1 /* Data References Analysis and Manipulation Utilities for Vectorization.
2 Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
3 Free Software Foundation, Inc.
4 Contributed by Dorit Naishlos <dorit@il.ibm.com>
5 and Ira Rosen <irar@il.ibm.com>
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 3, or (at your option) any later
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
25 #include "coretypes.h"
31 #include "basic-block.h"
32 #include "tree-pretty-print.h"
33 #include "gimple-pretty-print.h"
34 #include "tree-flow.h"
35 #include "tree-dump.h"
37 #include "tree-chrec.h"
38 #include "tree-scalar-evolution.h"
39 #include "tree-vectorizer.h"
40 #include "diagnostic-core.h"
42 /* Need to include rtl.h, expr.h, etc. for optabs. */
46 /* Return true if load- or store-lanes optab OPTAB is implemented for
47 COUNT vectors of type VECTYPE. NAME is the name of OPTAB. */
50 vect_lanes_optab_supported_p (const char *name, convert_optab optab,
51 tree vectype, unsigned HOST_WIDE_INT count)
53 enum machine_mode mode, array_mode;
56 mode = TYPE_MODE (vectype);
57 limit_p = !targetm.array_mode_supported_p (mode, count);
58 array_mode = mode_for_size (count * GET_MODE_BITSIZE (mode),
61 if (array_mode == BLKmode)
63 if (vect_print_dump_info (REPORT_DETAILS))
64 fprintf (vect_dump, "no array mode for %s[" HOST_WIDE_INT_PRINT_DEC "]",
65 GET_MODE_NAME (mode), count);
69 if (convert_optab_handler (optab, array_mode, mode) == CODE_FOR_nothing)
71 if (vect_print_dump_info (REPORT_DETAILS))
72 fprintf (vect_dump, "cannot use %s<%s><%s>",
73 name, GET_MODE_NAME (array_mode), GET_MODE_NAME (mode));
77 if (vect_print_dump_info (REPORT_DETAILS))
78 fprintf (vect_dump, "can use %s<%s><%s>",
79 name, GET_MODE_NAME (array_mode), GET_MODE_NAME (mode));
85 /* Return the smallest scalar part of STMT.
86 This is used to determine the vectype of the stmt. We generally set the
87 vectype according to the type of the result (lhs). For stmts whose
88 result-type is different than the type of the arguments (e.g., demotion,
89 promotion), vectype will be reset appropriately (later). Note that we have
90 to visit the smallest datatype in this function, because that determines the
91 VF. If the smallest datatype in the loop is present only as the rhs of a
92 promotion operation - we'd miss it.
93 Such a case, where a variable of this datatype does not appear in the lhs
94 anywhere in the loop, can only occur if it's an invariant: e.g.:
95 'int_x = (int) short_inv', which we'd expect to have been optimized away by
96 invariant motion. However, we cannot rely on invariant motion to always
97 take invariants out of the loop, and so in the case of promotion we also
98 have to check the rhs.
99 LHS_SIZE_UNIT and RHS_SIZE_UNIT contain the sizes of the corresponding
103 vect_get_smallest_scalar_type (gimple stmt, HOST_WIDE_INT *lhs_size_unit,
104 HOST_WIDE_INT *rhs_size_unit)
106 tree scalar_type = gimple_expr_type (stmt);
107 HOST_WIDE_INT lhs, rhs;
109 lhs = rhs = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (scalar_type));
111 if (is_gimple_assign (stmt)
112 && (gimple_assign_cast_p (stmt)
113 || gimple_assign_rhs_code (stmt) == WIDEN_MULT_EXPR
114 || gimple_assign_rhs_code (stmt) == FLOAT_EXPR))
116 tree rhs_type = TREE_TYPE (gimple_assign_rhs1 (stmt));
118 rhs = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (rhs_type));
120 scalar_type = rhs_type;
123 *lhs_size_unit = lhs;
124 *rhs_size_unit = rhs;
129 /* Find the place of the data-ref in STMT in the interleaving chain that starts
130 from FIRST_STMT. Return -1 if the data-ref is not a part of the chain. */
133 vect_get_place_in_interleaving_chain (gimple stmt, gimple first_stmt)
135 gimple next_stmt = first_stmt;
138 if (first_stmt != GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)))
141 while (next_stmt && next_stmt != stmt)
144 next_stmt = GROUP_NEXT_ELEMENT (vinfo_for_stmt (next_stmt));
154 /* Function vect_insert_into_interleaving_chain.
156 Insert DRA into the interleaving chain of DRB according to DRA's INIT. */
159 vect_insert_into_interleaving_chain (struct data_reference *dra,
160 struct data_reference *drb)
164 stmt_vec_info stmtinfo_a = vinfo_for_stmt (DR_STMT (dra));
165 stmt_vec_info stmtinfo_b = vinfo_for_stmt (DR_STMT (drb));
167 prev = GROUP_FIRST_ELEMENT (stmtinfo_b);
168 next = GROUP_NEXT_ELEMENT (vinfo_for_stmt (prev));
171 next_init = DR_INIT (STMT_VINFO_DATA_REF (vinfo_for_stmt (next)));
172 if (tree_int_cst_compare (next_init, DR_INIT (dra)) > 0)
175 GROUP_NEXT_ELEMENT (vinfo_for_stmt (prev)) = DR_STMT (dra);
176 GROUP_NEXT_ELEMENT (stmtinfo_a) = next;
180 next = GROUP_NEXT_ELEMENT (vinfo_for_stmt (prev));
183 /* We got to the end of the list. Insert here. */
184 GROUP_NEXT_ELEMENT (vinfo_for_stmt (prev)) = DR_STMT (dra);
185 GROUP_NEXT_ELEMENT (stmtinfo_a) = NULL;
189 /* Function vect_update_interleaving_chain.
191 For two data-refs DRA and DRB that are a part of a chain interleaved data
192 accesses, update the interleaving chain. DRB's INIT is smaller than DRA's.
194 There are four possible cases:
195 1. New stmts - both DRA and DRB are not a part of any chain:
198 2. DRB is a part of a chain and DRA is not:
199 no need to update FIRST_DR
200 no need to insert DRB
201 insert DRA according to init
202 3. DRA is a part of a chain and DRB is not:
203 if (init of FIRST_DR > init of DRB)
205 NEXT(FIRST_DR) = previous FIRST_DR
207 insert DRB according to its init
208 4. both DRA and DRB are in some interleaving chains:
209 choose the chain with the smallest init of FIRST_DR
210 insert the nodes of the second chain into the first one. */
213 vect_update_interleaving_chain (struct data_reference *drb,
214 struct data_reference *dra)
216 stmt_vec_info stmtinfo_a = vinfo_for_stmt (DR_STMT (dra));
217 stmt_vec_info stmtinfo_b = vinfo_for_stmt (DR_STMT (drb));
218 tree next_init, init_dra_chain, init_drb_chain;
219 gimple first_a, first_b;
221 gimple node, prev, next, first_stmt;
223 /* 1. New stmts - both DRA and DRB are not a part of any chain. */
224 if (!GROUP_FIRST_ELEMENT (stmtinfo_a) && !GROUP_FIRST_ELEMENT (stmtinfo_b))
226 GROUP_FIRST_ELEMENT (stmtinfo_a) = DR_STMT (drb);
227 GROUP_FIRST_ELEMENT (stmtinfo_b) = DR_STMT (drb);
228 GROUP_NEXT_ELEMENT (stmtinfo_b) = DR_STMT (dra);
232 /* 2. DRB is a part of a chain and DRA is not. */
233 if (!GROUP_FIRST_ELEMENT (stmtinfo_a) && GROUP_FIRST_ELEMENT (stmtinfo_b))
235 GROUP_FIRST_ELEMENT (stmtinfo_a) = GROUP_FIRST_ELEMENT (stmtinfo_b);
236 /* Insert DRA into the chain of DRB. */
237 vect_insert_into_interleaving_chain (dra, drb);
241 /* 3. DRA is a part of a chain and DRB is not. */
242 if (GROUP_FIRST_ELEMENT (stmtinfo_a) && !GROUP_FIRST_ELEMENT (stmtinfo_b))
244 gimple old_first_stmt = GROUP_FIRST_ELEMENT (stmtinfo_a);
245 tree init_old = DR_INIT (STMT_VINFO_DATA_REF (vinfo_for_stmt (
249 if (tree_int_cst_compare (init_old, DR_INIT (drb)) > 0)
251 /* DRB's init is smaller than the init of the stmt previously marked
252 as the first stmt of the interleaving chain of DRA. Therefore, we
253 update FIRST_STMT and put DRB in the head of the list. */
254 GROUP_FIRST_ELEMENT (stmtinfo_b) = DR_STMT (drb);
255 GROUP_NEXT_ELEMENT (stmtinfo_b) = old_first_stmt;
257 /* Update all the stmts in the list to point to the new FIRST_STMT. */
258 tmp = old_first_stmt;
261 GROUP_FIRST_ELEMENT (vinfo_for_stmt (tmp)) = DR_STMT (drb);
262 tmp = GROUP_NEXT_ELEMENT (vinfo_for_stmt (tmp));
267 /* Insert DRB in the list of DRA. */
268 vect_insert_into_interleaving_chain (drb, dra);
269 GROUP_FIRST_ELEMENT (stmtinfo_b) = GROUP_FIRST_ELEMENT (stmtinfo_a);
274 /* 4. both DRA and DRB are in some interleaving chains. */
275 first_a = GROUP_FIRST_ELEMENT (stmtinfo_a);
276 first_b = GROUP_FIRST_ELEMENT (stmtinfo_b);
277 if (first_a == first_b)
279 init_dra_chain = DR_INIT (STMT_VINFO_DATA_REF (vinfo_for_stmt (first_a)));
280 init_drb_chain = DR_INIT (STMT_VINFO_DATA_REF (vinfo_for_stmt (first_b)));
282 if (tree_int_cst_compare (init_dra_chain, init_drb_chain) > 0)
284 /* Insert the nodes of DRA chain into the DRB chain.
285 After inserting a node, continue from this node of the DRB chain (don't
286 start from the beginning. */
287 node = GROUP_FIRST_ELEMENT (stmtinfo_a);
288 prev = GROUP_FIRST_ELEMENT (stmtinfo_b);
289 first_stmt = first_b;
293 /* Insert the nodes of DRB chain into the DRA chain.
294 After inserting a node, continue from this node of the DRA chain (don't
295 start from the beginning. */
296 node = GROUP_FIRST_ELEMENT (stmtinfo_b);
297 prev = GROUP_FIRST_ELEMENT (stmtinfo_a);
298 first_stmt = first_a;
303 node_init = DR_INIT (STMT_VINFO_DATA_REF (vinfo_for_stmt (node)));
304 next = GROUP_NEXT_ELEMENT (vinfo_for_stmt (prev));
307 next_init = DR_INIT (STMT_VINFO_DATA_REF (vinfo_for_stmt (next)));
308 if (tree_int_cst_compare (next_init, node_init) > 0)
311 GROUP_NEXT_ELEMENT (vinfo_for_stmt (prev)) = node;
312 GROUP_NEXT_ELEMENT (vinfo_for_stmt (node)) = next;
317 next = GROUP_NEXT_ELEMENT (vinfo_for_stmt (prev));
321 /* We got to the end of the list. Insert here. */
322 GROUP_NEXT_ELEMENT (vinfo_for_stmt (prev)) = node;
323 GROUP_NEXT_ELEMENT (vinfo_for_stmt (node)) = NULL;
326 GROUP_FIRST_ELEMENT (vinfo_for_stmt (node)) = first_stmt;
327 node = GROUP_NEXT_ELEMENT (vinfo_for_stmt (node));
331 /* Check dependence between DRA and DRB for basic block vectorization.
332 If the accesses share same bases and offsets, we can compare their initial
333 constant offsets to decide whether they differ or not. In case of a read-
334 write dependence we check that the load is before the store to ensure that
335 vectorization will not change the order of the accesses. */
338 vect_drs_dependent_in_basic_block (struct data_reference *dra,
339 struct data_reference *drb)
341 HOST_WIDE_INT type_size_a, type_size_b, init_a, init_b;
344 /* We only call this function for pairs of loads and stores, but we verify
346 if (DR_IS_READ (dra) == DR_IS_READ (drb))
348 if (DR_IS_READ (dra))
354 /* Check that the data-refs have same bases and offsets. If not, we can't
355 determine if they are dependent. */
356 if (!operand_equal_p (DR_BASE_ADDRESS (dra), DR_BASE_ADDRESS (drb), 0)
357 || !dr_equal_offsets_p (dra, drb))
360 /* Check the types. */
361 type_size_a = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dra))));
362 type_size_b = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (drb))));
364 if (type_size_a != type_size_b
365 || !types_compatible_p (TREE_TYPE (DR_REF (dra)),
366 TREE_TYPE (DR_REF (drb))))
369 init_a = TREE_INT_CST_LOW (DR_INIT (dra));
370 init_b = TREE_INT_CST_LOW (DR_INIT (drb));
372 /* Two different locations - no dependence. */
373 if (init_a != init_b)
376 /* We have a read-write dependence. Check that the load is before the store.
377 When we vectorize basic blocks, vector load can be only before
378 corresponding scalar load, and vector store can be only after its
379 corresponding scalar store. So the order of the acceses is preserved in
380 case the load is before the store. */
381 earlier_stmt = get_earlier_stmt (DR_STMT (dra), DR_STMT (drb));
382 if (DR_IS_READ (STMT_VINFO_DATA_REF (vinfo_for_stmt (earlier_stmt))))
389 /* Function vect_check_interleaving.
391 Check if DRA and DRB are a part of interleaving. In case they are, insert
392 DRA and DRB in an interleaving chain. */
395 vect_check_interleaving (struct data_reference *dra,
396 struct data_reference *drb)
398 HOST_WIDE_INT type_size_a, type_size_b, diff_mod_size, step, init_a, init_b;
400 /* Check that the data-refs have same first location (except init) and they
401 are both either store or load (not load and store). */
402 if (!operand_equal_p (DR_BASE_ADDRESS (dra), DR_BASE_ADDRESS (drb), 0)
403 || !dr_equal_offsets_p (dra, drb)
404 || !tree_int_cst_compare (DR_INIT (dra), DR_INIT (drb))
405 || DR_IS_READ (dra) != DR_IS_READ (drb))
409 1. data-refs are of the same type
410 2. their steps are equal
411 3. the step (if greater than zero) is greater than the difference between
413 type_size_a = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dra))));
414 type_size_b = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (drb))));
416 if (type_size_a != type_size_b
417 || tree_int_cst_compare (DR_STEP (dra), DR_STEP (drb))
418 || !types_compatible_p (TREE_TYPE (DR_REF (dra)),
419 TREE_TYPE (DR_REF (drb))))
422 init_a = TREE_INT_CST_LOW (DR_INIT (dra));
423 init_b = TREE_INT_CST_LOW (DR_INIT (drb));
424 step = TREE_INT_CST_LOW (DR_STEP (dra));
428 /* If init_a == init_b + the size of the type * k, we have an interleaving,
429 and DRB is accessed before DRA. */
430 diff_mod_size = (init_a - init_b) % type_size_a;
432 if (step && (init_a - init_b) > step)
435 if (diff_mod_size == 0)
437 vect_update_interleaving_chain (drb, dra);
438 if (vect_print_dump_info (REPORT_DR_DETAILS))
440 fprintf (vect_dump, "Detected interleaving ");
441 print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
442 fprintf (vect_dump, " and ");
443 print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
450 /* If init_b == init_a + the size of the type * k, we have an
451 interleaving, and DRA is accessed before DRB. */
452 diff_mod_size = (init_b - init_a) % type_size_a;
454 if (step && (init_b - init_a) > step)
457 if (diff_mod_size == 0)
459 vect_update_interleaving_chain (dra, drb);
460 if (vect_print_dump_info (REPORT_DR_DETAILS))
462 fprintf (vect_dump, "Detected interleaving ");
463 print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
464 fprintf (vect_dump, " and ");
465 print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
474 /* Check if data references pointed by DR_I and DR_J are same or
475 belong to same interleaving group. Return FALSE if drs are
476 different, otherwise return TRUE. */
479 vect_same_range_drs (data_reference_p dr_i, data_reference_p dr_j)
481 gimple stmt_i = DR_STMT (dr_i);
482 gimple stmt_j = DR_STMT (dr_j);
484 if (operand_equal_p (DR_REF (dr_i), DR_REF (dr_j), 0)
485 || (GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt_i))
486 && GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt_j))
487 && (GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt_i))
488 == GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt_j)))))
494 /* If address ranges represented by DDR_I and DDR_J are equal,
495 return TRUE, otherwise return FALSE. */
498 vect_vfa_range_equal (ddr_p ddr_i, ddr_p ddr_j)
500 if ((vect_same_range_drs (DDR_A (ddr_i), DDR_A (ddr_j))
501 && vect_same_range_drs (DDR_B (ddr_i), DDR_B (ddr_j)))
502 || (vect_same_range_drs (DDR_A (ddr_i), DDR_B (ddr_j))
503 && vect_same_range_drs (DDR_B (ddr_i), DDR_A (ddr_j))))
509 /* Insert DDR into LOOP_VINFO list of ddrs that may alias and need to be
510 tested at run-time. Return TRUE if DDR was successfully inserted.
511 Return false if versioning is not supported. */
514 vect_mark_for_runtime_alias_test (ddr_p ddr, loop_vec_info loop_vinfo)
516 struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
518 if ((unsigned) PARAM_VALUE (PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS) == 0)
521 if (vect_print_dump_info (REPORT_DR_DETAILS))
523 fprintf (vect_dump, "mark for run-time aliasing test between ");
524 print_generic_expr (vect_dump, DR_REF (DDR_A (ddr)), TDF_SLIM);
525 fprintf (vect_dump, " and ");
526 print_generic_expr (vect_dump, DR_REF (DDR_B (ddr)), TDF_SLIM);
529 if (optimize_loop_nest_for_size_p (loop))
531 if (vect_print_dump_info (REPORT_DR_DETAILS))
532 fprintf (vect_dump, "versioning not supported when optimizing for size.");
536 /* FORNOW: We don't support versioning with outer-loop vectorization. */
539 if (vect_print_dump_info (REPORT_DR_DETAILS))
540 fprintf (vect_dump, "versioning not yet supported for outer-loops.");
544 VEC_safe_push (ddr_p, heap, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo), ddr);
549 /* Function vect_analyze_data_ref_dependence.
