lib/Transforms/IPO/PassManagerBuilder.cpp

   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
  29 using namespace llvm;
  30
  31 static cl::opt<bool>
  32 RunLoopVectorization("vectorize-loops",
  33                      cl::desc("Run the Loop vectorization passes"));
  34
  35 static cl::opt<bool>
  36 LateVectorization("late-vectorize", cl::init(false), cl::Hidden,
  37                   cl::desc("Run the vectorization pasess late in the pass "
  38                            "pipeline (after the inliner)"));
  39
  40 static cl::opt<bool>
  41 RunSLPVectorization("vectorize-slp",
  42                     cl::desc("Run the SLP vectorization passes"));
  43
  44 static cl::opt<bool>
  45 RunBBVectorization("vectorize-slp-aggressive",
  46                     cl::desc("Run the BB vectorization passes"));
  47
  48 static cl::opt<bool>
  49 UseGVNAfterVectorization("use-gvn-after-vectorization",
  50   cl::init(false), cl::Hidden,
  51   cl::desc("Run GVN instead of Early CSE after vectorization passes"));
  52
  53 static cl::opt<bool> UseNewSROA("use-new-sroa",
  54   cl::init(true), cl::Hidden,
  55   cl::desc("Enable the new, experimental SROA pass"));
  56
  57 PassManagerBuilder::PassManagerBuilder() {
  58     OptLevel = 2;
  59     SizeLevel = 0;
  60     LibraryInfo = 0;
  61     Inliner = 0;
  62     DisableUnitAtATime = false;
  63     DisableUnrollLoops = false;
  64     BBVectorize = RunBBVectorization;
  65     SLPVectorize = RunSLPVectorization;
  66     LoopVectorize = RunLoopVectorization;
  67     LateVectorize = LateVectorization;
  68 }
  69
  70 PassManagerBuilder::~PassManagerBuilder() {
  71   delete LibraryInfo;
  72   delete Inliner;
  73 }
  74
  75 /// Set of global extensions, automatically added as part of the standard set.
  76 static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
  77    PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
  78
  79 void PassManagerBuilder::addGlobalExtension(
  80     PassManagerBuilder::ExtensionPointTy Ty,
  81     PassManagerBuilder::ExtensionFn Fn) {
  82   GlobalExtensions->push_back(std::make_pair(Ty, Fn));
  83 }
  84
  85 void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
  86   Extensions.push_back(std::make_pair(Ty, Fn));
  87 }
  88
  89 void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
  90                                            PassManagerBase &PM) const {
  91   for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
  92     if ((*GlobalExtensions)[i].first == ETy)
  93       (*GlobalExtensions)[i].second(*this, PM);
  94   for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
  95     if (Extensions[i].first == ETy)
  96       Extensions[i].second(*this, PM);
  97 }
  98
  99 void
 100 PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
 101   // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
 102   // BasicAliasAnalysis wins if they disagree. This is intended to help
 103   // support "obvious" type-punning idioms.
 104   PM.add(createTypeBasedAliasAnalysisPass());
 105   PM.add(createBasicAliasAnalysisPass());
 106 }
 107
 108 void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
 109   addExtensionsToPM(EP_EarlyAsPossible, FPM);
 110
 111   // Add LibraryInfo if we have some.
 112   if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));
 113
 114   if (OptLevel == 0) return;
 115
 116   addInitialAliasAnalysisPasses(FPM);
 117
 118   FPM.add(createCFGSimplificationPass());
 119   if (UseNewSROA)
 120     FPM.add(createSROAPass());
 121   else
 122     FPM.add(createScalarReplAggregatesPass());
 123   FPM.add(createEarlyCSEPass());
 124   FPM.add(createLowerExpectIntrinsicPass());
 125 }
 126
 127 void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
 128   // If all optimizations are disabled, just run the always-inline pass.
 129   if (OptLevel == 0) {
 130     if (Inliner) {
 131       MPM.add(Inliner);
 132       Inliner = 0;
 133     }
 134
 135     // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
 136     // pass manager, but we don't want to add extensions into that pass manager.
