PassManagerBuilder.cpp revision e9a4411db4d3a05965630f668daf8071bf2d3513 
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>
36RunSLPVectorization("vectorize-slp",
37                    cl::desc("Run the SLP vectorization passes"));
38
39static cl::opt<bool>
40RunBBVectorization("vectorize-slp-aggressive",
41                    cl::desc("Run the BB vectorization passes"));
42
43static cl::opt<bool>
44UseGVNAfterVectorization("use-gvn-after-vectorization",
45  cl::init(false), cl::Hidden,
46  cl::desc("Run GVN instead of Early CSE after vectorization passes"));
47
48static cl::opt<bool> UseNewSROA("use-new-sroa",
49  cl::init(true), cl::Hidden,
50  cl::desc("Enable the new, experimental SROA pass"));
51
52PassManagerBuilder::PassManagerBuilder() {
53    OptLevel = 2;
54    SizeLevel = 0;
55    LibraryInfo = 0;
56    Inliner = 0;
57    DisableSimplifyLibCalls = false;
58    DisableUnitAtATime = false;
59    DisableUnrollLoops = false;
60    BBVectorize = RunBBVectorization;
61    SLPVectorize = RunSLPVectorization;
62    LoopVectorize = RunLoopVectorization;
63}
64
65PassManagerBuilder::~PassManagerBuilder() {
66  delete LibraryInfo;
67  delete Inliner;
68}
69
70/// Set of global extensions, automatically added as part of the standard set.
71static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
72   PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
73
74void PassManagerBuilder::addGlobalExtension(
75    PassManagerBuilder::ExtensionPointTy Ty,
76    PassManagerBuilder::ExtensionFn Fn) {
77  GlobalExtensions->push_back(std::make_pair(Ty, Fn));
78}
79
80void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
81  Extensions.push_back(std::make_pair(Ty, Fn));
82}
83
84void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
85                                           PassManagerBase &PM) const {
86  for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
87    if ((*GlobalExtensions)[i].first == ETy)
88      (*GlobalExtensions)[i].second(*this, PM);
89  for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
90    if (Extensions[i].first == ETy)
91      Extensions[i].second(*this, PM);
92}
93
94void
95PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
96  // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
97  // BasicAliasAnalysis wins if they disagree. This is intended to help
98  // support "obvious" type-punning idioms.
99  PM.add(createTypeBasedAliasAnalysisPass());
100  PM.add(createBasicAliasAnalysisPass());
101}
102
103void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
104  addExtensionsToPM(EP_EarlyAsPossible, FPM);
105
106  // Add LibraryInfo if we have some.
107  if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));
108
109  if (OptLevel == 0) return;
110
111  addInitialAliasAnalysisPasses(FPM);
112
113  FPM.add(createCFGSimplificationPass());
114  if (UseNewSROA)
115    FPM.add(createSROAPass());
116  else
117    FPM.add(createScalarReplAggregatesPass());
118  FPM.add(createEarlyCSEPass());
119  FPM.add(createLowerExpectIntrinsicPass());
120}
121
122void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
123  // If all optimizations are disabled, just run the always-inline pass.
124  if (OptLevel == 0) {
125    if (Inliner) {
126      MPM.add(Inliner);
127      Inliner = 0;
128    }
129
130    // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
131    // pass manager, but we don't want to add extensions into that pass manager.
132    // To prevent this we must insert a no-op module pass to reset the pass
133    // manager to get the same behavior as EP_OptimizerLast in non-O0 builds.
134    if (!GlobalExtensions->empty() || !Extensions.empty())
135      MPM.add(createBarrierNoopPass());
136
137    addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
138    return;
139  }
140
141  // Add LibraryInfo if we have some.
142  if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));
143
144  addInitialAliasAnalysisPasses(MPM);
145
146  if (!DisableUnitAtATime) {
147    addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
148
149    MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
150
151    MPM.add(createIPSCCPPass());              // IP SCCP
152    MPM.add(createDeadArgEliminationPass());  // Dead argument elimination
153
154    MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
155    MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
156  }
157
158  // Start of CallGraph SCC passes.
