clang 19.0.0git
CGLoopInfo.cpp
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1//===---- CGLoopInfo.cpp - LLVM CodeGen for loop metadata -*- C++ -*-------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "CGLoopInfo.h"
11#include "clang/AST/Attr.h"
12#include "clang/AST/Expr.h"
14#include "llvm/IR/BasicBlock.h"
15#include "llvm/IR/CFG.h"
16#include "llvm/IR/Constants.h"
17#include "llvm/IR/InstrTypes.h"
18#include "llvm/IR/Instructions.h"
19#include "llvm/IR/Metadata.h"
20#include <optional>
21using namespace clang::CodeGen;
22using namespace llvm;
23
24MDNode *
25LoopInfo::createLoopPropertiesMetadata(ArrayRef<Metadata *> LoopProperties) {
26 LLVMContext &Ctx = Header->getContext();
27 SmallVector<Metadata *, 4> NewLoopProperties;
28 NewLoopProperties.push_back(nullptr);
29 NewLoopProperties.append(LoopProperties.begin(), LoopProperties.end());
30
31 MDNode *LoopID = MDNode::getDistinct(Ctx, NewLoopProperties);
32 LoopID->replaceOperandWith(0, LoopID);
33 return LoopID;
34}
35
36MDNode *LoopInfo::createPipeliningMetadata(const LoopAttributes &Attrs,
37 ArrayRef<Metadata *> LoopProperties,
38 bool &HasUserTransforms) {
39 LLVMContext &Ctx = Header->getContext();
40
41 std::optional<bool> Enabled;
42 if (Attrs.PipelineDisabled)
43 Enabled = false;
44 else if (Attrs.PipelineInitiationInterval != 0)
45 Enabled = true;
46
47 if (Enabled != true) {
48 SmallVector<Metadata *, 4> NewLoopProperties;
49 if (Enabled == false) {
50 NewLoopProperties.append(LoopProperties.begin(), LoopProperties.end());
51 NewLoopProperties.push_back(
52 MDNode::get(Ctx, {MDString::get(Ctx, "llvm.loop.pipeline.disable"),
53 ConstantAsMetadata::get(ConstantInt::get(
54 llvm::Type::getInt1Ty(Ctx), 1))}));
55 LoopProperties = NewLoopProperties;
56 }
57 return createLoopPropertiesMetadata(LoopProperties);
58 }
59
61 Args.push_back(nullptr);
62 Args.append(LoopProperties.begin(), LoopProperties.end());
63
64 if (Attrs.PipelineInitiationInterval > 0) {
65 Metadata *Vals[] = {
66 MDString::get(Ctx, "llvm.loop.pipeline.initiationinterval"),
67 ConstantAsMetadata::get(ConstantInt::get(
68 llvm::Type::getInt32Ty(Ctx), Attrs.PipelineInitiationInterval))};
69 Args.push_back(MDNode::get(Ctx, Vals));
70 }
71
72 // No follow-up: This is the last transformation.
73
74 MDNode *LoopID = MDNode::getDistinct(Ctx, Args);
75 LoopID->replaceOperandWith(0, LoopID);
76 HasUserTransforms = true;
77 return LoopID;
78}
79
80MDNode *
81LoopInfo::createPartialUnrollMetadata(const LoopAttributes &Attrs,
82 ArrayRef<Metadata *> LoopProperties,
83 bool &HasUserTransforms) {
84 LLVMContext &Ctx = Header->getContext();
85
86 std::optional<bool> Enabled;
88 Enabled = false;
89 else if (Attrs.UnrollEnable == LoopAttributes::Full)
90 Enabled = std::nullopt;
91 else if (Attrs.UnrollEnable != LoopAttributes::Unspecified ||
92 Attrs.UnrollCount != 0)
93 Enabled = true;
94
95 if (Enabled != true) {
96 // createFullUnrollMetadata will already have added llvm.loop.unroll.disable
97 // if unrolling is disabled.
98 return createPipeliningMetadata(Attrs, LoopProperties, HasUserTransforms);
99 }
100
101 SmallVector<Metadata *, 4> FollowupLoopProperties;
102
103 // Apply all loop properties to the unrolled loop.
104 FollowupLoopProperties.append(LoopProperties.begin(), LoopProperties.end());
105
106 // Don't unroll an already unrolled loop.
