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
43PassManagerBuilder::PassManagerBuilder() {
44    OptLevel = 2;
45    SizeLevel = 0;
46    LibraryInfo = 0;
47    Inliner = 0;
48    DisableSimplifyLibCalls = false;
49    DisableUnitAtATime = false;
50    DisableUnrollLoops = false;
51    Vectorize = RunVectorization;
52}
53
54PassManagerBuilder::~PassManagerBuilder() {
55  delete LibraryInfo;
56  delete Inliner;
57}
58
59/// Set of global extensions, automatically added as part of the standard set.
60static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
61   PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
62
63void PassManagerBuilder::addGlobalExtension(
64    PassManagerBuilder::ExtensionPointTy Ty,
65    PassManagerBuilder::ExtensionFn Fn) {
66  GlobalExtensions->push_back(std::make_pair(Ty, Fn));
67}
68
69void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
70  Extensions.push_back(std::make_pair(Ty, Fn));
71}
72
73void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
74                                           PassManagerBase &PM) const {
75  for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
76    if ((*GlobalExtensions)[i].first == ETy)
77      (*GlobalExtensions)[i].second(*this, PM);
78  for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
79    if (Extensions[i].first == ETy)
80      Extensions[i].second(*this, PM);
81}
82
83void
84PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
85  // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
86  // BasicAliasAnalysis wins if they disagree. This is intended to help
87  // support "obvious" type-punning idioms.
88  PM.add(createTypeBasedAliasAnalysisPass());
89  PM.add(createBasicAliasAnalysisPass());
90}
91
92void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
93  addExtensionsToPM(EP_EarlyAsPossible, FPM);
94
95  // Add LibraryInfo if we have some.
96  if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));
97
98  if (OptLevel == 0) return;
99
100  addInitialAliasAnalysisPasses(FPM);
101
102  FPM.add(createCFGSimplificationPass());
103  FPM.add(createScalarReplAggregatesPass());
104  FPM.add(createEarlyCSEPass());
105  FPM.add(createLowerExpectIntrinsicPass());
106}
107
108void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
109  // If all optimizations are disabled, just run the always-inline pass.
110  if (OptLevel == 0) {
111    if (Inliner) {
112      MPM.add(Inliner);
113      Inliner = 0;
114    }
115    addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
116    return;
117  }
118
119  // Add LibraryInfo if we have some.
120  if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));
121
122  addInitialAliasAnalysisPasses(MPM);
123
124  if (!DisableUnitAtATime) {
125    addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
126
127    MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
128
129    MPM.add(createIPSCCPPass());              // IP SCCP
130    MPM.add(createDeadArgEliminationPass());  // Dead argument elimination
131
132    MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
133    MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
134  }
135
136  // Start of CallGraph SCC passes.
137  if (!DisableUnitAtATime)
138    MPM.add(createPruneEHPass());             // Remove dead EH info
139  if (Inliner) {
140    MPM.add(Inliner);
141    Inliner = 0;
142  }
143  if (!DisableUnitAtATime)
144    MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
145  if (OptLevel > 2)
146    MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
147
148  // Start of function pass.
149  // Break up aggregate allocas, using SSAUpdater.
150  MPM.add(createScalarReplAggregatesPass(-1, false));
151  MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
152  if (!DisableSimplifyLibCalls)
153    MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
154  MPM.add(createJumpThreadingPass());         // Thread jumps.
155  MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
156  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
157  MPM.add(createInstructionCombiningPass());  // Combine silly seq's
158
159  MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
160  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
161  MPM.add(createReassociatePass());           // Reassociate expressions
162  MPM.add(createLoopRotatePass());            // Rotate Loop
163  MPM.add(createLICMPass());                  // Hoist loop invariants
164  MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
165  MPM.add(createInstructionCombiningPass());
166  MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
167  MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
168  MPM.add(createLoopDeletionPass());          // Delete dead loops
169  if (!DisableUnrollLoops)
170    MPM.add(createLoopUnrollPass());          // Unroll small loops
171  addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
172
173  if (OptLevel > 1)
174    MPM.add(createGVNPass());                 // Remove redundancies
175  MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
176  MPM.add(createSCCPPass());                  // Constant prop with SCCP
177
178  // Run instcombine after redundancy elimination to exploit opportunities
179  // opened up by them.
180  MPM.add(createInstructionCombiningPass());
181  MPM.add(createJumpThreadingPass());         // Thread jumps
182  MPM.add(createCorrelatedValuePropagationPass());
183  MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
184
185  addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
186
187  if (Vectorize) {
188    MPM.add(createBBVectorizePass());
189    MPM.add(createInstructionCombiningPass());
190    if (OptLevel > 1 && UseGVNAfterVectorization)
191      MPM.add(createGVNPass());                   // Remove redundancies
192    else
193      MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
194  }
195
196  MPM.add(createAggressiveDCEPass());         // Delete dead instructions
197  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
198  MPM.add(createInstructionCombiningPass());  // Clean up after everything.
199
200  if (!DisableUnitAtATime) {
201    // FIXME: We shouldn't bother with this anymore.
202    MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
203
204    // GlobalOpt already deletes dead functions and globals, at -O3 try a
205    // late pass of GlobalDCE.  It is capable of deleting dead cycles.
