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