107 FollowupLoopProperties.push_back(
108 MDNode::get(Ctx, MDString::get(Ctx, "llvm.loop.unroll.disable")));
109
110 bool FollowupHasTransforms = false;
111 MDNode *Followup = createPipeliningMetadata(Attrs, FollowupLoopProperties,
112 FollowupHasTransforms);
113
115 Args.push_back(nullptr);
116 Args.append(LoopProperties.begin(), LoopProperties.end());
117
118 // Setting unroll.count
119 if (Attrs.UnrollCount > 0) {
120 Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.unroll.count"),
121 ConstantAsMetadata::get(ConstantInt::get(
122 llvm::Type::getInt32Ty(Ctx), Attrs.UnrollCount))};
123 Args.push_back(MDNode::get(Ctx, Vals));
124 }
125
126 // Setting unroll.full or unroll.disable
128 Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.unroll.enable")};
129 Args.push_back(MDNode::get(Ctx, Vals));
130 }
131
132 if (FollowupHasTransforms)
133 Args.push_back(MDNode::get(
134 Ctx, {MDString::get(Ctx, "llvm.loop.unroll.followup_all"), Followup}));
135
136 MDNode *LoopID = MDNode::getDistinct(Ctx, Args);
137 LoopID->replaceOperandWith(0, LoopID);
138 HasUserTransforms = true;
139 return LoopID;
140}
141
142MDNode *
143LoopInfo::createUnrollAndJamMetadata(const LoopAttributes &Attrs,
144 ArrayRef<Metadata *> LoopProperties,
145 bool &HasUserTransforms) {
146 LLVMContext &Ctx = Header->getContext();
147
148 std::optional<bool> Enabled;
150 Enabled = false;
151 else if (Attrs.UnrollAndJamEnable == LoopAttributes::Enable ||
152 Attrs.UnrollAndJamCount != 0)
153 Enabled = true;
154
155 if (Enabled != true) {
156 SmallVector<Metadata *, 4> NewLoopProperties;
157 if (Enabled == false) {
158 NewLoopProperties.append(LoopProperties.begin(), LoopProperties.end());
159 NewLoopProperties.push_back(MDNode::get(
160 Ctx, MDString::get(Ctx, "llvm.loop.unroll_and_jam.disable")));
161 LoopProperties = NewLoopProperties;
162 }
163 return createPartialUnrollMetadata(Attrs, LoopProperties,
164 HasUserTransforms);
165 }
166
167 SmallVector<Metadata *, 4> FollowupLoopProperties;
168 FollowupLoopProperties.append(LoopProperties.begin(), LoopProperties.end());
169 FollowupLoopProperties.push_back(
170 MDNode::get(Ctx, MDString::get(Ctx, "llvm.loop.unroll_and_jam.disable")));
171
172 bool FollowupHasTransforms = false;
173 MDNode *Followup = createPartialUnrollMetadata(Attrs, FollowupLoopProperties,
174 FollowupHasTransforms);
175
177 Args.push_back(nullptr);
178 Args.append(LoopProperties.begin(), LoopProperties.end());
179
180 // Setting unroll_and_jam.count
181 if (Attrs.UnrollAndJamCount > 0) {
182 Metadata *Vals[] = {
183 MDString::get(Ctx, "llvm.loop.unroll_and_jam.count"),
184 ConstantAsMetadata::get(ConstantInt::get(llvm::Type::getInt32Ty(Ctx),
185 Attrs.UnrollAndJamCount))};
186 Args.push_back(MDNode::get(Ctx, Vals));
187 }
188
190 Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.unroll_and_jam.enable")};
191 Args.push_back(MDNode::get(Ctx, Vals));
192 }
193
194 if (FollowupHasTransforms)
195 Args.push_back(MDNode::get(
196 Ctx, {MDString::get(Ctx, "llvm.loop.unroll_and_jam.followup_outer"),
197 Followup}));
198
199 if (UnrollAndJamInnerFollowup)
200 Args.push_back(MDNode::get(
201 Ctx, {MDString::get(Ctx, "llvm.loop.unroll_and_jam.followup_inner"),
202 UnrollAndJamInnerFollowup}));
203
204 MDNode *LoopID = MDNode::getDistinct(Ctx, Args);
205 LoopID->replaceOperandWith(0, LoopID);
206 HasUserTransforms = true;
207 return LoopID;
208}
209
210MDNode *
211LoopInfo::createLoopVectorizeMetadata(const LoopAttributes &Attrs,
212 ArrayRef<Metadata *> LoopProperties,
213 bool &HasUserTransforms) {
214 LLVMContext &Ctx = Header->getContext();
215
216 std::optional<bool> Enabled;
218 Enabled = false;
221 Attrs.InterleaveCount != 0 || Attrs.VectorizeWidth != 0 ||
223 Enabled = true;
224
225 if (Enabled != true) {
226 SmallVector<Metadata *, 4> NewLoopProperties;
227 if (Enabled == false) {
228 NewLoopProperties.append(LoopProperties.begin(), LoopProperties.end());
229 NewLoopProperties.push_back(
230 MDNode::get(Ctx, {MDString::get(Ctx, "llvm.loop.vectorize.enable"),
231 ConstantAsMetadata::get(ConstantInt::get(
232 llvm::Type::getInt1Ty(Ctx), 0))}));
233 LoopProperties = NewLoopProperties;
234 }
235 return createUnrollAndJamMetadata(Attrs, LoopProperties, HasUserTransforms);
236 }
237
238 // Apply all loop properties to the vectorized loop.
239 SmallVector<Metadata *, 4> FollowupLoopProperties;
240 FollowupLoopProperties.append(LoopProperties.begin(), LoopProperties.end());
241
242 // Don't vectorize an already vectorized loop.