551 Return TRUE if there (might) exist a dependence between a memory-reference
552 DRA and a memory-reference DRB. When versioning for alias may check a
553 dependence at run-time, return FALSE. Adjust *MAX_VF according to
554 the data dependence. */
557 vect_analyze_data_ref_dependence (struct data_dependence_relation *ddr,
558 loop_vec_info loop_vinfo, int *max_vf)
561 struct loop *loop = NULL;
562 struct data_reference *dra = DDR_A (ddr);
563 struct data_reference *drb = DDR_B (ddr);
564 stmt_vec_info stmtinfo_a = vinfo_for_stmt (DR_STMT (dra));
565 stmt_vec_info stmtinfo_b = vinfo_for_stmt (DR_STMT (drb));
566 lambda_vector dist_v;
567 unsigned int loop_depth;
569 /* Don't bother to analyze statements marked as unvectorizable. */
570 if (!STMT_VINFO_VECTORIZABLE (stmtinfo_a)
571 || !STMT_VINFO_VECTORIZABLE (stmtinfo_b))
574 if (DDR_ARE_DEPENDENT (ddr) == chrec_known)
576 /* Independent data accesses. */
577 vect_check_interleaving (dra, drb);
582 loop = LOOP_VINFO_LOOP (loop_vinfo);
584 if ((DR_IS_READ (dra) && DR_IS_READ (drb) && loop_vinfo) || dra == drb)
587 if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know)
593 if (vect_print_dump_info (REPORT_DR_DETAILS))
595 fprintf (vect_dump, "versioning for alias required: "
596 "can't determine dependence between ");
597 print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
598 fprintf (vect_dump, " and ");
599 print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
602 /* Add to list of ddrs that need to be tested at run-time. */
603 return !vect_mark_for_runtime_alias_test (ddr, loop_vinfo);
606 /* When vectorizing a basic block unknown depnedence can still mean
608 if (vect_check_interleaving (dra, drb))
611 /* Read-read is OK (we need this check here, after checking for
613 if (DR_IS_READ (dra) && DR_IS_READ (drb))
616 if (vect_print_dump_info (REPORT_DR_DETAILS))
618 fprintf (vect_dump, "can't determine dependence between ");
619 print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
620 fprintf (vect_dump, " and ");
621 print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
624 /* We do not vectorize basic blocks with write-write dependencies. */
625 if (DR_IS_WRITE (dra) && DR_IS_WRITE (drb))
628 /* Check that it's not a load-after-store dependence. */
629 earlier_stmt = get_earlier_stmt (DR_STMT (dra), DR_STMT (drb));
630 if (DR_IS_WRITE (STMT_VINFO_DATA_REF (vinfo_for_stmt (earlier_stmt))))
636 /* Versioning for alias is not yet supported for basic block SLP, and
637 dependence distance is unapplicable, hence, in case of known data
638 dependence, basic block vectorization is impossible for now. */
641 if (dra != drb && vect_check_interleaving (dra, drb))
644 if (vect_print_dump_info (REPORT_DR_DETAILS))
646 fprintf (vect_dump, "determined dependence between ");
647 print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
648 fprintf (vect_dump, " and ");
649 print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
652 /* Do not vectorize basic blcoks with write-write dependences. */
653 if (DR_IS_WRITE (dra) && DR_IS_WRITE (drb))
656 /* Check if this dependence is allowed in basic block vectorization. */
657 return vect_drs_dependent_in_basic_block (dra, drb);
660 /* Loop-based vectorization and known data dependence. */
661 if (DDR_NUM_DIST_VECTS (ddr) == 0)
663 if (vect_print_dump_info (REPORT_DR_DETAILS))
665 fprintf (vect_dump, "versioning for alias required: bad dist vector for ");
666 print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
667 fprintf (vect_dump, " and ");
668 print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
670 /* Add to list of ddrs that need to be tested at run-time. */
671 return !vect_mark_for_runtime_alias_test (ddr, loop_vinfo);
674 loop_depth = index_in_loop_nest (loop->num, DDR_LOOP_NEST (ddr));
675 FOR_EACH_VEC_ELT (lambda_vector, DDR_DIST_VECTS (ddr), i, dist_v)
677 int dist = dist_v[loop_depth];
679 if (vect_print_dump_info (REPORT_DR_DETAILS))
680 fprintf (vect_dump, "dependence distance = %d.", dist);
684 if (vect_print_dump_info (REPORT_DR_DETAILS))
686 fprintf (vect_dump, "dependence distance == 0 between ");
687 print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
688 fprintf (vect_dump, " and ");
689 print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
692 /* For interleaving, mark that there is a read-write dependency if
693 necessary. We check before that one of the data-refs is store. */
694 if (DR_IS_READ (dra))
695 GROUP_READ_WRITE_DEPENDENCE (stmtinfo_a) = true;
698 if (DR_IS_READ (drb))
699 GROUP_READ_WRITE_DEPENDENCE (stmtinfo_b) = true;
705 if (dist > 0 && DDR_REVERSED_P (ddr))
707 /* If DDR_REVERSED_P the order of the data-refs in DDR was
708 reversed (to make distance vector positive), and the actual
709 distance is negative. */
710 if (vect_print_dump_info (REPORT_DR_DETAILS))
711 fprintf (vect_dump, "dependence distance negative.");
716 && abs (dist) < *max_vf)
718 /* The dependence distance requires reduction of the maximal
719 vectorization factor. */
720 *max_vf = abs (dist);
721 if (vect_print_dump_info (REPORT_DR_DETAILS))
722 fprintf (vect_dump, "adjusting maximal vectorization factor to %i",
726 if (abs (dist) >= *max_vf)
728 /* Dependence distance does not create dependence, as far as
729 vectorization is concerned, in this case. */
730 if (vect_print_dump_info (REPORT_DR_DETAILS))
731 fprintf (vect_dump, "dependence distance >= VF.");
735 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
737 fprintf (vect_dump, "not vectorized, possible dependence "
738 "between data-refs ");
739 print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
740 fprintf (vect_dump, " and ");
741 print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
750 /* Function vect_analyze_data_ref_dependences.
752 Examine all the data references in the loop, and make sure there do not
753 exist any data dependences between them. Set *MAX_VF according to
754 the maximum vectorization factor the data dependences allow. */
757 vect_analyze_data_ref_dependences (loop_vec_info loop_vinfo,
758 bb_vec_info bb_vinfo, int *max_vf)
761 VEC (ddr_p, heap) *ddrs = NULL;
762 struct data_dependence_relation *ddr;
764 if (vect_print_dump_info (REPORT_DETAILS))
765 fprintf (vect_dump, "=== vect_analyze_dependences ===");
768 ddrs = LOOP_VINFO_DDRS (loop_vinfo);
770 ddrs = BB_VINFO_DDRS (bb_vinfo);
772 FOR_EACH_VEC_ELT (ddr_p, ddrs, i, ddr)
773 if (vect_analyze_data_ref_dependence (ddr, loop_vinfo, max_vf))
780 /* Function vect_compute_data_ref_alignment
782 Compute the misalignment of the data reference DR.
785 1. If during the misalignment computation it is found that the data reference
786 cannot be vectorized then false is returned.
787 2. DR_MISALIGNMENT (DR) is defined.
789 FOR NOW: No analysis is actually performed. Misalignment is calculated
790 only for trivial cases. TODO. */
793 vect_compute_data_ref_alignment (struct data_reference *dr)
795 gimple stmt = DR_STMT (dr);
796 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
797 loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
798 struct loop *loop = NULL;
799 tree ref = DR_REF (dr);
801 tree base, base_addr;
804 tree aligned_to, alignment;
806 if (vect_print_dump_info (REPORT_DETAILS))
807 fprintf (vect_dump, "vect_compute_data_ref_alignment:");
810 loop = LOOP_VINFO_LOOP (loop_vinfo);
812 /* Initialize misalignment to unknown. */
813 SET_DR_MISALIGNMENT (dr, -1);
815 misalign = DR_INIT (dr);
816 aligned_to = DR_ALIGNED_TO (dr);
817 base_addr = DR_BASE_ADDRESS (dr);
818 vectype = STMT_VINFO_VECTYPE (stmt_info);
820 /* In case the dataref is in an inner-loop of the loop that is being
821 vectorized (LOOP), we use the base and misalignment information
822 relative to the outer-loop (LOOP). This is ok only if the misalignment
823 stays the same throughout the execution of the inner-loop, which is why
824 we have to check that the stride of the dataref in the inner-loop evenly
825 divides by the vector size. */
826 if (loop && nested_in_vect_loop_p (loop, stmt))
828 tree step = DR_STEP (dr);
829 HOST_WIDE_INT dr_step = TREE_INT_CST_LOW (step);
831 if (dr_step % GET_MODE_SIZE (TYPE_MODE (vectype)) == 0)
833 if (vect_print_dump_info (REPORT_ALIGNMENT))
834 fprintf (vect_dump, "inner step divides the vector-size.");
835 misalign = STMT_VINFO_DR_INIT (stmt_info);
836 aligned_to = STMT_VINFO_DR_ALIGNED_TO (stmt_info);
837 base_addr = STMT_VINFO_DR_BASE_ADDRESS (stmt_info);
841 if (vect_print_dump_info (REPORT_ALIGNMENT))
842 fprintf (vect_dump, "inner step doesn't divide the vector-size.");
843 misalign = NULL_TREE;
847 base = build_fold_indirect_ref (base_addr);
848 alignment = ssize_int (TYPE_ALIGN (vectype)/BITS_PER_UNIT);
850 if ((aligned_to && tree_int_cst_compare (aligned_to, alignment) < 0)
853 if (vect_print_dump_info (REPORT_ALIGNMENT))
855 fprintf (vect_dump, "Unknown alignment for access: ");
856 print_generic_expr (vect_dump, base, TDF_SLIM);
862 && tree_int_cst_compare (ssize_int (DECL_ALIGN_UNIT (base)),
864 || (TREE_CODE (base_addr) == SSA_NAME
865 && tree_int_cst_compare (ssize_int (TYPE_ALIGN_UNIT (TREE_TYPE (
866 TREE_TYPE (base_addr)))),
868 || (get_pointer_alignment (base_addr) >= TYPE_ALIGN (vectype)))
871 base_aligned = false;
875 /* Do not change the alignment of global variables if
876 flag_section_anchors is enabled. */
877 if (!vect_can_force_dr_alignment_p (base, TYPE_ALIGN (vectype))
878 || (TREE_STATIC (base) && flag_section_anchors))
880 if (vect_print_dump_info (REPORT_DETAILS))
882 fprintf (vect_dump, "can't force alignment of ref: ");
883 print_generic_expr (vect_dump, ref, TDF_SLIM);
888 /* Force the alignment of the decl.
889 NOTE: This is the only change to the code we make during
890 the analysis phase, before deciding to vectorize the loop. */
891 if (vect_print_dump_info (REPORT_DETAILS))
893 fprintf (vect_dump, "force alignment of ");
894 print_generic_expr (vect_dump, ref, TDF_SLIM);
897 DECL_ALIGN (base) = TYPE_ALIGN (vectype);
898 DECL_USER_ALIGN (base) = 1;
901 /* At this point we assume that the base is aligned. */
902 gcc_assert (base_aligned
903 || (TREE_CODE (base) == VAR_DECL
904 && DECL_ALIGN (base) >= TYPE_ALIGN (vectype)));
906 /* If this is a backward running DR then first access in the larger
907 vectype actually is N-1 elements before the address in the DR.
908 Adjust misalign accordingly. */
909 if (tree_int_cst_compare (DR_STEP (dr), size_zero_node) < 0)
911 tree offset = ssize_int (TYPE_VECTOR_SUBPARTS (vectype) - 1);
912 /* DR_STEP(dr) is the same as -TYPE_SIZE of the scalar type,
913 otherwise we wouldn't be here. */
914 offset = fold_build2 (MULT_EXPR, ssizetype, offset, DR_STEP (dr));
915 /* PLUS because DR_STEP was negative. */
916 misalign = size_binop (PLUS_EXPR, misalign, offset);
919 /* Modulo alignment. */
920 misalign = size_binop (FLOOR_MOD_EXPR, misalign, alignment);
922 if (!host_integerp (misalign, 1))
924 /* Negative or overflowed misalignment value. */
925 if (vect_print_dump_info (REPORT_DETAILS))
926 fprintf (vect_dump, "unexpected misalign value");
930 SET_DR_MISALIGNMENT (dr, TREE_INT_CST_LOW (misalign));
932 if (vect_print_dump_info (REPORT_DETAILS))
934 fprintf (vect_dump, "misalign = %d bytes of ref ", DR_MISALIGNMENT (dr));
935 print_generic_expr (vect_dump, ref, TDF_SLIM);
942 /* Function vect_compute_data_refs_alignment
944 Compute the misalignment of data references in the loop.
945 Return FALSE if a data reference is found that cannot be vectorized. */
948 vect_compute_data_refs_alignment (loop_vec_info loop_vinfo,
949 bb_vec_info bb_vinfo)
951 VEC (data_reference_p, heap) *datarefs;
952 struct data_reference *dr;
956 datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
958 datarefs = BB_VINFO_DATAREFS (bb_vinfo);
960 FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
961 if (STMT_VINFO_VECTORIZABLE (vinfo_for_stmt (DR_STMT (dr)))
962 && !vect_compute_data_ref_alignment (dr))
966 /* Mark unsupported statement as unvectorizable. */
967 STMT_VINFO_VECTORIZABLE (vinfo_for_stmt (DR_STMT (dr))) = false;
978 /* Function vect_update_misalignment_for_peel
980 DR - the data reference whose misalignment is to be adjusted.
981 DR_PEEL - the data reference whose misalignment is being made
982 zero in the vector loop by the peel.
983 NPEEL - the number of iterations in the peel loop if the misalignment
984 of DR_PEEL is known at compile time. */
987 vect_update_misalignment_for_peel (struct data_reference *dr,
988 struct data_reference *dr_peel, int npeel)
991 VEC(dr_p,heap) *same_align_drs;
992 struct data_reference *current_dr;
993 int dr_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (dr))));
994 int dr_peel_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (dr_peel))));
995 stmt_vec_info stmt_info = vinfo_for_stmt (DR_STMT (dr));
996 stmt_vec_info peel_stmt_info = vinfo_for_stmt (DR_STMT (dr_peel));
998 /* For interleaved data accesses the step in the loop must be multiplied by
999 the size of the interleaving group. */
1000 if (STMT_VINFO_STRIDED_ACCESS (stmt_info))
1001 dr_size *= GROUP_SIZE (vinfo_for_stmt (GROUP_FIRST_ELEMENT (stmt_info)));
1002 if (STMT_VINFO_STRIDED_ACCESS (peel_stmt_info))
1003 dr_peel_size *= GROUP_SIZE (peel_stmt_info);
1005 /* It can be assumed that the data refs with the same alignment as dr_peel
1006 are aligned in the vector loop. */
1008 = STMT_VINFO_SAME_ALIGN_REFS (vinfo_for_stmt (DR_STMT (dr_peel)));
1009 FOR_EACH_VEC_ELT (dr_p, same_align_drs, i, current_dr)
1011 if (current_dr != dr)
1013 gcc_assert (DR_MISALIGNMENT (dr) / dr_size ==
1014 DR_MISALIGNMENT (dr_peel) / dr_peel_size);
1015 SET_DR_MISALIGNMENT (dr, 0);
1019 if (known_alignment_for_access_p (dr)
1020 && known_alignment_for_access_p (dr_peel))
1022 bool negative = tree_int_cst_compare (DR_STEP (dr), size_zero_node) < 0;
1023 int misal = DR_MISALIGNMENT (dr);
1024 tree vectype = STMT_VINFO_VECTYPE (stmt_info);
1025 misal += negative ? -npeel * dr_size : npeel * dr_size;
1026 misal &= GET_MODE_SIZE (TYPE_MODE (vectype)) - 1;
1027 SET_DR_MISALIGNMENT (dr, misal);
1031 if (vect_print_dump_info (REPORT_DETAILS))
1032 fprintf (vect_dump, "Setting misalignment to -1.");
1033 SET_DR_MISALIGNMENT (dr, -1);
1037 /* Function vect_verify_datarefs_alignment
1039 Return TRUE if all data references in the loop can be
1040 handled with respect to alignment. */
1043 vect_verify_datarefs_alignment (loop_vec_info loop_vinfo, bb_vec_info bb_vinfo)
1045 VEC (data_reference_p, heap) *datarefs;
1046 struct data_reference *dr;
1047 enum dr_alignment_support supportable_dr_alignment;
1051 datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
1053 datarefs = BB_VINFO_DATAREFS (bb_vinfo);
1055 FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
1057 gimple stmt = DR_STMT (dr);
1058 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
1060 /* For interleaving, only the alignment of the first access matters.
1061 Skip statements marked as not vectorizable. */
1062 if ((STMT_VINFO_STRIDED_ACCESS (stmt_info)
1063 && GROUP_FIRST_ELEMENT (stmt_info) != stmt)
1064 || !STMT_VINFO_VECTORIZABLE (stmt_info))
1067 supportable_dr_alignment = vect_supportable_dr_alignment (dr, false);
1068 if (!supportable_dr_alignment)
1070 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
1072 if (DR_IS_READ (dr))
1074 "not vectorized: unsupported unaligned load.");
1077 "not vectorized: unsupported unaligned store.");
1079 print_generic_expr (vect_dump, DR_REF (dr), TDF_SLIM);
1083 if (supportable_dr_alignment != dr_aligned
1084 && vect_print_dump_info (REPORT_ALIGNMENT))
1085 fprintf (vect_dump, "Vectorizing an unaligned access.");
1091 /* Function vector_alignment_reachable_p
1093 Return true if vector alignment for DR is reachable by peeling
1094 a few loop iterations. Return false otherwise. */
1097 vector_alignment_reachable_p (struct data_reference *dr)
1099 gimple stmt = DR_STMT (dr);
1100 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
1101 tree vectype = STMT_VINFO_VECTYPE (stmt_info);
1103 if (STMT_VINFO_STRIDED_ACCESS (stmt_info))
1105 /* For interleaved access we peel only if number of iterations in
1106 the prolog loop ({VF - misalignment}), is a multiple of the
1107 number of the interleaved accesses. */
1108 int elem_size, mis_in_elements;
1109 int nelements = TYPE_VECTOR_SUBPARTS (vectype);
1111 /* FORNOW: handle only known alignment. */
1112 if (!known_alignment_for_access_p (dr))
1115 elem_size = GET_MODE_SIZE (TYPE_MODE (vectype)) / nelements;
1116 mis_in_elements = DR_MISALIGNMENT (dr) / elem_size;
1118 if ((nelements - mis_in_elements) % GROUP_SIZE (stmt_info))
1122 /* If misalignment is known at the compile time then allow peeling
1123 only if natural alignment is reachable through peeling. */
1124 if (known_alignment_for_access_p (dr) && !aligned_access_p (dr))
1126 HOST_WIDE_INT elmsize =
1127 int_cst_value (TYPE_SIZE_UNIT (TREE_TYPE (vectype)));
1128 if (vect_print_dump_info (REPORT_DETAILS))
1130 fprintf (vect_dump, "data size =" HOST_WIDE_INT_PRINT_DEC, elmsize);
1131 fprintf (vect_dump, ". misalignment = %d. ", DR_MISALIGNMENT (dr));
1133 if (DR_MISALIGNMENT (dr) % elmsize)
1135 if (vect_print_dump_info (REPORT_DETAILS))
1136 fprintf (vect_dump, "data size does not divide the misalignment.\n");
1141 if (!known_alignment_for_access_p (dr))
1143 tree type = (TREE_TYPE (DR_REF (dr)));
1144 tree ba = DR_BASE_OBJECT (dr);
1145 bool is_packed = false;
1148 is_packed = contains_packed_reference (ba);
1150 if (compare_tree_int (TYPE_SIZE (type), TYPE_ALIGN (type)) > 0)
1153 if (vect_print_dump_info (REPORT_DETAILS))
1154 fprintf (vect_dump, "Unknown misalignment, is_packed = %d",is_packed);
1155 if (targetm.vectorize.vector_alignment_reachable (type, is_packed))
1165 /* Calculate the cost of the memory access represented by DR. */
1168 vect_get_data_access_cost (struct data_reference *dr,
1169 unsigned int *inside_cost,
1170 unsigned int *outside_cost)
1172 gimple stmt = DR_STMT (dr);
1173 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
1174 int nunits = TYPE_VECTOR_SUBPARTS (STMT_VINFO_VECTYPE (stmt_info));
1175 loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
1176 int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
1177 int ncopies = vf / nunits;
1178 bool supportable_dr_alignment = vect_supportable_dr_alignment (dr, true);
1180 if (!supportable_dr_alignment)
1181 *inside_cost = VECT_MAX_COST;
1184 if (DR_IS_READ (dr))
1185 vect_get_load_cost (dr, ncopies, true, inside_cost, outside_cost);
1187 vect_get_store_cost (dr, ncopies, inside_cost);
1190 if (vect_print_dump_info (REPORT_COST))
1191 fprintf (vect_dump, "vect_get_data_access_cost: inside_cost = %d, "
1192 "outside_cost = %d.", *inside_cost, *outside_cost);
1197 vect_peeling_hash (const void *elem)
1199 const struct _vect_peel_info *peel_info;
1201 peel_info = (const struct _vect_peel_info *) elem;
1202 return (hashval_t) peel_info->npeel;
1207 vect_peeling_hash_eq (const void *elem1, const void *elem2)
1209 const struct _vect_peel_info *a, *b;
1211 a = (const struct _vect_peel_info *) elem1;
1212 b = (const struct _vect_peel_info *) elem2;
1213 return (a->npeel == b->npeel);
1217 /* Insert DR into peeling hash table with NPEEL as key. */
1220 vect_peeling_hash_insert (loop_vec_info loop_vinfo, struct data_reference *dr,
1223 struct _vect_peel_info elem, *slot;
1225 bool supportable_dr_alignment = vect_supportable_dr_alignment (dr, true);
1228 slot = (vect_peel_info) htab_find (LOOP_VINFO_PEELING_HTAB (loop_vinfo),
1234 slot = XNEW (struct _vect_peel_info);
1235 slot->npeel = npeel;
1238 new_slot = htab_find_slot (LOOP_VINFO_PEELING_HTAB (loop_vinfo), slot,
1243 if (!supportable_dr_alignment && !flag_vect_cost_model)
1244 slot->count += VECT_MAX_COST;
1248 /* Traverse peeling hash table to find peeling option that aligns maximum
1249 number of data accesses. */
1252 vect_peeling_hash_get_most_frequent (void **slot, void *data)
1254 vect_peel_info elem = (vect_peel_info) *slot;
1255 vect_peel_extended_info max = (vect_peel_extended_info) data;
1257 if (elem->count > max->peel_info.count
1258 || (elem->count == max->peel_info.count
1259 && max->peel_info.npeel > elem->npeel))
1261 max->peel_info.npeel = elem->npeel;
1262 max->peel_info.count = elem->count;
1263 max->peel_info.dr = elem->dr;
1270 /* Traverse peeling hash table and calculate cost for each peeling option.
