PassManagerBuilder.cpp revision 7d4c87ef6eea424b7a28392ea11137ed77b44b57 
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/Target/TargetLibraryInfo.h"
25#include "llvm/Transforms/Scalar.h"
26#include "llvm/Transforms/IPO.h"
27#include "llvm/ADT/SmallVector.h"
28#include "llvm/Support/ManagedStatic.h"
29
30using namespace llvm;
31
32PassManagerBuilder::PassManagerBuilder() {
33    OptLevel = 2;
34    SizeLevel = 0;
35    LibraryInfo = 0;
36    Inliner = 0;
37    DisableSimplifyLibCalls = false;
38    DisableUnitAtATime = false;
39    DisableUnrollLoops = false;
40}
41
42PassManagerBuilder::~PassManagerBuilder() {
43  delete LibraryInfo;
44  delete Inliner;
45}
46
47/// Set of global extensions, automatically added as part of the standard set.
48static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
49   PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
50
51void PassManagerBuilder::addGlobalExtension(
52    PassManagerBuilder::ExtensionPointTy Ty,
53    PassManagerBuilder::ExtensionFn Fn) {
54  GlobalExtensions->push_back(std::make_pair(Ty, Fn));
55}
56
57void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
58  Extensions.push_back(std::make_pair(Ty, Fn));
59}
60
61void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
62                                           PassManagerBase &PM) const {
63  for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
64    if ((*GlobalExtensions)[i].first == ETy)
65      (*GlobalExtensions)[i].second(*this, PM);
66  for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
67    if (Extensions[i].first == ETy)
68      Extensions[i].second(*this, PM);
69}
70
71void
72PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
73  // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
74  // BasicAliasAnalysis wins if they disagree. This is intended to help
75  // support "obvious" type-punning idioms.
76  PM.add(createTypeBasedAliasAnalysisPass());
77  PM.add(createBasicAliasAnalysisPass());
78}
79
80void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
81  addExtensionsToPM(EP_EarlyAsPossible, FPM);
82
83  // Add LibraryInfo if we have some.
84  if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));
85
86  if (OptLevel == 0) return;
87
88  addInitialAliasAnalysisPasses(FPM);
89
90  FPM.add(createCFGSimplificationPass());
91  FPM.add(createScalarReplAggregatesPass());
92  FPM.add(createEarlyCSEPass());
93  FPM.add(createLowerExpectIntrinsicPass());
94}
95
96void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
97  // If all optimizations are disabled, just run the always-inline pass.
98  if (OptLevel == 0) {
99    if (Inliner) {
100      MPM.add(Inliner);
101      Inliner = 0;
102    }
103    addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
104    return;
105  }
106
107  // Add LibraryInfo if we have some.
108  if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));
109
110  addInitialAliasAnalysisPasses(MPM);
111
112  if (!DisableUnitAtATime) {
113    addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
114
115    MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
116
117    MPM.add(createIPSCCPPass());              // IP SCCP
118    MPM.add(createDeadArgEliminationPass());  // Dead argument elimination
119
120    MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
121    MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
122  }
123
124  // Start of CallGraph SCC passes.
125  if (!DisableUnitAtATime)
126    MPM.add(createPruneEHPass());             // Remove dead EH info
127  if (Inliner) {
128    MPM.add(Inliner);
129    Inliner = 0;
130  }
131  if (!DisableUnitAtATime)
132    MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
133  if (OptLevel > 2)
134    MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
135
136  // Start of function pass.
137  // Break up aggregate allocas, using SSAUpdater.
138  MPM.add(createScalarReplAggregatesPass(-1, false));
139  MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
140  if (!DisableSimplifyLibCalls)
141    MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
142  MPM.add(createJumpThreadingPass());         // Thread jumps.
143  MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
144  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
145  MPM.add(createInstructionCombiningPass());  // Combine silly seq's
146
147  MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
148  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
149  MPM.add(createReassociatePass());           // Reassociate expressions
150  MPM.add(createLoopRotatePass());            // Rotate Loop
151  MPM.add(createLICMPass());                  // Hoist loop invariants
152  MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
153  MPM.add(createInstructionCombiningPass());
154  MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
155  MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
156  MPM.add(createLoopDeletionPass());          // Delete dead loops
157  if (!DisableUnrollLoops)
158    MPM.add(createLoopUnrollPass());          // Unroll small loops
159  addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
160
161  if (OptLevel > 1)
162    MPM.add(createGVNPass());                 // Remove redundancies
163  MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
164  MPM.add(createSCCPPass());                  // Constant prop with SCCP
165
166  // Run instcombine after redundancy elimination to exploit opportunities
167  // opened up by them.
168  MPM.add(createInstructionCombiningPass());
169  MPM.add(createJumpThreadingPass());         // Thread jumps
170  MPM.add(createCorrelatedValuePropagationPass());
171  MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
172
173  addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
174
175  MPM.add(createAggressiveDCEPass());         // Delete dead instructions
176  MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
177  MPM.add(createInstructionCombiningPass());  // Clean up after everything.
178
179  if (!DisableUnitAtATime) {
180    // FIXME: We shouldn't bother with this anymore.
181    MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
182
183    // GlobalOpt already deletes dead functions and globals, at -O3 try a
184    // late pass of GlobalDCE.  It is capable of deleting dead cycles.
