2011-08-19 Andrew Stubbs <ams@codesourcery.com>
[official-gcc.git] / gcc / tree-vectorizer.c
blob77fb0344ad52a9d90be4161ac9eed939922284d7
1 /* Vectorizer
2 Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
3 Free Software Foundation, Inc.
4 Contributed by Dorit Naishlos <dorit@il.ibm.com>
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Loop and basic block vectorizer.
24 This file contains drivers for the three vectorizers:
25 (1) loop vectorizer (inter-iteration parallelism),
26 (2) loop-aware SLP (intra-iteration parallelism) (invoked by the loop
27 vectorizer)
28 (3) BB vectorizer (out-of-loops), aka SLP
30 The rest of the vectorizer's code is organized as follows:
31 - tree-vect-loop.c - loop specific parts such as reductions, etc. These are
32 used by drivers (1) and (2).
33 - tree-vect-loop-manip.c - vectorizer's loop control-flow utilities, used by
34 drivers (1) and (2).
35 - tree-vect-slp.c - BB vectorization specific analysis and transformation,
36 used by drivers (2) and (3).
37 - tree-vect-stmts.c - statements analysis and transformation (used by all).
38 - tree-vect-data-refs.c - vectorizer specific data-refs analysis and
39 manipulations (used by all).
40 - tree-vect-patterns.c - vectorizable code patterns detector (used by all)
42 Here's a poor attempt at illustrating that:
44 tree-vectorizer.c:
45 loop_vect() loop_aware_slp() slp_vect()
46 | / \ /
47 | / \ /
48 tree-vect-loop.c tree-vect-slp.c
49 | \ \ / / |
50 | \ \/ / |
51 | \ /\ / |
52 | \ / \ / |
53 tree-vect-stmts.c tree-vect-data-refs.c
54 \ /
55 tree-vect-patterns.c
58 #include "config.h"
59 #include "system.h"
60 #include "coretypes.h"
61 #include "tm.h"
62 #include "ggc.h"
63 #include "tree.h"
64 #include "tree-pretty-print.h"
65 #include "tree-flow.h"
66 #include "tree-dump.h"
67 #include "cfgloop.h"
68 #include "cfglayout.h"
69 #include "tree-vectorizer.h"
70 #include "tree-pass.h"
71 #include "timevar.h"
73 /* vect_dump will be set to stderr or dump_file if exist. */
74 FILE *vect_dump;
76 /* vect_verbosity_level set to an invalid value
77 to mark that it's uninitialized. */
78 static enum vect_verbosity_levels vect_verbosity_level = MAX_VERBOSITY_LEVEL;
80 /* Loop or bb location. */
81 LOC vect_location;
83 /* Vector mapping GIMPLE stmt to stmt_vec_info. */
84 VEC(vec_void_p,heap) *stmt_vec_info_vec;
88 /* Function vect_set_dump_settings.
90 Fix the verbosity level of the vectorizer if the
91 requested level was not set explicitly using the flag
92 -ftree-vectorizer-verbose=N.
93 Decide where to print the debugging information (dump_file/stderr).
94 If the user defined the verbosity level, but there is no dump file,
95 print to stderr, otherwise print to the dump file. */
97 static void
98 vect_set_dump_settings (bool slp)
100 vect_dump = dump_file;
102 /* Check if the verbosity level was defined by the user: */
103 if (user_vect_verbosity_level != MAX_VERBOSITY_LEVEL)
105 vect_verbosity_level = user_vect_verbosity_level;
106 /* Ignore user defined verbosity if dump flags require higher level of
107 verbosity. */
108 if (dump_file)
110 if (((dump_flags & TDF_DETAILS)
111 && vect_verbosity_level >= REPORT_DETAILS)
112 || ((dump_flags & TDF_STATS)
113 && vect_verbosity_level >= REPORT_UNVECTORIZED_LOCATIONS))
114 return;
116 else
118 /* If there is no dump file, print to stderr in case of loop
119 vectorization. */
120 if (!slp)
121 vect_dump = stderr;
123 return;
127 /* User didn't specify verbosity level: */
128 if (dump_file && (dump_flags & TDF_DETAILS))
129 vect_verbosity_level = REPORT_DETAILS;
130 else if (dump_file && (dump_flags & TDF_STATS))
131 vect_verbosity_level = REPORT_UNVECTORIZED_LOCATIONS;
132 else
133 vect_verbosity_level = REPORT_NONE;
135 gcc_assert (dump_file || vect_verbosity_level == REPORT_NONE);
139 /* Function debug_loop_details.
141 For vectorization debug dumps. */
143 bool
144 vect_print_dump_info (enum vect_verbosity_levels vl)
146 if (vl > vect_verbosity_level)
147 return false;
149 if (!current_function_decl || !vect_dump)
150 return false;
152 if (vect_location == UNKNOWN_LOC)
153 fprintf (vect_dump, "\n%s:%d: note: ",
154 DECL_SOURCE_FILE (current_function_decl),
155 DECL_SOURCE_LINE (current_function_decl));
156 else
157 fprintf (vect_dump, "\n%s:%d: note: ",
158 LOC_FILE (vect_location), LOC_LINE (vect_location));
160 return true;
164 /* Function vectorize_loops.