243 FollowupLoopProperties.push_back(
244 MDNode::get(Ctx, MDString::get(Ctx, "llvm.loop.isvectorized")));
245
246 bool FollowupHasTransforms = false;
247 MDNode *Followup = createUnrollAndJamMetadata(Attrs, FollowupLoopProperties,
248 FollowupHasTransforms);
249
251 Args.push_back(nullptr);
252 Args.append(LoopProperties.begin(), LoopProperties.end());
253
254 // Setting vectorize.predicate when it has been specified and vectorization
255 // has not been disabled.
256 bool IsVectorPredicateEnabled = false;
258 IsVectorPredicateEnabled =
260
261 Metadata *Vals[] = {
262 MDString::get(Ctx, "llvm.loop.vectorize.predicate.enable"),
263 ConstantAsMetadata::get(ConstantInt::get(llvm::Type::getInt1Ty(Ctx),
264 IsVectorPredicateEnabled))};
265 Args.push_back(MDNode::get(Ctx, Vals));
266 }
267
268 // Setting vectorize.width
269 if (Attrs.VectorizeWidth > 0) {
270 Metadata *Vals[] = {
271 MDString::get(Ctx, "llvm.loop.vectorize.width"),
272 ConstantAsMetadata::get(ConstantInt::get(llvm::Type::getInt32Ty(Ctx),
273 Attrs.VectorizeWidth))};
274
275 Args.push_back(MDNode::get(Ctx, Vals));
276 }
277
279 bool IsScalable = Attrs.VectorizeScalable == LoopAttributes::Enable;
280 Metadata *Vals[] = {
281 MDString::get(Ctx, "llvm.loop.vectorize.scalable.enable"),
282 ConstantAsMetadata::get(
283 ConstantInt::get(llvm::Type::getInt1Ty(Ctx), IsScalable))};
284 Args.push_back(MDNode::get(Ctx, Vals));
285 }
286
287 // Setting interleave.count
288 if (Attrs.InterleaveCount > 0) {
289 Metadata *Vals[] = {
290 MDString::get(Ctx, "llvm.loop.interleave.count"),
291 ConstantAsMetadata::get(ConstantInt::get(llvm::Type::getInt32Ty(Ctx),
292 Attrs.InterleaveCount))};
293 Args.push_back(MDNode::get(Ctx, Vals));
294 }
295
296 // vectorize.enable is set if:
297 // 1) loop hint vectorize.enable is set, or
298 // 2) it is implied when vectorize.predicate is set, or
299 // 3) it is implied when vectorize.width is set to a value > 1
300 // 4) it is implied when vectorize.scalable.enable is true
301 // 5) it is implied when vectorize.width is unset (0) and the user
302 // explicitly requested fixed-width vectorization, i.e.
303 // vectorize.scalable.enable is false.
305 (IsVectorPredicateEnabled && Attrs.VectorizeWidth != 1) ||
306 Attrs.VectorizeWidth > 1 ||
309 Attrs.VectorizeWidth != 1)) {
310 bool AttrVal = Attrs.VectorizeEnable != LoopAttributes::Disable;
311 Args.push_back(
312 MDNode::get(Ctx, {MDString::get(Ctx, "llvm.loop.vectorize.enable"),
313 ConstantAsMetadata::get(ConstantInt::get(
314 llvm::Type::getInt1Ty(Ctx), AttrVal))}));
315 }
316
317 if (FollowupHasTransforms)
318 Args.push_back(MDNode::get(
319 Ctx,
320 {MDString::get(Ctx, "llvm.loop.vectorize.followup_all"), Followup}));
321
322 MDNode *LoopID = MDNode::getDistinct(Ctx, Args);
323 LoopID->replaceOperandWith(0, LoopID);
324 HasUserTransforms = true;
325 return LoopID;
326}
327
328MDNode *
329LoopInfo::createLoopDistributeMetadata(const LoopAttributes &Attrs,
330 ArrayRef<Metadata *> LoopProperties,
331 bool &HasUserTransforms) {
332 LLVMContext &Ctx = Header->getContext();
333
334 std::optional<bool> Enabled;
336 Enabled = false;
338 Enabled = true;
339
340 if (Enabled != true) {
341 SmallVector<Metadata *, 4> NewLoopProperties;
342 if (Enabled == false) {
343 NewLoopProperties.append(LoopProperties.begin(), LoopProperties.end());
344 NewLoopProperties.push_back(
345 MDNode::get(Ctx, {MDString::get(Ctx, "llvm.loop.distribute.enable"),
346 ConstantAsMetadata::get(ConstantInt::get(
347 llvm::Type::getInt1Ty(Ctx), 0))}));
348 LoopProperties = NewLoopProperties;
349 }
350 return createLoopVectorizeMetadata(Attrs, LoopProperties,
351 HasUserTransforms);
352 }
353
354 bool FollowupHasTransforms = false;
355 MDNode *Followup =
356 createLoopVectorizeMetadata(Attrs, LoopProperties, FollowupHasTransforms);
357
359 Args.push_back(nullptr);
360 Args.append(LoopProperties.begin(), LoopProperties.end());
361
362 Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.distribute.enable"),
363 ConstantAsMetadata::get(ConstantInt::get(
364 llvm::Type::getInt1Ty(Ctx),
