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