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
  18 #include "llvm-c/Transforms/PassManagerBuilder.h"
  19
  20 #include "llvm/PassManager.h"
  21 #include "llvm/DefaultPasses.h"
  22 #include "llvm/PassManager.h"
  23 #include "llvm/Analysis/Passes.h"
  24 #include "llvm/Analysis/Verifier.h"
  25 #include "llvm/Support/CommandLine.h"
  26 #include "llvm/Target/TargetLibraryInfo.h"
  27 #include "llvm/Transforms/Scalar.h"
  28 #include "llvm/Transforms/Vectorize.h"
  29 #include "llvm/Transforms/IPO.h"
  30 #include "llvm/ADT/SmallVector.h"
  31 #include "llvm/Support/ManagedStatic.h"
  32
  33 using namespace llvm;
  34
  35 static cl::opt<bool>
  36 RunVectorization("vectorize", cl::desc("Run vectorization passes"));
  37
  38 PassManagerBuilder::PassManagerBuilder() {
  39     OptLevel = 2;
  40     SizeLevel = 0;
  41     LibraryInfo = 0;
  42     Inliner = 0;
  43     DisableSimplifyLibCalls = false;
  44     DisableUnitAtATime = false;
  45     DisableUnrollLoops = false;
  46     Vectorize = RunVectorization;
  47 }
  48
  49 PassManagerBuilder::~PassManagerBuilder() {
  50   delete LibraryInfo;
  51   delete Inliner;
  52 }
  53
  54 /// Set of global extensions, automatically added as part of the standard set.
  55 static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
  56    PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
  57
  58 void PassManagerBuilder::addGlobalExtension(
  59     PassManagerBuilder::ExtensionPointTy Ty,
  60     PassManagerBuilder::ExtensionFn Fn) {
  61   GlobalExtensions->push_back(std::make_pair(Ty, Fn));
  62 }
  63
  64 void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
  65   Extensions.push_back(std::make_pair(Ty, Fn));
  66 }
  67
  68 void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
  69                                            PassManagerBase &PM) const {
  70   for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
  71     if ((*GlobalExtensions)[i].first == ETy)
  72       (*GlobalExtensions)[i].second(*this, PM);
  73   for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
  74     if (Extensions[i].first == ETy)
  75       Extensions[i].second(*this, PM);
  76 }
  77
  78 void
  79 PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
  80   // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
  81   // BasicAliasAnalysis wins if they disagree. This is intended to help
  82   // support "obvious" type-punning idioms.
  83   PM.add(createTypeBasedAliasAnalysisPass());
  84   PM.add(createBasicAliasAnalysisPass());
  85 }
  86
  87 void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
  88   addExtensionsToPM(EP_EarlyAsPossible, FPM);
  89
  90   // Add LibraryInfo if we have some.
  91   if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));
  92
  93   if (OptLevel == 0) return;
  94
  95   addInitialAliasAnalysisPasses(FPM);
  96
  97   FPM.add(createCFGSimplificationPass());
  98   FPM.add(createScalarReplAggregatesPass());
  99   FPM.add(createEarlyCSEPass());
 100   FPM.add(createLowerExpectIntrinsicPass());
 101 }
 102
 103 void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
 104   // If all optimizations are disabled, just run the always-inline pass.
 105   if (OptLevel == 0) {
 106     if (Inliner) {
 107       MPM.add(Inliner);
 108       Inliner = 0;
 109     }
 110     addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
 111     return;
 112   }
 113
 114   // Add LibraryInfo if we have some.
 115   if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));
 116
 117   addInitialAliasAnalysisPasses(MPM);
 118
 119   if (!DisableUnitAtATime) {
 120     addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
 121
 122     MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
 123
 124     MPM.add(createIPSCCPPass());              // IP SCCP
 125     MPM.add(createDeadArgEliminationPass());  // Dead argument elimination
 126
 127     MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
 128     MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
 129   }
 130
 131   // Start of CallGraph SCC passes.
 132   if (!DisableUnitAtATime)
 133     MPM.add(createPruneEHPass());             // Remove dead EH info
 134   if (Inliner) {
 135     MPM.add(Inliner);
 136     Inliner = 0;
 137   }
 138   if (!DisableUnitAtATime)
 139     MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
 140   if (OptLevel > 2)
 141     MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
 142
 143   // Start of function pass.