1271 Find the one with the lowest cost. */
1274 vect_peeling_hash_get_lowest_cost (void **slot, void *data)
1276 vect_peel_info elem = (vect_peel_info) *slot;
1277 vect_peel_extended_info min = (vect_peel_extended_info) data;
1278 int save_misalignment, dummy;
1279 unsigned int inside_cost = 0, outside_cost = 0, i;
1280 gimple stmt = DR_STMT (elem->dr);
1281 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
1282 loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
1283 VEC (data_reference_p, heap) *datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
1284 struct data_reference *dr;
1286 FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
1288 stmt = DR_STMT (dr);
1289 stmt_info = vinfo_for_stmt (stmt);
1290 /* For interleaving, only the alignment of the first access
1292 if (STMT_VINFO_STRIDED_ACCESS (stmt_info)
1293 && GROUP_FIRST_ELEMENT (stmt_info) != stmt)
1296 save_misalignment = DR_MISALIGNMENT (dr);
1297 vect_update_misalignment_for_peel (dr, elem->dr, elem->npeel);
1298 vect_get_data_access_cost (dr, &inside_cost, &outside_cost);
1299 SET_DR_MISALIGNMENT (dr, save_misalignment);
1302 outside_cost += vect_get_known_peeling_cost (loop_vinfo, elem->npeel, &dummy,
1303 vect_get_single_scalar_iteraion_cost (loop_vinfo));
1305 if (inside_cost < min->inside_cost
1306 || (inside_cost == min->inside_cost && outside_cost < min->outside_cost))
1308 min->inside_cost = inside_cost;
1309 min->outside_cost = outside_cost;
1310 min->peel_info.dr = elem->dr;
1311 min->peel_info.npeel = elem->npeel;
1318 /* Choose best peeling option by traversing peeling hash table and either
1319 choosing an option with the lowest cost (if cost model is enabled) or the
1320 option that aligns as many accesses as possible. */
1322 static struct data_reference *
1323 vect_peeling_hash_choose_best_peeling (loop_vec_info loop_vinfo,
1324 unsigned int *npeel)
1326 struct _vect_peel_extended_info res;
1328 res.peel_info.dr = NULL;
1330 if (flag_vect_cost_model)
1332 res.inside_cost = INT_MAX;
1333 res.outside_cost = INT_MAX;
1334 htab_traverse (LOOP_VINFO_PEELING_HTAB (loop_vinfo),
1335 vect_peeling_hash_get_lowest_cost, &res);
1339 res.peel_info.count = 0;
1340 htab_traverse (LOOP_VINFO_PEELING_HTAB (loop_vinfo),
1341 vect_peeling_hash_get_most_frequent, &res);
1344 *npeel = res.peel_info.npeel;
1345 return res.peel_info.dr;
1349 /* Function vect_enhance_data_refs_alignment
1351 This pass will use loop versioning and loop peeling in order to enhance
1352 the alignment of data references in the loop.
1354 FOR NOW: we assume that whatever versioning/peeling takes place, only the
1355 original loop is to be vectorized. Any other loops that are created by
1356 the transformations performed in this pass - are not supposed to be
1357 vectorized. This restriction will be relaxed.
1359 This pass will require a cost model to guide it whether to apply peeling
1360 or versioning or a combination of the two. For example, the scheme that
1361 intel uses when given a loop with several memory accesses, is as follows:
1362 choose one memory access ('p') which alignment you want to force by doing
1363 peeling. Then, either (1) generate a loop in which 'p' is aligned and all
1364 other accesses are not necessarily aligned, or (2) use loop versioning to
1365 generate one loop in which all accesses are aligned, and another loop in
1366 which only 'p' is necessarily aligned.
1368 ("Automatic Intra-Register Vectorization for the Intel Architecture",
1369 Aart J.C. Bik, Milind Girkar, Paul M. Grey and Ximmin Tian, International
1370 Journal of Parallel Programming, Vol. 30, No. 2, April 2002.)
1372 Devising a cost model is the most critical aspect of this work. It will
1373 guide us on which access to peel for, whether to use loop versioning, how
1374 many versions to create, etc. The cost model will probably consist of
1375 generic considerations as well as target specific considerations (on
1376 powerpc for example, misaligned stores are more painful than misaligned
1379 Here are the general steps involved in alignment enhancements:
1381 -- original loop, before alignment analysis:
1382 for (i=0; i<N; i++){
1383 x = q[i]; # DR_MISALIGNMENT(q) = unknown
1384 p[i] = y; # DR_MISALIGNMENT(p) = unknown
1387 -- After vect_compute_data_refs_alignment:
1388 for (i=0; i<N; i++){
1389 x = q[i]; # DR_MISALIGNMENT(q) = 3
1390 p[i] = y; # DR_MISALIGNMENT(p) = unknown
1393 -- Possibility 1: we do loop versioning:
1395 for (i=0; i<N; i++){ # loop 1A
1396 x = q[i]; # DR_MISALIGNMENT(q) = 3
1397 p[i] = y; # DR_MISALIGNMENT(p) = 0
1401 for (i=0; i<N; i++){ # loop 1B
1402 x = q[i]; # DR_MISALIGNMENT(q) = 3
1403 p[i] = y; # DR_MISALIGNMENT(p) = unaligned
1407 -- Possibility 2: we do loop peeling:
1408 for (i = 0; i < 3; i++){ # (scalar loop, not to be vectorized).
1412 for (i = 3; i < N; i++){ # loop 2A
1413 x = q[i]; # DR_MISALIGNMENT(q) = 0
1414 p[i] = y; # DR_MISALIGNMENT(p) = unknown
1417 -- Possibility 3: combination of loop peeling and versioning:
1418 for (i = 0; i < 3; i++){ # (scalar loop, not to be vectorized).
1423 for (i = 3; i<N; i++){ # loop 3A
1424 x = q[i]; # DR_MISALIGNMENT(q) = 0
1425 p[i] = y; # DR_MISALIGNMENT(p) = 0
1429 for (i = 3; i<N; i++){ # loop 3B
1430 x = q[i]; # DR_MISALIGNMENT(q) = 0
1431 p[i] = y; # DR_MISALIGNMENT(p) = unaligned
1435 These loops are later passed to loop_transform to be vectorized. The
1436 vectorizer will use the alignment information to guide the transformation
1437 (whether to generate regular loads/stores, or with special handling for
1441 vect_enhance_data_refs_alignment (loop_vec_info loop_vinfo)
1443 VEC (data_reference_p, heap) *datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
1444 struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
1445 enum dr_alignment_support supportable_dr_alignment;
1446 struct data_reference *dr0 = NULL, *first_store = NULL;
1447 struct data_reference *dr;
1449 bool do_peeling = false;
1450 bool do_versioning = false;
1453 stmt_vec_info stmt_info;
1454 int vect_versioning_for_alias_required;
1455 unsigned int npeel = 0;
1456 bool all_misalignments_unknown = true;
1457 unsigned int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
1458 unsigned possible_npeel_number = 1;
1460 unsigned int nelements, mis, same_align_drs_max = 0;
1462 if (vect_print_dump_info (REPORT_DETAILS))
1463 fprintf (vect_dump, "=== vect_enhance_data_refs_alignment ===");
1465 /* While cost model enhancements are expected in the future, the high level
1466 view of the code at this time is as follows:
1468 A) If there is a misaligned access then see if peeling to align
1469 this access can make all data references satisfy
1470 vect_supportable_dr_alignment. If so, update data structures
1471 as needed and return true.
1473 B) If peeling wasn't possible and there is a data reference with an
1474 unknown misalignment that does not satisfy vect_supportable_dr_alignment
1475 then see if loop versioning checks can be used to make all data
1476 references satisfy vect_supportable_dr_alignment. If so, update
1477 data structures as needed and return true.
1479 C) If neither peeling nor versioning were successful then return false if
1480 any data reference does not satisfy vect_supportable_dr_alignment.
1482 D) Return true (all data references satisfy vect_supportable_dr_alignment).
1484 Note, Possibility 3 above (which is peeling and versioning together) is not
1485 being done at this time. */
1487 /* (1) Peeling to force alignment. */
1489 /* (1.1) Decide whether to perform peeling, and how many iterations to peel:
1491 + How many accesses will become aligned due to the peeling
1492 - How many accesses will become unaligned due to the peeling,
1493 and the cost of misaligned accesses.
1494 - The cost of peeling (the extra runtime checks, the increase
1497 FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
1499 stmt = DR_STMT (dr);
1500 stmt_info = vinfo_for_stmt (stmt);
1502 if (!STMT_VINFO_RELEVANT (stmt_info))
1505 /* For interleaving, only the alignment of the first access
1507 if (STMT_VINFO_STRIDED_ACCESS (stmt_info)
1508 && GROUP_FIRST_ELEMENT (stmt_info) != stmt)
1511 /* For invariant accesses there is nothing to enhance. */
1512 if (integer_zerop (DR_STEP (dr)))
1515 supportable_dr_alignment = vect_supportable_dr_alignment (dr, true);
1516 do_peeling = vector_alignment_reachable_p (dr);
1519 if (known_alignment_for_access_p (dr))
1521 unsigned int npeel_tmp;
1522 bool negative = tree_int_cst_compare (DR_STEP (dr),
1523 size_zero_node) < 0;
1525 /* Save info about DR in the hash table. */
1526 if (!LOOP_VINFO_PEELING_HTAB (loop_vinfo))
1527 LOOP_VINFO_PEELING_HTAB (loop_vinfo) =
1528 htab_create (1, vect_peeling_hash,
1529 vect_peeling_hash_eq, free);
1531 vectype = STMT_VINFO_VECTYPE (stmt_info);
1532 nelements = TYPE_VECTOR_SUBPARTS (vectype);
1533 mis = DR_MISALIGNMENT (dr) / GET_MODE_SIZE (TYPE_MODE (
1534 TREE_TYPE (DR_REF (dr))));
1535 npeel_tmp = (negative
1536 ? (mis - nelements) : (nelements - mis))
1539 /* For multiple types, it is possible that the bigger type access
1540 will have more than one peeling option. E.g., a loop with two
1541 types: one of size (vector size / 4), and the other one of
1542 size (vector size / 8). Vectorization factor will 8. If both
1543 access are misaligned by 3, the first one needs one scalar
1544 iteration to be aligned, and the second one needs 5. But the
1545 the first one will be aligned also by peeling 5 scalar
1546 iterations, and in that case both accesses will be aligned.
1547 Hence, except for the immediate peeling amount, we also want
1548 to try to add full vector size, while we don't exceed
1549 vectorization factor.
1550 We do this automtically for cost model, since we calculate cost
1551 for every peeling option. */
1552 if (!flag_vect_cost_model)
1553 possible_npeel_number = vf /nelements;
1555 /* Handle the aligned case. We may decide to align some other
1556 access, making DR unaligned. */
1557 if (DR_MISALIGNMENT (dr) == 0)
1560 if (!flag_vect_cost_model)
1561 possible_npeel_number++;
1564 for (j = 0; j < possible_npeel_number; j++)
1566 gcc_assert (npeel_tmp <= vf);
1567 vect_peeling_hash_insert (loop_vinfo, dr, npeel_tmp);
1568 npeel_tmp += nelements;
1571 all_misalignments_unknown = false;
1572 /* Data-ref that was chosen for the case that all the
1573 misalignments are unknown is not relevant anymore, since we
1574 have a data-ref with known alignment. */
1579 /* If we don't know all the misalignment values, we prefer
1580 peeling for data-ref that has maximum number of data-refs
1581 with the same alignment, unless the target prefers to align
1582 stores over load. */
1583 if (all_misalignments_unknown)
1585 if (same_align_drs_max < VEC_length (dr_p,
1586 STMT_VINFO_SAME_ALIGN_REFS (stmt_info))
1589 same_align_drs_max = VEC_length (dr_p,
1590 STMT_VINFO_SAME_ALIGN_REFS (stmt_info));
1594 if (!first_store && DR_IS_WRITE (dr))
1598 /* If there are both known and unknown misaligned accesses in the
1599 loop, we choose peeling amount according to the known
1603 if (!supportable_dr_alignment)
1606 if (!first_store && DR_IS_WRITE (dr))
1613 if (!aligned_access_p (dr))
1615 if (vect_print_dump_info (REPORT_DETAILS))
1616 fprintf (vect_dump, "vector alignment may not be reachable");
1623 vect_versioning_for_alias_required
1624 = LOOP_REQUIRES_VERSIONING_FOR_ALIAS (loop_vinfo);
1626 /* Temporarily, if versioning for alias is required, we disable peeling
1627 until we support peeling and versioning. Often peeling for alignment
1628 will require peeling for loop-bound, which in turn requires that we
1629 know how to adjust the loop ivs after the loop. */
1630 if (vect_versioning_for_alias_required
1631 || !vect_can_advance_ivs_p (loop_vinfo)
1632 || !slpeel_can_duplicate_loop_p (loop, single_exit (loop)))
1635 if (do_peeling && all_misalignments_unknown
1636 && vect_supportable_dr_alignment (dr0, false))
1639 /* Check if the target requires to prefer stores over loads, i.e., if
1640 misaligned stores are more expensive than misaligned loads (taking
1641 drs with same alignment into account). */
1642 if (first_store && DR_IS_READ (dr0))
1644 unsigned int load_inside_cost = 0, load_outside_cost = 0;
1645 unsigned int store_inside_cost = 0, store_outside_cost = 0;
1646 unsigned int load_inside_penalty = 0, load_outside_penalty = 0;
1647 unsigned int store_inside_penalty = 0, store_outside_penalty = 0;
1649 vect_get_data_access_cost (dr0, &load_inside_cost,
1650 &load_outside_cost);
1651 vect_get_data_access_cost (first_store, &store_inside_cost,
1652 &store_outside_cost);
1654 /* Calculate the penalty for leaving FIRST_STORE unaligned (by
1655 aligning the load DR0). */
1656 load_inside_penalty = store_inside_cost;
1657 load_outside_penalty = store_outside_cost;
1658 for (i = 0; VEC_iterate (dr_p, STMT_VINFO_SAME_ALIGN_REFS
1659 (vinfo_for_stmt (DR_STMT (first_store))),
1662 if (DR_IS_READ (dr))
1664 load_inside_penalty += load_inside_cost;
1665 load_outside_penalty += load_outside_cost;
1669 load_inside_penalty += store_inside_cost;
1670 load_outside_penalty += store_outside_cost;
1673 /* Calculate the penalty for leaving DR0 unaligned (by
1674 aligning the FIRST_STORE). */
1675 store_inside_penalty = load_inside_cost;
1676 store_outside_penalty = load_outside_cost;
1677 for (i = 0; VEC_iterate (dr_p, STMT_VINFO_SAME_ALIGN_REFS
1678 (vinfo_for_stmt (DR_STMT (dr0))),
1681 if (DR_IS_READ (dr))
1683 store_inside_penalty += load_inside_cost;
1684 store_outside_penalty += load_outside_cost;
1688 store_inside_penalty += store_inside_cost;
1689 store_outside_penalty += store_outside_cost;
1692 if (load_inside_penalty > store_inside_penalty
1693 || (load_inside_penalty == store_inside_penalty
1694 && load_outside_penalty > store_outside_penalty))
1698 /* In case there are only loads with different unknown misalignments, use
1699 peeling only if it may help to align other accesses in the loop. */
1700 if (!first_store && !VEC_length (dr_p, STMT_VINFO_SAME_ALIGN_REFS
1701 (vinfo_for_stmt (DR_STMT (dr0))))
1702 && vect_supportable_dr_alignment (dr0, false)
1703 != dr_unaligned_supported)
1707 if (do_peeling && !dr0)
1709 /* Peeling is possible, but there is no data access that is not supported
1710 unless aligned. So we try to choose the best possible peeling. */
1712 /* We should get here only if there are drs with known misalignment. */
1713 gcc_assert (!all_misalignments_unknown);
1715 /* Choose the best peeling from the hash table. */
1716 dr0 = vect_peeling_hash_choose_best_peeling (loop_vinfo, &npeel);
1723 stmt = DR_STMT (dr0);
1724 stmt_info = vinfo_for_stmt (stmt);
1725 vectype = STMT_VINFO_VECTYPE (stmt_info);
1726 nelements = TYPE_VECTOR_SUBPARTS (vectype);
1728 if (known_alignment_for_access_p (dr0))
1730 bool negative = tree_int_cst_compare (DR_STEP (dr0),
1731 size_zero_node) < 0;
1734 /* Since it's known at compile time, compute the number of
1735 iterations in the peeled loop (the peeling factor) for use in
1736 updating DR_MISALIGNMENT values. The peeling factor is the
1737 vectorization factor minus the misalignment as an element
1739 mis = DR_MISALIGNMENT (dr0);
1740 mis /= GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (dr0))));
1741 npeel = ((negative ? mis - nelements : nelements - mis)
1745 /* For interleaved data access every iteration accesses all the
1746 members of the group, therefore we divide the number of iterations
1747 by the group size. */
1748 stmt_info = vinfo_for_stmt (DR_STMT (dr0));
1749 if (STMT_VINFO_STRIDED_ACCESS (stmt_info))
1750 npeel /= GROUP_SIZE (stmt_info);
1752 if (vect_print_dump_info (REPORT_DETAILS))
1753 fprintf (vect_dump, "Try peeling by %d", npeel);
1756 /* Ensure that all data refs can be vectorized after the peel. */
1757 FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
1759 int save_misalignment;
1764 stmt = DR_STMT (dr);
1765 stmt_info = vinfo_for_stmt (stmt);
1766 /* For interleaving, only the alignment of the first access
1768 if (STMT_VINFO_STRIDED_ACCESS (stmt_info)
1769 && GROUP_FIRST_ELEMENT (stmt_info) != stmt)
1772 save_misalignment = DR_MISALIGNMENT (dr);
1773 vect_update_misalignment_for_peel (dr, dr0, npeel);
1774 supportable_dr_alignment = vect_supportable_dr_alignment (dr, false);
1775 SET_DR_MISALIGNMENT (dr, save_misalignment);
1777 if (!supportable_dr_alignment)
1784 if (do_peeling && known_alignment_for_access_p (dr0) && npeel == 0)
1786 stat = vect_verify_datarefs_alignment (loop_vinfo, NULL);
1795 /* (1.2) Update the DR_MISALIGNMENT of each data reference DR_i.