159  if (!DisableUnitAtATime)
160    MPM.add(createPruneEHPass());             // Remove dead EH info
161  if (Inliner) {
162    MPM.add(Inliner);
163    Inliner = 0;
164  }
165  if (!DisableUnitAtATime)
166    MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
167  if (OptLevel > 2)
168    MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
169
170  // Start of function pass.
171  // Break up aggregate allocas, using SSAUpdater.
172  if (UseNewSROA)
173    MPM.add(createSROAPass(/*RequiresDomTree*/ false));
174  else
175    MPM.add(createScalarReplAggregatesPass(-1, false));
176  MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
177  if (!DisableSimplifyLibCalls)
178    MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
179  MPM.add(createJumpThreadingPass());         // Thread jumps.
180  MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
181  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
182  MPM.add(createInstructionCombiningPass());  // Combine silly seq's
183
184  MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
185  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
186  MPM.add(createReassociatePass());           // Reassociate expressions
187  MPM.add(createLoopRotatePass());            // Rotate Loop
188  MPM.add(createLICMPass());                  // Hoist loop invariants
189  MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
190  MPM.add(createInstructionCombiningPass());
191  MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
192  MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
193  MPM.add(createLoopDeletionPass());          // Delete dead loops
194
195  if (LoopVectorize && OptLevel > 2)
196    MPM.add(createLoopVectorizePass());
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 (SLPVectorize)
217    MPM.add(createSLPVectorizerPass());     // Vectorize parallel scalar chains.
218
219  if (BBVectorize) {
220    MPM.add(createBBVectorizePass());
221    MPM.add(createInstructionCombiningPass());
222    if (OptLevel > 1 && UseGVNAfterVectorization)
223      MPM.add(createGVNPass());                   // Remove redundancies
224    else
225      MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
226
227    // BBVectorize may have significantly shortened a loop body; unroll again.
228    if (!DisableUnrollLoops)
229      MPM.add(createLoopUnrollPass());
230  }
231
232  MPM.add(createAggressiveDCEPass());         // Delete dead instructions
233  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
234  MPM.add(createInstructionCombiningPass());  // Clean up after everything.
235
236  if (!DisableUnitAtATime) {
237    // FIXME: We shouldn't bother with this anymore.
238    MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
239
240    // GlobalOpt already deletes dead functions and globals, at -O2 try a
241    // late pass of GlobalDCE.  It is capable of deleting dead cycles.
242    if (OptLevel > 1) {
243      MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
244      MPM.add(createConstantMergePass());     // Merge dup global constants
245    }
246  }
247  addExtensionsToPM(EP_OptimizerLast, MPM);
248}
249
250void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
251                                                bool Internalize,
252                                                bool RunInliner,
253                                                bool DisableGVNLoadPRE) {
254  // Provide AliasAnalysis services for optimizations.
255  addInitialAliasAnalysisPasses(PM);
256
257  // Now that composite has been compiled, scan through the module, looking
258  // for a main function.  If main is defined, mark all other functions
259  // internal.
260  if (Internalize) {
261    std::vector<const char*> E;
262    E.push_back("main");
263    PM.add(createInternalizePass(E));
264  }
265
266  // Propagate constants at call sites into the functions they call.  This
267  // opens opportunities for globalopt (and inlining) by substituting function
268  // pointers passed as arguments to direct uses of functions.
269  PM.add(createIPSCCPPass());
270
271  // Now that we internalized some globals, see if we can hack on them!
272  PM.add(createGlobalOptimizerPass());
273
274  // Linking modules together can lead to duplicated global constants, only
275  // keep one copy of each constant.
276  PM.add(createConstantMergePass());
277
278  // Remove unused arguments from functions.
279  PM.add(createDeadArgEliminationPass());
280
281  // Reduce the code after globalopt and ipsccp.  Both can open up significant
282  // simplification opportunities, and both can propagate functions through
283  // function pointers.  When this happens, we often have to resolve varargs
284  // calls, etc, so let instcombine do this.
