xref: /llvm-project/polly/lib/Support/RegisterPasses.cpp (revision 65bc259a97cd8cc70907b65f59aff728245ba9c0)
1 //===------ RegisterPasses.cpp - Add the Polly Passes to default passes  --===//
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 // This file composes the individual LLVM-IR passes provided by Polly to a
10 // functional polyhedral optimizer. The polyhedral optimizer is automatically
11 // made available to LLVM based compilers by loading the Polly shared library
12 // into such a compiler.
13 //
14 // The Polly optimizer is made available by executing a static constructor that
15 // registers the individual Polly passes in the LLVM pass manager builder. The
16 // passes are registered such that the default behaviour of the compiler is not
17 // changed, but that the flag '-polly' provided at optimization level '-O3'
18 // enables additional polyhedral optimizations.
19 //===----------------------------------------------------------------------===//
20 
21 #include "polly/RegisterPasses.h"
22 #include "polly/Canonicalization.h"
23 #include "polly/CodeGen/CodeGeneration.h"
24 #include "polly/CodeGen/IslAst.h"
25 #include "polly/CodePreparation.h"
26 #include "polly/DeLICM.h"
27 #include "polly/DeadCodeElimination.h"
28 #include "polly/DependenceInfo.h"
29 #include "polly/ForwardOpTree.h"
30 #include "polly/JSONExporter.h"
31 #include "polly/LinkAllPasses.h"
32 #include "polly/MaximalStaticExpansion.h"
33 #include "polly/PolyhedralInfo.h"
34 #include "polly/PruneUnprofitable.h"
35 #include "polly/ScheduleOptimizer.h"
36 #include "polly/ScopDetection.h"
37 #include "polly/ScopGraphPrinter.h"
38 #include "polly/ScopInfo.h"
39 #include "polly/Simplify.h"
40 #include "polly/Support/DumpFunctionPass.h"
41 #include "polly/Support/DumpModulePass.h"
42 #include "llvm/Analysis/CFGPrinter.h"
43 #include "llvm/Config/llvm-config.h" // for LLVM_VERSION_STRING
44 #include "llvm/IR/LegacyPassManager.h"
45 #include "llvm/IR/PassManager.h"
46 #include "llvm/IR/Verifier.h"
47 #include "llvm/Passes/PassBuilder.h"
48 #include "llvm/Passes/PassPlugin.h"
49 #include "llvm/Support/CommandLine.h"
50 #include "llvm/Support/TargetSelect.h"
51 #include "llvm/Transforms/IPO.h"
52 
53 namespace cl = llvm::cl;
54 
55 using llvm::FunctionPassManager;
56 using llvm::OptimizationLevel;
57 using llvm::PassBuilder;
58 using llvm::PassInstrumentationCallbacks;
59 
60 cl::OptionCategory PollyCategory("Polly Options",
61                                  "Configure the polly loop optimizer");
62 
63 namespace polly {
64 static cl::opt<bool>
65     PollyEnabled("polly",
66                  cl::desc("Enable the polly optimizer (with -O1, -O2 or -O3)"),
67                  cl::cat(PollyCategory));
68 
69 static cl::opt<bool> PollyDetectOnly(
70     "polly-only-scop-detection",
71     cl::desc("Only run scop detection, but no other optimizations"),
72     cl::cat(PollyCategory));
73 
74 enum PassPositionChoice { POSITION_EARLY, POSITION_BEFORE_VECTORIZER };
75 
76 enum OptimizerChoice { OPTIMIZER_NONE, OPTIMIZER_ISL };
77 
78 static cl::opt<PassPositionChoice> PassPosition(
79     "polly-position", cl::desc("Where to run polly in the pass pipeline"),
80     cl::values(clEnumValN(POSITION_EARLY, "early", "Before everything"),
81                clEnumValN(POSITION_BEFORE_VECTORIZER, "before-vectorizer",
82                           "Right before the vectorizer")),
83     cl::Hidden, cl::init(POSITION_BEFORE_VECTORIZER), cl::cat(PollyCategory));
84 
85 static cl::opt<OptimizerChoice>
86     Optimizer("polly-optimizer", cl::desc("Select the scheduling optimizer"),
87               cl::values(clEnumValN(OPTIMIZER_NONE, "none", "No optimizer"),
88                          clEnumValN(OPTIMIZER_ISL, "isl",
89                                     "The isl scheduling optimizer")),
90               cl::Hidden, cl::init(OPTIMIZER_ISL), cl::cat(PollyCategory));
