PassManagerBuilder.cpp revision 79c07d2a36282b09b9c5d0aa65ebf4bff017621b 
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
18#include "llvm-c/Transforms/PassManagerBuilder.h"
19
20#include "llvm/PassManager.h"
21#include "llvm/DefaultPasses.h"
22#include "llvm/PassManager.h"
23#include "llvm/Analysis/Passes.h"
24#include "llvm/Analysis/Verifier.h"
25#include "llvm/Support/CommandLine.h"
26#include "llvm/Target/TargetLibraryInfo.h"
27#include "llvm/Transforms/Scalar.h"
28#include "llvm/Transforms/Vectorize.h"
29#include "llvm/Transforms/IPO.h"
30#include "llvm/ADT/SmallVector.h"
31#include "llvm/Support/ManagedStatic.h"
32
33using namespace llvm;
34
35static cl::opt<bool>
36RunLoopVectorization("vectorize-loops",
37                     cl::desc("Run the Loop vectorization passes"));
38
39static cl::opt<bool>
40RunBBVectorization("vectorize", cl::desc("Run the BB vectorization passes"));
41
42static cl::opt<bool>
43UseGVNAfterVectorization("use-gvn-after-vectorization",
44  cl::init(false), cl::Hidden,
45  cl::desc("Run GVN instead of Early CSE after vectorization passes"));
46
47static cl::opt<bool> UseNewSROA("use-new-sroa",
48  cl::init(true), cl::Hidden,
49  cl::desc("Enable the new, experimental SROA pass"));
50
51PassManagerBuilder::PassManagerBuilder() {
52    OptLevel = 2;
53    SizeLevel = 0;
54    LibraryInfo = 0;
55    Inliner = 0;
56    DisableSimplifyLibCalls = false;
57    DisableUnitAtATime = false;
58    DisableUnrollLoops = false;
59    Vectorize = RunBBVectorization;
60    LoopVectorize = RunLoopVectorization;
61}
62
63PassManagerBuilder::~PassManagerBuilder() {
64  delete LibraryInfo;
65  delete Inliner;
66}
67
68/// Set of global extensions, automatically added as part of the standard set.
69static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
70   PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
71
72void PassManagerBuilder::addGlobalExtension(
73    PassManagerBuilder::ExtensionPointTy Ty,
74    PassManagerBuilder::ExtensionFn Fn) {
75  GlobalExtensions->push_back(std::make_pair(Ty, Fn));
76}
77
78void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
79  Extensions.push_back(std::make_pair(Ty, Fn));
80}
81
82void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
83                                           PassManagerBase &PM) const {
84  for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
85    if ((*GlobalExtensions)[i].first == ETy)
86      (*GlobalExtensions)[i].second(*this, PM);
87  for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
88    if (Extensions[i].first == ETy)
89      Extensions[i].second(*this, PM);
90}
91
92void
93PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
94  // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
95  // BasicAliasAnalysis wins if they disagree. This is intended to help
96  // support "obvious" type-punning idioms.
97  PM.add(createTypeBasedAliasAnalysisPass());
98  PM.add(createBasicAliasAnalysisPass());
99}
100
101void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
102  addExtensionsToPM(EP_EarlyAsPossible, FPM);
103
104  // Add LibraryInfo if we have some.
105  if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));
106
107  if (OptLevel == 0) return;
108
109  addInitialAliasAnalysisPasses(FPM);
110
111  FPM.add(createCFGSimplificationPass());
112  if (UseNewSROA)
113    FPM.add(createSROAPass());
114  else
115    FPM.add(createScalarReplAggregatesPass());
116  FPM.add(createEarlyCSEPass());
117  FPM.add(createLowerExpectIntrinsicPass());
118}
119
120void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
121  // If all optimizations are disabled, just run the always-inline pass.
122  if (OptLevel == 0) {
123    if (Inliner) {
124      MPM.add(Inliner);
125      Inliner = 0;
126    }
127
128    // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
129    // pass manager, but we don't want to add extensions into that pass manager.
130    // To prevent this we must insert a no-op module pass to reset the pass
131    // manager to get the same behavior as EP_OptimizerLast in non-O0 builds.
132    if (!GlobalExtensions->empty() || !Extensions.empty())
133      MPM.add(createBarrierNoopPass());
134
135    addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
136    return;
137  }
138
139  // Add LibraryInfo if we have some.
