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