1796 If the misalignment of DR_i is identical to that of dr0 then set
1797 DR_MISALIGNMENT (DR_i) to zero. If the misalignment of DR_i and
1798 dr0 are known at compile time then increment DR_MISALIGNMENT (DR_i)
1799 by the peeling factor times the element size of DR_i (MOD the
1800 vectorization factor times the size). Otherwise, the
1801 misalignment of DR_i must be set to unknown. */
1802 FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
1804 vect_update_misalignment_for_peel (dr, dr0, npeel);
1806 LOOP_VINFO_UNALIGNED_DR (loop_vinfo) = dr0;
1808 LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo) = npeel;
1810 LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo) = DR_MISALIGNMENT (dr0);
1811 SET_DR_MISALIGNMENT (dr0, 0);
1812 if (vect_print_dump_info (REPORT_ALIGNMENT))
1813 fprintf (vect_dump, "Alignment of access forced using peeling.");
1815 if (vect_print_dump_info (REPORT_DETAILS))
1816 fprintf (vect_dump, "Peeling for alignment will be applied.");
1818 stat = vect_verify_datarefs_alignment (loop_vinfo, NULL);
1825 /* (2) Versioning to force alignment. */
1827 /* Try versioning if:
1828 1) flag_tree_vect_loop_version is TRUE
1829 2) optimize loop for speed
1830 3) there is at least one unsupported misaligned data ref with an unknown
1832 4) all misaligned data refs with a known misalignment are supported, and
1833 5) the number of runtime alignment checks is within reason. */
1836 flag_tree_vect_loop_version
1837 && optimize_loop_nest_for_speed_p (loop)
1838 && (!loop->inner); /* FORNOW */
1842 FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
1844 stmt = DR_STMT (dr);
1845 stmt_info = vinfo_for_stmt (stmt);
1847 /* For interleaving, only the alignment of the first access
1849 if (aligned_access_p (dr)
1850 || (STMT_VINFO_STRIDED_ACCESS (stmt_info)
1851 && GROUP_FIRST_ELEMENT (stmt_info) != stmt))
1854 supportable_dr_alignment = vect_supportable_dr_alignment (dr, false);
1856 if (!supportable_dr_alignment)
1862 if (known_alignment_for_access_p (dr)
1863 || VEC_length (gimple,
1864 LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo))
1865 >= (unsigned) PARAM_VALUE (PARAM_VECT_MAX_VERSION_FOR_ALIGNMENT_CHECKS))
1867 do_versioning = false;
1871 stmt = DR_STMT (dr);
1872 vectype = STMT_VINFO_VECTYPE (vinfo_for_stmt (stmt));
1873 gcc_assert (vectype);
1875 /* The rightmost bits of an aligned address must be zeros.
1876 Construct the mask needed for this test. For example,
1877 GET_MODE_SIZE for the vector mode V4SI is 16 bytes so the
1878 mask must be 15 = 0xf. */
1879 mask = GET_MODE_SIZE (TYPE_MODE (vectype)) - 1;
1881 /* FORNOW: use the same mask to test all potentially unaligned
1882 references in the loop. The vectorizer currently supports
1883 a single vector size, see the reference to
1884 GET_MODE_NUNITS (TYPE_MODE (vectype)) where the
1885 vectorization factor is computed. */
1886 gcc_assert (!LOOP_VINFO_PTR_MASK (loop_vinfo)
1887 || LOOP_VINFO_PTR_MASK (loop_vinfo) == mask);
1888 LOOP_VINFO_PTR_MASK (loop_vinfo) = mask;
1889 VEC_safe_push (gimple, heap,
1890 LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo),
1895 /* Versioning requires at least one misaligned data reference. */
1896 if (!LOOP_REQUIRES_VERSIONING_FOR_ALIGNMENT (loop_vinfo))
1897 do_versioning = false;
1898 else if (!do_versioning)
1899 VEC_truncate (gimple, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo), 0);
1904 VEC(gimple,heap) *may_misalign_stmts
1905 = LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo);
1908 /* It can now be assumed that the data references in the statements
1909 in LOOP_VINFO_MAY_MISALIGN_STMTS will be aligned in the version
1910 of the loop being vectorized. */
1911 FOR_EACH_VEC_ELT (gimple, may_misalign_stmts, i, stmt)
1913 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
1914 dr = STMT_VINFO_DATA_REF (stmt_info);
1915 SET_DR_MISALIGNMENT (dr, 0);
1916 if (vect_print_dump_info (REPORT_ALIGNMENT))
1917 fprintf (vect_dump, "Alignment of access forced using versioning.");
1920 if (vect_print_dump_info (REPORT_DETAILS))
1921 fprintf (vect_dump, "Versioning for alignment will be applied.");
1923 /* Peeling and versioning can't be done together at this time. */
1924 gcc_assert (! (do_peeling && do_versioning));
1926 stat = vect_verify_datarefs_alignment (loop_vinfo, NULL);
1931 /* This point is reached if neither peeling nor versioning is being done. */
1932 gcc_assert (! (do_peeling || do_versioning));
1934 stat = vect_verify_datarefs_alignment (loop_vinfo, NULL);
1939 /* Function vect_find_same_alignment_drs.
1941 Update group and alignment relations according to the chosen
1942 vectorization factor. */
1945 vect_find_same_alignment_drs (struct data_dependence_relation *ddr,
1946 loop_vec_info loop_vinfo)
1949 struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
1950 int vectorization_factor = LOOP_VINFO_VECT_FACTOR (loop_vinfo);
1951 struct data_reference *dra = DDR_A (ddr);
1952 struct data_reference *drb = DDR_B (ddr);
1953 stmt_vec_info stmtinfo_a = vinfo_for_stmt (DR_STMT (dra));
1954 stmt_vec_info stmtinfo_b = vinfo_for_stmt (DR_STMT (drb));
1955 int dra_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (dra))));
1956 int drb_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (drb))));
1957 lambda_vector dist_v;
1958 unsigned int loop_depth;
1960 if (DDR_ARE_DEPENDENT (ddr) == chrec_known)
1966 if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know)
1969 /* Loop-based vectorization and known data dependence. */
1970 if (DDR_NUM_DIST_VECTS (ddr) == 0)
1973 /* Data-dependence analysis reports a distance vector of zero
1974 for data-references that overlap only in the first iteration
1975 but have different sign step (see PR45764).
1976 So as a sanity check require equal DR_STEP. */
1977 if (!operand_equal_p (DR_STEP (dra), DR_STEP (drb), 0))
1980 loop_depth = index_in_loop_nest (loop->num, DDR_LOOP_NEST (ddr));
1981 FOR_EACH_VEC_ELT (lambda_vector, DDR_DIST_VECTS (ddr), i, dist_v)
1983 int dist = dist_v[loop_depth];
1985 if (vect_print_dump_info (REPORT_DR_DETAILS))
1986 fprintf (vect_dump, "dependence distance = %d.", dist);
1988 /* Same loop iteration. */
1990 || (dist % vectorization_factor == 0 && dra_size == drb_size))
1992 /* Two references with distance zero have the same alignment. */
1993 VEC_safe_push (dr_p, heap, STMT_VINFO_SAME_ALIGN_REFS (stmtinfo_a), drb);
1994 VEC_safe_push (dr_p, heap, STMT_VINFO_SAME_ALIGN_REFS (stmtinfo_b), dra);
1995 if (vect_print_dump_info (REPORT_ALIGNMENT))
1996 fprintf (vect_dump, "accesses have the same alignment.");
1997 if (vect_print_dump_info (REPORT_DR_DETAILS))
1999 fprintf (vect_dump, "dependence distance modulo vf == 0 between ");
2000 print_generic_expr (vect_dump, DR_REF (dra), TDF_SLIM);
2001 fprintf (vect_dump, " and ");
2002 print_generic_expr (vect_dump, DR_REF (drb), TDF_SLIM);
2009 /* Function vect_analyze_data_refs_alignment
2011 Analyze the alignment of the data-references in the loop.
2012 Return FALSE if a data reference is found that cannot be vectorized. */
2015 vect_analyze_data_refs_alignment (loop_vec_info loop_vinfo,
2016 bb_vec_info bb_vinfo)
2018 if (vect_print_dump_info (REPORT_DETAILS))
2019 fprintf (vect_dump, "=== vect_analyze_data_refs_alignment ===");
2021 /* Mark groups of data references with same alignment using
2022 data dependence information. */
2025 VEC (ddr_p, heap) *ddrs = LOOP_VINFO_DDRS (loop_vinfo);
2026 struct data_dependence_relation *ddr;
2029 FOR_EACH_VEC_ELT (ddr_p, ddrs, i, ddr)
2030 vect_find_same_alignment_drs (ddr, loop_vinfo);
2033 if (!vect_compute_data_refs_alignment (loop_vinfo, bb_vinfo))
2035 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
2037 "not vectorized: can't calculate alignment for data ref.");
2045 /* Analyze groups of strided accesses: check that DR belongs to a group of
2046 strided accesses of legal size, step, etc. Detect gaps, single element
2047 interleaving, and other special cases. Set strided access info.
2048 Collect groups of strided stores for further use in SLP analysis. */
2051 vect_analyze_group_access (struct data_reference *dr)
2053 tree step = DR_STEP (dr);
2054 tree scalar_type = TREE_TYPE (DR_REF (dr));
2055 HOST_WIDE_INT type_size = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (scalar_type));
2056 gimple stmt = DR_STMT (dr);
2057 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
2058 loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
2059 bb_vec_info bb_vinfo = STMT_VINFO_BB_VINFO (stmt_info);
2060 HOST_WIDE_INT dr_step = TREE_INT_CST_LOW (step);
2061 HOST_WIDE_INT stride, last_accessed_element = 1;
2062 bool slp_impossible = false;
2063 struct loop *loop = NULL;
2066 loop = LOOP_VINFO_LOOP (loop_vinfo);
2068 /* For interleaving, STRIDE is STEP counted in elements, i.e., the size of the
2069 interleaving group (including gaps). */
2070 stride = dr_step / type_size;
2072 /* Not consecutive access is possible only if it is a part of interleaving. */
2073 if (!GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)))
2075 /* Check if it this DR is a part of interleaving, and is a single
2076 element of the group that is accessed in the loop. */
2078 /* Gaps are supported only for loads. STEP must be a multiple of the type
2079 size. The size of the group must be a power of 2. */
2081 && (dr_step % type_size) == 0
2083 && exact_log2 (stride) != -1)
2085 GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)) = stmt;
2086 GROUP_SIZE (vinfo_for_stmt (stmt)) = stride;
2087 if (vect_print_dump_info (REPORT_DR_DETAILS))
2089 fprintf (vect_dump, "Detected single element interleaving ");
2090 print_generic_expr (vect_dump, DR_REF (dr), TDF_SLIM);
2091 fprintf (vect_dump, " step ");
2092 print_generic_expr (vect_dump, step, TDF_SLIM);
2097 if (vect_print_dump_info (REPORT_DETAILS))
2098 fprintf (vect_dump, "Data access with gaps requires scalar "
2102 if (vect_print_dump_info (REPORT_DETAILS))
2103 fprintf (vect_dump, "Peeling for outer loop is not"
2108 LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
2114 if (vect_print_dump_info (REPORT_DETAILS))
2116 fprintf (vect_dump, "not consecutive access ");
2117 print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
2122 /* Mark the statement as unvectorizable. */
2123 STMT_VINFO_VECTORIZABLE (vinfo_for_stmt (DR_STMT (dr))) = false;
2130 if (GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)) == stmt)
2132 /* First stmt in the interleaving chain. Check the chain. */
2133 gimple next = GROUP_NEXT_ELEMENT (vinfo_for_stmt (stmt));
2134 struct data_reference *data_ref = dr;
2135 unsigned int count = 1;
2137 tree prev_init = DR_INIT (data_ref);
2139 HOST_WIDE_INT diff, count_in_bytes, gaps = 0;
2143 /* Skip same data-refs. In case that two or more stmts share
2144 data-ref (supported only for loads), we vectorize only the first
2145 stmt, and the rest get their vectorized loads from the first
2147 if (!tree_int_cst_compare (DR_INIT (data_ref),
2148 DR_INIT (STMT_VINFO_DATA_REF (
2149 vinfo_for_stmt (next)))))
2151 if (DR_IS_WRITE (data_ref))
2153 if (vect_print_dump_info (REPORT_DETAILS))
2154 fprintf (vect_dump, "Two store stmts share the same dr.");
2158 /* Check that there is no load-store dependencies for this loads
2159 to prevent a case of load-store-load to the same location. */
2160 if (GROUP_READ_WRITE_DEPENDENCE (vinfo_for_stmt (next))
2161 || GROUP_READ_WRITE_DEPENDENCE (vinfo_for_stmt (prev)))
2163 if (vect_print_dump_info (REPORT_DETAILS))
2165 "READ_WRITE dependence in interleaving.");
2169 /* For load use the same data-ref load. */
2170 GROUP_SAME_DR_STMT (vinfo_for_stmt (next)) = prev;
2173 next = GROUP_NEXT_ELEMENT (vinfo_for_stmt (next));
2179 /* Check that all the accesses have the same STEP. */
2180 next_step = DR_STEP (STMT_VINFO_DATA_REF (vinfo_for_stmt (next)));
2181 if (tree_int_cst_compare (step, next_step))
2183 if (vect_print_dump_info (REPORT_DETAILS))
2184 fprintf (vect_dump, "not consecutive access in interleaving");
2188 data_ref = STMT_VINFO_DATA_REF (vinfo_for_stmt (next));
2189 /* Check that the distance between two accesses is equal to the type
2190 size. Otherwise, we have gaps. */
2191 diff = (TREE_INT_CST_LOW (DR_INIT (data_ref))
2192 - TREE_INT_CST_LOW (prev_init)) / type_size;
2195 /* FORNOW: SLP of accesses with gaps is not supported. */
2196 slp_impossible = true;
2197 if (DR_IS_WRITE (data_ref))
2199 if (vect_print_dump_info (REPORT_DETAILS))
2200 fprintf (vect_dump, "interleaved store with gaps");
2207 last_accessed_element += diff;
2209 /* Store the gap from the previous member of the group. If there is no
2210 gap in the access, GROUP_GAP is always 1. */
2211 GROUP_GAP (vinfo_for_stmt (next)) = diff;
2213 prev_init = DR_INIT (data_ref);
2214 next = GROUP_NEXT_ELEMENT (vinfo_for_stmt (next));
2215 /* Count the number of data-refs in the chain. */
2219 /* COUNT is the number of accesses found, we multiply it by the size of
2220 the type to get COUNT_IN_BYTES. */
2221 count_in_bytes = type_size * count;
2223 /* Check that the size of the interleaving (including gaps) is not
2224 greater than STEP. */
2225 if (dr_step && dr_step < count_in_bytes + gaps * type_size)
2227 if (vect_print_dump_info (REPORT_DETAILS))
2229 fprintf (vect_dump, "interleaving size is greater than step for ");
2230 print_generic_expr (vect_dump, DR_REF (dr), TDF_SLIM);
2235 /* Check that the size of the interleaving is equal to STEP for stores,
2236 i.e., that there are no gaps. */
2237 if (dr_step && dr_step != count_in_bytes)
2239 if (DR_IS_READ (dr))
2241 slp_impossible = true;
2242 /* There is a gap after the last load in the group. This gap is a
2243 difference between the stride and the number of elements. When
2244 there is no gap, this difference should be 0. */
2245 GROUP_GAP (vinfo_for_stmt (stmt)) = stride - count;
2249 if (vect_print_dump_info (REPORT_DETAILS))
2250 fprintf (vect_dump, "interleaved store with gaps");
2255 /* Check that STEP is a multiple of type size. */
2256 if (dr_step && (dr_step % type_size) != 0)
2258 if (vect_print_dump_info (REPORT_DETAILS))
2260 fprintf (vect_dump, "step is not a multiple of type size: step ");
2261 print_generic_expr (vect_dump, step, TDF_SLIM);
2262 fprintf (vect_dump, " size ");
2263 print_generic_expr (vect_dump, TYPE_SIZE_UNIT (scalar_type),
2272 GROUP_SIZE (vinfo_for_stmt (stmt)) = stride;
2273 if (vect_print_dump_info (REPORT_DETAILS))
2274 fprintf (vect_dump, "Detected interleaving of size %d", (int)stride);
2276 /* SLP: create an SLP data structure for every interleaving group of
2277 stores for further analysis in vect_analyse_slp. */
2278 if (DR_IS_WRITE (dr) && !slp_impossible)
2281 VEC_safe_push (gimple, heap, LOOP_VINFO_STRIDED_STORES (loop_vinfo),
2284 VEC_safe_push (gimple, heap, BB_VINFO_STRIDED_STORES (bb_vinfo),
2288 /* There is a gap in the end of the group. */
2289 if (stride - last_accessed_element > 0 && loop_vinfo)
2291 if (vect_print_dump_info (REPORT_DETAILS))
2292 fprintf (vect_dump, "Data access with gaps requires scalar "
2296 if (vect_print_dump_info (REPORT_DETAILS))
2297 fprintf (vect_dump, "Peeling for outer loop is not supported");
2301 LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
2309 /* Analyze the access pattern of the data-reference DR.
