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