206    if (OptLevel > 2)
207      MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
208
209    if (OptLevel > 1)
210      MPM.add(createConstantMergePass());     // Merge dup global constants
211  }
212  addExtensionsToPM(EP_OptimizerLast, MPM);
213}
214
215void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
216                                                bool Internalize,
217                                                bool RunInliner,
218                                                bool DisableGVNLoadPRE) {
219  // Provide AliasAnalysis services for optimizations.
220  addInitialAliasAnalysisPasses(PM);
221
222  // Now that composite has been compiled, scan through the module, looking
223  // for a main function.  If main is defined, mark all other functions
224  // internal.
225  if (Internalize)
226    PM.add(createInternalizePass(true));
227
228  // Propagate constants at call sites into the functions they call.  This
229  // opens opportunities for globalopt (and inlining) by substituting function
230  // pointers passed as arguments to direct uses of functions.
231  PM.add(createIPSCCPPass());
232
233  // Now that we internalized some globals, see if we can hack on them!
234  PM.add(createGlobalOptimizerPass());
235
236  // Linking modules together can lead to duplicated global constants, only
237  // keep one copy of each constant.
238  PM.add(createConstantMergePass());
239
240  // Remove unused arguments from functions.
241  PM.add(createDeadArgEliminationPass());
242
243  // Reduce the code after globalopt and ipsccp.  Both can open up significant
244  // simplification opportunities, and both can propagate functions through
245  // function pointers.  When this happens, we often have to resolve varargs
246  // calls, etc, so let instcombine do this.
247  PM.add(createInstructionCombiningPass());
248
249  // Inline small functions
250  if (RunInliner)
251    PM.add(createFunctionInliningPass());
252
253  PM.add(createPruneEHPass());   // Remove dead EH info.
254
255  // Optimize globals again if we ran the inliner.
256  if (RunInliner)
257    PM.add(createGlobalOptimizerPass());
258  PM.add(createGlobalDCEPass()); // Remove dead functions.
259
260  // If we didn't decide to inline a function, check to see if we can
261  // transform it to pass arguments by value instead of by reference.
262  PM.add(createArgumentPromotionPass());
263
264  // The IPO passes may leave cruft around.  Clean up after them.
265  PM.add(createInstructionCombiningPass());
266  PM.add(createJumpThreadingPass());
267  // Break up allocas
268  PM.add(createScalarReplAggregatesPass());
269
270  // Run a few AA driven optimizations here and now, to cleanup the code.
271  PM.add(createFunctionAttrsPass()); // Add nocapture.
272  PM.add(createGlobalsModRefPass()); // IP alias analysis.
273
274  PM.add(createLICMPass());                 // Hoist loop invariants.
275  PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
276  PM.add(createMemCpyOptPass());            // Remove dead memcpys.
277  // Nuke dead stores.
278  PM.add(createDeadStoreEliminationPass());
279
280  // Cleanup and simplify the code after the scalar optimizations.
281  PM.add(createInstructionCombiningPass());
282
283  PM.add(createJumpThreadingPass());
284
285  // Delete basic blocks, which optimization passes may have killed.
286  PM.add(createCFGSimplificationPass());
287
288  // Now that we have optimized the program, discard unreachable functions.
289  PM.add(createGlobalDCEPass());
290}
291
292LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate(void) {
293  PassManagerBuilder *PMB = new PassManagerBuilder();
294  return wrap(PMB);
295}
296
297void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
298  PassManagerBuilder *Builder = unwrap(PMB);
299  delete Builder;
300}
301
302void
303LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
304                                  unsigned OptLevel) {
305  PassManagerBuilder *Builder = unwrap(PMB);
306  Builder->OptLevel = OptLevel;
307}
308
309void
310LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
311                                   unsigned SizeLevel) {
312  PassManagerBuilder *Builder = unwrap(PMB);
313  Builder->SizeLevel = SizeLevel;
314}
315
316void
317LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
318                                            LLVMBool Value) {
319  PassManagerBuilder *Builder = unwrap(PMB);
320  Builder->DisableUnitAtATime = Value;
321}
322
323void
324LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
325                                            LLVMBool Value) {
326  PassManagerBuilder *Builder = unwrap(PMB);
327  Builder->DisableUnrollLoops = Value;
328}
329
330void
331LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
332                                                 LLVMBool Value) {
333  PassManagerBuilder *Builder = unwrap(PMB);
334  Builder->DisableSimplifyLibCalls = Value;
335}
336
337void
338LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
339                                              unsigned Threshold) {
340  PassManagerBuilder *Builder = unwrap(PMB);
341  Builder->Inliner = createFunctionInliningPass(Threshold);
342}
343
344void
345LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
346                                                  LLVMPassManagerRef PM) {
347  PassManagerBuilder *Builder = unwrap(PMB);
348  FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
349  Builder->populateFunctionPassManager(*FPM);
350}
351
352void
353LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
354                                                LLVMPassManagerRef PM) {
355  PassManagerBuilder *Builder = unwrap(PMB);
356  PassManagerBase *MPM = unwrap(PM);
357  Builder->populateModulePassManager(*MPM);
358}
359
360void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
361                                                  LLVMPassManagerRef PM,
362                                                  bool Internalize,
363                                                  bool RunInliner) {
364  PassManagerBuilder *Builder = unwrap(PMB);
365  PassManagerBase *LPM = unwrap(PM);
366  Builder->populateLTOPassManager(*LPM, Internalize, RunInliner);
367}
368