2310 In case of non-consecutive accesses call vect_analyze_group_access() to
2311 analyze groups of strided accesses. */
2314 vect_analyze_data_ref_access (struct data_reference *dr)
2316 tree step = DR_STEP (dr);
2317 tree scalar_type = TREE_TYPE (DR_REF (dr));
2318 gimple stmt = DR_STMT (dr);
2319 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
2320 loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
2321 struct loop *loop = NULL;
2322 HOST_WIDE_INT dr_step = TREE_INT_CST_LOW (step);
2325 loop = LOOP_VINFO_LOOP (loop_vinfo);
2327 if (loop_vinfo && !step)
2329 if (vect_print_dump_info (REPORT_DETAILS))
2330 fprintf (vect_dump, "bad data-ref access in loop");
2334 /* Allow invariant loads in loops. */
2335 if (loop_vinfo && dr_step == 0)
2337 GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)) = NULL;
2338 return DR_IS_READ (dr);
2341 if (loop && nested_in_vect_loop_p (loop, stmt))
2343 /* Interleaved accesses are not yet supported within outer-loop
2344 vectorization for references in the inner-loop. */
2345 GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)) = NULL;
2347 /* For the rest of the analysis we use the outer-loop step. */
2348 step = STMT_VINFO_DR_STEP (stmt_info);
2349 dr_step = TREE_INT_CST_LOW (step);
2353 if (vect_print_dump_info (REPORT_ALIGNMENT))
2354 fprintf (vect_dump, "zero step in outer loop.");
2355 if (DR_IS_READ (dr))
2363 if (!tree_int_cst_compare (step, TYPE_SIZE_UNIT (scalar_type))
2365 && !compare_tree_int (TYPE_SIZE_UNIT (scalar_type), -dr_step)))
2367 /* Mark that it is not interleaving. */
2368 GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt)) = NULL;
2372 if (loop && nested_in_vect_loop_p (loop, stmt))
2374 if (vect_print_dump_info (REPORT_ALIGNMENT))
2375 fprintf (vect_dump, "strided access in outer loop.");
2379 /* Not consecutive access - check if it's a part of interleaving group. */
2380 return vect_analyze_group_access (dr);
2384 /* Function vect_analyze_data_ref_accesses.
2386 Analyze the access pattern of all the data references in the loop.
2388 FORNOW: the only access pattern that is considered vectorizable is a
2389 simple step 1 (consecutive) access.
2391 FORNOW: handle only arrays and pointer accesses. */
2394 vect_analyze_data_ref_accesses (loop_vec_info loop_vinfo, bb_vec_info bb_vinfo)
2397 VEC (data_reference_p, heap) *datarefs;
2398 struct data_reference *dr;
2400 if (vect_print_dump_info (REPORT_DETAILS))
2401 fprintf (vect_dump, "=== vect_analyze_data_ref_accesses ===");
2404 datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
2406 datarefs = BB_VINFO_DATAREFS (bb_vinfo);
2408 FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
2409 if (STMT_VINFO_VECTORIZABLE (vinfo_for_stmt (DR_STMT (dr)))
2410 && !vect_analyze_data_ref_access (dr))
2412 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
2413 fprintf (vect_dump, "not vectorized: complicated access pattern.");
2417 /* Mark the statement as not vectorizable. */
2418 STMT_VINFO_VECTORIZABLE (vinfo_for_stmt (DR_STMT (dr))) = false;
2428 /* Function vect_prune_runtime_alias_test_list.
2430 Prune a list of ddrs to be tested at run-time by versioning for alias.
2431 Return FALSE if resulting list of ddrs is longer then allowed by
2432 PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS, otherwise return TRUE. */
2435 vect_prune_runtime_alias_test_list (loop_vec_info loop_vinfo)
2437 VEC (ddr_p, heap) * ddrs =
2438 LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo);
2441 if (vect_print_dump_info (REPORT_DETAILS))
2442 fprintf (vect_dump, "=== vect_prune_runtime_alias_test_list ===");
2444 for (i = 0; i < VEC_length (ddr_p, ddrs); )
2449 ddr_i = VEC_index (ddr_p, ddrs, i);
2452 for (j = 0; j < i; j++)
2454 ddr_p ddr_j = VEC_index (ddr_p, ddrs, j);
2456 if (vect_vfa_range_equal (ddr_i, ddr_j))
2458 if (vect_print_dump_info (REPORT_DR_DETAILS))
2460 fprintf (vect_dump, "found equal ranges ");
2461 print_generic_expr (vect_dump, DR_REF (DDR_A (ddr_i)), TDF_SLIM);
2462 fprintf (vect_dump, ", ");
2463 print_generic_expr (vect_dump, DR_REF (DDR_B (ddr_i)), TDF_SLIM);
2464 fprintf (vect_dump, " and ");
2465 print_generic_expr (vect_dump, DR_REF (DDR_A (ddr_j)), TDF_SLIM);
2466 fprintf (vect_dump, ", ");
2467 print_generic_expr (vect_dump, DR_REF (DDR_B (ddr_j)), TDF_SLIM);
2476 VEC_ordered_remove (ddr_p, ddrs, i);
2482 if (VEC_length (ddr_p, ddrs) >
2483 (unsigned) PARAM_VALUE (PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS))
2485 if (vect_print_dump_info (REPORT_DR_DETAILS))
2488 "disable versioning for alias - max number of generated "
2489 "checks exceeded.");
2492 VEC_truncate (ddr_p, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo), 0);
2500 /* Check whether a non-affine read in stmt is suitable for gather load
2501 and if so, return a builtin decl for that operation. */
2504 vect_check_gather (gimple stmt, loop_vec_info loop_vinfo, tree *basep,
2505 tree *offp, int *scalep)
2507 HOST_WIDE_INT scale = 1, pbitpos, pbitsize;
2508 struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo);
2509 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
2510 struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
2511 tree offtype = NULL_TREE;
2512 tree decl, base, off;
2513 enum machine_mode pmode;
2514 int punsignedp, pvolatilep;
2516 /* The gather builtins need address of the form
2517 loop_invariant + vector * {1, 2, 4, 8}
2519 loop_invariant + sign_extend (vector) * { 1, 2, 4, 8 }.
2520 Unfortunately DR_BASE_ADDRESS/DR_OFFSET can be a mixture
2521 of loop invariants/SSA_NAMEs defined in the loop, with casts,
2522 multiplications and additions in it. To get a vector, we need
2523 a single SSA_NAME that will be defined in the loop and will
2524 contain everything that is not loop invariant and that can be
2525 vectorized. The following code attempts to find such a preexistng
2526 SSA_NAME OFF and put the loop invariants into a tree BASE
2527 that can be gimplified before the loop. */
2528 base = get_inner_reference (DR_REF (dr), &pbitsize, &pbitpos, &off,
2529 &pmode, &punsignedp, &pvolatilep, false);
2530 gcc_assert (base != NULL_TREE && (pbitpos % BITS_PER_UNIT) == 0);
2532 if (TREE_CODE (base) == MEM_REF)
2534 if (!integer_zerop (TREE_OPERAND (base, 1)))
2536 if (off == NULL_TREE)
2538 double_int moff = mem_ref_offset (base);
2539 off = double_int_to_tree (sizetype, moff);
2542 off = size_binop (PLUS_EXPR, off,
2543 fold_convert (sizetype, TREE_OPERAND (base, 1)));
2545 base = TREE_OPERAND (base, 0);
2548 base = build_fold_addr_expr (base);
2550 if (off == NULL_TREE)
2551 off = size_zero_node;
2553 /* If base is not loop invariant, either off is 0, then we start with just
2554 the constant offset in the loop invariant BASE and continue with base
2555 as OFF, otherwise give up.
2556 We could handle that case by gimplifying the addition of base + off
2557 into some SSA_NAME and use that as off, but for now punt. */
2558 if (!expr_invariant_in_loop_p (loop, base))
2560 if (!integer_zerop (off))
2563 base = size_int (pbitpos / BITS_PER_UNIT);
2565 /* Otherwise put base + constant offset into the loop invariant BASE
2566 and continue with OFF. */
2569 base = fold_convert (sizetype, base);
2570 base = size_binop (PLUS_EXPR, base, size_int (pbitpos / BITS_PER_UNIT));
2573 /* OFF at this point may be either a SSA_NAME or some tree expression
2574 from get_inner_reference. Try to peel off loop invariants from it
2575 into BASE as long as possible. */
2577 while (offtype == NULL_TREE)
2579 enum tree_code code;
2580 tree op0, op1, add = NULL_TREE;
2582 if (TREE_CODE (off) == SSA_NAME)
2584 gimple def_stmt = SSA_NAME_DEF_STMT (off);
2586 if (expr_invariant_in_loop_p (loop, off))
2589 if (gimple_code (def_stmt) != GIMPLE_ASSIGN)
2592 op0 = gimple_assign_rhs1 (def_stmt);
2593 code = gimple_assign_rhs_code (def_stmt);
2594 op1 = gimple_assign_rhs2 (def_stmt);
2598 if (get_gimple_rhs_class (TREE_CODE (off)) == GIMPLE_TERNARY_RHS)
2600 code = TREE_CODE (off);
2601 extract_ops_from_tree (off, &code, &op0, &op1);
2605 case POINTER_PLUS_EXPR:
2607 if (expr_invariant_in_loop_p (loop, op0))
2612 add = fold_convert (sizetype, add);
2614 add = size_binop (MULT_EXPR, add, size_int (scale));
2615 base = size_binop (PLUS_EXPR, base, add);
2618 if (expr_invariant_in_loop_p (loop, op1))
2626 if (expr_invariant_in_loop_p (loop, op1))
2628 add = fold_convert (sizetype, op1);
2629 add = size_binop (MINUS_EXPR, size_zero_node, add);
2635 if (scale == 1 && host_integerp (op1, 0))
2637 scale = tree_low_cst (op1, 0);
2646 if (!POINTER_TYPE_P (TREE_TYPE (op0))
2647 && !INTEGRAL_TYPE_P (TREE_TYPE (op0)))
2649 if (TYPE_PRECISION (TREE_TYPE (op0))
2650 == TYPE_PRECISION (TREE_TYPE (off)))
2655 if (TYPE_PRECISION (TREE_TYPE (op0))
2656 < TYPE_PRECISION (TREE_TYPE (off)))
2659 offtype = TREE_TYPE (off);
2670 /* If at the end OFF still isn't a SSA_NAME or isn't
2671 defined in the loop, punt. */
2672 if (TREE_CODE (off) != SSA_NAME
2673 || expr_invariant_in_loop_p (loop, off))
2676 if (offtype == NULL_TREE)
2677 offtype = TREE_TYPE (off);
2679 decl = targetm.vectorize.builtin_gather (STMT_VINFO_VECTYPE (stmt_info),
2681 if (decl == NULL_TREE)
2694 /* Function vect_analyze_data_refs.
2696 Find all the data references in the loop or basic block.
2698 The general structure of the analysis of data refs in the vectorizer is as
2700 1- vect_analyze_data_refs(loop/bb): call
2701 compute_data_dependences_for_loop/bb to find and analyze all data-refs
2702 in the loop/bb and their dependences.
2703 2- vect_analyze_dependences(): apply dependence testing using ddrs.
2704 3- vect_analyze_drs_alignment(): check that ref_stmt.alignment is ok.
2705 4- vect_analyze_drs_access(): check that ref_stmt.step is ok.
2710 vect_analyze_data_refs (loop_vec_info loop_vinfo,
2711 bb_vec_info bb_vinfo,
2714 struct loop *loop = NULL;
2715 basic_block bb = NULL;
2717 VEC (data_reference_p, heap) *datarefs;
2718 struct data_reference *dr;
2720 bool res, stop_bb_analysis = false;
2722 if (vect_print_dump_info (REPORT_DETAILS))
2723 fprintf (vect_dump, "=== vect_analyze_data_refs ===\n");
2727 loop = LOOP_VINFO_LOOP (loop_vinfo);
2728 res = compute_data_dependences_for_loop
2730 &LOOP_VINFO_LOOP_NEST (loop_vinfo),
2731 &LOOP_VINFO_DATAREFS (loop_vinfo),
2732 &LOOP_VINFO_DDRS (loop_vinfo));
2736 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
2737 fprintf (vect_dump, "not vectorized: loop contains function calls"
2738 " or data references that cannot be analyzed");
2742 datarefs = LOOP_VINFO_DATAREFS (loop_vinfo);
2746 bb = BB_VINFO_BB (bb_vinfo);
2747 res = compute_data_dependences_for_bb (bb, true,
2748 &BB_VINFO_DATAREFS (bb_vinfo),
2749 &BB_VINFO_DDRS (bb_vinfo));
2752 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
2753 fprintf (vect_dump, "not vectorized: basic block contains function"
2754 " calls or data references that cannot be analyzed");
2758 datarefs = BB_VINFO_DATAREFS (bb_vinfo);
2761 /* Go through the data-refs, check that the analysis succeeded. Update
2762 pointer from stmt_vec_info struct to DR and vectype. */
2764 FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, dr)
2767 stmt_vec_info stmt_info;
2768 tree base, offset, init;
2769 bool gather = false;
2772 if (!dr || !DR_REF (dr))
2774 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
2775 fprintf (vect_dump, "not vectorized: unhandled data-ref ");
2780 stmt = DR_STMT (dr);
2781 stmt_info = vinfo_for_stmt (stmt);
2783 if (stop_bb_analysis)
2785 STMT_VINFO_VECTORIZABLE (stmt_info) = false;
2789 /* Check that analysis of the data-ref succeeded. */
2790 if (!DR_BASE_ADDRESS (dr) || !DR_OFFSET (dr) || !DR_INIT (dr)
2793 /* If target supports vector gather loads, see if they can't
2797 && !TREE_THIS_VOLATILE (DR_REF (dr))
2798 && targetm.vectorize.builtin_gather != NULL
2799 && !nested_in_vect_loop_p (loop, stmt))
2801 struct data_reference *newdr
2802 = create_data_ref (NULL, loop_containing_stmt (stmt),
2803 DR_REF (dr), stmt, true);
2804 gcc_assert (newdr != NULL && DR_REF (newdr));
2805 if (DR_BASE_ADDRESS (newdr)
2806 && DR_OFFSET (newdr)
2809 && integer_zerop (DR_STEP (newdr)))
2815 free_data_ref (newdr);
2820 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
2822 fprintf (vect_dump, "not vectorized: data ref analysis "
2824 print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
2829 STMT_VINFO_VECTORIZABLE (stmt_info) = false;
2830 stop_bb_analysis = true;
2838 if (TREE_CODE (DR_BASE_ADDRESS (dr)) == INTEGER_CST)
2840 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
2841 fprintf (vect_dump, "not vectorized: base addr of dr is a "
2846 STMT_VINFO_VECTORIZABLE (stmt_info) = false;
2847 stop_bb_analysis = true;
2856 if (TREE_THIS_VOLATILE (DR_REF (dr)))
2858 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
2860 fprintf (vect_dump, "not vectorized: volatile type ");
2861 print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
2866 STMT_VINFO_VECTORIZABLE (stmt_info) = false;
2867 stop_bb_analysis = true;
2874 base = unshare_expr (DR_BASE_ADDRESS (dr));
2875 offset = unshare_expr (DR_OFFSET (dr));
2876 init = unshare_expr (DR_INIT (dr));
2878 if (stmt_can_throw_internal (stmt))
2880 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
2882 fprintf (vect_dump, "not vectorized: statement can throw an "
2884 print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
2889 STMT_VINFO_VECTORIZABLE (stmt_info) = false;
2890 stop_bb_analysis = true;
2899 /* Update DR field in stmt_vec_info struct. */
2901 /* If the dataref is in an inner-loop of the loop that is considered for
2902 for vectorization, we also want to analyze the access relative to
2903 the outer-loop (DR contains information only relative to the
2904 inner-most enclosing loop). We do that by building a reference to the
2905 first location accessed by the inner-loop, and analyze it relative to
2907 if (loop && nested_in_vect_loop_p (loop, stmt))
2909 tree outer_step, outer_base, outer_init;
2910 HOST_WIDE_INT pbitsize, pbitpos;
2912 enum machine_mode pmode;
2913 int punsignedp, pvolatilep;
2914 affine_iv base_iv, offset_iv;
2917 /* Build a reference to the first location accessed by the
2918 inner-loop: *(BASE+INIT). (The first location is actually
2919 BASE+INIT+OFFSET, but we add OFFSET separately later). */
2920 tree inner_base = build_fold_indirect_ref
2921 (fold_build_pointer_plus (base, init));
2923 if (vect_print_dump_info (REPORT_DETAILS))
2925 fprintf (vect_dump, "analyze in outer-loop: ");
2926 print_generic_expr (vect_dump, inner_base, TDF_SLIM);
2929 outer_base = get_inner_reference (inner_base, &pbitsize, &pbitpos,
2930 &poffset, &pmode, &punsignedp, &pvolatilep, false);
2931 gcc_assert (outer_base != NULL_TREE);
2933 if (pbitpos % BITS_PER_UNIT != 0)
2935 if (vect_print_dump_info (REPORT_DETAILS))
2936 fprintf (vect_dump, "failed: bit offset alignment.\n");
2940 outer_base = build_fold_addr_expr (outer_base);
2941 if (!simple_iv (loop, loop_containing_stmt (stmt), outer_base,
2944 if (vect_print_dump_info (REPORT_DETAILS))
2945 fprintf (vect_dump, "failed: evolution of base is not affine.\n");
2952 poffset = fold_build2 (PLUS_EXPR, TREE_TYPE (offset), offset,
2960 offset_iv.base = ssize_int (0);
2961 offset_iv.step = ssize_int (0);
2963 else if (!simple_iv (loop, loop_containing_stmt (stmt), poffset,
2966 if (vect_print_dump_info (REPORT_DETAILS))
2967 fprintf (vect_dump, "evolution of offset is not affine.\n");
2971 outer_init = ssize_int (pbitpos / BITS_PER_UNIT);
2972 split_constant_offset (base_iv.base, &base_iv.base, &dinit);
2973 outer_init = size_binop (PLUS_EXPR, outer_init, dinit);
2974 split_constant_offset (offset_iv.base, &offset_iv.base, &dinit);
2975 outer_init = size_binop (PLUS_EXPR, outer_init, dinit);
2977 outer_step = size_binop (PLUS_EXPR,
2978 fold_convert (ssizetype, base_iv.step),
2979 fold_convert (ssizetype, offset_iv.step));
2981 STMT_VINFO_DR_STEP (stmt_info) = outer_step;
2982 /* FIXME: Use canonicalize_base_object_address (base_iv.base); */
2983 STMT_VINFO_DR_BASE_ADDRESS (stmt_info) = base_iv.base;
2984 STMT_VINFO_DR_INIT (stmt_info) = outer_init;
2985 STMT_VINFO_DR_OFFSET (stmt_info) =
2986 fold_convert (ssizetype, offset_iv.base);
2987 STMT_VINFO_DR_ALIGNED_TO (stmt_info) =
2988 size_int (highest_pow2_factor (offset_iv.base));
2990 if (vect_print_dump_info (REPORT_DETAILS))
2992 fprintf (vect_dump, "\touter base_address: ");
2993 print_generic_expr (vect_dump, STMT_VINFO_DR_BASE_ADDRESS (stmt_info), TDF_SLIM);
2994 fprintf (vect_dump, "\n\touter offset from base address: ");
2995 print_generic_expr (vect_dump, STMT_VINFO_DR_OFFSET (stmt_info), TDF_SLIM);
2996 fprintf (vect_dump, "\n\touter constant offset from base address: ");
2997 print_generic_expr (vect_dump, STMT_VINFO_DR_INIT (stmt_info), TDF_SLIM);
2998 fprintf (vect_dump, "\n\touter step: ");
2999 print_generic_expr (vect_dump, STMT_VINFO_DR_STEP (stmt_info), TDF_SLIM);
3000 fprintf (vect_dump, "\n\touter aligned to: ");
3001 print_generic_expr (vect_dump, STMT_VINFO_DR_ALIGNED_TO (stmt_info), TDF_SLIM);
3005 if (STMT_VINFO_DATA_REF (stmt_info))
3007 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
3010 "not vectorized: more than one data ref in stmt: ");
3011 print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
3016 STMT_VINFO_VECTORIZABLE (stmt_info) = false;
3017 stop_bb_analysis = true;
3026 STMT_VINFO_DATA_REF (stmt_info) = dr;
3028 /* Set vectype for STMT. */
3029 scalar_type = TREE_TYPE (DR_REF (dr));
3030 STMT_VINFO_VECTYPE (stmt_info) =
3031 get_vectype_for_scalar_type (scalar_type);
3032 if (!STMT_VINFO_VECTYPE (stmt_info))
3034 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
3037 "not vectorized: no vectype for stmt: ");
3038 print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
3039 fprintf (vect_dump, " scalar_type: ");
3040 print_generic_expr (vect_dump, scalar_type, TDF_DETAILS);
3045 /* Mark the statement as not vectorizable. */
3046 STMT_VINFO_VECTORIZABLE (stmt_info) = false;
3047 stop_bb_analysis = true;
3053 STMT_VINFO_DATA_REF (stmt_info) = NULL;
3059 /* Adjust the minimal vectorization factor according to the
3061 vf = TYPE_VECTOR_SUBPARTS (STMT_VINFO_VECTYPE (stmt_info));
3067 unsigned int j, k, n;
3068 struct data_reference *olddr
3069 = VEC_index (data_reference_p, datarefs, i);
3070 VEC (ddr_p, heap) *ddrs = LOOP_VINFO_DDRS (loop_vinfo);
3071 struct data_dependence_relation *ddr, *newddr;
3074 VEC (loop_p, heap) *nest = LOOP_VINFO_LOOP_NEST (loop_vinfo);
3076 if (!vect_check_gather (stmt, loop_vinfo, NULL, &off, NULL)
3077 || get_vectype_for_scalar_type (TREE_TYPE (off)) == NULL_TREE)
3079 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
3082 "not vectorized: not suitable for gather ");
3083 print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
3088 n = VEC_length (data_reference_p, datarefs) - 1;
3089 for (j = 0, k = i - 1; j < i; j++)
3091 ddr = VEC_index (ddr_p, ddrs, k);
3092 gcc_assert (DDR_B (ddr) == olddr);
3093 newddr = initialize_data_dependence_relation (DDR_A (ddr), dr,
3095 VEC_replace (ddr_p, ddrs, k, newddr);
3096 free_dependence_relation (ddr);
3098 && DR_IS_WRITE (DDR_A (newddr))
3099 && DDR_ARE_DEPENDENT (newddr) != chrec_known)
3105 n = k + VEC_length (data_reference_p, datarefs) - i - 1;
3108 ddr = VEC_index (ddr_p, ddrs, k);
3109 gcc_assert (DDR_A (ddr) == olddr);
3110 newddr = initialize_data_dependence_relation (dr, DDR_B (ddr),
3112 VEC_replace (ddr_p, ddrs, k, newddr);
3113 free_dependence_relation (ddr);
3115 && DR_IS_WRITE (DDR_B (newddr))
3116 && DDR_ARE_DEPENDENT (newddr) != chrec_known)
3120 k = VEC_length (ddr_p, ddrs)
3121 - VEC_length (data_reference_p, datarefs) + i;
3122 ddr = VEC_index (ddr_p, ddrs, k);
3123 gcc_assert (DDR_A (ddr) == olddr && DDR_B (ddr) == olddr);
3124 newddr = initialize_data_dependence_relation (dr, dr, nest);
3125 compute_self_dependence (newddr);
3126 VEC_replace (ddr_p, ddrs, k, newddr);
3127 free_dependence_relation (ddr);
3128 VEC_replace (data_reference_p, datarefs, i, dr);
3132 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS))
3135 "not vectorized: data dependence conflict"
3136 " prevents gather");
3137 print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM);
3142 STMT_VINFO_GATHER_P (stmt_info) = true;
3150 /* Function vect_get_new_vect_var.
