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 static cl::opt<bool>
  39 UseGVNAfterVectorization("use-gvn-after-vectorization",
  40   cl::init(false), cl::Hidden,
  41   cl::desc("Run GVN instead of Early CSE after vectorization passes"));
  42
  43 PassManagerBuilder::PassManagerBuilder() {
  44     OptLevel = 2;
  45     SizeLevel = 0;
  46     LibraryInfo = 0;
  47     Inliner = 0;
  48     DisableSimplifyLibCalls = false;
  49     DisableUnitAtATime = false;
  50     DisableUnrollLoops = false;
  51     Vectorize = RunVectorization;
  52 }
  53
  54 PassManagerBuilder::~PassManagerBuilder() {
  55   delete LibraryInfo;
  56   delete Inliner;
  57 }
  58
  59 /// Set of global extensions, automatically added as part of the standard set.
  60 static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
  61    PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
  62
  63 void PassManagerBuilder::addGlobalExtension(
  64     PassManagerBuilder::ExtensionPointTy Ty,
  65     PassManagerBuilder::ExtensionFn Fn) {
  66   GlobalExtensions->push_back(std::make_pair(Ty, Fn));
  67 }
  68
  69 void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
  70   Extensions.push_back(std::make_pair(Ty, Fn));
  71 }
  72
  73 void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
  74                                            PassManagerBase &PM) const {
  75   for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
  76     if ((*GlobalExtensions)[i].first == ETy)
  77       (*GlobalExtensions)[i].second(*this, PM);
  78   for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
  79     if (Extensions[i].first == ETy)
  80       Extensions[i].second(*this, PM);
  81 }
  82
  83 void
  84 PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
  85   // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
  86   // BasicAliasAnalysis wins if they disagree. This is intended to help
  87   // support "obvious" type-punning idioms.
  88   PM.add(createTypeBasedAliasAnalysisPass());
  89   PM.add(createBasicAliasAnalysisPass());
  90 }
  91
  92 void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
  93   addExtensionsToPM(EP_EarlyAsPossible, FPM);
  94
  95   // Add LibraryInfo if we have some.
  96   if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));
  97
  98   if (OptLevel == 0) return;
  99
 100   addInitialAliasAnalysisPasses(FPM);
 101
 102   FPM.add(createCFGSimplificationPass());
 103   FPM.add(createScalarReplAggregatesPass());
 104   FPM.add(createEarlyCSEPass());
 105   FPM.add(createLowerExpectIntrinsicPass());
 106 }
 107
 108 void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
 109   // If all optimizations are disabled, just run the always-inline pass.
 110   if (OptLevel == 0) {
 111     if (Inliner) {
 112       MPM.add(Inliner);
 113       Inliner = 0;
 114     }
 115     addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
 116     return;
 117   }
 118
 119   // Add LibraryInfo if we have some.
 120   if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));
 121
 122   addInitialAliasAnalysisPasses(MPM);
 123
 124   if (!DisableUnitAtATime) {
 125     addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
 126
 127     MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
 128
 129     MPM.add(createIPSCCPPass());              // IP SCCP
 130     MPM.add(createDeadArgEliminationPass());  // Dead argument elimination
 131
 132     MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
 133     MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
 134   }
 135
 136   // Start of CallGraph SCC passes.
 137   if (!DisableUnitAtATime)
 138     MPM.add(createPruneEHPass());             // Remove dead EH info
 139   if (Inliner) {
 140     MPM.add(Inliner);
 141     Inliner = 0;
 142   }
 143   if (!DisableUnitAtATime)
 144     MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
 145   if (OptLevel > 2)
 146     MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
 147
 148   // Start of function pass.
 149   // Break up aggregate allocas, using SSAUpdater.