91 
92 enum CodeGenChoice { CODEGEN_FULL, CODEGEN_AST, CODEGEN_NONE };
93 static cl::opt<CodeGenChoice> CodeGeneration(
94     "polly-code-generation", cl::desc("How much code-generation to perform"),
95     cl::values(clEnumValN(CODEGEN_FULL, "full", "AST and IR generation"),
96                clEnumValN(CODEGEN_AST, "ast", "Only AST generation"),
97                clEnumValN(CODEGEN_NONE, "none", "No code generation")),
98     cl::Hidden, cl::init(CODEGEN_FULL), cl::cat(PollyCategory));
99 
100 VectorizerChoice PollyVectorizerChoice;
101 
102 static cl::opt<VectorizerChoice, true> Vectorizer(
103     "polly-vectorizer", cl::desc("Select the vectorization strategy"),
104     cl::values(
105         clEnumValN(VECTORIZER_NONE, "none", "No Vectorization"),
106         clEnumValN(
107             VECTORIZER_STRIPMINE, "stripmine",
108             "Strip-mine outer loops for the loop-vectorizer to trigger")),
109     cl::location(PollyVectorizerChoice), cl::init(VECTORIZER_NONE),
110     cl::cat(PollyCategory));
111 
112 static cl::opt<bool> ImportJScop(
113     "polly-import",
114     cl::desc("Import the polyhedral description of the detected Scops"),
115     cl::Hidden, cl::cat(PollyCategory));
116 
117 static cl::opt<bool> FullyIndexedStaticExpansion(
118     "polly-enable-mse",
119     cl::desc("Fully expand the memory accesses of the detected Scops"),
120     cl::Hidden, cl::cat(PollyCategory));
121 
122 static cl::opt<bool> ExportJScop(
123     "polly-export",
124     cl::desc("Export the polyhedral description of the detected Scops"),
125     cl::Hidden, cl::cat(PollyCategory));
126 
127 static cl::opt<bool> DeadCodeElim("polly-run-dce",
128                                   cl::desc("Run the dead code elimination"),
129                                   cl::Hidden, cl::cat(PollyCategory));
130 
131 static cl::opt<bool> PollyViewer(
132     "polly-show",
133     cl::desc("Highlight the code regions that will be optimized in a "
134              "(CFG BBs and LLVM-IR instructions)"),
135     cl::cat(PollyCategory));
136 
137 static cl::opt<bool> PollyOnlyViewer(
138     "polly-show-only",
139     cl::desc("Highlight the code regions that will be optimized in "
140              "a (CFG only BBs)"),
141     cl::init(false), cl::cat(PollyCategory));
142 
143 static cl::opt<bool>
144     PollyPrinter("polly-dot", cl::desc("Enable the Polly DOT printer in -O3"),
145                  cl::Hidden, cl::value_desc("Run the Polly DOT printer at -O3"),
146                  cl::init(false), cl::cat(PollyCategory));
147 
148 static cl::opt<bool> PollyOnlyPrinter(
149     "polly-dot-only",
150     cl::desc("Enable the Polly DOT printer in -O3 (no BB content)"), cl::Hidden,
151     cl::value_desc("Run the Polly DOT printer at -O3 (no BB content"),
152     cl::init(false), cl::cat(PollyCategory));
153 
154 static cl::opt<bool>
155     CFGPrinter("polly-view-cfg",
156                cl::desc("Show the Polly CFG right after code generation"),
157                cl::Hidden, cl::init(false), cl::cat(PollyCategory));
158 
159 static cl::opt<bool>
160     EnableForwardOpTree("polly-enable-optree",
161                         cl::desc("Enable operand tree forwarding"), cl::Hidden,
162                         cl::init(true), cl::cat(PollyCategory));
163 
164 static cl::opt<bool>
165     DumpBefore("polly-dump-before",
166                cl::desc("Dump module before Polly transformations into a file "
167                         "suffixed with \"-before\""),
168                cl::init(false), cl::cat(PollyCategory));
169 
170 static cl::list<std::string> DumpBeforeFile(
171     "polly-dump-before-file",
172     cl::desc("Dump module before Polly transformations to the given file"),
173     cl::cat(PollyCategory));
174 
175 static cl::opt<bool>
176     DumpAfter("polly-dump-after",
177               cl::desc("Dump module after Polly transformations into a file "