366 Args.push_back(MDNode::get(Ctx, Vals));
367
368 if (FollowupHasTransforms)
369 Args.push_back(MDNode::get(
370 Ctx,
371 {MDString::get(Ctx, "llvm.loop.distribute.followup_all"), Followup}));
372
373 MDNode *LoopID = MDNode::getDistinct(Ctx, Args);
374 LoopID->replaceOperandWith(0, LoopID);
375 HasUserTransforms = true;
376 return LoopID;
377}
378
379MDNode *LoopInfo::createFullUnrollMetadata(const LoopAttributes &Attrs,
380 ArrayRef<Metadata *> LoopProperties,
381 bool &HasUserTransforms) {
382 LLVMContext &Ctx = Header->getContext();
383
384 std::optional<bool> Enabled;
386 Enabled = false;
387 else if (Attrs.UnrollEnable == LoopAttributes::Full)
388 Enabled = true;
389
390 if (Enabled != true) {
391 SmallVector<Metadata *, 4> NewLoopProperties;
392 if (Enabled == false) {
393 NewLoopProperties.append(LoopProperties.begin(), LoopProperties.end());
394 NewLoopProperties.push_back(
395 MDNode::get(Ctx, MDString::get(Ctx, "llvm.loop.unroll.disable")));
396 LoopProperties = NewLoopProperties;
397 }
398 return createLoopDistributeMetadata(Attrs, LoopProperties,
399 HasUserTransforms);
400 }
401
403 Args.push_back(nullptr);
404 Args.append(LoopProperties.begin(), LoopProperties.end());
405 Args.push_back(MDNode::get(Ctx, MDString::get(Ctx, "llvm.loop.unroll.full")));
406
407 // No follow-up: there is no loop after full unrolling.
408 // TODO: Warn if there are transformations after full unrolling.
409
410 MDNode *LoopID = MDNode::getDistinct(Ctx, Args);
411 LoopID->replaceOperandWith(0, LoopID);
412 HasUserTransforms = true;
413 return LoopID;
414}
415
416MDNode *LoopInfo::createMetadata(
417 const LoopAttributes &Attrs,
418 llvm::ArrayRef<llvm::Metadata *> AdditionalLoopProperties,
419 bool &HasUserTransforms) {
420 SmallVector<Metadata *, 3> LoopProperties;
421
422 // If we have a valid start debug location for the loop, add it.
423 if (StartLoc) {
424 LoopProperties.push_back(StartLoc.getAsMDNode());
425
426 // If we also have a valid end debug location for the loop, add it.
427 if (EndLoc)
428 LoopProperties.push_back(EndLoc.getAsMDNode());
429 }
430
431 LLVMContext &Ctx = Header->getContext();
432 if (Attrs.MustProgress)
433 LoopProperties.push_back(
434 MDNode::get(Ctx, MDString::get(Ctx, "llvm.loop.mustprogress")));
435
436 assert(!!AccGroup == Attrs.IsParallel &&
437 "There must be an access group iff the loop is parallel");
438 if (Attrs.IsParallel) {
439 LoopProperties.push_back(MDNode::get(
440 Ctx, {MDString::get(Ctx, "llvm.loop.parallel_accesses"), AccGroup}));
441 }
442
443 // Setting clang::code_align attribute.
444 if (Attrs.CodeAlign > 0) {
445 Metadata *Vals[] = {MDString::get(Ctx, "llvm.loop.align"),
446 ConstantAsMetadata::get(ConstantInt::get(
447 llvm::Type::getInt32Ty(Ctx), Attrs.CodeAlign))};
448 LoopProperties.push_back(MDNode::get(Ctx, Vals));
449 }
450
451 LoopProperties.insert(LoopProperties.end(), AdditionalLoopProperties.begin(),
452 AdditionalLoopProperties.end());
453 return createFullUnrollMetadata(Attrs, LoopProperties, HasUserTransforms);
454}
455
457 : IsParallel(IsParallel), VectorizeEnable(LoopAttributes::Unspecified),
458 UnrollEnable(LoopAttributes::Unspecified),
459 UnrollAndJamEnable(LoopAttributes::Unspecified),
460 VectorizePredicateEnable(LoopAttributes::Unspecified), VectorizeWidth(0),
461 VectorizeScalable(LoopAttributes::Unspecified), InterleaveCount(0),
462 UnrollCount(0), UnrollAndJamCount(0),
463 DistributeEnable(LoopAttributes::Unspecified), PipelineDisabled(false),
464 PipelineInitiationInterval(0), CodeAlign(0), MustProgress(false) {}
465
467 IsParallel = false;
468 VectorizeWidth = 0;
470 InterleaveCount = 0;
471 UnrollCount = 0;
478 PipelineDisabled = false;
480 CodeAlign = 0;
481 MustProgress = false;
482}
483
484LoopInfo::LoopInfo(BasicBlock *Header, const LoopAttributes &Attrs,
485 const llvm::DebugLoc &StartLoc, const llvm::DebugLoc &EndLoc,
487 : Header(Header), Attrs(Attrs), StartLoc(StartLoc), EndLoc(EndLoc),
488 Parent(Parent) {
489
490 if (Attrs.IsParallel) {
491 // Create an access group for this loop.