166 Entry point to loop vectorization phase. */
168 unsigned
169 vectorize_loops (void)
171 unsigned int i;
172 unsigned int num_vectorized_loops = 0;
173 unsigned int vect_loops_num;
174 loop_iterator li;
175 struct loop *loop;
177 vect_loops_num = number_of_loops ();
179 /* Bail out if there are no loops. */
180 if (vect_loops_num <= 1)
181 return 0;
183 /* Fix the verbosity level if not defined explicitly by the user. */
184 vect_set_dump_settings (false);
186 init_stmt_vec_info_vec ();
188 /* ----------- Analyze loops. ----------- */
190 /* If some loop was duplicated, it gets bigger number
191 than all previously defined loops. This fact allows us to run
192 only over initial loops skipping newly generated ones. */
193 FOR_EACH_LOOP (li, loop, 0)
194 if (optimize_loop_nest_for_speed_p (loop))
196 loop_vec_info loop_vinfo;
198 vect_location = find_loop_location (loop);
199 loop_vinfo = vect_analyze_loop (loop);
200 loop->aux = loop_vinfo;
202 if (!loop_vinfo || !LOOP_VINFO_VECTORIZABLE_P (loop_vinfo))
203 continue;
205 vect_transform_loop (loop_vinfo);
206 num_vectorized_loops++;
209 vect_location = UNKNOWN_LOC;
211 statistics_counter_event (cfun, "Vectorized loops", num_vectorized_loops);
212 if (vect_print_dump_info (REPORT_UNVECTORIZED_LOCATIONS)
213 || (num_vectorized_loops > 0
214 && vect_print_dump_info (REPORT_VECTORIZED_LOCATIONS)))
215 fprintf (vect_dump, "vectorized %u loops in function.\n",
216 num_vectorized_loops);
218 /* ----------- Finalize. ----------- */
220 mark_sym_for_renaming (gimple_vop (cfun));
222 for (i = 1; i < vect_loops_num; i++)
224 loop_vec_info loop_vinfo;
226 loop = get_loop (i);
227 if (!loop)
228 continue;
229 loop_vinfo = (loop_vec_info) loop->aux;
230 destroy_loop_vec_info (loop_vinfo, true);
231 loop->aux = NULL;
234 free_stmt_vec_info_vec ();
236 return num_vectorized_loops > 0 ? TODO_cleanup_cfg : 0;
240 /* Entry point to basic block SLP phase. */
242 static unsigned int
243 execute_vect_slp (void)
245 basic_block bb;
247 /* Fix the verbosity level if not defined explicitly by the user. */
248 vect_set_dump_settings (true);
250 init_stmt_vec_info_vec ();
252 FOR_EACH_BB (bb)
254 vect_location = find_bb_location (bb);
256 if (vect_slp_analyze_bb (bb))
258 vect_slp_transform_bb (bb);
260 if (vect_print_dump_info (REPORT_VECTORIZED_LOCATIONS))
261 fprintf (vect_dump, "basic block vectorized using SLP\n");
265 free_stmt_vec_info_vec ();
266 return 0;
269 static bool
270 gate_vect_slp (void)
272 /* Apply SLP either if the vectorizer is on and the user didn't specify
273 whether to run SLP or not, or if the SLP flag was set by the user. */
274 return ((flag_tree_vectorize != 0 && flag_tree_slp_vectorize != 0)
275 || flag_tree_slp_vectorize == 1);
278 struct gimple_opt_pass pass_slp_vectorize =
281 GIMPLE_PASS,
282 "slp", /* name */
283 gate_vect_slp, /* gate */
284 execute_vect_slp, /* execute */
285 NULL, /* sub */
286 NULL, /* next */
287 0, /* static_pass_number */
288 TV_TREE_SLP_VECTORIZATION, /* tv_id */
289 PROP_ssa | PROP_cfg, /* properties_required */
290 0, /* properties_provided */
291 0, /* properties_destroyed */
292 0, /* todo_flags_start */
293 TODO_ggc_collect
294 | TODO_verify_ssa
295 | TODO_update_ssa
296 | TODO_verify_stmts /* todo_flags_finish */
301 /* Increase alignment of global arrays to improve vectorization potential.
302 TODO:
303 - Consider also structs that have an array field.
304 - Use ipa analysis to prune arrays that can't be vectorized?
305 This should involve global alignment analysis and in the future also
306 array padding. */
308 static unsigned int
309 increase_alignment (void)
311 struct varpool_node *vnode;
313 /* Increase the alignment of all global arrays for vectorization. */
314 for (vnode = varpool_nodes_queue;
315 vnode;
316 vnode = vnode->next_needed)
318 tree vectype, decl = vnode->decl;
319 tree t;
320 unsigned int alignment;
322 t = TREE_TYPE(decl);
323 if (TREE_CODE (t) != ARRAY_TYPE)
324 continue;
325 vectype = get_vectype_for_scalar_type (strip_array_types (t));
326 if (!vectype)
327 continue;
328 alignment = TYPE_ALIGN (vectype);
329 if (DECL_ALIGN (decl) >= alignment)
330 continue;
332 if (vect_can_force_dr_alignment_p (decl, alignment))
334 DECL_ALIGN (decl) = TYPE_ALIGN (vectype);
335 DECL_USER_ALIGN (decl) = 1;
336 if (dump_file)
338 fprintf (dump_file, "Increasing alignment of decl: ");
339 print_generic_expr (dump_file, decl, TDF_SLIM);
340 fprintf (dump_file, "\n");
344 return 0;
348 static bool
349 gate_increase_alignment (void)
351 return flag_section_anchors && flag_tree_vectorize;
355 struct simple_ipa_opt_pass pass_ipa_increase_alignment =
358 SIMPLE_IPA_PASS,
359 "increase_alignment", /* name */
360 gate_increase_alignment, /* gate */
361 increase_alignment, /* execute */
362 NULL, /* sub */
363 NULL, /* next */
364 0, /* static_pass_number */
365 TV_IPA_OPT, /* tv_id */
366 0, /* properties_required */
367 0, /* properties_provided */
368 0, /* properties_destroyed */
369 0, /* todo_flags_start */
370 0 /* todo_flags_finish */