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