492 LLVMContext &Ctx = Header->getContext();
493 AccGroup = MDNode::getDistinct(Ctx, {});
494 }
495
496 if (!Attrs.IsParallel && Attrs.VectorizeWidth == 0 &&
498 Attrs.InterleaveCount == 0 && Attrs.UnrollCount == 0 &&
499 Attrs.UnrollAndJamCount == 0 && !Attrs.PipelineDisabled &&
500 Attrs.PipelineInitiationInterval == 0 &&
506 Attrs.CodeAlign == 0 && !StartLoc && !EndLoc && !Attrs.MustProgress)
507 return;
508
509 TempLoopID = MDNode::getTemporary(Header->getContext(), std::nullopt);
510}
511
513 // We did not annotate the loop body instructions because there are no
514 // attributes for this loop.
515 if (!TempLoopID)
516 return;
517
518 MDNode *LoopID;
519 LoopAttributes CurLoopAttr = Attrs;
520 LLVMContext &Ctx = Header->getContext();
521
522 if (Parent && (Parent->Attrs.UnrollAndJamEnable ||
523 Parent->Attrs.UnrollAndJamCount != 0)) {
524 // Parent unroll-and-jams this loop.
525 // Split the transformations in those that happens before the unroll-and-jam
526 // and those after.
527
528 LoopAttributes BeforeJam, AfterJam;
529
530 BeforeJam.IsParallel = AfterJam.IsParallel = Attrs.IsParallel;
531
532 BeforeJam.VectorizeWidth = Attrs.VectorizeWidth;
533 BeforeJam.VectorizeScalable = Attrs.VectorizeScalable;
534 BeforeJam.InterleaveCount = Attrs.InterleaveCount;
535 BeforeJam.VectorizeEnable = Attrs.VectorizeEnable;
536 BeforeJam.DistributeEnable = Attrs.DistributeEnable;
538
539 switch (Attrs.UnrollEnable) {
542 BeforeJam.UnrollEnable = Attrs.UnrollEnable;
543 AfterJam.UnrollEnable = Attrs.UnrollEnable;
544 break;
547 break;
550 break;
551 }
552
554 AfterJam.UnrollCount = Attrs.UnrollCount;
555 AfterJam.PipelineDisabled = Attrs.PipelineDisabled;
557
558 // If this loop is subject of an unroll-and-jam by the parent loop, and has
559 // an unroll-and-jam annotation itself, we have to decide whether to first
560 // apply the parent's unroll-and-jam or this loop's unroll-and-jam. The
561 // UnrollAndJam pass processes loops from inner to outer, so we apply the
562 // inner first.
563 BeforeJam.UnrollAndJamCount = Attrs.UnrollAndJamCount;
564 BeforeJam.UnrollAndJamEnable = Attrs.UnrollAndJamEnable;
565
566 // Set the inner followup metadata to process by the outer loop. Only
567 // consider the first inner loop.
568 if (!Parent->UnrollAndJamInnerFollowup) {
569 // Splitting the attributes into a BeforeJam and an AfterJam part will
570 // stop 'llvm.loop.isvectorized' (generated by vectorization in BeforeJam)
571 // to be forwarded to the AfterJam part. We detect the situation here and
572 // add it manually.
573 SmallVector<Metadata *, 1> BeforeLoopProperties;
576 BeforeJam.InterleaveCount != 0 || BeforeJam.VectorizeWidth != 0 ||
578 BeforeLoopProperties.push_back(
579 MDNode::get(Ctx, MDString::get(Ctx, "llvm.loop.isvectorized")));
580
581 bool InnerFollowupHasTransform = false;
582 MDNode *InnerFollowup = createMetadata(AfterJam, BeforeLoopProperties,
583 InnerFollowupHasTransform);
584 if (InnerFollowupHasTransform)
585 Parent->UnrollAndJamInnerFollowup = InnerFollowup;
586 }
587
588 CurLoopAttr = BeforeJam;
589 }
590
591 bool HasUserTransforms = false;
592 LoopID = createMetadata(CurLoopAttr, {}, HasUserTransforms);
593 TempLoopID->replaceAllUsesWith(LoopID);
594}
595
596void LoopInfoStack::push(BasicBlock *Header, const llvm::DebugLoc &StartLoc,
597 const llvm::DebugLoc &EndLoc) {
598 Active.emplace_back(
599 new LoopInfo(Header, StagedAttrs, StartLoc, EndLoc,
600 Active.empty() ? nullptr : Active.back().get()));
601 // Clear the attributes so nested loops do not inherit them.
