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