PassManagerBuilder.cpp revision 57e6b2d1f3de0bf459e96f7038e692d624f7e580 
1//===- PassManagerBuilder.cpp - Build Standard Pass -----------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines the PassManagerBuilder class, which is used to set up a
11// "standard" optimization sequence suitable for languages like C and C++.
12//
13//===----------------------------------------------------------------------===//
14
15
16#include "llvm/Transforms/IPO/PassManagerBuilder.h"
17#include "llvm-c/Transforms/PassManagerBuilder.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/Analysis/Passes.h"
20#include "llvm/Analysis/Verifier.h"
21#include "llvm/PassManager.h"
22#include "llvm/Support/CommandLine.h"
23#include "llvm/Support/ManagedStatic.h"
24#include "llvm/Target/TargetLibraryInfo.h"
25#include "llvm/Transforms/IPO.h"
26#include "llvm/Transforms/Scalar.h"
27#include "llvm/Transforms/Vectorize.h"
28
29using namespace llvm;
30
31static cl::opt<bool>
32RunLoopVectorization("vectorize-loops",
33                     cl::desc("Run the Loop vectorization passes"));
34
35static cl::opt<bool>
36LateVectorization("late-vectorize", cl::init(false), cl::Hidden,
37                  cl::desc("Run the vectorization pasess late in the pass "
38                           "pipeline (after the inliner)"));
39
40static cl::opt<bool>
41RunSLPVectorization("vectorize-slp",
42                    cl::desc("Run the SLP vectorization passes"));
43
44static cl::opt<bool>
45RunBBVectorization("vectorize-slp-aggressive",
46                    cl::desc("Run the BB vectorization passes"));
47
48static cl::opt<bool>
49UseGVNAfterVectorization("use-gvn-after-vectorization",
50  cl::init(false), cl::Hidden,
51  cl::desc("Run GVN instead of Early CSE after vectorization passes"));
52
53static cl::opt<bool> UseNewSROA("use-new-sroa",
54  cl::init(true), cl::Hidden,
55  cl::desc("Enable the new, experimental SROA pass"));
56
57PassManagerBuilder::PassManagerBuilder() {
58    OptLevel = 2;
59    SizeLevel = 0;
60    LibraryInfo = 0;
61    Inliner = 0;
62    DisableUnitAtATime = false;
63    DisableUnrollLoops = false;
64    BBVectorize = RunBBVectorization;
65    SLPVectorize = RunSLPVectorization;
66    LoopVectorize = RunLoopVectorization;
67    LateVectorize = LateVectorization;
68}
69
70PassManagerBuilder::~PassManagerBuilder() {
71  delete LibraryInfo;
72  delete Inliner;
73}
74
75/// Set of global extensions, automatically added as part of the standard set.
76static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
77   PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
78
79void PassManagerBuilder::addGlobalExtension(
80    PassManagerBuilder::ExtensionPointTy Ty,
81    PassManagerBuilder::ExtensionFn Fn) {
82  GlobalExtensions->push_back(std::make_pair(Ty, Fn));
83}
84
85void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
86  Extensions.push_back(std::make_pair(Ty, Fn));
87}
88
89void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
90                                           PassManagerBase &PM) const {
91  for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
92    if ((*GlobalExtensions)[i].first == ETy)
93      (*GlobalExtensions)[i].second(*this, PM);
94  for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
95    if (Extensions[i].first == ETy)
96      Extensions[i].second(*this, PM);
97}
98
99void
100PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
101  // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
102  // BasicAliasAnalysis wins if they disagree. This is intended to help
103  // support "obvious" type-punning idioms.
104  PM.add(createTypeBasedAliasAnalysisPass());
105  PM.add(createBasicAliasAnalysisPass());
106}
107
108void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
109  addExtensionsToPM(EP_EarlyAsPossible, FPM);
110
111  // Add LibraryInfo if we have some.