602 StagedAttrs.clear();
603}
604
605void LoopInfoStack::push(BasicBlock *Header, clang::ASTContext &Ctx,
606 const clang::CodeGenOptions &CGOpts,
608 const llvm::DebugLoc &StartLoc,
609 const llvm::DebugLoc &EndLoc, bool MustProgress) {
610 // Identify loop hint attributes from Attrs.
611 for (const auto *Attr : Attrs) {
612 const LoopHintAttr *LH = dyn_cast<LoopHintAttr>(Attr);
613 const OpenCLUnrollHintAttr *OpenCLHint =
614 dyn_cast<OpenCLUnrollHintAttr>(Attr);
615
616 // Skip non loop hint attributes
617 if (!LH && !OpenCLHint) {
618 continue;
619 }
620
621 LoopHintAttr::OptionType Option = LoopHintAttr::Unroll;
622 LoopHintAttr::LoopHintState State = LoopHintAttr::Disable;
623 unsigned ValueInt = 1;
624 // Translate opencl_unroll_hint attribute argument to
625 // equivalent LoopHintAttr enums.
626 // OpenCL v2.0 s6.11.5:
627 // 0 - enable unroll (no argument).
628 // 1 - disable unroll.
629 // other positive integer n - unroll by n.
630 if (OpenCLHint) {
631 ValueInt = OpenCLHint->getUnrollHint();
632 if (ValueInt == 0) {
633 State = LoopHintAttr::Enable;
634 } else if (ValueInt != 1) {
635 Option = LoopHintAttr::UnrollCount;
636 State = LoopHintAttr::Numeric;
637 }
638 } else if (LH) {
639 auto *ValueExpr = LH->getValue();
640 if (ValueExpr) {
641 llvm::APSInt ValueAPS = ValueExpr->EvaluateKnownConstInt(Ctx);
642 ValueInt = ValueAPS.getSExtValue();
643 }
644
645 Option = LH->getOption();
646 State = LH->getState();
647 }
648 switch (State) {
649 case LoopHintAttr::Disable:
650 switch (Option) {
651 case LoopHintAttr::Vectorize:
652 // Disable vectorization by specifying a width of 1.
655 break;
656 case LoopHintAttr::Interleave:
657 // Disable interleaving by speciyfing a count of 1.
659 break;
660 case LoopHintAttr::Unroll:
662 break;
663 case LoopHintAttr::UnrollAndJam:
665 break;
666 case LoopHintAttr::VectorizePredicate:
668 break;
669 case LoopHintAttr::Distribute:
670 setDistributeState(false);
671 break;
672 case LoopHintAttr::PipelineDisabled:
674 break;
675 case LoopHintAttr::UnrollCount:
676 case LoopHintAttr::UnrollAndJamCount:
677 case LoopHintAttr::VectorizeWidth:
678 case LoopHintAttr::InterleaveCount:
679 case LoopHintAttr::PipelineInitiationInterval:
680 llvm_unreachable("Options cannot be disabled.");
681 break;
682 }
683 break;
684 case LoopHintAttr::Enable:
685 switch (Option) {
686 case LoopHintAttr::Vectorize:
687 case LoopHintAttr::Interleave:
688 setVectorizeEnable(true);
689 break;
690 case LoopHintAttr::Unroll:
692 break;
693 case LoopHintAttr::UnrollAndJam:
695 break;
696 case LoopHintAttr::VectorizePredicate:
698 break;
699 case LoopHintAttr::Distribute:
700 setDistributeState(true);
701 break;
702 case LoopHintAttr::UnrollCount:
703 case LoopHintAttr::UnrollAndJamCount:
704 case LoopHintAttr::VectorizeWidth:
705 case LoopHintAttr::InterleaveCount:
706 case LoopHintAttr::PipelineDisabled:
707 case LoopHintAttr::PipelineInitiationInterval:
708 llvm_unreachable("Options cannot enabled.");
709 break;
710 }
711 break;
712 case LoopHintAttr::AssumeSafety:
713 switch (Option) {
714 case LoopHintAttr::Vectorize:
715 case LoopHintAttr::Interleave:
716 // Apply "llvm.mem.parallel_loop_access" metadata to load/stores.