178                        "suffixed with \"-after\""),
179               cl::init(false), cl::cat(PollyCategory));
180 
181 static cl::list<std::string> DumpAfterFile(
182     "polly-dump-after-file",
183     cl::desc("Dump module after Polly transformations to the given file"),
184     cl::cat(PollyCategory));
185 
186 static cl::opt<bool>
187     EnableDeLICM("polly-enable-delicm",
188                  cl::desc("Eliminate scalar loop carried dependences"),
189                  cl::Hidden, cl::init(true), cl::cat(PollyCategory));
190 
191 static cl::opt<bool>
192     EnableSimplify("polly-enable-simplify",
193                    cl::desc("Simplify SCoP after optimizations"),
194                    cl::init(true), cl::cat(PollyCategory));
195 
196 static cl::opt<bool> EnablePruneUnprofitable(
197     "polly-enable-prune-unprofitable",
198     cl::desc("Bail out on unprofitable SCoPs before rescheduling"), cl::Hidden,
199     cl::init(true), cl::cat(PollyCategory));
200 
201 namespace {
202 
203 /// Initialize Polly passes when library is loaded.
204 ///
205 /// We use the constructor of a statically declared object to initialize the
206 /// different Polly passes right after the Polly library is loaded. This ensures
207 /// that the Polly passes are available e.g. in the 'opt' tool.
208 struct StaticInitializer {
209   StaticInitializer() {
210     llvm::PassRegistry &Registry = *llvm::PassRegistry::getPassRegistry();
211     polly::initializePollyPasses(Registry);
212   }
213 };
214 static StaticInitializer InitializeEverything;
215 } // end of anonymous namespace.
216 
217 void initializePollyPasses(llvm::PassRegistry &Registry) {
218   initializeCodeGenerationPass(Registry);
219 
220   initializeCodePreparationPass(Registry);
221   initializeDeadCodeElimWrapperPassPass(Registry);
222   initializeDependenceInfoPass(Registry);
223   initializeDependenceInfoPrinterLegacyPassPass(Registry);
224   initializeDependenceInfoWrapperPassPass(Registry);
225   initializeDependenceInfoPrinterLegacyFunctionPassPass(Registry);
226   initializeJSONExporterPass(Registry);
227   initializeJSONImporterPass(Registry);
228   initializeJSONImporterPrinterLegacyPassPass(Registry);
229   initializeMaximalStaticExpanderWrapperPassPass(Registry);
230   initializeIslAstInfoWrapperPassPass(Registry);
231   initializeIslAstInfoPrinterLegacyPassPass(Registry);
232   initializeIslScheduleOptimizerWrapperPassPass(Registry);
233   initializeIslScheduleOptimizerPrinterLegacyPassPass(Registry);
234   initializePollyCanonicalizePass(Registry);
235   initializePolyhedralInfoPass(Registry);
236   initializePolyhedralInfoPrinterLegacyPassPass(Registry);
237   initializeScopDetectionWrapperPassPass(Registry);
238   initializeScopDetectionPrinterLegacyPassPass(Registry);
239   initializeScopInlinerPass(Registry);
240   initializeScopInfoRegionPassPass(Registry);
241   initializeScopInfoPrinterLegacyRegionPassPass(Registry);
242   initializeScopInfoWrapperPassPass(Registry);
243   initializeScopInfoPrinterLegacyFunctionPassPass(Registry);
244   initializeFlattenSchedulePass(Registry);
245   initializeFlattenSchedulePrinterLegacyPassPass(Registry);
246   initializeForwardOpTreeWrapperPassPass(Registry);
247   initializeForwardOpTreePrinterLegacyPassPass(Registry);
248   initializeDeLICMWrapperPassPass(Registry);
249   initializeDeLICMPrinterLegacyPassPass(Registry);
250   initializeSimplifyWrapperPassPass(Registry);
251   initializeSimplifyPrinterLegacyPassPass(Registry);
252   initializeDumpModuleWrapperPassPass(Registry);
253   initializePruneUnprofitableWrapperPassPass(Registry);
254 }
255 
256 static bool shouldEnablePollyForOptimization() { return PollyEnabled; }
257 
258 static bool shouldEnablePollyForDiagnostic() {
259   // FIXME: PollyTrackFailures is user-controlled, should not be set
260   // programmatically.