140  if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));
141
142  addInitialAliasAnalysisPasses(MPM);
143
144  if (!DisableUnitAtATime) {
145    addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
146
147    MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
148
149    MPM.add(createIPSCCPPass());              // IP SCCP
150    MPM.add(createDeadArgEliminationPass());  // Dead argument elimination
151
152    MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
153    MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
154  }
155
156  // Start of CallGraph SCC passes.
157  if (!DisableUnitAtATime)
158    MPM.add(createPruneEHPass());             // Remove dead EH info
159  if (Inliner) {
160    MPM.add(Inliner);
161    Inliner = 0;
162  }
163  if (!DisableUnitAtATime)
164    MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
165  if (OptLevel > 2)
166    MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
167
168  // Start of function pass.
169  // Break up aggregate allocas, using SSAUpdater.
170  if (UseNewSROA)
171    MPM.add(createSROAPass(/*RequiresDomTree*/ false));
172  else
173    MPM.add(createScalarReplAggregatesPass(-1, false));
174  MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
175  if (!DisableSimplifyLibCalls)
176    MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
177  MPM.add(createJumpThreadingPass());         // Thread jumps.
178  MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
179  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
180  MPM.add(createInstructionCombiningPass());  // Combine silly seq's
181
182  MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
183  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
184  MPM.add(createReassociatePass());           // Reassociate expressions
185  MPM.add(createLoopRotatePass());            // Rotate Loop
186  MPM.add(createLICMPass());                  // Hoist loop invariants
187  MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
188  MPM.add(createInstructionCombiningPass());
189  MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
190  MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
191  MPM.add(createLoopDeletionPass());          // Delete dead loops
192
193  if (LoopVectorize) {
194    MPM.add(createLoopVectorizePass());
195    MPM.add(createLICMPass());
196  }
197
198  if (!DisableUnrollLoops)
199    MPM.add(createLoopUnrollPass());          // Unroll small loops
200  addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
201
202  if (OptLevel > 1)
203    MPM.add(createGVNPass());                 // Remove redundancies
204  MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
205  MPM.add(createSCCPPass());                  // Constant prop with SCCP
206
207  // Run instcombine after redundancy elimination to exploit opportunities
208  // opened up by them.
209  MPM.add(createInstructionCombiningPass());
210  MPM.add(createJumpThreadingPass());         // Thread jumps
211  MPM.add(createCorrelatedValuePropagationPass());
212  MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
213
214  addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
215
216  if (Vectorize) {
217    MPM.add(createBBVectorizePass());
218    MPM.add(createInstructionCombiningPass());
219    if (OptLevel > 1 && UseGVNAfterVectorization)
220      MPM.add(createGVNPass());                   // Remove redundancies
221    else
222      MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
223  }
224
225  MPM.add(createAggressiveDCEPass());         // Delete dead instructions
226  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
227  MPM.add(createInstructionCombiningPass());  // Clean up after everything.
228
229  if (!DisableUnitAtATime) {
230    // FIXME: We shouldn't bother with this anymore.
231    MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
232
233    // GlobalOpt already deletes dead functions and globals, at -O2 try a
234    // late pass of GlobalDCE.  It is capable of deleting dead cycles.
235    if (OptLevel > 1) {
236      MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
237      MPM.add(createConstantMergePass());     // Merge dup global constants
238    }
239  }
240  addExtensionsToPM(EP_OptimizerLast, MPM);
241}
242
243void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
244                                                bool Internalize,
245                                                bool RunInliner,
246                                                bool DisableGVNLoadPRE) {
247  // Provide AliasAnalysis services for optimizations.
248  addInitialAliasAnalysisPasses(PM);
249
250  // Now that composite has been compiled, scan through the module, looking
251  // for a main function.  If main is defined, mark all other functions
252  // internal.
253  if (Internalize) {
254    std::vector<const char*> E;
255    E.push_back("main");
256    PM.add(createInternalizePass(E));
257  }
258
259  // Propagate constants at call sites into the functions they call.  This
260  // opens opportunities for globalopt (and inlining) by substituting function
261  // pointers passed as arguments to direct uses of functions.
262  PM.add(createIPSCCPPass());
263
264  // Now that we internalized some globals, see if we can hack on them!
265  PM.add(createGlobalOptimizerPass());
266
267  // Linking modules together can lead to duplicated global constants, only
268  // keep one copy of each constant.