717 setParallel(true);
718 setVectorizeEnable(true);
719 break;
720 case LoopHintAttr::Unroll:
721 case LoopHintAttr::UnrollAndJam:
722 case LoopHintAttr::VectorizePredicate:
723 case LoopHintAttr::UnrollCount:
724 case LoopHintAttr::UnrollAndJamCount:
725 case LoopHintAttr::VectorizeWidth:
726 case LoopHintAttr::InterleaveCount:
727 case LoopHintAttr::Distribute:
728 case LoopHintAttr::PipelineDisabled:
729 case LoopHintAttr::PipelineInitiationInterval:
730 llvm_unreachable("Options cannot be used to assume mem safety.");
731 break;
732 }
733 break;
734 case LoopHintAttr::Full:
735 switch (Option) {
736 case LoopHintAttr::Unroll:
738 break;
739 case LoopHintAttr::UnrollAndJam:
741 break;
742 case LoopHintAttr::Vectorize:
743 case LoopHintAttr::Interleave:
744 case LoopHintAttr::UnrollCount:
745 case LoopHintAttr::UnrollAndJamCount:
746 case LoopHintAttr::VectorizeWidth:
747 case LoopHintAttr::InterleaveCount:
748 case LoopHintAttr::Distribute:
749 case LoopHintAttr::PipelineDisabled:
750 case LoopHintAttr::PipelineInitiationInterval:
751 case LoopHintAttr::VectorizePredicate:
752 llvm_unreachable("Options cannot be used with 'full' hint.");
753 break;
754 }
755 break;
756 case LoopHintAttr::FixedWidth:
757 case LoopHintAttr::ScalableWidth:
758 switch (Option) {
759 case LoopHintAttr::VectorizeWidth:
760 setVectorizeScalable(State == LoopHintAttr::ScalableWidth
763 if (LH->getValue())
764 setVectorizeWidth(ValueInt);
765 break;
766 default:
767 llvm_unreachable("Options cannot be used with 'scalable' hint.");
768 break;
769 }
770 break;
771 case LoopHintAttr::Numeric:
772 switch (Option) {
773 case LoopHintAttr::InterleaveCount:
774 setInterleaveCount(ValueInt);
775 break;
776 case LoopHintAttr::UnrollCount:
777 setUnrollCount(ValueInt);
778 break;
779 case LoopHintAttr::UnrollAndJamCount:
780 setUnrollAndJamCount(ValueInt);
781 break;
782 case LoopHintAttr::PipelineInitiationInterval:
784 break;
785 case LoopHintAttr::Unroll:
786 case LoopHintAttr::UnrollAndJam:
787 case LoopHintAttr::VectorizePredicate:
788 case LoopHintAttr::Vectorize:
789 case LoopHintAttr::VectorizeWidth:
790 case LoopHintAttr::Interleave:
791 case LoopHintAttr::Distribute:
792 case LoopHintAttr::PipelineDisabled:
793 llvm_unreachable("Options cannot be assigned a value.");
794 break;
795 }
796 break;
797 }
798 }
799
800 // Identify loop attribute 'code_align' from Attrs.
801 // For attribute code_align:
802 // n - 'llvm.loop.align i32 n' metadata will be emitted.
803 if (const auto *CodeAlign = getSpecificAttr<const CodeAlignAttr>(Attrs)) {
804 const auto *CE = cast<ConstantExpr>(CodeAlign->getAlignment());
805 llvm::APSInt ArgVal = CE->getResultAsAPSInt();
806 setCodeAlign(ArgVal.getSExtValue());
807 }
808
809 setMustProgress(MustProgress);
810
811 if (CGOpts.OptimizationLevel > 0)
812 // Disable unrolling for the loop, if unrolling is disabled (via
813 // -fno-unroll-loops) and no pragmas override the decision.
814 if (!CGOpts.UnrollLoops &&
816 StagedAttrs.UnrollCount == 0))
818
819 /// Stage the attributes.
820 push(Header, StartLoc, EndLoc);
821}
822
824 assert(!Active.empty() && "No active loops to pop");
825 Active.back()->finish();
826 Active.pop_back();
827}
828
829void LoopInfoStack::InsertHelper(Instruction *I) const {
830 if (I->mayReadOrWriteMemory()) {
831 SmallVector<Metadata *, 4> AccessGroups;
832 for (const auto &AL : Active) {
833 // Here we assume that every loop that has an access group is parallel.
834 if (MDNode *Group = AL->getAccessGroup())
835 AccessGroups.push_back(Group);
836 }
837 MDNode *UnionMD = nullptr;
838 if (AccessGroups.size() == 1)
839 UnionMD = cast<MDNode>(AccessGroups[0]);
840 else if (AccessGroups.size() >= 2)
841 UnionMD = MDNode::get(I->getContext(), AccessGroups);
842 I->setMetadata("llvm.access.group", UnionMD);
843 }
844
845 if (!hasInfo())
846 return;
847
848 const LoopInfo &L = getInfo();
849 if (!L.getLoopID())
850 return;
851
852 if (I->isTerminator()) {
853 for (BasicBlock *Succ : successors(I))
854 if (Succ == L.getHeader()) {
855 I->setMetadata(llvm::LLVMContext::MD_loop, L.getLoopID());
856 break;
857 }
858 return;
859 }
860}
Defines the clang::ASTContext interface.
NodeId Parent
Definition: ASTDiff.cpp:191
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:182
Attr - This represents one attribute.
Definition: Attr.h:42
CodeGenOptions - Track various options which control how the code is optimized and passed to the back...
void setPipelineDisabled(bool S)
Set the pipeline disabled state.
Definition: CGLoopInfo.h:285
void setUnrollCount(unsigned C)
Set the unroll count for the next loop pushed.
Definition: CGLoopInfo.h:279
bool hasInfo() const
Returns true if there is LoopInfo on the stack.
Definition: CGLoopInfo.h:299
void setVectorizeWidth(unsigned W)
Set the vectorize width for the next loop pushed.