 144   // Break up aggregate allocas, using SSAUpdater.
 145   MPM.add(createScalarReplAggregatesPass(-1, false));
 146   MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 147   if (!DisableSimplifyLibCalls)
 148     MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
 149   MPM.add(createJumpThreadingPass());         // Thread jumps.
 150   MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
 151   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 152   MPM.add(createInstructionCombiningPass());  // Combine silly seq's
 153
 154   MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
 155   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 156   MPM.add(createReassociatePass());           // Reassociate expressions
 157   MPM.add(createLoopRotatePass());            // Rotate Loop
 158   MPM.add(createLICMPass());                  // Hoist loop invariants
 159   MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
 160   MPM.add(createInstructionCombiningPass());
 161   MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
 162   MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
 163   MPM.add(createLoopDeletionPass());          // Delete dead loops
 164   if (!DisableUnrollLoops)
 165     MPM.add(createLoopUnrollPass());          // Unroll small loops
 166   addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
 167
 168   if (OptLevel > 1)
 169     MPM.add(createGVNPass());                 // Remove redundancies
 170   MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
 171   MPM.add(createSCCPPass());                  // Constant prop with SCCP
 172
 173   // Run instcombine after redundancy elimination to exploit opportunities
 174   // opened up by them.
 175   MPM.add(createInstructionCombiningPass());
 176   MPM.add(createJumpThreadingPass());         // Thread jumps
 177   MPM.add(createCorrelatedValuePropagationPass());
 178   MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
 179
 180   addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
 181
 182   if (Vectorize) {
 183     MPM.add(createBBVectorizePass());
 184     MPM.add(createInstructionCombiningPass());
 185     if (OptLevel > 1)
 186       MPM.add(createGVNPass());                 // Remove redundancies
 187   }
 188
 189   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
 190   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 191   MPM.add(createInstructionCombiningPass());  // Clean up after everything.
 192
 193   if (!DisableUnitAtATime) {
 194     // FIXME: We shouldn't bother with this anymore.
 195     MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
 196
 197     // GlobalOpt already deletes dead functions and globals, at -O3 try a
 198     // late pass of GlobalDCE.  It is capable of deleting dead cycles.
 199     if (OptLevel > 2)
 200       MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
 201
 202     if (OptLevel > 1)
 203       MPM.add(createConstantMergePass());     // Merge dup global constants
 204   }
 205   addExtensionsToPM(EP_OptimizerLast, MPM);
 206 }
 207
 208 void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
 209                                                 bool Internalize,
 210                                                 bool RunInliner,
 211                                                 bool DisableGVNLoadPRE) {
 212   // Provide AliasAnalysis services for optimizations.
 213   addInitialAliasAnalysisPasses(PM);
 214
 215   // Now that composite has been compiled, scan through the module, looking
 216   // for a main function.  If main is defined, mark all other functions
 217   // internal.
 218   if (Internalize)
 219     PM.add(createInternalizePass(true));
 220
 221   // Propagate constants at call sites into the functions they call.  This
 222   // opens opportunities for globalopt (and inlining) by substituting function
 223   // pointers passed as arguments to direct uses of functions.
 224   PM.add(createIPSCCPPass());
 225
 226   // Now that we internalized some globals, see if we can hack on them!
 227   PM.add(createGlobalOptimizerPass());
 228
 229   // Linking modules together can lead to duplicated global constants, only
 230   // keep one copy of each constant.
 231   PM.add(createConstantMergePass());
 232
 233   // Remove unused arguments from functions.
 234   PM.add(createDeadArgEliminationPass());
 235
 236   // Reduce the code after globalopt and ipsccp.  Both can open up significant
 237   // simplification opportunities, and both can propagate functions through
 238   // function pointers.  When this happens, we often have to resolve varargs
 239   // calls, etc, so let instcombine do this.
 240   PM.add(createInstructionCombiningPass());
 241
 242   // Inline small functions
 243   if (RunInliner)
 244     PM.add(createFunctionInliningPass());
 245
 246   PM.add(createPruneEHPass());   // Remove dead EH info.
 247
 248   // Optimize globals again if we ran the inliner.