 137     // To prevent this we must insert a no-op module pass to reset the pass
 138     // manager to get the same behavior as EP_OptimizerLast in non-O0 builds.
 139     if (!GlobalExtensions->empty() || !Extensions.empty())
 140       MPM.add(createBarrierNoopPass());
 141
 142     addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
 143     return;
 144   }
 145
 146   // Add LibraryInfo if we have some.
 147   if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));
 148
 149   addInitialAliasAnalysisPasses(MPM);
 150
 151   if (!DisableUnitAtATime) {
 152     addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
 153
 154     MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
 155
 156     MPM.add(createIPSCCPPass());              // IP SCCP
 157     MPM.add(createDeadArgEliminationPass());  // Dead argument elimination
 158
 159     MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
 160     MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
 161   }
 162
 163   // Start of CallGraph SCC passes.
 164   if (!DisableUnitAtATime)
 165     MPM.add(createPruneEHPass());             // Remove dead EH info
 166   if (Inliner) {
 167     MPM.add(Inliner);
 168     Inliner = 0;
 169   }
 170   if (!DisableUnitAtATime)
 171     MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
 172   if (OptLevel > 2)
 173     MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
 174
 175   // Start of function pass.
 176   // Break up aggregate allocas, using SSAUpdater.
 177   if (UseNewSROA)
 178     MPM.add(createSROAPass(/*RequiresDomTree*/ false));
 179   else
 180     MPM.add(createScalarReplAggregatesPass(-1, false));
 181   MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 182   MPM.add(createJumpThreadingPass());         // Thread jumps.
 183   MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
 184   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 185   MPM.add(createInstructionCombiningPass());  // Combine silly seq's
 186
 187   MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
 188   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 189   MPM.add(createReassociatePass());           // Reassociate expressions
 190   MPM.add(createLoopRotatePass());            // Rotate Loop
 191   MPM.add(createLICMPass());                  // Hoist loop invariants
 192   MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
 193   MPM.add(createInstructionCombiningPass());
 194   MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
 195   MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
 196   MPM.add(createLoopDeletionPass());          // Delete dead loops
 197
 198   if (!LateVectorize && LoopVectorize && OptLevel > 1 && SizeLevel < 2)
 199       MPM.add(createLoopVectorizePass());
 200
 201   if (!DisableUnrollLoops)
 202     MPM.add(createLoopUnrollPass());          // Unroll small loops
 203   addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
 204
 205   if (OptLevel > 1)
 206     MPM.add(createGVNPass());                 // Remove redundancies
 207   MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
 208   MPM.add(createSCCPPass());                  // Constant prop with SCCP
 209
 210   // Run instcombine after redundancy elimination to exploit opportunities
 211   // opened up by them.
 212   MPM.add(createInstructionCombiningPass());
 213   MPM.add(createJumpThreadingPass());         // Thread jumps
 214   MPM.add(createCorrelatedValuePropagationPass());
 215   MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
 216
 217   addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
 218
 219   if (!LateVectorize) {
 220     if (SLPVectorize)
 221       MPM.add(createSLPVectorizerPass());   // Vectorize parallel scalar chains.
 222
 223     if (BBVectorize) {
 224       MPM.add(createBBVectorizePass());
 225       MPM.add(createInstructionCombiningPass());
 226       if (OptLevel > 1 && UseGVNAfterVectorization)
 227         MPM.add(createGVNPass());           // Remove redundancies
 228       else
 229         MPM.add(createEarlyCSEPass());      // Catch trivial redundancies
 230
 231       // BBVectorize may have significantly shortened a loop body; unroll again.
 232       if (!DisableUnrollLoops)
 233         MPM.add(createLoopUnrollPass());
 234     }
 235   }
 236
 237   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
 238   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 239   MPM.add(createInstructionCombiningPass());  // Clean up after everything.
 240
 241   // As an experimental mode, run any vectorization passes in a separate
 242   // pipeline from the CGSCC pass manager that runs iteratively with the
 243   // inliner.
 244   if (LateVectorize) {
 245     // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
 246     // pass manager that we are specifically trying to avoid. To prevent this
 247     // we must insert a no-op module pass to reset the pass manager.