185    if (OptLevel > 2)
186      MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
187
188    if (OptLevel > 1)
189      MPM.add(createConstantMergePass());     // Merge dup global constants
190  }
191}
192
193void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
194                                                bool Internalize,
195                                                bool RunInliner) {
196  // Provide AliasAnalysis services for optimizations.
197  addInitialAliasAnalysisPasses(PM);
198
199  // Now that composite has been compiled, scan through the module, looking
200  // for a main function.  If main is defined, mark all other functions
201  // internal.
202  if (Internalize)
203    PM.add(createInternalizePass(true));
204
205  // Propagate constants at call sites into the functions they call.  This
206  // opens opportunities for globalopt (and inlining) by substituting function
207  // pointers passed as arguments to direct uses of functions.
208  PM.add(createIPSCCPPass());
209
210  // Now that we internalized some globals, see if we can hack on them!
211  PM.add(createGlobalOptimizerPass());
212
213  // Linking modules together can lead to duplicated global constants, only
214  // keep one copy of each constant.
215  PM.add(createConstantMergePass());
216
217  // Remove unused arguments from functions.
218  PM.add(createDeadArgEliminationPass());
219
220  // Reduce the code after globalopt and ipsccp.  Both can open up significant
221  // simplification opportunities, and both can propagate functions through
222  // function pointers.  When this happens, we often have to resolve varargs
223  // calls, etc, so let instcombine do this.
224  PM.add(createInstructionCombiningPass());
225
226  // Inline small functions
227  if (RunInliner)
228    PM.add(createFunctionInliningPass());
229
230  PM.add(createPruneEHPass());   // Remove dead EH info.
231
232  // Optimize globals again if we ran the inliner.
233  if (RunInliner)
234    PM.add(createGlobalOptimizerPass());
235  PM.add(createGlobalDCEPass()); // Remove dead functions.
236
237  // If we didn't decide to inline a function, check to see if we can
238  // transform it to pass arguments by value instead of by reference.
239  PM.add(createArgumentPromotionPass());
240
241  // The IPO passes may leave cruft around.  Clean up after them.
242  PM.add(createInstructionCombiningPass());
243  PM.add(createJumpThreadingPass());
244  // Break up allocas
245  PM.add(createScalarReplAggregatesPass());
246
247  // Run a few AA driven optimizations here and now, to cleanup the code.
248  PM.add(createFunctionAttrsPass()); // Add nocapture.
249  PM.add(createGlobalsModRefPass()); // IP alias analysis.
250
251  PM.add(createLICMPass());      // Hoist loop invariants.
252  PM.add(createGVNPass());       // Remove redundancies.
253  PM.add(createMemCpyOptPass()); // Remove dead memcpys.
254  // Nuke dead stores.
255  PM.add(createDeadStoreEliminationPass());
256
257  // Cleanup and simplify the code after the scalar optimizations.
258  PM.add(createInstructionCombiningPass());
259
260  PM.add(createJumpThreadingPass());
261
262  // Delete basic blocks, which optimization passes may have killed.
263  PM.add(createCFGSimplificationPass());
264
265  // Now that we have optimized the program, discard unreachable functions.
266  PM.add(createGlobalDCEPass());
267}
268
269LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate(void) {
270  PassManagerBuilder *PMB = new PassManagerBuilder();
271  return wrap(PMB);
272}
273
274void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
275  PassManagerBuilder *Builder = unwrap(PMB);
276  delete Builder;
277}
278
279void
280LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
281                                  unsigned OptLevel) {
282  PassManagerBuilder *Builder = unwrap(PMB);
283  Builder->OptLevel = OptLevel;
284}
285
286void
287LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
288                                   unsigned SizeLevel) {
289  PassManagerBuilder *Builder = unwrap(PMB);
290  Builder->SizeLevel = SizeLevel;
291}
292
293void
294LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
295                                            LLVMBool Value) {
296  PassManagerBuilder *Builder = unwrap(PMB);
297  Builder->DisableUnitAtATime = Value;
298}
299
300void
301LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
302                                            LLVMBool Value) {
303  PassManagerBuilder *Builder = unwrap(PMB);
304  Builder->DisableUnrollLoops = Value;
305}
306
307void
308LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
309                                                 LLVMBool Value) {
310  PassManagerBuilder *Builder = unwrap(PMB);
311  Builder->DisableSimplifyLibCalls = Value;
312}
313
314void
315LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
316                                              unsigned Threshold) {
317  PassManagerBuilder *Builder = unwrap(PMB);
318  Builder->Inliner = createFunctionInliningPass(Threshold);
319}
320
321void
322LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
323                                                  LLVMPassManagerRef PM) {
324  PassManagerBuilder *Builder = unwrap(PMB);
325  FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
326  Builder->populateFunctionPassManager(*FPM);
327}
328
329void
330LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
331                                                LLVMPassManagerRef PM) {
332  PassManagerBuilder *Builder = unwrap(PMB);
333  PassManagerBase *MPM = unwrap(PM);
334  Builder->populateModulePassManager(*MPM);
335}
336
337void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
338                                                  LLVMPassManagerRef PM,
339                                                  bool Internalize,
340                                                  bool RunInliner) {
341  PassManagerBuilder *Builder = unwrap(PMB);
342  PassManagerBase *LPM = unwrap(PM);
343  Builder->populateLTOPassManager(*LPM, Internalize, RunInliner);
344}
345