261   if (PollyOnlyPrinter || PollyPrinter || PollyOnlyViewer || PollyViewer)
262     PollyTrackFailures = true;
263 
264   return PollyOnlyPrinter || PollyPrinter || PollyOnlyViewer || PollyViewer ||
265          ExportJScop;
266 }
267 
268 /// Register Polly passes such that they form a polyhedral optimizer.
269 ///
270 /// The individual Polly passes are registered in the pass manager such that
271 /// they form a full polyhedral optimizer. The flow of the optimizer starts with
272 /// a set of preparing transformations that canonicalize the LLVM-IR such that
273 /// the LLVM-IR is easier for us to understand and to optimizes. On the
274 /// canonicalized LLVM-IR we first run the ScopDetection pass, which detects
275 /// static control flow regions. Those regions are then translated by the
276 /// ScopInfo pass into a polyhedral representation. As a next step, a scheduling
277 /// optimizer is run on the polyhedral representation and finally the optimized
278 /// polyhedral representation is code generated back to LLVM-IR.
279 ///
280 /// Besides this core functionality, we optionally schedule passes that provide
281 /// a graphical view of the scops (Polly[Only]Viewer, Polly[Only]Printer), that
282 /// allow the export/import of the polyhedral representation
283 /// (JSCON[Exporter|Importer]) or that show the cfg after code generation.
284 ///
285 /// For certain parts of the Polly optimizer, several alternatives are provided:
286 ///
287 /// As scheduling optimizer we support the isl scheduling optimizer
288 /// (http://freecode.com/projects/isl).
289 /// It is also possible to run Polly with no optimizer. This mode is mainly
290 /// provided to analyze the run and compile time changes caused by the
291 /// scheduling optimizer.
292 ///
293 /// Polly supports the isl internal code generator.
294 
295 /// Add the pass sequence required for Polly to the New Pass Manager.
296 ///
297 /// @param PM           The pass manager itself.
298 /// @param Level        The optimization level. Used for the cleanup of Polly's
299 ///                     output.
300 /// @param EnableForOpt Whether to add Polly IR transformations. If False, only
301 ///                     the analysis passes are added, skipping Polly itself.
302 ///                     The IR may still be modified.
303 static void buildCommonPollyPipeline(FunctionPassManager &PM,
304                                      OptimizationLevel Level,
305                                      bool EnableForOpt) {
306   PassBuilder PB;
307   ScopPassManager SPM;
308 
309   PM.addPass(CodePreparationPass());
310 
311   // TODO add utility passes for the various command line options, once they're
312   // ported
313 
314   if (PollyDetectOnly) {
315     // Don't add more passes other than the ScopPassManager's detection passes.