 248     MPM.add(createBarrierNoopPass());
 249
 250     // Add the various vectorization passes and relevant cleanup passes for
 251     // them since we are no longer in the middle of the main scalar pipeline.
 252     if (LoopVectorize && OptLevel > 1 && SizeLevel < 2) {
 253       MPM.add(createLoopVectorizePass());
 254
 255       if (!DisableUnrollLoops)
 256         MPM.add(createLoopUnrollPass());    // Unroll small loops
 257
 258       // FIXME: Is this necessary/useful? Should we also do SimplifyCFG?
 259       MPM.add(createInstructionCombiningPass());
 260     }
 261
 262     if (SLPVectorize) {
 263       MPM.add(createSLPVectorizerPass());   // Vectorize parallel scalar chains.
 264
 265       // FIXME: Is this necessary/useful? Should we also do SimplifyCFG?
 266       MPM.add(createInstructionCombiningPass());
 267     }
 268
 269     if (BBVectorize) {
 270       MPM.add(createBBVectorizePass());
 271       MPM.add(createInstructionCombiningPass());
 272       if (OptLevel > 1 && UseGVNAfterVectorization)
 273         MPM.add(createGVNPass());           // Remove redundancies
 274       else
 275         MPM.add(createEarlyCSEPass());      // Catch trivial redundancies
 276
 277       // BBVectorize may have significantly shortened a loop body; unroll again.
 278       if (!DisableUnrollLoops)
 279         MPM.add(createLoopUnrollPass());
 280     }
 281   }
 282
 283   if (!DisableUnitAtATime) {
 284     // FIXME: We shouldn't bother with this anymore.
 285     MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
 286
 287     // GlobalOpt already deletes dead functions and globals, at -O2 try a
 288     // late pass of GlobalDCE.  It is capable of deleting dead cycles.
 289     if (OptLevel > 1) {
 290       MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
 291       MPM.add(createConstantMergePass());     // Merge dup global constants
 292     }
 293   }
 294   addExtensionsToPM(EP_OptimizerLast, MPM);
 295 }
 296
 297 void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
 298                                                 bool Internalize,
 299                                                 bool RunInliner,
 300                                                 bool DisableGVNLoadPRE) {
 301   // Provide AliasAnalysis services for optimizations.
 302   addInitialAliasAnalysisPasses(PM);
 303
 304   // Now that composite has been compiled, scan through the module, looking
 305   // for a main function.  If main is defined, mark all other functions
 306   // internal.
 307   if (Internalize) {
 308     std::vector<const char*> E;
 309     E.push_back("main");
 310     PM.add(createInternalizePass(E));
 311   }
 312
 313   // Propagate constants at call sites into the functions they call.  This
 314   // opens opportunities for globalopt (and inlining) by substituting function
 315   // pointers passed as arguments to direct uses of functions.
 316   PM.add(createIPSCCPPass());
 317
 318   // Now that we internalized some globals, see if we can hack on them!
 319   PM.add(createGlobalOptimizerPass());
 320
 321   // Linking modules together can lead to duplicated global constants, only
 322   // keep one copy of each constant.
 323   PM.add(createConstantMergePass());
 324
 325   // Remove unused arguments from functions.
 326   PM.add(createDeadArgEliminationPass());
 327
 328   // Reduce the code after globalopt and ipsccp.  Both can open up significant
 329   // simplification opportunities, and both can propagate functions through
 330   // function pointers.  When this happens, we often have to resolve varargs
 331   // calls, etc, so let instcombine do this.
 332   PM.add(createInstructionCombiningPass());
 333
 334   // Inline small functions
 335   if (RunInliner)
 336     PM.add(createFunctionInliningPass());
 337
 338   PM.add(createPruneEHPass());   // Remove dead EH info.
 339
 340   // Optimize globals again if we ran the inliner.
 341   if (RunInliner)
 342     PM.add(createGlobalOptimizerPass());
 343   PM.add(createGlobalDCEPass()); // Remove dead functions.
 344
 345   // If we didn't decide to inline a function, check to see if we can
 346   // transform it to pass arguments by value instead of by reference.