Definition: CGLoopInfo.h:269
void InsertHelper(llvm::Instruction *I) const
Function called by the CodeGenFunction when an instruction is created.
Definition: CGLoopInfo.cpp:829
void setDistributeState(bool Enable=true)
Set the next pushed loop as a distribution candidate.
Definition: CGLoopInfo.h:248
void setParallel(bool Enable=true)
Set the next pushed loop as parallel.
Definition: CGLoopInfo.h:239
void setInterleaveCount(unsigned C)
Set the interleave count for the next loop pushed.
Definition: CGLoopInfo.h:276
void setUnrollState(const LoopAttributes::LVEnableState &State)
Set the next pushed loop unroll state.
Definition: CGLoopInfo.h:254
void setVectorizeScalable(const LoopAttributes::LVEnableState &State)
Definition: CGLoopInfo.h:271
void setVectorizePredicateState(const LoopAttributes::LVEnableState &State)
Set the next pushed vectorize predicate state.
Definition: CGLoopInfo.h:259
void pop()
End the current loop.
Definition: CGLoopInfo.cpp:823
void setCodeAlign(unsigned C)
Set value of code align for the next loop pushed.
Definition: CGLoopInfo.h:293
void push(llvm::BasicBlock *Header, const llvm::DebugLoc &StartLoc, const llvm::DebugLoc &EndLoc)
Begin a new structured loop.
void setMustProgress(bool P)
Set no progress for the next loop pushed.
Definition: CGLoopInfo.h:296
void setUnrollAndJamState(const LoopAttributes::LVEnableState &State)
Set the next pushed loop unroll_and_jam state.
Definition: CGLoopInfo.h:264
void setUnrollAndJamCount(unsigned C)
Set the unroll count for the next loop pushed.
Definition: CGLoopInfo.h:282
const LoopInfo & getInfo() const
Return the LoopInfo for the current loop.
Definition: CGLoopInfo.h:302
void setPipelineInitiationInterval(unsigned C)
Set the pipeline initiation interval.
Definition: CGLoopInfo.h:288
void setVectorizeEnable(bool Enable=true)
Set the next pushed loop 'vectorize.enable'.
Definition: CGLoopInfo.h:242
Information used when generating a structured loop.
Definition: CGLoopInfo.h:90
llvm::BasicBlock * getHeader() const
Get the header block of this loop.
Definition: CGLoopInfo.h:101
LoopInfo(llvm::BasicBlock *Header, const LoopAttributes &Attrs, const llvm::DebugLoc &StartLoc, const llvm::DebugLoc &EndLoc, LoopInfo *Parent)
Construct a new LoopInfo for the loop with entry Header.
Definition: CGLoopInfo.cpp:484
llvm::MDNode * getLoopID() const
Get the loop id metadata for this loop.
Definition: CGLoopInfo.h:98
void finish()
Create the loop's metadata.
Definition: CGLoopInfo.cpp:512
Diagnostic wrappers for TextAPI types for error reporting.
Definition: Dominators.h:30
#define false
Definition: stdbool.h:26
Attributes that may be specified on loops.
Definition: CGLoopInfo.h:36
unsigned UnrollCount
llvm.unroll.
Definition: CGLoopInfo.h:68
bool MustProgress
Value for whether the loop is required to make progress.
Definition: CGLoopInfo.h:86
unsigned InterleaveCount
Value for llvm.loop.interleave.count metadata.
Definition: CGLoopInfo.h:65
LoopAttributes(bool IsParallel=false)
Definition: CGLoopInfo.cpp:456
bool IsParallel
Generate llvm.loop.parallel metadata for loads and stores.
Definition: CGLoopInfo.h:41
LVEnableState VectorizeScalable
Definition: CGLoopInfo.h:62
LVEnableState UnrollAndJamEnable
Value for llvm.loop.unroll_and_jam.* metadata (enable, disable, or full).
Definition: CGLoopInfo.h:53
unsigned UnrollAndJamCount
llvm.unroll.
Definition: CGLoopInfo.h:71
LVEnableState VectorizePredicateEnable
Value for llvm.loop.vectorize.predicate metadata.
Definition: CGLoopInfo.h:56
LVEnableState DistributeEnable
Value for llvm.loop.distribute.enable metadata.
Definition: CGLoopInfo.h:74
bool PipelineDisabled
Value for llvm.loop.pipeline.disable metadata.
Definition: CGLoopInfo.h:77
unsigned CodeAlign
Value for 'llvm.loop.align' metadata.
Definition: CGLoopInfo.h:83
LVEnableState UnrollEnable
Value for llvm.loop.unroll.* metadata (enable, disable, or full).
Definition: CGLoopInfo.h:50
unsigned VectorizeWidth
Value for llvm.loop.vectorize.width metadata.
Definition: CGLoopInfo.h:59
unsigned PipelineInitiationInterval
Value for llvm.loop.pipeline.iicount metadata.
Definition: CGLoopInfo.h:80
LVEnableState VectorizeEnable
Value for llvm.loop.vectorize.enable metadata.
Definition: CGLoopInfo.h:47