112  if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));
113
114  if (OptLevel == 0) return;
115
116  addInitialAliasAnalysisPasses(FPM);
117
118  FPM.add(createCFGSimplificationPass());
119  if (UseNewSROA)
120    FPM.add(createSROAPass());
121  else
122    FPM.add(createScalarReplAggregatesPass());
123  FPM.add(createEarlyCSEPass());
124  FPM.add(createLowerExpectIntrinsicPass());
125}
126
127void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
128  // If all optimizations are disabled, just run the always-inline pass.
129  if (OptLevel == 0) {
130    if (Inliner) {
131      MPM.add(Inliner);
132      Inliner = 0;
133    }
134
135    // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
136    // pass manager, but we don't want to add extensions into that pass manager.
137    // To prevent this we must insert a no-op module pass to reset the pass
138    // manager to get the same behavior as EP_OptimizerLast in non-O0 builds.
139    if (!GlobalExtensions->empty() || !Extensions.empty())
140      MPM.add(createBarrierNoopPass());
141
142    addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
143    return;
144  }
145
146  // Add LibraryInfo if we have some.
147  if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));
148
149  addInitialAliasAnalysisPasses(MPM);
150
151  if (!DisableUnitAtATime) {
152    addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
153
154    MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
155
156    MPM.add(createIPSCCPPass());              // IP SCCP
157    MPM.add(createDeadArgEliminationPass());  // Dead argument elimination
158
159    MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
160    MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
161  }
162
163  // Start of CallGraph SCC passes.
164  if (!DisableUnitAtATime)
165    MPM.add(createPruneEHPass());             // Remove dead EH info
166  if (Inliner) {
167    MPM.add(Inliner);
168    Inliner = 0;
169  }
170  if (!DisableUnitAtATime)
171    MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
172  if (OptLevel > 2)
173    MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
174
175  // Start of function pass.
176  // Break up aggregate allocas, using SSAUpdater.
177  if (UseNewSROA)
178    MPM.add(createSROAPass(/*RequiresDomTree*/ false));
179  else
180    MPM.add(createScalarReplAggregatesPass(-1, false));
181  MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
182  MPM.add(createJumpThreadingPass());         // Thread jumps.
183  MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
184  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
185  MPM.add(createInstructionCombiningPass());  // Combine silly seq's
186
187  MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
188  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
189  MPM.add(createReassociatePass());           // Reassociate expressions
190  MPM.add(createLoopRotatePass());            // Rotate Loop
191  MPM.add(createLICMPass());                  // Hoist loop invariants
192  MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
193  MPM.add(createInstructionCombiningPass());
194  MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
195  MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
196  MPM.add(createLoopDeletionPass());          // Delete dead loops
197
198  if (!LateVectorize && LoopVectorize && OptLevel > 1 && SizeLevel < 2)
199      MPM.add(createLoopVectorizePass());
200
201  if (!DisableUnrollLoops)
202    MPM.add(createLoopUnrollPass());          // Unroll small loops
203  addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
204
205  if (OptLevel > 1)
206    MPM.add(createGVNPass());                 // Remove redundancies
207  MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
208  MPM.add(createSCCPPass());                  // Constant prop with SCCP
209
210  // Run instcombine after redundancy elimination to exploit opportunities
211  // opened up by them.
212  MPM.add(createInstructionCombiningPass());
213  MPM.add(createJumpThreadingPass());         // Thread jumps
214  MPM.add(createCorrelatedValuePropagationPass());
215  MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
216
217  addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
218
219  if (!LateVectorize) {
220    if (SLPVectorize)
221      MPM.add(createSLPVectorizerPass());   // Vectorize parallel scalar chains.
222
223    if (BBVectorize) {
224      MPM.add(createBBVectorizePass());
225      MPM.add(createInstructionCombiningPass());
226      if (OptLevel > 1 && UseGVNAfterVectorization)
227        MPM.add(createGVNPass());           // Remove redundancies
228      else
229        MPM.add(createEarlyCSEPass());      // Catch trivial redundancies
230
231      // BBVectorize may have significantly shortened a loop body; unroll again.