 347   PM.add(createArgumentPromotionPass());
 348
 349   // The IPO passes may leave cruft around.  Clean up after them.
 350   PM.add(createInstructionCombiningPass());
 351   PM.add(createJumpThreadingPass());
 352   // Break up allocas
 353   if (UseNewSROA)
 354     PM.add(createSROAPass());
 355   else
 356     PM.add(createScalarReplAggregatesPass());
 357
 358   // Run a few AA driven optimizations here and now, to cleanup the code.
 359   PM.add(createFunctionAttrsPass()); // Add nocapture.
 360   PM.add(createGlobalsModRefPass()); // IP alias analysis.
 361
 362   PM.add(createLICMPass());                 // Hoist loop invariants.
 363   PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
 364   PM.add(createMemCpyOptPass());            // Remove dead memcpys.
 365   // Nuke dead stores.
 366   PM.add(createDeadStoreEliminationPass());
 367
 368   // Cleanup and simplify the code after the scalar optimizations.
 369   PM.add(createInstructionCombiningPass());
 370
 371   PM.add(createJumpThreadingPass());
 372
 373   // Delete basic blocks, which optimization passes may have killed.
 374   PM.add(createCFGSimplificationPass());
 375
 376   // Now that we have optimized the program, discard unreachable functions.
 377   PM.add(createGlobalDCEPass());
 378 }
 379
 380 inline PassManagerBuilder *unwrap(LLVMPassManagerBuilderRef P) {
 381     return reinterpret_cast<PassManagerBuilder*>(P);
 382 }
 383
 384 inline LLVMPassManagerBuilderRef wrap(PassManagerBuilder *P) {
 385   return reinterpret_cast<LLVMPassManagerBuilderRef>(P);
 386 }
 387
 388 LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate() {
 389   PassManagerBuilder *PMB = new PassManagerBuilder();
 390   return wrap(PMB);
 391 }
 392
 393 void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
 394   PassManagerBuilder *Builder = unwrap(PMB);
 395   delete Builder;
 396 }
 397
 398 void
 399 LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
 400                                   unsigned OptLevel) {
 401   PassManagerBuilder *Builder = unwrap(PMB);
 402   Builder->OptLevel = OptLevel;
 403 }
 404
 405 void
 406 LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
 407                                    unsigned SizeLevel) {
 408   PassManagerBuilder *Builder = unwrap(PMB);
 409   Builder->SizeLevel = SizeLevel;
 410 }
 411
 412 void
 413 LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
 414                                             LLVMBool Value) {
 415   PassManagerBuilder *Builder = unwrap(PMB);
 416   Builder->DisableUnitAtATime = Value;
 417 }
 418
 419 void
 420 LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
 421                                             LLVMBool Value) {
 422   PassManagerBuilder *Builder = unwrap(PMB);
 423   Builder->DisableUnrollLoops = Value;
 424 }
 425
 426 void
 427 LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
 428                                                  LLVMBool Value) {
 429   // NOTE: The simplify-libcalls pass has been removed.
 430 }
 431
 432 void
 433 LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
 434                                               unsigned Threshold) {
 435   PassManagerBuilder *Builder = unwrap(PMB);
 436   Builder->Inliner = createFunctionInliningPass(Threshold);
 437 }
 438
 439 void
 440 LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
 441                                                   LLVMPassManagerRef PM) {
 442   PassManagerBuilder *Builder = unwrap(PMB);
 443   FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
 444   Builder->populateFunctionPassManager(*FPM);
 445 }
 446
 447 void
 448 LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
 449                                                 LLVMPassManagerRef PM) {
 450   PassManagerBuilder *Builder = unwrap(PMB);
 451   PassManagerBase *MPM = unwrap(PM);
 452   Builder->populateModulePassManager(*MPM);
 453 }
 454
 455 void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
 456                                                   LLVMPassManagerRef PM,
 457                                                   LLVMBool Internalize,
 458                                                   LLVMBool RunInliner) {
 459   PassManagerBuilder *Builder = unwrap(PMB);
 460   PassManagerBase *LPM = unwrap(PM);
 461   Builder->populateLTOPassManager(*LPM, Internalize != 0, RunInliner != 0);
 462 }