316     PM.addPass(createFunctionToScopPassAdaptor(std::move(SPM)));
317     return;
318   }
319 
320   if (PollyViewer)
321     PM.addPass(ScopViewer());
322   if (PollyOnlyViewer)
323     PM.addPass(ScopOnlyViewer());
324   if (PollyPrinter)
325     PM.addPass(ScopPrinter());
326   if (PollyOnlyPrinter)
327     PM.addPass(ScopOnlyPrinter());
328   if (EnableSimplify)
329     SPM.addPass(SimplifyPass(0));
330   if (EnableForwardOpTree)
331     SPM.addPass(ForwardOpTreePass());
332   if (EnableDeLICM)
333     SPM.addPass(DeLICMPass());
334   if (EnableSimplify)
335     SPM.addPass(SimplifyPass(1));
336 
337   if (ImportJScop)
338     SPM.addPass(JSONImportPass());
339 
340   if (DeadCodeElim)
341     SPM.addPass(DeadCodeElimPass());
342 
343   if (FullyIndexedStaticExpansion)
344     SPM.addPass(MaximalStaticExpansionPass());
345 
346   if (EnablePruneUnprofitable)
347     SPM.addPass(PruneUnprofitablePass());
348 
349   switch (Optimizer) {
350   case OPTIMIZER_NONE:
351     break; /* Do nothing */
352   case OPTIMIZER_ISL:
353     SPM.addPass(IslScheduleOptimizerPass());
354     break;
355   }
356 
357   if (ExportJScop)
358     SPM.addPass(JSONExportPass());
359 
360   if (!EnableForOpt)
361     return;
362 
363   switch (CodeGeneration) {
364   case CODEGEN_AST:
365     SPM.addPass(
366         llvm::RequireAnalysisPass<IslAstAnalysis, Scop, ScopAnalysisManager,
367                                   ScopStandardAnalysisResults &,
368                                   SPMUpdater &>());
369     break;
370   case CODEGEN_FULL:
371     SPM.addPass(CodeGenerationPass());
372     break;
373   case CODEGEN_NONE:
374     break;
375   }
376 
377   PM.addPass(createFunctionToScopPassAdaptor(std::move(SPM)));
378   PM.addPass(PB.buildFunctionSimplificationPipeline(
379       Level, llvm::ThinOrFullLTOPhase::None)); // Cleanup
380 
381   if (CFGPrinter)
382     PM.addPass(llvm::CFGPrinterPass());
383 }
384 
385 static void buildEarlyPollyPipeline(llvm::ModulePassManager &MPM,
386                                     llvm::OptimizationLevel Level) {
387   bool EnableForOpt =
388       shouldEnablePollyForOptimization() && Level.isOptimizingForSpeed();
389   if (!shouldEnablePollyForDiagnostic() && !EnableForOpt)
390     return;
391 
392   FunctionPassManager FPM = buildCanonicalicationPassesForNPM(MPM, Level);
393 
394   if (DumpBefore || !DumpBeforeFile.empty()) {
395     MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
396 
397     if (DumpBefore)
398       MPM.addPass(DumpModulePass("-before", true));
399     for (auto &Filename : DumpBeforeFile)
400       MPM.addPass(DumpModulePass(Filename, false));
401 
402     FPM = FunctionPassManager();
403   }
404 
405   buildCommonPollyPipeline(FPM, Level, EnableForOpt);
406   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
407 
408   if (DumpAfter)
409     MPM.addPass(DumpModulePass("-after", true));
410   for (auto &Filename : DumpAfterFile)
411     MPM.addPass(DumpModulePass(Filename, false));
412 }
413 
414 static void buildLatePollyPipeline(FunctionPassManager &PM,
415                                    llvm::OptimizationLevel Level) {
416   bool EnableForOpt =
417       shouldEnablePollyForOptimization() && Level.isOptimizingForSpeed();
418   if (!shouldEnablePollyForDiagnostic() && !EnableForOpt)
419     return;
420 
421   if (DumpBefore)
422     PM.addPass(DumpFunctionPass("-before"));
423   if (!DumpBeforeFile.empty())
424     llvm::report_fatal_error(
425         "Option -polly-dump-before-file at -polly-position=late "
426         "not supported with NPM",
427         false);
428 
429   buildCommonPollyPipeline(PM, Level, EnableForOpt);
430 
431   if (DumpAfter)
432     PM.addPass(DumpFunctionPass("-after"));
433   if (!DumpAfterFile.empty())
434     llvm::report_fatal_error(
435         "Option -polly-dump-after-file at -polly-position=late "
436         "not supported with NPM",
437         false);
438 }
439 
440 static OwningScopAnalysisManagerFunctionProxy