3152 Returns a name for a new variable. The current naming scheme appends the
3153 prefix "vect_" or "vect_p" (depending on the value of VAR_KIND) to
3154 the name of vectorizer generated variables, and appends that to NAME if
3158 vect_get_new_vect_var (tree type, enum vect_var_kind var_kind, const char *name)
3165 case vect_simple_var:
3168 case vect_scalar_var:
3171 case vect_pointer_var:
3180 char* tmp = concat (prefix, name, NULL);
3181 new_vect_var = create_tmp_var (type, tmp);
3185 new_vect_var = create_tmp_var (type, prefix);
3187 /* Mark vector typed variable as a gimple register variable. */
3188 if (TREE_CODE (type) == VECTOR_TYPE)
3189 DECL_GIMPLE_REG_P (new_vect_var) = true;
3191 return new_vect_var;
3195 /* Function vect_create_addr_base_for_vector_ref.
3197 Create an expression that computes the address of the first memory location
3198 that will be accessed for a data reference.
3201 STMT: The statement containing the data reference.
3202 NEW_STMT_LIST: Must be initialized to NULL_TREE or a statement list.
3203 OFFSET: Optional. If supplied, it is be added to the initial address.
3204 LOOP: Specify relative to which loop-nest should the address be computed.
3205 For example, when the dataref is in an inner-loop nested in an
3206 outer-loop that is now being vectorized, LOOP can be either the
3207 outer-loop, or the inner-loop. The first memory location accessed
3208 by the following dataref ('in' points to short):
3215 if LOOP=i_loop: &in (relative to i_loop)
3216 if LOOP=j_loop: &in+i*2B (relative to j_loop)
3219 1. Return an SSA_NAME whose value is the address of the memory location of
3220 the first vector of the data reference.
3221 2. If new_stmt_list is not NULL_TREE after return then the caller must insert
3222 these statement(s) which define the returned SSA_NAME.
3224 FORNOW: We are only handling array accesses with step 1. */
3227 vect_create_addr_base_for_vector_ref (gimple stmt,
3228 gimple_seq *new_stmt_list,
3232 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
3233 struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
3234 tree data_ref_base = unshare_expr (DR_BASE_ADDRESS (dr));
3236 tree data_ref_base_var;
3238 tree addr_base, addr_expr;
3240 gimple_seq seq = NULL;
3241 tree base_offset = unshare_expr (DR_OFFSET (dr));
3242 tree init = unshare_expr (DR_INIT (dr));
3244 tree step = TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr)));
3245 loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
3248 if (loop_vinfo && loop && loop != (gimple_bb (stmt))->loop_father)
3250 struct loop *outer_loop = LOOP_VINFO_LOOP (loop_vinfo);
3252 gcc_assert (nested_in_vect_loop_p (outer_loop, stmt));
3254 data_ref_base = unshare_expr (STMT_VINFO_DR_BASE_ADDRESS (stmt_info));
3255 base_offset = unshare_expr (STMT_VINFO_DR_OFFSET (stmt_info));
3256 init = unshare_expr (STMT_VINFO_DR_INIT (stmt_info));
3260 base_name = build_fold_indirect_ref (data_ref_base);
3263 base_offset = ssize_int (0);
3264 init = ssize_int (0);
3265 base_name = build_fold_indirect_ref (unshare_expr (DR_REF (dr)));
3268 data_ref_base_var = create_tmp_var (TREE_TYPE (data_ref_base), "batmp");
3269 add_referenced_var (data_ref_base_var);
3270 data_ref_base = force_gimple_operand (data_ref_base, &seq, true,
3272 gimple_seq_add_seq (new_stmt_list, seq);
3274 /* Create base_offset */
3275 base_offset = size_binop (PLUS_EXPR,
3276 fold_convert (sizetype, base_offset),
3277 fold_convert (sizetype, init));
3278 dest = create_tmp_var (sizetype, "base_off");
3279 add_referenced_var (dest);
3280 base_offset = force_gimple_operand (base_offset, &seq, true, dest);
3281 gimple_seq_add_seq (new_stmt_list, seq);
3285 tree tmp = create_tmp_var (sizetype, "offset");
3287 add_referenced_var (tmp);
3288 offset = fold_build2 (MULT_EXPR, sizetype,
3289 fold_convert (sizetype, offset), step);
3290 base_offset = fold_build2 (PLUS_EXPR, sizetype,
3291 base_offset, offset);
3292 base_offset = force_gimple_operand (base_offset, &seq, false, tmp);
3293 gimple_seq_add_seq (new_stmt_list, seq);
3296 /* base + base_offset */
3298 addr_base = fold_build_pointer_plus (data_ref_base, base_offset);
3301 addr_base = build1 (ADDR_EXPR,
3302 build_pointer_type (TREE_TYPE (DR_REF (dr))),
3303 unshare_expr (DR_REF (dr)));
3306 vect_ptr_type = build_pointer_type (STMT_VINFO_VECTYPE (stmt_info));
3307 base = get_base_address (DR_REF (dr));
3309 && TREE_CODE (base) == MEM_REF)
3311 = build_qualified_type (vect_ptr_type,
3312 TYPE_QUALS (TREE_TYPE (TREE_OPERAND (base, 0))));
3314 vec_stmt = fold_convert (vect_ptr_type, addr_base);
3315 addr_expr = vect_get_new_vect_var (vect_ptr_type, vect_pointer_var,
3316 get_name (base_name));
3317 add_referenced_var (addr_expr);
3318 vec_stmt = force_gimple_operand (vec_stmt, &seq, false, addr_expr);
3319 gimple_seq_add_seq (new_stmt_list, seq);
3321 if (DR_PTR_INFO (dr)
3322 && TREE_CODE (vec_stmt) == SSA_NAME)
3324 duplicate_ssa_name_ptr_info (vec_stmt, DR_PTR_INFO (dr));
3327 SSA_NAME_PTR_INFO (vec_stmt)->align = 1;
3328 SSA_NAME_PTR_INFO (vec_stmt)->misalign = 0;
3332 if (vect_print_dump_info (REPORT_DETAILS))
3334 fprintf (vect_dump, "created ");
3335 print_generic_expr (vect_dump, vec_stmt, TDF_SLIM);
3342 /* Function vect_create_data_ref_ptr.
3344 Create a new pointer-to-AGGR_TYPE variable (ap), that points to the first
3345 location accessed in the loop by STMT, along with the def-use update
3346 chain to appropriately advance the pointer through the loop iterations.
3347 Also set aliasing information for the pointer. This pointer is used by
3348 the callers to this function to create a memory reference expression for
3349 vector load/store access.
3352 1. STMT: a stmt that references memory. Expected to be of the form
3353 GIMPLE_ASSIGN <name, data-ref> or
3354 GIMPLE_ASSIGN <data-ref, name>.
3355 2. AGGR_TYPE: the type of the reference, which should be either a vector
3357 3. AT_LOOP: the loop where the vector memref is to be created.
3358 4. OFFSET (optional): an offset to be added to the initial address accessed
3359 by the data-ref in STMT.
3360 5. BSI: location where the new stmts are to be placed if there is no loop
3361 6. ONLY_INIT: indicate if ap is to be updated in the loop, or remain
3362 pointing to the initial address.
3365 1. Declare a new ptr to vector_type, and have it point to the base of the
3366 data reference (initial addressed accessed by the data reference).
3367 For example, for vector of type V8HI, the following code is generated:
3370 ap = (v8hi *)initial_address;
3372 if OFFSET is not supplied:
3373 initial_address = &a[init];
3374 if OFFSET is supplied:
3375 initial_address = &a[init + OFFSET];
3377 Return the initial_address in INITIAL_ADDRESS.
3379 2. If ONLY_INIT is true, just return the initial pointer. Otherwise, also
3380 update the pointer in each iteration of the loop.
3382 Return the increment stmt that updates the pointer in PTR_INCR.
3384 3. Set INV_P to true if the access pattern of the data reference in the
3385 vectorized loop is invariant. Set it to false otherwise.
3387 4. Return the pointer. */
3390 vect_create_data_ref_ptr (gimple stmt, tree aggr_type, struct loop *at_loop,
3391 tree offset, tree *initial_address,
3392 gimple_stmt_iterator *gsi, gimple *ptr_incr,
3393 bool only_init, bool *inv_p)
3396 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
3397 loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
3398 struct loop *loop = NULL;
3399 bool nested_in_vect_loop = false;
3400 struct loop *containing_loop = NULL;
3405 gimple_seq new_stmt_list = NULL;
3409 struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
3411 gimple_stmt_iterator incr_gsi;
3414 tree indx_before_incr, indx_after_incr;
3417 bb_vec_info bb_vinfo = STMT_VINFO_BB_VINFO (stmt_info);
3420 gcc_assert (TREE_CODE (aggr_type) == ARRAY_TYPE
3421 || TREE_CODE (aggr_type) == VECTOR_TYPE);
3425 loop = LOOP_VINFO_LOOP (loop_vinfo);
3426 nested_in_vect_loop = nested_in_vect_loop_p (loop, stmt);
3427 containing_loop = (gimple_bb (stmt))->loop_father;
3428 pe = loop_preheader_edge (loop);
3432 gcc_assert (bb_vinfo);
3437 /* Check the step (evolution) of the load in LOOP, and record
3438 whether it's invariant. */
3439 if (nested_in_vect_loop)
3440 step = STMT_VINFO_DR_STEP (stmt_info);
3442 step = DR_STEP (STMT_VINFO_DATA_REF (stmt_info));
3444 if (tree_int_cst_compare (step, size_zero_node) == 0)
3448 negative = tree_int_cst_compare (step, size_zero_node) < 0;
3450 /* Create an expression for the first address accessed by this load
3452 base_name = build_fold_indirect_ref (unshare_expr (DR_BASE_ADDRESS (dr)));
3454 if (vect_print_dump_info (REPORT_DETAILS))
3456 tree data_ref_base = base_name;
3457 fprintf (vect_dump, "create %s-pointer variable to type: ",
3458 tree_code_name[(int) TREE_CODE (aggr_type)]);
3459 print_generic_expr (vect_dump, aggr_type, TDF_SLIM);
3460 if (TREE_CODE (data_ref_base) == VAR_DECL
3461 || TREE_CODE (data_ref_base) == ARRAY_REF)
3462 fprintf (vect_dump, " vectorizing an array ref: ");
3463 else if (TREE_CODE (data_ref_base) == COMPONENT_REF)
3464 fprintf (vect_dump, " vectorizing a record based array ref: ");
3465 else if (TREE_CODE (data_ref_base) == SSA_NAME)
3466 fprintf (vect_dump, " vectorizing a pointer ref: ");
3467 print_generic_expr (vect_dump, base_name, TDF_SLIM);
3470 /* (1) Create the new aggregate-pointer variable. */
3471 aggr_ptr_type = build_pointer_type (aggr_type);
3472 base = get_base_address (DR_REF (dr));
3474 && TREE_CODE (base) == MEM_REF)
3476 = build_qualified_type (aggr_ptr_type,
3477 TYPE_QUALS (TREE_TYPE (TREE_OPERAND (base, 0))));
3478 aggr_ptr = vect_get_new_vect_var (aggr_ptr_type, vect_pointer_var,
3479 get_name (base_name));
3481 /* Vector and array types inherit the alias set of their component
3482 type by default so we need to use a ref-all pointer if the data
3483 reference does not conflict with the created aggregated data
3484 reference because it is not addressable. */
3485 if (!alias_sets_conflict_p (get_deref_alias_set (aggr_ptr),
3486 get_alias_set (DR_REF (dr))))
3489 = build_pointer_type_for_mode (aggr_type,
3490 TYPE_MODE (aggr_ptr_type), true);
3491 aggr_ptr = vect_get_new_vect_var (aggr_ptr_type, vect_pointer_var,
3492 get_name (base_name));
3495 /* Likewise for any of the data references in the stmt group. */
3496 else if (STMT_VINFO_GROUP_SIZE (stmt_info) > 1)
3498 gimple orig_stmt = STMT_VINFO_GROUP_FIRST_ELEMENT (stmt_info);
3501 tree lhs = gimple_assign_lhs (orig_stmt);
3502 if (!alias_sets_conflict_p (get_deref_alias_set (aggr_ptr),
3503 get_alias_set (lhs)))
3506 = build_pointer_type_for_mode (aggr_type,
3507 TYPE_MODE (aggr_ptr_type), true);
3509 = vect_get_new_vect_var (aggr_ptr_type, vect_pointer_var,
3510 get_name (base_name));
3514 orig_stmt = STMT_VINFO_GROUP_NEXT_ELEMENT (vinfo_for_stmt (orig_stmt));
3519 add_referenced_var (aggr_ptr);
3521 /* Note: If the dataref is in an inner-loop nested in LOOP, and we are
3522 vectorizing LOOP (i.e., outer-loop vectorization), we need to create two
3523 def-use update cycles for the pointer: one relative to the outer-loop
3524 (LOOP), which is what steps (3) and (4) below do. The other is relative
3525 to the inner-loop (which is the inner-most loop containing the dataref),
3526 and this is done be step (5) below.
3528 When vectorizing inner-most loops, the vectorized loop (LOOP) is also the
3529 inner-most loop, and so steps (3),(4) work the same, and step (5) is
3530 redundant. Steps (3),(4) create the following:
3533 LOOP: vp1 = phi(vp0,vp2)
3539 If there is an inner-loop nested in loop, then step (5) will also be
3540 applied, and an additional update in the inner-loop will be created:
3543 LOOP: vp1 = phi(vp0,vp2)
3545 inner: vp3 = phi(vp1,vp4)
3546 vp4 = vp3 + inner_step
3552 /* (2) Calculate the initial address of the aggregate-pointer, and set
3553 the aggregate-pointer to point to it before the loop. */
3555 /* Create: (&(base[init_val+offset]) in the loop preheader. */
3557 new_temp = vect_create_addr_base_for_vector_ref (stmt, &new_stmt_list,
3563 new_bb = gsi_insert_seq_on_edge_immediate (pe, new_stmt_list);
3564 gcc_assert (!new_bb);
3567 gsi_insert_seq_before (gsi, new_stmt_list, GSI_SAME_STMT);
3570 *initial_address = new_temp;
3572 /* Create: p = (aggr_type *) initial_base */
3573 if (TREE_CODE (new_temp) != SSA_NAME
3574 || !useless_type_conversion_p (aggr_ptr_type, TREE_TYPE (new_temp)))
3576 vec_stmt = gimple_build_assign (aggr_ptr,
3577 fold_convert (aggr_ptr_type, new_temp));
3578 aggr_ptr_init = make_ssa_name (aggr_ptr, vec_stmt);
3579 /* Copy the points-to information if it exists. */
3580 if (DR_PTR_INFO (dr))
3581 duplicate_ssa_name_ptr_info (aggr_ptr_init, DR_PTR_INFO (dr));
3582 gimple_assign_set_lhs (vec_stmt, aggr_ptr_init);
3585 new_bb = gsi_insert_on_edge_immediate (pe, vec_stmt);
3586 gcc_assert (!new_bb);
3589 gsi_insert_before (gsi, vec_stmt, GSI_SAME_STMT);
3592 aggr_ptr_init = new_temp;
3594 /* (3) Handle the updating of the aggregate-pointer inside the loop.
