert (EDGE_COUNT (merge_bb->preds) == 2);
4719       new_exit_bb = split_edge (single_exit (loop));
4720       new_exit_e = single_exit (loop);
4721       e = EDGE_SUCC (new_exit_bb, 0);
4722
4723       for (orig_phi = phi_nodes (merge_bb); orig_phi;
4724            orig_phi = PHI_CHAIN (orig_phi))
4725         {
4726           new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)),
4727                                      new_exit_bb);
4728           arg = PHI_ARG_DEF_FROM_EDGE (orig_phi, e);
4729           add_phi_arg (new_phi, arg, new_exit_e);
4730           SET_PHI_ARG_DEF (orig_phi, e->dest_idx, PHI_RESULT (new_phi));
4731         }
4732
4733       /** end loop-exit-fixes after versioning  **/
4734
4735       update_ssa (TODO_update_ssa);
4736       cond_exp_bsi = bsi_last (condition_bb);
4737       bsi_insert_before (&cond_exp_bsi, cond_expr_stmt_list, BSI_SAME_STMT);
4738     }
4739
4740   /* CHECKME: we wouldn't need this if we called update_ssa once
4741      for all loops.  */
4742   bitmap_zero (vect_memsyms_to_rename);
4743
4744   /* Peel the loop if there are data refs with unknown alignment.
4745      Only one data ref with unknown store is allowed.  */
4746
4747   if (LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo))
4748     vect_do_peeling_for_alignment (loop_vinfo);
4749
4750   /* If the loop has a symbolic number of iterations 'n' (i.e. it's not a
4751      compile time constant), or it is a constant that doesn't divide by the
4752      vectorization factor, then an epilog loop needs to be created.
4753      We therefore duplicate the loop: the original loop will be vectorized,
4754      and will compute the first (n/VF) iterations. The second copy of the loop
4755      will remain scalar and will compute the remaining (n%VF) iterations.
4756      (VF is the vectorization factor).  */
4757
4758   if (!LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)
4759       || (LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)
4760           && LOOP_VINFO_INT_NITERS (loop_vinfo) % vectorization_factor != 0))
4761     vect_do_peeling_for_loop_bound (loop_vinfo, &ratio);
4762   else
4763     ratio = build_int_cst (TREE_TYPE (LOOP_VINFO_NITERS (loop_vinfo)),
4764                 LOOP_VINFO_INT_NITERS (loop_vinfo) / vectorization_factor);
4765
4766   /* 1) Make sure the loop header has exactly two entries
4767      2) Make sure we have a preheader basic block.  */
4768
4769   gcc_assert (EDGE_COUNT (loop->header->preds) == 2);
4770
4771   split_edge (loop_preheader_edge (loop));
4772
4773   /* FORNOW: the vectorizer supports only loops which body consist
4774      of one basic block (header + empty latch). When the vectorizer will
4775      support more involved loop forms, the order by which the BBs are
4776      traversed need to be reconsidered.  */
4777
4778   for (i = 0; i < nbbs; i++)
4779     {
4780       basic_block bb = bbs[i];
4781
4782       for (si = bsi_start (bb); !bsi_end_p (si);)
4783         {
4784           tree stmt = bsi_stmt (si);
4785           stmt_vec_info stmt_info;
4786           bool is_store;
4787
4788           if (vect_print_dump_info (REPORT_DETAILS))
4789             {
4790               fprintf (vect_dump, "------>vectorizing statement: ");
4791               print_generic_expr (vect_dump, stmt, TDF_SLIM);
4792             }
4793           stmt_info = vinfo_for_stmt (stmt);
4794           gcc_assert (stmt_info);
4795           if (!STMT_VINFO_RELEVANT_P (stmt_info)
4796               && !STMT_VINFO_LIVE_P (stmt_info))
4797             {
4798               bsi_next (&si);
4799               continue;
4800             }
4801
4802           if ((TYPE_VECTOR_SUBPARTS (STMT_VINFO_VECTYPE (stmt_info))
4803                  != (unsigned HOST_WIDE_INT) vectorization_factor)
4804               && vect_print_dump_info (REPORT_DETAILS))
4805             fprintf (vect_dump, "multiple-types.");
4806
4807           /* -------- vectorize statement ------------ */
4808           if (vect_print_dump_info (REPORT_DETAILS))
4809             fprintf (vect_dump, "transform statement.");
4810
4811           strided_store = false;
4812           is_store = vect_transform_stmt (stmt, &si, &strided_store);
4813           if (is_store)
4814             {
4815               stmt_ann_t ann;
4816               if (DR_GROUP_FIRST_DR (stmt_info))
4817                 {
4818                   /* Interleaving. If IS_STORE is TRUE, the vectorization of the
4819                      interleaving chain was completed - free all the stores in
4820                      the chain.  */
4821                   tree next = DR_GROUP_FIRST_DR (stmt_info);
4822                   tree tmp;
4823                   stmt_vec_info next_stmt_info;
4824
4825                   while (next)
4826                     {
4827                       next_stmt_info = vinfo_for_stmt (next);
4828                       /* Free the attached stmt_vec_info and remove the stmt.  */
4829                       ann = stmt_ann (next);
4830                       tmp = DR_GROUP_NEXT_DR (next_stmt_info);
4831                       free (next_stmt_info);
4832                       set_stmt_info (ann, NULL);
4833                       next = tmp;
4834                     }
4835                   bsi_remove (&si, true);
4836                   continue;
4837                 }
4838               else
4839                 {
4840                   /* Free the attached stmt_vec_info and remove the stmt.  */
4841                   ann = stmt_ann (stmt);
4842                   free (stmt_info);
4843                   set_stmt_info (ann, NULL);
4844                   bsi_remove (&si, true);
4845                   continue;
4846                 }
4847             }
4848           else
4849             {
4850               if (strided_store)
4851                 {
4852                   /* This is case of skipped interleaved store. We don't free
4853                      its stmt_vec_info.  */
4854                   bsi_remove (&si, true);
4855                   continue;
4856                 }
4857             }
4858           bsi_next (&si);
4859         }                       /* stmts in BB */
4860     }                           /* BBs in loop */
4861
4862   slpeel_make_loop_iterate_ntimes (loop, ratio);
4863
4864   mark_set_for_renaming (vect_memsyms_to_rename);
4865
4866   /* The memory tags and pointers in vectorized statements need to
4867      have their SSA forms updated.  FIXME, why can't this be delayed
4868      until all the loops have been transformed?  */
4869   update_ssa (TODO_update_ssa);
4870
4871   if (vect_print_dump_info (REPORT_VECTORIZED_LOOPS))
4872     fprintf (vect_dump, "LOOP VECTORIZED.");
4873 }