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