269  PM.add(createConstantMergePass());
270
271  // Remove unused arguments from functions.
272  PM.add(createDeadArgEliminationPass());
273
274  // Reduce the code after globalopt and ipsccp.  Both can open up significant
275  // simplification opportunities, and both can propagate functions through
276  // function pointers.  When this happens, we often have to resolve varargs
277  // calls, etc, so let instcombine do this.
278  PM.add(createInstructionCombiningPass());
279
280  // Inline small functions
281  if (RunInliner)
282    PM.add(createFunctionInliningPass());
283
284  PM.add(createPruneEHPass());   // Remove dead EH info.
285
286  // Optimize globals again if we ran the inliner.
287  if (RunInliner)
288    PM.add(createGlobalOptimizerPass());
289  PM.add(createGlobalDCEPass()); // Remove dead functions.
290
291  // If we didn't decide to inline a function, check to see if we can
292  // transform it to pass arguments by value instead of by reference.
293  PM.add(createArgumentPromotionPass());
294
295  // The IPO passes may leave cruft around.  Clean up after them.
296  PM.add(createInstructionCombiningPass());
297  PM.add(createJumpThreadingPass());
298  // Break up allocas
299  if (UseNewSROA)
300    PM.add(createSROAPass());
301  else
302    PM.add(createScalarReplAggregatesPass());
303
304  // Run a few AA driven optimizations here and now, to cleanup the code.
305  PM.add(createFunctionAttrsPass()); // Add nocapture.
306  PM.add(createGlobalsModRefPass()); // IP alias analysis.
307
308  PM.add(createLICMPass());                 // Hoist loop invariants.
309  PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
310  PM.add(createMemCpyOptPass());            // Remove dead memcpys.
311  // Nuke dead stores.
312  PM.add(createDeadStoreEliminationPass());
313
314  // Cleanup and simplify the code after the scalar optimizations.
315  PM.add(createInstructionCombiningPass());
316
317  PM.add(createJumpThreadingPass());
318
319  // Delete basic blocks, which optimization passes may have killed.
320  PM.add(createCFGSimplificationPass());
321
322  // Now that we have optimized the program, discard unreachable functions.
323  PM.add(createGlobalDCEPass());
324}
325
326LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate() {
327  PassManagerBuilder *PMB = new PassManagerBuilder();
328  return wrap(PMB);
329}
330
331void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
332  PassManagerBuilder *Builder = unwrap(PMB);
333  delete Builder;
334}
335
336void
337LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
338                                  unsigned OptLevel) {
339  PassManagerBuilder *Builder = unwrap(PMB);
340  Builder->OptLevel = OptLevel;
341}
342
343void
344LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
345                                   unsigned SizeLevel) {
346  PassManagerBuilder *Builder = unwrap(PMB);
347  Builder->SizeLevel = SizeLevel;
348}
349
350void
351LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
352                                            LLVMBool Value) {
353  PassManagerBuilder *Builder = unwrap(PMB);
354  Builder->DisableUnitAtATime = Value;
355}
356
357void
358LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
359                                            LLVMBool Value) {
360  PassManagerBuilder *Builder = unwrap(PMB);
361  Builder->DisableUnrollLoops = Value;
362}
363
364void
365LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
366                                                 LLVMBool Value) {
367  PassManagerBuilder *Builder = unwrap(PMB);
368  Builder->DisableSimplifyLibCalls = Value;
369}
370
371void
372LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
373                                              unsigned Threshold) {
374  PassManagerBuilder *Builder = unwrap(PMB);
375  Builder->Inliner = createFunctionInliningPass(Threshold);
376}
377
378void
379LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
380                                                  LLVMPassManagerRef PM) {
381  PassManagerBuilder *Builder = unwrap(PMB);
382  FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
383  Builder->populateFunctionPassManager(*FPM);
384}
385
386void
387LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
388                                                LLVMPassManagerRef PM) {
389  PassManagerBuilder *Builder = unwrap(PMB);
390  PassManagerBase *MPM = unwrap(PM);
391  Builder->populateModulePassManager(*MPM);
392}
393
394void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
395                                                  LLVMPassManagerRef PM,
396                                                  bool Internalize,
397                                                  bool RunInliner) {
398  PassManagerBuilder *Builder = unwrap(PMB);
399  PassManagerBase *LPM = unwrap(PM);
400  Builder->populateLTOPassManager(*LPM, Internalize, RunInliner);
401}
402