 150   MPM.add(createScalarReplAggregatesPass(-1, false));
 151   MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 152   if (!DisableSimplifyLibCalls)
 153     MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
 154   MPM.add(createJumpThreadingPass());         // Thread jumps.
 155   MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
 156   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 157   MPM.add(createInstructionCombiningPass());  // Combine silly seq's
 158
 159   MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
 160   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 161   MPM.add(createReassociatePass());           // Reassociate expressions
 162   MPM.add(createLoopRotatePass());            // Rotate Loop
 163   MPM.add(createLICMPass());                  // Hoist loop invariants
 164   MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
 165   MPM.add(createInstructionCombiningPass());
 166   MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
 167   MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
 168   MPM.add(createLoopDeletionPass());          // Delete dead loops
 169   if (!DisableUnrollLoops)
 170     MPM.add(createLoopUnrollPass());          // Unroll small loops
 171   addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
 172
 173   if (OptLevel > 1)
 174     MPM.add(createGVNPass());                 // Remove redundancies
 175   MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
 176   MPM.add(createSCCPPass());                  // Constant prop with SCCP
 177
 178   // Run instcombine after redundancy elimination to exploit opportunities
 179   // opened up by them.
 180   MPM.add(createInstructionCombiningPass());
 181   MPM.add(createJumpThreadingPass());         // Thread jumps
 182   MPM.add(createCorrelatedValuePropagationPass());
 183   MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
 184
 185   addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
 186
 187   if (Vectorize) {
 188     MPM.add(createBBVectorizePass());
 189     MPM.add(createInstructionCombiningPass());
 190     if (OptLevel > 1 && UseGVNAfterVectorization)
 191       MPM.add(createGVNPass());                   // Remove redundancies
 192     else
 193       MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 194   }
 195
 196   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
 197   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 198   MPM.add(createInstructionCombiningPass());  // Clean up after everything.
 199
 200   if (!DisableUnitAtATime) {
 201     // FIXME: We shouldn't bother with this anymore.
 202     MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
 203
 204     // GlobalOpt already deletes dead functions and globals, at -O3 try a
 205     // late pass of GlobalDCE.  It is capable of deleting dead cycles.
 206     if (OptLevel > 2)
 207       MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
 208
 209     if (OptLevel > 1)
 210       MPM.add(createConstantMergePass());     // Merge dup global constants
 211   }
 212   addExtensionsToPM(EP_OptimizerLast, MPM);
 213 }
 214
 215 void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
 216                                                 bool Internalize,
 217                                                 bool RunInliner,
 218                                                 bool DisableGVNLoadPRE) {
 219   // Provide AliasAnalysis services for optimizations.
 220   addInitialAliasAnalysisPasses(PM);
 221
 222   // Now that composite has been compiled, scan through the module, looking
 223   // for a main function.  If main is defined, mark all other functions
 224   // internal.
 225   if (Internalize)
 226     PM.add(createInternalizePass(true));
 227
 228   // Propagate constants at call sites into the functions they call.  This
 229   // opens opportunities for globalopt (and inlining) by substituting function
 230   // pointers passed as arguments to direct uses of functions.
 231   PM.add(createIPSCCPPass());
 232
 233   // Now that we internalized some globals, see if we can hack on them!
 234   PM.add(createGlobalOptimizerPass());
 235
 236   // Linking modules together can lead to duplicated global constants, only
 237   // keep one copy of each constant.
 238   PM.add(createConstantMergePass());
 239
 240   // Remove unused arguments from functions.
 241   PM.add(createDeadArgEliminationPass());
 242
 243   // Reduce the code after globalopt and ipsccp.  Both can open up significant
 244   // simplification opportunities, and both can propagate functions through
 245   // function pointers.  When this happens, we often have to resolve varargs
 246   // calls, etc, so let instcombine do this.
 247   PM.add(createInstructionCombiningPass());
 248
 249   // Inline small functions
 250   if (RunInliner)
 251     PM.add(createFunctionInliningPass());
 252
 253   PM.add(createPruneEHPass());   // Remove dead EH info.
 254
 255   // Optimize globals again if we ran the inliner.