 249   if (RunInliner)
 250     PM.add(createGlobalOptimizerPass());
 251   PM.add(createGlobalDCEPass()); // Remove dead functions.
 252
 253   // If we didn't decide to inline a function, check to see if we can
 254   // transform it to pass arguments by value instead of by reference.
 255   PM.add(createArgumentPromotionPass());
 256
 257   // The IPO passes may leave cruft around.  Clean up after them.
 258   PM.add(createInstructionCombiningPass());
 259   PM.add(createJumpThreadingPass());
 260   // Break up allocas
 261   PM.add(createScalarReplAggregatesPass());
 262
 263   // Run a few AA driven optimizations here and now, to cleanup the code.
 264   PM.add(createFunctionAttrsPass()); // Add nocapture.
 265   PM.add(createGlobalsModRefPass()); // IP alias analysis.
 266
 267   PM.add(createLICMPass());                 // Hoist loop invariants.
 268   PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
 269   PM.add(createMemCpyOptPass());            // Remove dead memcpys.
 270   // Nuke dead stores.
 271   PM.add(createDeadStoreEliminationPass());
 272
 273   // Cleanup and simplify the code after the scalar optimizations.
 274   PM.add(createInstructionCombiningPass());
 275
 276   PM.add(createJumpThreadingPass());
 277
 278   // Delete basic blocks, which optimization passes may have killed.
 279   PM.add(createCFGSimplificationPass());
 280
 281   // Now that we have optimized the program, discard unreachable functions.
 282   PM.add(createGlobalDCEPass());
 283 }
 284
 285 LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate(void) {
 286   PassManagerBuilder *PMB = new PassManagerBuilder();
 287   return wrap(PMB);
 288 }
 289
 290 void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
 291   PassManagerBuilder *Builder = unwrap(PMB);
 292   delete Builder;
 293 }
 294
 295 void
 296 LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
 297                                   unsigned OptLevel) {
 298   PassManagerBuilder *Builder = unwrap(PMB);
 299   Builder->OptLevel = OptLevel;
 300 }
 301
 302 void
 303 LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
 304                                    unsigned SizeLevel) {
 305   PassManagerBuilder *Builder = unwrap(PMB);
 306   Builder->SizeLevel = SizeLevel;
 307 }
 308
 309 void
 310 LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
 311                                             LLVMBool Value) {
 312   PassManagerBuilder *Builder = unwrap(PMB);
 313   Builder->DisableUnitAtATime = Value;
 314 }
 315
 316 void
 317 LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
 318                                             LLVMBool Value) {
 319   PassManagerBuilder *Builder = unwrap(PMB);
 320   Builder->DisableUnrollLoops = Value;
 321 }
 322
 323 void
 324 LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
 325                                                  LLVMBool Value) {
 326   PassManagerBuilder *Builder = unwrap(PMB);
 327   Builder->DisableSimplifyLibCalls = Value;
 328 }
 329
 330 void
 331 LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
 332                                               unsigned Threshold) {
 333   PassManagerBuilder *Builder = unwrap(PMB);
 334   Builder->Inliner = createFunctionInliningPass(Threshold);
 335 }
 336
 337 void
 338 LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
 339                                                   LLVMPassManagerRef PM) {
 340   PassManagerBuilder *Builder = unwrap(PMB);
 341   FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
 342   Builder->populateFunctionPassManager(*FPM);
 343 }
 344
 345 void
 346 LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
 347                                                 LLVMPassManagerRef PM) {
 348   PassManagerBuilder *Builder = unwrap(PMB);
 349   PassManagerBase *MPM = unwrap(PM);
 350   Builder->populateModulePassManager(*MPM);
 351 }
 352
 353 void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
 354                                                   LLVMPassManagerRef PM,
 355                                                   bool Internalize,
 356                                                   bool RunInliner) {
 357   PassManagerBuilder *Builder = unwrap(PMB);
 358   PassManagerBase *LPM = unwrap(PM);
 359   Builder->populateLTOPassManager(*LPM, Internalize, RunInliner);
 360 }