285  PM.add(createInstructionCombiningPass());
286
287  // Inline small functions
288  if (RunInliner)
289    PM.add(createFunctionInliningPass());
290
291  PM.add(createPruneEHPass());   // Remove dead EH info.
292
293  // Optimize globals again if we ran the inliner.
294  if (RunInliner)
295    PM.add(createGlobalOptimizerPass());
296  PM.add(createGlobalDCEPass()); // Remove dead functions.
297
298  // If we didn't decide to inline a function, check to see if we can
299  // transform it to pass arguments by value instead of by reference.
300  PM.add(createArgumentPromotionPass());
301
302  // The IPO passes may leave cruft around.  Clean up after them.
303  PM.add(createInstructionCombiningPass());
304  PM.add(createJumpThreadingPass());
305  // Break up allocas
306  if (UseNewSROA)
307    PM.add(createSROAPass());
308  else
309    PM.add(createScalarReplAggregatesPass());
310
311  // Run a few AA driven optimizations here and now, to cleanup the code.
312  PM.add(createFunctionAttrsPass()); // Add nocapture.
313  PM.add(createGlobalsModRefPass()); // IP alias analysis.
314
315  PM.add(createLICMPass());                 // Hoist loop invariants.
316  PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
317  PM.add(createMemCpyOptPass());            // Remove dead memcpys.
318  // Nuke dead stores.
319  PM.add(createDeadStoreEliminationPass());
320
321  // Cleanup and simplify the code after the scalar optimizations.
322  PM.add(createInstructionCombiningPass());
323
324  PM.add(createJumpThreadingPass());
325
326  // Delete basic blocks, which optimization passes may have killed.
327  PM.add(createCFGSimplificationPass());
328
329  // Now that we have optimized the program, discard unreachable functions.
330  PM.add(createGlobalDCEPass());
331}
332
333LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate() {
334  PassManagerBuilder *PMB = new PassManagerBuilder();
335  return wrap(PMB);
336}
337
338void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
339  PassManagerBuilder *Builder = unwrap(PMB);
340  delete Builder;
341}
342
343void
344LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
345                                  unsigned OptLevel) {
346  PassManagerBuilder *Builder = unwrap(PMB);
347  Builder->OptLevel = OptLevel;
348}
349
350void
351LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
352                                   unsigned SizeLevel) {
353  PassManagerBuilder *Builder = unwrap(PMB);
354  Builder->SizeLevel = SizeLevel;
355}
356
357void
358LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
359                                            LLVMBool Value) {
360  PassManagerBuilder *Builder = unwrap(PMB);
361  Builder->DisableUnitAtATime = Value;
362}
363
364void
365LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
366                                            LLVMBool Value) {
367  PassManagerBuilder *Builder = unwrap(PMB);
368  Builder->DisableUnrollLoops = Value;
369}
370
371void
372LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
373                                                 LLVMBool Value) {
374  PassManagerBuilder *Builder = unwrap(PMB);
375  Builder->DisableSimplifyLibCalls = Value;
376}
377
378void
379LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
380                                              unsigned Threshold) {
381  PassManagerBuilder *Builder = unwrap(PMB);
382  Builder->Inliner = createFunctionInliningPass(Threshold);
383}
384
385void
386LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
387                                                  LLVMPassManagerRef PM) {
388  PassManagerBuilder *Builder = unwrap(PMB);
389  FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
390  Builder->populateFunctionPassManager(*FPM);
391}
392
393void
394LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
395                                                LLVMPassManagerRef PM) {
396  PassManagerBuilder *Builder = unwrap(PMB);
397  PassManagerBase *MPM = unwrap(PM);
398  Builder->populateModulePassManager(*MPM);
399}
400
401void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
402                                                  LLVMPassManagerRef PM,
403                                                  LLVMBool Internalize,
404                                                  LLVMBool RunInliner) {
405  PassManagerBuilder *Builder = unwrap(PMB);
406  PassManagerBase *LPM = unwrap(PM);
407  Builder->populateLTOPassManager(*LPM, Internalize != 0, RunInliner != 0);
408}
409