 256   if (RunInliner)
 257     PM.add(createGlobalOptimizerPass());
 258   PM.add(createGlobalDCEPass()); // Remove dead functions.
 259
 260   // If we didn't decide to inline a function, check to see if we can
 261   // transform it to pass arguments by value instead of by reference.
 262   PM.add(createArgumentPromotionPass());
 263
 264   // The IPO passes may leave cruft around.  Clean up after them.
 265   PM.add(createInstructionCombiningPass());
 266   PM.add(createJumpThreadingPass());
 267   // Break up allocas
 268   PM.add(createScalarReplAggregatesPass());
 269
 270   // Run a few AA driven optimizations here and now, to cleanup the code.
 271   PM.add(createFunctionAttrsPass()); // Add nocapture.
 272   PM.add(createGlobalsModRefPass()); // IP alias analysis.
 273
 274   PM.add(createLICMPass());                 // Hoist loop invariants.
 275   PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
 276   PM.add(createMemCpyOptPass());            // Remove dead memcpys.
 277   // Nuke dead stores.
 278   PM.add(createDeadStoreEliminationPass());
 279
 280   // Cleanup and simplify the code after the scalar optimizations.
 281   PM.add(createInstructionCombiningPass());
 282
 283   PM.add(createJumpThreadingPass());
 284
 285   // Delete basic blocks, which optimization passes may have killed.
 286   PM.add(createCFGSimplificationPass());
 287
 288   // Now that we have optimized the program, discard unreachable functions.
 289   PM.add(createGlobalDCEPass());
 290 }
 291
 292 LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate(void) {
 293   PassManagerBuilder *PMB = new PassManagerBuilder();
 294   return wrap(PMB);
 295 }
 296
 297 void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
 298   PassManagerBuilder *Builder = unwrap(PMB);
 299   delete Builder;
 300 }
 301
 302 void
 303 LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
 304                                   unsigned OptLevel) {
 305   PassManagerBuilder *Builder = unwrap(PMB);
 306   Builder->OptLevel = OptLevel;
 307 }
 308
 309 void
 310 LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
 311                                    unsigned SizeLevel) {
 312   PassManagerBuilder *Builder = unwrap(PMB);
 313   Builder->SizeLevel = SizeLevel;
 314 }
 315
 316 void
 317 LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
 318                                             LLVMBool Value) {
 319   PassManagerBuilder *Builder = unwrap(PMB);
 320   Builder->DisableUnitAtATime = Value;
 321 }
 322
 323 void
 324 LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
 325                                             LLVMBool Value) {
 326   PassManagerBuilder *Builder = unwrap(PMB);
 327   Builder->DisableUnrollLoops = Value;
 328 }
 329
 330 void
 331 LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
 332                                                  LLVMBool Value) {
 333   PassManagerBuilder *Builder = unwrap(PMB);
 334   Builder->DisableSimplifyLibCalls = Value;
 335 }
 336
 337 void
 338 LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
 339                                               unsigned Threshold) {
 340   PassManagerBuilder *Builder = unwrap(PMB);
 341   Builder->Inliner = createFunctionInliningPass(Threshold);
 342 }
 343
 344 void
 345 LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
 346                                                   LLVMPassManagerRef PM) {
 347   PassManagerBuilder *Builder = unwrap(PMB);
 348   FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
 349   Builder->populateFunctionPassManager(*FPM);
 350 }
 351
 352 void
 353 LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
 354                                                 LLVMPassManagerRef PM) {
 355   PassManagerBuilder *Builder = unwrap(PMB);
 356   PassManagerBase *MPM = unwrap(PM);
 357   Builder->populateModulePassManager(*MPM);
 358 }
 359
 360 void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
 361                                                   LLVMPassManagerRef PM,
 362                                                   bool Internalize,
 363                                                   bool RunInliner) {
 364   PassManagerBuilder *Builder = unwrap(PMB);
 365   PassManagerBase *LPM = unwrap(PM);
 366   Builder->populateLTOPassManager(*LPM, Internalize, RunInliner);
 367 }