3595 This is needed when ONLY_INIT is false, and also when AT_LOOP is the
3596 inner-loop nested in LOOP (during outer-loop vectorization). */
3598 /* No update in loop is required. */
3599 if (only_init && (!loop_vinfo || at_loop == loop))
3600 aptr = aggr_ptr_init;
3603 /* The step of the aggregate pointer is the type size. */
3604 tree step = TYPE_SIZE_UNIT (aggr_type);
3605 /* One exception to the above is when the scalar step of the load in
3606 LOOP is zero. In this case the step here is also zero. */
3608 step = size_zero_node;
3610 step = fold_build1 (NEGATE_EXPR, TREE_TYPE (step), step);
3612 standard_iv_increment_position (loop, &incr_gsi, &insert_after);
3614 create_iv (aggr_ptr_init,
3615 fold_convert (aggr_ptr_type, step),
3616 aggr_ptr, loop, &incr_gsi, insert_after,
3617 &indx_before_incr, &indx_after_incr);
3618 incr = gsi_stmt (incr_gsi);
3619 set_vinfo_for_stmt (incr, new_stmt_vec_info (incr, loop_vinfo, NULL));
3621 /* Copy the points-to information if it exists. */
3622 if (DR_PTR_INFO (dr))
3624 duplicate_ssa_name_ptr_info (indx_before_incr, DR_PTR_INFO (dr));
3625 duplicate_ssa_name_ptr_info (indx_after_incr, DR_PTR_INFO (dr));
3630 aptr = indx_before_incr;
3633 if (!nested_in_vect_loop || only_init)
3637 /* (4) Handle the updating of the aggregate-pointer inside the inner-loop
3638 nested in LOOP, if exists. */
3640 gcc_assert (nested_in_vect_loop);
3643 standard_iv_increment_position (containing_loop, &incr_gsi,
3645 create_iv (aptr, fold_convert (aggr_ptr_type, DR_STEP (dr)), aggr_ptr,
3646 containing_loop, &incr_gsi, insert_after, &indx_before_incr,
3648 incr = gsi_stmt (incr_gsi);
3649 set_vinfo_for_stmt (incr, new_stmt_vec_info (incr, loop_vinfo, NULL));
3651 /* Copy the points-to information if it exists. */
3652 if (DR_PTR_INFO (dr))
3654 duplicate_ssa_name_ptr_info (indx_before_incr, DR_PTR_INFO (dr));
3655 duplicate_ssa_name_ptr_info (indx_after_incr, DR_PTR_INFO (dr));
3660 return indx_before_incr;
3667 /* Function bump_vector_ptr
3669 Increment a pointer (to a vector type) by vector-size. If requested,
3670 i.e. if PTR-INCR is given, then also connect the new increment stmt
3671 to the existing def-use update-chain of the pointer, by modifying
3672 the PTR_INCR as illustrated below:
3674 The pointer def-use update-chain before this function:
3675 DATAREF_PTR = phi (p_0, p_2)
3677 PTR_INCR: p_2 = DATAREF_PTR + step
3679 The pointer def-use update-chain after this function:
3680 DATAREF_PTR = phi (p_0, p_2)
3682 NEW_DATAREF_PTR = DATAREF_PTR + BUMP
3684 PTR_INCR: p_2 = NEW_DATAREF_PTR + step
3687 DATAREF_PTR - ssa_name of a pointer (to vector type) that is being updated
3689 PTR_INCR - optional. The stmt that updates the pointer in each iteration of
3690 the loop. The increment amount across iterations is expected
3692 BSI - location where the new update stmt is to be placed.
3693 STMT - the original scalar memory-access stmt that is being vectorized.
3694 BUMP - optional. The offset by which to bump the pointer. If not given,
3695 the offset is assumed to be vector_size.
3697 Output: Return NEW_DATAREF_PTR as illustrated above.
3702 bump_vector_ptr (tree dataref_ptr, gimple ptr_incr, gimple_stmt_iterator *gsi,
3703 gimple stmt, tree bump)
3705 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
3706 struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
3707 tree vectype = STMT_VINFO_VECTYPE (stmt_info);
3708 tree ptr_var = SSA_NAME_VAR (dataref_ptr);
3709 tree update = TYPE_SIZE_UNIT (vectype);
3712 use_operand_p use_p;
3713 tree new_dataref_ptr;
3718 incr_stmt = gimple_build_assign_with_ops (POINTER_PLUS_EXPR, ptr_var,
3719 dataref_ptr, update);
3720 new_dataref_ptr = make_ssa_name (ptr_var, incr_stmt);
3721 gimple_assign_set_lhs (incr_stmt, new_dataref_ptr);
3722 vect_finish_stmt_generation (stmt, incr_stmt, gsi);
3724 /* Copy the points-to information if it exists. */
3725 if (DR_PTR_INFO (dr))
3727 duplicate_ssa_name_ptr_info (new_dataref_ptr, DR_PTR_INFO (dr));
3728 SSA_NAME_PTR_INFO (new_dataref_ptr)->align = 1;
3729 SSA_NAME_PTR_INFO (new_dataref_ptr)->misalign = 0;
3733 return new_dataref_ptr;
3735 /* Update the vector-pointer's cross-iteration increment. */
3736 FOR_EACH_SSA_USE_OPERAND (use_p, ptr_incr, iter, SSA_OP_USE)
3738 tree use = USE_FROM_PTR (use_p);
3740 if (use == dataref_ptr)
3741 SET_USE (use_p, new_dataref_ptr);
3743 gcc_assert (tree_int_cst_compare (use, update) == 0);
3746 return new_dataref_ptr;
3750 /* Function vect_create_destination_var.
3752 Create a new temporary of type VECTYPE. */
3755 vect_create_destination_var (tree scalar_dest, tree vectype)
3758 const char *new_name;
3760 enum vect_var_kind kind;
3762 kind = vectype ? vect_simple_var : vect_scalar_var;
3763 type = vectype ? vectype : TREE_TYPE (scalar_dest);
3765 gcc_assert (TREE_CODE (scalar_dest) == SSA_NAME);
3767 new_name = get_name (scalar_dest);
3770 vec_dest = vect_get_new_vect_var (type, kind, new_name);
3771 add_referenced_var (vec_dest);
3776 /* Function vect_strided_store_supported.
3778 Returns TRUE is INTERLEAVE_HIGH and INTERLEAVE_LOW operations are supported,
3779 and FALSE otherwise. */
3782 vect_strided_store_supported (tree vectype, unsigned HOST_WIDE_INT count)
3784 optab ih_optab, il_optab;
3785 enum machine_mode mode;
3787 mode = TYPE_MODE (vectype);
3789 /* vect_permute_store_chain requires the group size to be a power of two. */
3790 if (exact_log2 (count) == -1)
3792 if (vect_print_dump_info (REPORT_DETAILS))
3793 fprintf (vect_dump, "the size of the group of strided accesses"
3794 " is not a power of 2");
3798 /* Check that the operation is supported. */
3799 ih_optab = optab_for_tree_code (VEC_INTERLEAVE_HIGH_EXPR,
3800 vectype, optab_default);
3801 il_optab = optab_for_tree_code (VEC_INTERLEAVE_LOW_EXPR,
3802 vectype, optab_default);
3803 if (il_optab && ih_optab
3804 && optab_handler (ih_optab, mode) != CODE_FOR_nothing
3805 && optab_handler (il_optab, mode) != CODE_FOR_nothing)
3808 if (can_vec_perm_for_code_p (VEC_INTERLEAVE_HIGH_EXPR, mode, NULL)
3809 && can_vec_perm_for_code_p (VEC_INTERLEAVE_LOW_EXPR, mode, NULL))
3812 if (vect_print_dump_info (REPORT_DETAILS))
3813 fprintf (vect_dump, "interleave op not supported by target.");
3818 /* Return TRUE if vec_store_lanes is available for COUNT vectors of
3822 vect_store_lanes_supported (tree vectype, unsigned HOST_WIDE_INT count)
3824 return vect_lanes_optab_supported_p ("vec_store_lanes",
3825 vec_store_lanes_optab,
3830 /* Function vect_permute_store_chain.
3832 Given a chain of interleaved stores in DR_CHAIN of LENGTH that must be
3833 a power of 2, generate interleave_high/low stmts to reorder the data
3834 correctly for the stores. Return the final references for stores in
3837 E.g., LENGTH is 4 and the scalar type is short, i.e., VF is 8.
3838 The input is 4 vectors each containing 8 elements. We assign a number to
3839 each element, the input sequence is:
3841 1st vec: 0 1 2 3 4 5 6 7
3842 2nd vec: 8 9 10 11 12 13 14 15
3843 3rd vec: 16 17 18 19 20 21 22 23
3844 4th vec: 24 25 26 27 28 29 30 31
3846 The output sequence should be:
3848 1st vec: 0 8 16 24 1 9 17 25
3849 2nd vec: 2 10 18 26 3 11 19 27
3850 3rd vec: 4 12 20 28 5 13 21 30
3851 4th vec: 6 14 22 30 7 15 23 31
3853 i.e., we interleave the contents of the four vectors in their order.
3855 We use interleave_high/low instructions to create such output. The input of
3856 each interleave_high/low operation is two vectors:
3859 the even elements of the result vector are obtained left-to-right from the
3860 high/low elements of the first vector. The odd elements of the result are
3861 obtained left-to-right from the high/low elements of the second vector.
3862 The output of interleave_high will be: 0 4 1 5
3863 and of interleave_low: 2 6 3 7
3866 The permutation is done in log LENGTH stages. In each stage interleave_high
3867 and interleave_low stmts are created for each pair of vectors in DR_CHAIN,
3868 where the first argument is taken from the first half of DR_CHAIN and the
3869 second argument from it's second half.
3872 I1: interleave_high (1st vec, 3rd vec)
3873 I2: interleave_low (1st vec, 3rd vec)
3874 I3: interleave_high (2nd vec, 4th vec)
3875 I4: interleave_low (2nd vec, 4th vec)
3877 The output for the first stage is:
3879 I1: 0 16 1 17 2 18 3 19
3880 I2: 4 20 5 21 6 22 7 23
3881 I3: 8 24 9 25 10 26 11 27
3882 I4: 12 28 13 29 14 30 15 31
3884 The output of the second stage, i.e. the final result is:
3886 I1: 0 8 16 24 1 9 17 25
3887 I2: 2 10 18 26 3 11 19 27
3888 I3: 4 12 20 28 5 13 21 30
3889 I4: 6 14 22 30 7 15 23 31. */
3892 vect_permute_store_chain (VEC(tree,heap) *dr_chain,
3893 unsigned int length,
3895 gimple_stmt_iterator *gsi,
3896 VEC(tree,heap) **result_chain)
3898 tree perm_dest, vect1, vect2, high, low;
3900 tree vectype = STMT_VINFO_VECTYPE (vinfo_for_stmt (stmt));
3903 enum tree_code high_code, low_code;
3905 gcc_assert (vect_strided_store_supported (vectype, length));
3907 *result_chain = VEC_copy (tree, heap, dr_chain);
3909 for (i = 0; i < exact_log2 (length); i++)
3911 for (j = 0; j < length/2; j++)
3913 vect1 = VEC_index (tree, dr_chain, j);
3914 vect2 = VEC_index (tree, dr_chain, j+length/2);
3916 /* Create interleaving stmt:
3917 in the case of big endian:
3918 high = interleave_high (vect1, vect2)
3919 and in the case of little endian:
3920 high = interleave_low (vect1, vect2). */
3921 perm_dest = create_tmp_var (vectype, "vect_inter_high");
3922 DECL_GIMPLE_REG_P (perm_dest) = 1;
3923 add_referenced_var (perm_dest);
3924 if (BYTES_BIG_ENDIAN)
3926 high_code = VEC_INTERLEAVE_HIGH_EXPR;
3927 low_code = VEC_INTERLEAVE_LOW_EXPR;
3931 low_code = VEC_INTERLEAVE_HIGH_EXPR;
3932 high_code = VEC_INTERLEAVE_LOW_EXPR;
3934 perm_stmt = gimple_build_assign_with_ops (high_code, perm_dest,
3936 high = make_ssa_name (perm_dest, perm_stmt);
3937 gimple_assign_set_lhs (perm_stmt, high);
3938 vect_finish_stmt_generation (stmt, perm_stmt, gsi);
3939 VEC_replace (tree, *result_chain, 2*j, high);
3941 /* Create interleaving stmt:
3942 in the case of big endian:
3943 low = interleave_low (vect1, vect2)
3944 and in the case of little endian:
3945 low = interleave_high (vect1, vect2). */
3946 perm_dest = create_tmp_var (vectype, "vect_inter_low");
3947 DECL_GIMPLE_REG_P (perm_dest) = 1;
3948 add_referenced_var (perm_dest);
3949 perm_stmt = gimple_build_assign_with_ops (low_code, perm_dest,
3951 low = make_ssa_name (perm_dest, perm_stmt);
3952 gimple_assign_set_lhs (perm_stmt, low);
3953 vect_finish_stmt_generation (stmt, perm_stmt, gsi);
3954 VEC_replace (tree, *result_chain, 2*j+1, low);
3956 dr_chain = VEC_copy (tree, heap, *result_chain);
3960 /* Function vect_setup_realignment
3962 This function is called when vectorizing an unaligned load using
3963 the dr_explicit_realign[_optimized] scheme.
3964 This function generates the following code at the loop prolog:
3967 x msq_init = *(floor(p)); # prolog load
3968 realignment_token = call target_builtin;
3970 x msq = phi (msq_init, ---)
3972 The stmts marked with x are generated only for the case of
3973 dr_explicit_realign_optimized.
3975 The code above sets up a new (vector) pointer, pointing to the first
3976 location accessed by STMT, and a "floor-aligned" load using that pointer.
3977 It also generates code to compute the "realignment-token" (if the relevant
3978 target hook was defined), and creates a phi-node at the loop-header bb
3979 whose arguments are the result of the prolog-load (created by this
3980 function) and the result of a load that takes place in the loop (to be
3981 created by the caller to this function).
3983 For the case of dr_explicit_realign_optimized:
3984 The caller to this function uses the phi-result (msq) to create the
3985 realignment code inside the loop, and sets up the missing phi argument,
3988 msq = phi (msq_init, lsq)
3989 lsq = *(floor(p')); # load in loop
3990 result = realign_load (msq, lsq, realignment_token);
3992 For the case of dr_explicit_realign:
3994 msq = *(floor(p)); # load in loop
3996 lsq = *(floor(p')); # load in loop
3997 result = realign_load (msq, lsq, realignment_token);
4000 STMT - (scalar) load stmt to be vectorized. This load accesses
4001 a memory location that may be unaligned.
4002 BSI - place where new code is to be inserted.
4003 ALIGNMENT_SUPPORT_SCHEME - which of the two misalignment handling schemes
4007 REALIGNMENT_TOKEN - the result of a call to the builtin_mask_for_load
4008 target hook, if defined.
4009 Return value - the result of the loop-header phi node. */
4012 vect_setup_realignment (gimple stmt, gimple_stmt_iterator *gsi,
4013 tree *realignment_token,
4014 enum dr_alignment_support alignment_support_scheme,
4016 struct loop **at_loop)
4018 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
4019 tree vectype = STMT_VINFO_VECTYPE (stmt_info);
4020 loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
4021 struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info);
4022 struct loop *loop = NULL;
4024 tree scalar_dest = gimple_assign_lhs (stmt);
4031 tree msq_init = NULL_TREE;
4034 tree msq = NULL_TREE;
4035 gimple_seq stmts = NULL;
4037 bool compute_in_loop = false;
4038 bool nested_in_vect_loop = false;
4039 struct loop *containing_loop = (gimple_bb (stmt))->loop_father;
4040 struct loop *loop_for_initial_load = NULL;
4044 loop = LOOP_VINFO_LOOP (loop_vinfo);
4045 nested_in_vect_loop = nested_in_vect_loop_p (loop, stmt);
4048 gcc_assert (alignment_support_scheme == dr_explicit_realign
4049 || alignment_support_scheme == dr_explicit_realign_optimized);
4051 /* We need to generate three things:
4052 1. the misalignment computation
4053 2. the extra vector load (for the optimized realignment scheme).
4054 3. the phi node for the two vectors from which the realignment is
4055 done (for the optimized realignment scheme). */
4057 /* 1. Determine where to generate the misalignment computation.
4059 If INIT_ADDR is NULL_TREE, this indicates that the misalignment
4060 calculation will be generated by this function, outside the loop (in the
4061 preheader). Otherwise, INIT_ADDR had already been computed for us by the
4062 caller, inside the loop.
4064 Background: If the misalignment remains fixed throughout the iterations of
4065 the loop, then both realignment schemes are applicable, and also the
4066 misalignment computation can be done outside LOOP. This is because we are
4067 vectorizing LOOP, and so the memory accesses in LOOP advance in steps that
4068 are a multiple of VS (the Vector Size), and therefore the misalignment in
4069 different vectorized LOOP iterations is always the same.
4070 The problem arises only if the memory access is in an inner-loop nested
4071 inside LOOP, which is now being vectorized using outer-loop vectorization.
4072 This is the only case when the misalignment of the memory access may not
4073 remain fixed throughout the iterations of the inner-loop (as explained in
4074 detail in vect_supportable_dr_alignment). In this case, not only is the
4075 optimized realignment scheme not applicable, but also the misalignment
4076 computation (and generation of the realignment token that is passed to
4077 REALIGN_LOAD) have to be done inside the loop.
4079 In short, INIT_ADDR indicates whether we are in a COMPUTE_IN_LOOP mode
4080 or not, which in turn determines if the misalignment is computed inside
4081 the inner-loop, or outside LOOP. */
4083 if (init_addr != NULL_TREE || !loop_vinfo)
4085 compute_in_loop = true;
4086 gcc_assert (alignment_support_scheme == dr_explicit_realign);
4090 /* 2. Determine where to generate the extra vector load.
4092 For the optimized realignment scheme, instead of generating two vector
4093 loads in each iteration, we generate a single extra vector load in the
4094 preheader of the loop, and in each iteration reuse the result of the
4095 vector load from the previous iteration. In case the memory access is in
4096 an inner-loop nested inside LOOP, which is now being vectorized using
4097 outer-loop vectorization, we need to determine whether this initial vector
4098 load should be generated at the preheader of the inner-loop, or can be
4099 generated at the preheader of LOOP. If the memory access has no evolution
4100 in LOOP, it can be generated in the preheader of LOOP. Otherwise, it has
4101 to be generated inside LOOP (in the preheader of the inner-loop). */
4103 if (nested_in_vect_loop)
4105 tree outerloop_step = STMT_VINFO_DR_STEP (stmt_info);
4106 bool invariant_in_outerloop =
4107 (tree_int_cst_compare (outerloop_step, size_zero_node) == 0);
4108 loop_for_initial_load = (invariant_in_outerloop ? loop : loop->inner);
4111 loop_for_initial_load = loop;
4113 *at_loop = loop_for_initial_load;
4115 if (loop_for_initial_load)
4116 pe = loop_preheader_edge (loop_for_initial_load);
4118 /* 3. For the case of the optimized realignment, create the first vector
4119 load at the loop preheader. */
4121 if (alignment_support_scheme == dr_explicit_realign_optimized)
4123 /* Create msq_init = *(floor(p1)) in the loop preheader */
4125 gcc_assert (!compute_in_loop);
4126 vec_dest = vect_create_destination_var (scalar_dest, vectype);
4127 ptr = vect_create_data_ref_ptr (stmt, vectype, loop_for_initial_load,
4128 NULL_TREE, &init_addr, NULL, &inc,
4130 new_stmt = gimple_build_assign_with_ops
4131 (BIT_AND_EXPR, NULL_TREE, ptr,
4132 build_int_cst (TREE_TYPE (ptr),
4133 -(HOST_WIDE_INT)TYPE_ALIGN_UNIT (vectype)));
4134 new_temp = make_ssa_name (SSA_NAME_VAR (ptr), new_stmt);
4135 gimple_assign_set_lhs (new_stmt, new_temp);
4136 new_bb = gsi_insert_on_edge_immediate (pe, new_stmt);
4137 gcc_assert (!new_bb);
4139 = build2 (MEM_REF, TREE_TYPE (vec_dest), new_temp,
4140 build_int_cst (reference_alias_ptr_type (DR_REF (dr)), 0));
4141 new_stmt = gimple_build_assign (vec_dest, data_ref);
4142 new_temp = make_ssa_name (vec_dest, new_stmt);
4143 gimple_assign_set_lhs (new_stmt, new_temp);
4144 mark_symbols_for_renaming (new_stmt);
4147 new_bb = gsi_insert_on_edge_immediate (pe, new_stmt);
4148 gcc_assert (!new_bb);
4151 gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
4153 msq_init = gimple_assign_lhs (new_stmt);
4156 /* 4. Create realignment token using a target builtin, if available.