441 createScopAnalyses(FunctionAnalysisManager &FAM,
442                    PassInstrumentationCallbacks *PIC) {
443   OwningScopAnalysisManagerFunctionProxy Proxy;
444 #define SCOP_ANALYSIS(NAME, CREATE_PASS)                                       \
445   Proxy.getManager().registerPass([PIC] {                                      \
446     (void)PIC;                                                                 \
447     return CREATE_PASS;                                                        \
448   });
449 #include "PollyPasses.def"
450 
451   Proxy.getManager().registerPass(
452       [&FAM] { return FunctionAnalysisManagerScopProxy(FAM); });
453   return Proxy;
454 }
455 
456 static void registerFunctionAnalyses(FunctionAnalysisManager &FAM,
457                                      PassInstrumentationCallbacks *PIC) {
458 
459 #define FUNCTION_ANALYSIS(NAME, CREATE_PASS)                                   \
460   FAM.registerPass([] { return CREATE_PASS; });
461 
462 #include "PollyPasses.def"
463 
464   FAM.registerPass([&FAM, PIC] { return createScopAnalyses(FAM, PIC); });
465 }
466 
467 static bool
468 parseFunctionPipeline(StringRef Name, FunctionPassManager &FPM,
469                       ArrayRef<PassBuilder::PipelineElement> Pipeline) {
470   if (llvm::parseAnalysisUtilityPasses<OwningScopAnalysisManagerFunctionProxy>(
471           "polly-scop-analyses", Name, FPM))
472     return true;
473 
474 #define FUNCTION_ANALYSIS(NAME, CREATE_PASS)                                   \
475   if (llvm::parseAnalysisUtilityPasses<                                        \
476           std::remove_reference<decltype(CREATE_PASS)>::type>(NAME, Name,      \
477                                                               FPM))            \
478     return true;
479 
480 #define FUNCTION_PASS(NAME, CREATE_PASS)                                       \
481   if (Name == NAME) {                                                          \
482     FPM.addPass(CREATE_PASS);                                                  \
483     return true;                                                               \
484   }
485 
486 #include "PollyPasses.def"
487   return false;
488 }
489 
490 static bool parseScopPass(StringRef Name, ScopPassManager &SPM,
491                           PassInstrumentationCallbacks *PIC) {
492 #define SCOP_ANALYSIS(NAME, CREATE_PASS)                                       \
493   if (llvm::parseAnalysisUtilityPasses<                                        \
494           std::remove_reference<decltype(CREATE_PASS)>::type>(NAME, Name,      \
495                                                               SPM))            \
496     return true;
497 
498 #define SCOP_PASS(NAME, CREATE_PASS)                                           \
499   if (Name == NAME) {                                                          \
500     SPM.addPass(CREATE_PASS);                                                  \
501     return true;                                                               \
502   }
503 
504 #include "PollyPasses.def"
505 
506   return false;
507 }
508 
509 static bool parseScopPipeline(StringRef Name, FunctionPassManager &FPM,
510                               PassInstrumentationCallbacks *PIC,
511                               ArrayRef<PassBuilder::PipelineElement> Pipeline) {
512   if (Name != "scop")
513     return false;
514   if (!Pipeline.empty()) {
515     ScopPassManager SPM;
516     for (const auto &E : Pipeline)
517       if (!parseScopPass(E.Name, SPM, PIC))
518         return false;
519     FPM.addPass(createFunctionToScopPassAdaptor(std::move(SPM)));
520   }
521   return true;
522 }
523 
524 static bool isScopPassName(StringRef Name) {
525 #define SCOP_ANALYSIS(NAME, CREATE_PASS)                                       \
526   if (Name == "require<" NAME ">")                                             \