232      if (!DisableUnrollLoops)
233        MPM.add(createLoopUnrollPass());
234    }
235  }
236
237  MPM.add(createAggressiveDCEPass());         // Delete dead instructions
238  MPM.add(createCFGSimplificationPass(true)); // Merge & remove BBs
239  MPM.add(createInstructionCombiningPass());  // Clean up after everything.
240
241  // As an experimental mode, run any vectorization passes in a separate
242  // pipeline from the CGSCC pass manager that runs iteratively with the
243  // inliner.
244  if (LateVectorize) {
245    // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
246    // pass manager that we are specifically trying to avoid. To prevent this
247    // we must insert a no-op module pass to reset the pass manager.
248    MPM.add(createBarrierNoopPass());
249
250    // Add the various vectorization passes and relevant cleanup passes for
251    // them since we are no longer in the middle of the main scalar pipeline.
252    if (LoopVectorize && OptLevel > 1 && SizeLevel < 2) {
253      MPM.add(createLoopVectorizePass());
254
255      if (!DisableUnrollLoops)
256        MPM.add(createLoopUnrollPass());    // Unroll small loops
257
258      // FIXME: Is this necessary/useful? Should we also do SimplifyCFG?
259      MPM.add(createInstructionCombiningPass());
260    }
261
262    if (SLPVectorize) {
263      MPM.add(createSLPVectorizerPass());   // Vectorize parallel scalar chains.
264
265      // FIXME: Is this necessary/useful? Should we also do SimplifyCFG?
266      MPM.add(createInstructionCombiningPass());
267    }
268
269    if (BBVectorize) {
270      MPM.add(createBBVectorizePass());
271      MPM.add(createInstructionCombiningPass());
272      if (OptLevel > 1 && UseGVNAfterVectorization)
273        MPM.add(createGVNPass());           // Remove redundancies
274      else
275        MPM.add(createEarlyCSEPass());      // Catch trivial redundancies
276
277      // BBVectorize may have significantly shortened a loop body; unroll again.
278      if (!DisableUnrollLoops)
279        MPM.add(createLoopUnrollPass());
280    }
281  }
282
283  if (!DisableUnitAtATime) {
284    // FIXME: We shouldn't bother with this anymore.
285    MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
286
287    // GlobalOpt already deletes dead functions and globals, at -O2 try a
288    // late pass of GlobalDCE.  It is capable of deleting dead cycles.
289    if (OptLevel > 1) {
290      MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
291      MPM.add(createConstantMergePass());     // Merge dup global constants
292    }
293  }
294  addExtensionsToPM(EP_OptimizerLast, MPM);
295}
296
297void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
298                                                bool Internalize,
299                                                bool RunInliner,
300                                                bool DisableGVNLoadPRE) {
301  // Provide AliasAnalysis services for optimizations.
302  addInitialAliasAnalysisPasses(PM);
303
304  // Now that composite has been compiled, scan through the module, looking
305  // for a main function.  If main is defined, mark all other functions
306  // internal.
307  if (Internalize) {
308    std::vector<const char*> E;
309    E.push_back("main");
310    PM.add(createInternalizePass(E));
311  }
312
313  // Propagate constants at call sites into the functions they call.  This
314  // opens opportunities for globalopt (and inlining) by substituting function
315  // pointers passed as arguments to direct uses of functions.
316  PM.add(createIPSCCPPass());
317
318  // Now that we internalized some globals, see if we can hack on them!
319  PM.add(createGlobalOptimizerPass());
320
321  // Linking modules together can lead to duplicated global constants, only
322  // keep one copy of each constant.
323  PM.add(createConstantMergePass());
324
325  // Remove unused arguments from functions.
326  PM.add(createDeadArgEliminationPass());
327
328  // Reduce the code after globalopt and ipsccp.  Both can open up significant
329  // simplification opportunities, and both can propagate functions through
330  // function pointers.  When this happens, we often have to resolve varargs
331  // calls, etc, so let instcombine do this.
332  PM.add(createInstructionCombiningPass());
333
334  // Inline small functions
335  if (RunInliner)
336    PM.add(createFunctionInliningPass());
337
338  PM.add(createPruneEHPass());   // Remove dead EH info.
339
340  // Optimize globals again if we ran the inliner.