4157 It is done either inside the containing loop, or before LOOP (as
4158 determined above). */
4160 if (targetm.vectorize.builtin_mask_for_load)
4164 /* Compute INIT_ADDR - the initial addressed accessed by this memref. */
4167 /* Generate the INIT_ADDR computation outside LOOP. */
4168 init_addr = vect_create_addr_base_for_vector_ref (stmt, &stmts,
4172 pe = loop_preheader_edge (loop);
4173 new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts);
4174 gcc_assert (!new_bb);
4177 gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
4180 builtin_decl = targetm.vectorize.builtin_mask_for_load ();
4181 new_stmt = gimple_build_call (builtin_decl, 1, init_addr);
4183 vect_create_destination_var (scalar_dest,
4184 gimple_call_return_type (new_stmt));
4185 new_temp = make_ssa_name (vec_dest, new_stmt);
4186 gimple_call_set_lhs (new_stmt, new_temp);
4188 if (compute_in_loop)
4189 gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
4192 /* Generate the misalignment computation outside LOOP. */
4193 pe = loop_preheader_edge (loop);
4194 new_bb = gsi_insert_on_edge_immediate (pe, new_stmt);
4195 gcc_assert (!new_bb);
4198 *realignment_token = gimple_call_lhs (new_stmt);
4200 /* The result of the CALL_EXPR to this builtin is determined from
4201 the value of the parameter and no global variables are touched
4202 which makes the builtin a "const" function. Requiring the
4203 builtin to have the "const" attribute makes it unnecessary
4204 to call mark_call_clobbered. */
4205 gcc_assert (TREE_READONLY (builtin_decl));
4208 if (alignment_support_scheme == dr_explicit_realign)
4211 gcc_assert (!compute_in_loop);
4212 gcc_assert (alignment_support_scheme == dr_explicit_realign_optimized);
4215 /* 5. Create msq = phi <msq_init, lsq> in loop */
4217 pe = loop_preheader_edge (containing_loop);
4218 vec_dest = vect_create_destination_var (scalar_dest, vectype);
4219 msq = make_ssa_name (vec_dest, NULL);
4220 phi_stmt = create_phi_node (msq, containing_loop->header);
4221 SSA_NAME_DEF_STMT (msq) = phi_stmt;
4222 add_phi_arg (phi_stmt, msq_init, pe, UNKNOWN_LOCATION);
4228 /* Function vect_strided_load_supported.
4230 Returns TRUE is EXTRACT_EVEN and EXTRACT_ODD operations are supported,
4231 and FALSE otherwise. */
4234 vect_strided_load_supported (tree vectype, unsigned HOST_WIDE_INT count)
4236 optab ee_optab, eo_optab;
4237 enum machine_mode mode;
4239 mode = TYPE_MODE (vectype);
4241 /* vect_permute_load_chain requires the group size to be a power of two. */
4242 if (exact_log2 (count) == -1)
4244 if (vect_print_dump_info (REPORT_DETAILS))
4245 fprintf (vect_dump, "the size of the group of strided accesses"
4246 " is not a power of 2");
4250 ee_optab = optab_for_tree_code (VEC_EXTRACT_EVEN_EXPR,
4251 vectype, optab_default);
4252 eo_optab = optab_for_tree_code (VEC_EXTRACT_ODD_EXPR,
4253 vectype, optab_default);
4254 if (ee_optab && eo_optab
4255 && optab_handler (ee_optab, mode) != CODE_FOR_nothing
4256 && optab_handler (eo_optab, mode) != CODE_FOR_nothing)
4259 if (can_vec_perm_for_code_p (VEC_EXTRACT_EVEN_EXPR, mode, NULL)
4260 && can_vec_perm_for_code_p (VEC_EXTRACT_ODD_EXPR, mode, NULL))
4263 if (vect_print_dump_info (REPORT_DETAILS))
4264 fprintf (vect_dump, "extract even/odd not supported by target");
4268 /* Return TRUE if vec_load_lanes is available for COUNT vectors of
4272 vect_load_lanes_supported (tree vectype, unsigned HOST_WIDE_INT count)
4274 return vect_lanes_optab_supported_p ("vec_load_lanes",
4275 vec_load_lanes_optab,
4279 /* Function vect_permute_load_chain.
4281 Given a chain of interleaved loads in DR_CHAIN of LENGTH that must be
4282 a power of 2, generate extract_even/odd stmts to reorder the input data
4283 correctly. Return the final references for loads in RESULT_CHAIN.
4285 E.g., LENGTH is 4 and the scalar type is short, i.e., VF is 8.
4286 The input is 4 vectors each containing 8 elements. We assign a number to each
4287 element, the input sequence is:
4289 1st vec: 0 1 2 3 4 5 6 7
4290 2nd vec: 8 9 10 11 12 13 14 15
4291 3rd vec: 16 17 18 19 20 21 22 23
4292 4th vec: 24 25 26 27 28 29 30 31
4294 The output sequence should be:
4296 1st vec: 0 4 8 12 16 20 24 28
4297 2nd vec: 1 5 9 13 17 21 25 29
4298 3rd vec: 2 6 10 14 18 22 26 30
4299 4th vec: 3 7 11 15 19 23 27 31
4301 i.e., the first output vector should contain the first elements of each
4302 interleaving group, etc.
4304 We use extract_even/odd instructions to create such output. The input of
4305 each extract_even/odd operation is two vectors
4309 and the output is the vector of extracted even/odd elements. The output of
4310 extract_even will be: 0 2 4 6
4311 and of extract_odd: 1 3 5 7
4314 The permutation is done in log LENGTH stages. In each stage extract_even
4315 and extract_odd stmts are created for each pair of vectors in DR_CHAIN in
4316 their order. In our example,
4318 E1: extract_even (1st vec, 2nd vec)
4319 E2: extract_odd (1st vec, 2nd vec)
4320 E3: extract_even (3rd vec, 4th vec)
4321 E4: extract_odd (3rd vec, 4th vec)
4323 The output for the first stage will be:
4325 E1: 0 2 4 6 8 10 12 14
4326 E2: 1 3 5 7 9 11 13 15
4327 E3: 16 18 20 22 24 26 28 30
4328 E4: 17 19 21 23 25 27 29 31
4330 In order to proceed and create the correct sequence for the next stage (or
4331 for the correct output, if the second stage is the last one, as in our
4332 example), we first put the output of extract_even operation and then the
4333 output of extract_odd in RESULT_CHAIN (which is then copied to DR_CHAIN).
4334 The input for the second stage is:
4336 1st vec (E1): 0 2 4 6 8 10 12 14
4337 2nd vec (E3): 16 18 20 22 24 26 28 30
4338 3rd vec (E2): 1 3 5 7 9 11 13 15
4339 4th vec (E4): 17 19 21 23 25 27 29 31
4341 The output of the second stage:
4343 E1: 0 4 8 12 16 20 24 28
4344 E2: 2 6 10 14 18 22 26 30
4345 E3: 1 5 9 13 17 21 25 29
4346 E4: 3 7 11 15 19 23 27 31
4348 And RESULT_CHAIN after reordering:
4350 1st vec (E1): 0 4 8 12 16 20 24 28
4351 2nd vec (E3): 1 5 9 13 17 21 25 29
4352 3rd vec (E2): 2 6 10 14 18 22 26 30
4353 4th vec (E4): 3 7 11 15 19 23 27 31. */
4356 vect_permute_load_chain (VEC(tree,heap) *dr_chain,
4357 unsigned int length,
4359 gimple_stmt_iterator *gsi,
4360 VEC(tree,heap) **result_chain)
4362 tree perm_dest, data_ref, first_vect, second_vect;
4364 tree vectype = STMT_VINFO_VECTYPE (vinfo_for_stmt (stmt));
4368 gcc_assert (vect_strided_load_supported (vectype, length));
4370 *result_chain = VEC_copy (tree, heap, dr_chain);
4371 for (i = 0; i < exact_log2 (length); i++)
4373 for (j = 0; j < length; j +=2)
4375 first_vect = VEC_index (tree, dr_chain, j);
4376 second_vect = VEC_index (tree, dr_chain, j+1);
4378 /* data_ref = permute_even (first_data_ref, second_data_ref); */
4379 perm_dest = create_tmp_var (vectype, "vect_perm_even");
4380 DECL_GIMPLE_REG_P (perm_dest) = 1;
4381 add_referenced_var (perm_dest);
4383 perm_stmt = gimple_build_assign_with_ops (VEC_EXTRACT_EVEN_EXPR,
4384 perm_dest, first_vect,
4387 data_ref = make_ssa_name (perm_dest, perm_stmt);
4388 gimple_assign_set_lhs (perm_stmt, data_ref);
4389 vect_finish_stmt_generation (stmt, perm_stmt, gsi);
4390 mark_symbols_for_renaming (perm_stmt);
4392 VEC_replace (tree, *result_chain, j/2, data_ref);
4394 /* data_ref = permute_odd (first_data_ref, second_data_ref); */
4395 perm_dest = create_tmp_var (vectype, "vect_perm_odd");
4396 DECL_GIMPLE_REG_P (perm_dest) = 1;
4397 add_referenced_var (perm_dest);
4399 perm_stmt = gimple_build_assign_with_ops (VEC_EXTRACT_ODD_EXPR,
4400 perm_dest, first_vect,
4402 data_ref = make_ssa_name (perm_dest, perm_stmt);
4403 gimple_assign_set_lhs (perm_stmt, data_ref);
4404 vect_finish_stmt_generation (stmt, perm_stmt, gsi);
4405 mark_symbols_for_renaming (perm_stmt);
4407 VEC_replace (tree, *result_chain, j/2+length/2, data_ref);
4409 dr_chain = VEC_copy (tree, heap, *result_chain);
4414 /* Function vect_transform_strided_load.
4416 Given a chain of input interleaved data-refs (in DR_CHAIN), build statements
4417 to perform their permutation and ascribe the result vectorized statements to
4418 the scalar statements.
4422 vect_transform_strided_load (gimple stmt, VEC(tree,heap) *dr_chain, int size,
4423 gimple_stmt_iterator *gsi)
4425 VEC(tree,heap) *result_chain = NULL;
4427 /* DR_CHAIN contains input data-refs that are a part of the interleaving.
4428 RESULT_CHAIN is the output of vect_permute_load_chain, it contains permuted
4429 vectors, that are ready for vector computation. */
4430 result_chain = VEC_alloc (tree, heap, size);
4431 vect_permute_load_chain (dr_chain, size, stmt, gsi, &result_chain);
4432 vect_record_strided_load_vectors (stmt, result_chain);
4433 VEC_free (tree, heap, result_chain);
4436 /* RESULT_CHAIN contains the output of a group of strided loads that were
4437 generated as part of the vectorization of STMT. Assign the statement
4438 for each vector to the associated scalar statement. */
4441 vect_record_strided_load_vectors (gimple stmt, VEC(tree,heap) *result_chain)
4443 gimple first_stmt = GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt));
4444 gimple next_stmt, new_stmt;
4445 unsigned int i, gap_count;
4448 /* Put a permuted data-ref in the VECTORIZED_STMT field.
4449 Since we scan the chain starting from it's first node, their order
4450 corresponds the order of data-refs in RESULT_CHAIN. */
4451 next_stmt = first_stmt;
4453 FOR_EACH_VEC_ELT (tree, result_chain, i, tmp_data_ref)
4458 /* Skip the gaps. Loads created for the gaps will be removed by dead
4459 code elimination pass later. No need to check for the first stmt in
4460 the group, since it always exists.
4461 GROUP_GAP is the number of steps in elements from the previous
4462 access (if there is no gap GROUP_GAP is 1). We skip loads that
4463 correspond to the gaps. */
4464 if (next_stmt != first_stmt
4465 && gap_count < GROUP_GAP (vinfo_for_stmt (next_stmt)))
4473 new_stmt = SSA_NAME_DEF_STMT (tmp_data_ref);
4474 /* We assume that if VEC_STMT is not NULL, this is a case of multiple
4475 copies, and we put the new vector statement in the first available
4477 if (!STMT_VINFO_VEC_STMT (vinfo_for_stmt (next_stmt)))
4478 STMT_VINFO_VEC_STMT (vinfo_for_stmt (next_stmt)) = new_stmt;
4481 if (!GROUP_SAME_DR_STMT (vinfo_for_stmt (next_stmt)))
4484 STMT_VINFO_VEC_STMT (vinfo_for_stmt (next_stmt));
4486 STMT_VINFO_RELATED_STMT (vinfo_for_stmt (prev_stmt));
4489 prev_stmt = rel_stmt;
4491 STMT_VINFO_RELATED_STMT (vinfo_for_stmt (rel_stmt));
4494 STMT_VINFO_RELATED_STMT (vinfo_for_stmt (prev_stmt)) =
4499 next_stmt = GROUP_NEXT_ELEMENT (vinfo_for_stmt (next_stmt));
4501 /* If NEXT_STMT accesses the same DR as the previous statement,
4502 put the same TMP_DATA_REF as its vectorized statement; otherwise
4503 get the next data-ref from RESULT_CHAIN. */
4504 if (!next_stmt || !GROUP_SAME_DR_STMT (vinfo_for_stmt (next_stmt)))
4510 /* Function vect_force_dr_alignment_p.
4512 Returns whether the alignment of a DECL can be forced to be aligned
4513 on ALIGNMENT bit boundary. */
4516 vect_can_force_dr_alignment_p (const_tree decl, unsigned int alignment)
4518 if (TREE_CODE (decl) != VAR_DECL)
4521 if (DECL_EXTERNAL (decl))
4524 if (TREE_ASM_WRITTEN (decl))
4527 if (TREE_STATIC (decl))
4528 return (alignment <= MAX_OFILE_ALIGNMENT);
4530 return (alignment <= MAX_STACK_ALIGNMENT);
4534 /* Return whether the data reference DR is supported with respect to its
4536 If CHECK_ALIGNED_ACCESSES is TRUE, check if the access is supported even
4537 it is aligned, i.e., check if it is possible to vectorize it with different
4540 enum dr_alignment_support
4541 vect_supportable_dr_alignment (struct data_reference *dr,
4542 bool check_aligned_accesses)
4544 gimple stmt = DR_STMT (dr);
4545 stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
4546 tree vectype = STMT_VINFO_VECTYPE (stmt_info);
4547 enum machine_mode mode = TYPE_MODE (vectype);
4548 loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info);
4549 struct loop *vect_loop = NULL;
4550 bool nested_in_vect_loop = false;
4552 if (aligned_access_p (dr) && !check_aligned_accesses)
4557 vect_loop = LOOP_VINFO_LOOP (loop_vinfo);
4558 nested_in_vect_loop = nested_in_vect_loop_p (vect_loop, stmt);
4561 /* Possibly unaligned access. */
4563 /* We can choose between using the implicit realignment scheme (generating
4564 a misaligned_move stmt) and the explicit realignment scheme (generating
4565 aligned loads with a REALIGN_LOAD). There are two variants to the
4566 explicit realignment scheme: optimized, and unoptimized.
4567 We can optimize the realignment only if the step between consecutive
4568 vector loads is equal to the vector size. Since the vector memory
4569 accesses advance in steps of VS (Vector Size) in the vectorized loop, it
4570 is guaranteed that the misalignment amount remains the same throughout the
4571 execution of the vectorized loop. Therefore, we can create the
4572 "realignment token" (the permutation mask that is passed to REALIGN_LOAD)
4573 at the loop preheader.
4575 However, in the case of outer-loop vectorization, when vectorizing a
4576 memory access in the inner-loop nested within the LOOP that is now being
4577 vectorized, while it is guaranteed that the misalignment of the
4578 vectorized memory access will remain the same in different outer-loop
4579 iterations, it is *not* guaranteed that is will remain the same throughout
4580 the execution of the inner-loop. This is because the inner-loop advances
4581 with the original scalar step (and not in steps of VS). If the inner-loop
4582 step happens to be a multiple of VS, then the misalignment remains fixed
4583 and we can use the optimized realignment scheme. For example:
4589 When vectorizing the i-loop in the above example, the step between
4590 consecutive vector loads is 1, and so the misalignment does not remain
4591 fixed across the execution of the inner-loop, and the realignment cannot
4592 be optimized (as illustrated in the following pseudo vectorized loop):
4594 for (i=0; i<N; i+=4)
4595 for (j=0; j<M; j++){
4596 vs += vp[i+j]; // misalignment of &vp[i+j] is {0,1,2,3,0,1,2,3,...}
4597 // when j is {0,1,2,3,4,5,6,7,...} respectively.
4598 // (assuming that we start from an aligned address).
4601 We therefore have to use the unoptimized realignment scheme:
4603 for (i=0; i<N; i+=4)
4604 for (j=k; j<M; j+=4)
4605 vs += vp[i+j]; // misalignment of &vp[i+j] is always k (assuming
4606 // that the misalignment of the initial address is
4609 The loop can then be vectorized as follows:
4611 for (k=0; k<4; k++){
4612 rt = get_realignment_token (&vp[k]);
4613 for (i=0; i<N; i+=4){
4615 for (j=k; j<M; j+=4){
4617 va = REALIGN_LOAD <v1,v2,rt>;
4624 if (DR_IS_READ (dr))
4626 bool is_packed = false;
4627 tree type = (TREE_TYPE (DR_REF (dr)));
4629 if (optab_handler (vec_realign_load_optab, mode) != CODE_FOR_nothing
4630 && (!targetm.vectorize.builtin_mask_for_load
4631 || targetm.vectorize.builtin_mask_for_load ()))
4633 tree vectype = STMT_VINFO_VECTYPE (stmt_info);
4634 if ((nested_in_vect_loop
4635 && (TREE_INT_CST_LOW (DR_STEP (dr))
4636 != GET_MODE_SIZE (TYPE_MODE (vectype))))
4638 return dr_explicit_realign;
4640 return dr_explicit_realign_optimized;
4642 if (!known_alignment_for_access_p (dr))
4644 tree ba = DR_BASE_OBJECT (dr);
4647 is_packed = contains_packed_reference (ba);
4650 if (targetm.vectorize.
4651 support_vector_misalignment (mode, type,
4652 DR_MISALIGNMENT (dr), is_packed))
4653 /* Can't software pipeline the loads, but can at least do them. */
4654 return dr_unaligned_supported;
4658 bool is_packed = false;
4659 tree type = (TREE_TYPE (DR_REF (dr)));
4661 if (!known_alignment_for_access_p (dr))
4663 tree ba = DR_BASE_OBJECT (dr);
4666 is_packed = contains_packed_reference (ba);
4669 if (targetm.vectorize.
4670 support_vector_misalignment (mode, type,
4671 DR_MISALIGNMENT (dr), is_packed))
4672 return dr_unaligned_supported;
4676 return dr_unaligned_unsupported;