527     return true;                                                               \
528   if (Name == "invalidate<" NAME ">")                                          \
529     return true;
530 
531 #define SCOP_PASS(NAME, CREATE_PASS)                                           \
532   if (Name == NAME)                                                            \
533     return true;
534 
535 #include "PollyPasses.def"
536 
537   return false;
538 }
539 
540 static bool
541 parseTopLevelPipeline(llvm::ModulePassManager &MPM,
542                       PassInstrumentationCallbacks *PIC,
543                       ArrayRef<PassBuilder::PipelineElement> Pipeline) {
544   std::vector<PassBuilder::PipelineElement> FullPipeline;
545   StringRef FirstName = Pipeline.front().Name;
546 
547   if (!isScopPassName(FirstName))
548     return false;
549 
550   FunctionPassManager FPM;
551   ScopPassManager SPM;
552 
553   for (auto &Element : Pipeline) {
554     auto &Name = Element.Name;
555     auto &InnerPipeline = Element.InnerPipeline;
556     if (!InnerPipeline.empty()) // Scop passes don't have inner pipelines
557       return false;
558     if (!parseScopPass(Name, SPM, PIC))
559       return false;
560   }
561 
562   FPM.addPass(createFunctionToScopPassAdaptor(std::move(SPM)));
563   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
564 
565   return true;
566 }
567 
568 /// Register Polly to be available as an optimizer
569 ///
570 ///
571 /// We can currently run Polly at two different points int the pass manager.
572 /// a) very early, b) right before the vectorizer.
573 ///
574 /// The default is currently a), to register Polly such that it runs as early as
575 /// possible. This has several implications:
576 ///
577 ///   1) We need to schedule more canonicalization passes
578 ///
579 ///   As nothing is run before Polly, it is necessary to run a set of preparing
580 ///   transformations before Polly to canonicalize the LLVM-IR and to allow
581 ///   Polly to detect and understand the code.
582 ///
583 ///   2) We get the full -O3 optimization sequence after Polly
584 ///
585 ///   The LLVM-IR that is generated by Polly has been optimized on a high level,
586 ///   but it may be rather inefficient on the lower/scalar level. By scheduling
587 ///   Polly before all other passes, we have the full sequence of -O3
588 ///   optimizations behind us, such that inefficiencies on the low level can
589 ///   be optimized away.
590 ///
591 /// We are currently evaluating the benefit or running Polly at b). b) is nice
592 /// as everything is fully inlined and canonicalized, but we need to be able to
593 /// handle LICMed code to make it useful.
594 void registerPollyPasses(PassBuilder &PB) {
595   PassInstrumentationCallbacks *PIC = PB.getPassInstrumentationCallbacks();
596   PB.registerAnalysisRegistrationCallback([PIC](FunctionAnalysisManager &FAM) {
597     registerFunctionAnalyses(FAM, PIC);
598   });
599   PB.registerPipelineParsingCallback(parseFunctionPipeline);
600   PB.registerPipelineParsingCallback(
601       [PIC](StringRef Name, FunctionPassManager &FPM,
602             ArrayRef<PassBuilder::PipelineElement> Pipeline) -> bool {
603         return parseScopPipeline(Name, FPM, PIC, Pipeline);
604       });
605   PB.registerParseTopLevelPipelineCallback(
606       [PIC](llvm::ModulePassManager &MPM,
607             ArrayRef<PassBuilder::PipelineElement> Pipeline) -> bool {
608         return parseTopLevelPipeline(MPM, PIC, Pipeline);
609       });
610 
611   switch (PassPosition) {
612   case POSITION_EARLY:
613     PB.registerPipelineStartEPCallback(buildEarlyPollyPipeline);
614     break;
615   case POSITION_BEFORE_VECTORIZER:
616     PB.registerVectorizerStartEPCallback(buildLatePollyPipeline);
617     break;
618   }
619 }
620 } // namespace polly
621 
622 llvm::PassPluginLibraryInfo getPollyPluginInfo() {
623   return {LLVM_PLUGIN_API_VERSION, "Polly", LLVM_VERSION_STRING,
624           polly::registerPollyPasses};
625 }
626