341  if (RunInliner)
342    PM.add(createGlobalOptimizerPass());
343  PM.add(createGlobalDCEPass()); // Remove dead functions.
344
345  // If we didn't decide to inline a function, check to see if we can
346  // transform it to pass arguments by value instead of by reference.
347  PM.add(createArgumentPromotionPass());
348
349  // The IPO passes may leave cruft around.  Clean up after them.
350  PM.add(createInstructionCombiningPass());
351  PM.add(createJumpThreadingPass());
352  // Break up allocas
353  if (UseNewSROA)
354    PM.add(createSROAPass());
355  else
356    PM.add(createScalarReplAggregatesPass());
357
358  // Run a few AA driven optimizations here and now, to cleanup the code.
359  PM.add(createFunctionAttrsPass()); // Add nocapture.
360  PM.add(createGlobalsModRefPass()); // IP alias analysis.
361
362  PM.add(createLICMPass());                 // Hoist loop invariants.
363  PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
364  PM.add(createMemCpyOptPass());            // Remove dead memcpys.
365  // Nuke dead stores.
366  PM.add(createDeadStoreEliminationPass());
367
368  // Cleanup and simplify the code after the scalar optimizations.
369  PM.add(createInstructionCombiningPass());
370
371  PM.add(createJumpThreadingPass());
372
373  // Delete basic blocks, which optimization passes may have killed.
374  PM.add(createCFGSimplificationPass(true));
375
376  // Now that we have optimized the program, discard unreachable functions.
377  PM.add(createGlobalDCEPass());
378}
379
380inline PassManagerBuilder *unwrap(LLVMPassManagerBuilderRef P) {
381    return reinterpret_cast<PassManagerBuilder*>(P);
382}
383
384inline LLVMPassManagerBuilderRef wrap(PassManagerBuilder *P) {
385  return reinterpret_cast<LLVMPassManagerBuilderRef>(P);
386}
387
388LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate() {
389  PassManagerBuilder *PMB = new PassManagerBuilder();
390  return wrap(PMB);
391}
392
393void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
394  PassManagerBuilder *Builder = unwrap(PMB);
395  delete Builder;
396}
397
398void
399LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
400                                  unsigned OptLevel) {
401  PassManagerBuilder *Builder = unwrap(PMB);
402  Builder->OptLevel = OptLevel;
403}
404
405void
406LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
407                                   unsigned SizeLevel) {
408  PassManagerBuilder *Builder = unwrap(PMB);
409  Builder->SizeLevel = SizeLevel;
410}
411
412void
413LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
414                                            LLVMBool Value) {
415  PassManagerBuilder *Builder = unwrap(PMB);
416  Builder->DisableUnitAtATime = Value;
417}
418
419void
420LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
421                                            LLVMBool Value) {
422  PassManagerBuilder *Builder = unwrap(PMB);
423  Builder->DisableUnrollLoops = Value;
424}
425
426void
427LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
428                                                 LLVMBool Value) {
429  // NOTE: The simplify-libcalls pass has been removed.
430}
431
432void
433LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
434                                              unsigned Threshold) {
435  PassManagerBuilder *Builder = unwrap(PMB);
436  Builder->Inliner = createFunctionInliningPass(Threshold);
437}
438
439void
440LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
441                                                  LLVMPassManagerRef PM) {
442  PassManagerBuilder *Builder = unwrap(PMB);
443  FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
444  Builder->populateFunctionPassManager(*FPM);
445}
446
447void
448LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
449                                                LLVMPassManagerRef PM) {
450  PassManagerBuilder *Builder = unwrap(PMB);
451  PassManagerBase *MPM = unwrap(PM);
452  Builder->populateModulePassManager(*MPM);
453}
454
455void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
456                                                  LLVMPassManagerRef PM,
457                                                  LLVMBool Internalize,
458                                                  LLVMBool RunInliner) {
459  PassManagerBuilder *Builder = unwrap(PMB);
460  PassManagerBase *LPM = unwrap(PM);
461  Builder->populateLTOPassManager(*LPM, Internalize != 0, RunInliner != 0);
462}
463