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", cl::desc("Run the Loop vectorization passes"));
  37
  38 static cl::opt<bool>
  39 RunBBVectorization("vectorize", cl::desc("Run the BB vectorization passes"));
  40
  41 static cl::opt<bool>
  42 UseGVNAfterVectorization("use-gvn-after-vectorization",
  43   cl::init(false), cl::Hidden,
  44   cl::desc("Run GVN instead of Early CSE after vectorization passes"));
  45
  46 static cl::opt<bool> UseNewSROA("use-new-sroa",
  47   cl::init(true), cl::Hidden,
  48   cl::desc("Enable the new, experimental SROA pass"));
  49
  50 PassManagerBuilder::PassManagerBuilder() {
  51     OptLevel = 2;
  52     SizeLevel = 0;
  53     LibraryInfo = 0;
  54     Inliner = 0;
  55     DisableSimplifyLibCalls = false;
  56     DisableUnitAtATime = false;
  57     DisableUnrollLoops = false;
  58     BBVectorize = RunBBVectorization;
  59     LoopVectorize = RunLoopVectorization;
  60 }
  61
  62 PassManagerBuilder::~PassManagerBuilder() {
  63   delete LibraryInfo;
  64   delete Inliner;
  65 }
  66
  67 /// Set of global extensions, automatically added as part of the standard set.
  68 static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
  69    PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
  70
  71 void PassManagerBuilder::addGlobalExtension(
  72     PassManagerBuilder::ExtensionPointTy Ty,
  73     PassManagerBuilder::ExtensionFn Fn) {
  74   GlobalExtensions->push_back(std::make_pair(Ty, Fn));
  75 }
  76
  77 void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
  78   Extensions.push_back(std::make_pair(Ty, Fn));
  79 }
  80
  81 void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
  82                                            PassManagerBase &PM) const {
  83   for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
  84     if ((*GlobalExtensions)[i].first == ETy)
  85       (*GlobalExtensions)[i].second(*this, PM);
  86   for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
  87     if (Extensions[i].first == ETy)
  88       Extensions[i].second(*this, PM);
  89 }
  90
  91 void
  92 PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
  93   // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
  94   // BasicAliasAnalysis wins if they disagree. This is intended to help
  95   // support "obvious" type-punning idioms.
  96   PM.add(createTypeBasedAliasAnalysisPass());
  97   PM.add(createBasicAliasAnalysisPass());
  98 }
  99
 100 void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
 101   addExtensionsToPM(EP_EarlyAsPossible, FPM);
 102
 103   // Add LibraryInfo if we have some.
 104   if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));
 105
 106   if (OptLevel == 0) return;
 107
 108   addInitialAliasAnalysisPasses(FPM);
 109
 110   FPM.add(createCFGSimplificationPass());
 111   if (UseNewSROA)
 112     FPM.add(createSROAPass());
 113   else
 114     FPM.add(createScalarReplAggregatesPass());
 115   FPM.add(createEarlyCSEPass());
 116   FPM.add(createLowerExpectIntrinsicPass());
 117 }
 118
 119 void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
 120   // If all optimizations are disabled, just run the always-inline pass.
 121   if (OptLevel == 0) {
 122     if (Inliner) {
 123       MPM.add(Inliner);
 124       Inliner = 0;
 125     }
 126
 127     // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
 128     // pass manager, but we don't want to add extensions into that pass manager.
 129     // To prevent this we must insert a no-op module pass to reset the pass
 130     // manager to get the same behavior as EP_OptimizerLast in non-O0 builds.
 131     if (!GlobalExtensions->empty() || !Extensions.empty())
 132       MPM.add(createBarrierNoopPass());
 133
 134     addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
 135     return;
 136   }
 137
 138   // Add LibraryInfo if we have some.
 139   if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));
 140
 141   addInitialAliasAnalysisPasses(MPM);
 142
 143   if (!DisableUnitAtATime) {
 144     addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
 145
 146     MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
 147
 148     MPM.add(createIPSCCPPass());              // IP SCCP
 149     MPM.add(createDeadArgEliminationPass());  // Dead argument elimination
 150
 151     MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
 152     MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
 153   }
 154
 155   // Start of CallGraph SCC passes.
 156   if (!DisableUnitAtATime)
 157     MPM.add(createPruneEHPass());             // Remove dead EH info
 158   if (Inliner) {
 159     MPM.add(Inliner);
 160     Inliner = 0;
 161   }
 162   if (!DisableUnitAtATime)
 163     MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
 164   if (OptLevel > 2)
 165     MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
 166
 167   // Start of function pass.
 168   // Break up aggregate allocas, using SSAUpdater.
 169   if (UseNewSROA)
 170     MPM.add(createSROAPass(/*RequiresDomTree*/ false));
 171   else
 172     MPM.add(createScalarReplAggregatesPass(-1, false));
 173   MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 174   if (!DisableSimplifyLibCalls)
 175     MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
 176   MPM.add(createJumpThreadingPass());         // Thread jumps.
 177   MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
 178   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 179   MPM.add(createInstructionCombiningPass());  // Combine silly seq's
 180
 181   MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
 182   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 183   MPM.add(createReassociatePass());           // Reassociate expressions
 184   MPM.add(createLoopRotatePass());            // Rotate Loop
 185   MPM.add(createLICMPass());                  // Hoist loop invariants
 186   MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
 187   MPM.add(createInstructionCombiningPass());
 188   MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
 189   MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
 190   MPM.add(createLoopDeletionPass());          // Delete dead loops
 191
 192   if (LoopVectorize) {
 193     MPM.add(createLoopVectorizePass());
 194     MPM.add(createLICMPass());
 195   }
 196
 197   if (!DisableUnrollLoops)
 198     MPM.add(createLoopUnrollPass());          // Unroll small loops
 199   addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
 200
 201   if (OptLevel > 1)
 202     MPM.add(createGVNPass());                 // Remove redundancies
 203   MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
 204   MPM.add(createSCCPPass());                  // Constant prop with SCCP
 205
 206   // Run instcombine after redundancy elimination to exploit opportunities
 207   // opened up by them.
 208   MPM.add(createInstructionCombiningPass());
 209   MPM.add(createJumpThreadingPass());         // Thread jumps
 210   MPM.add(createCorrelatedValuePropagationPass());
 211   MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
 212
 213   addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
 214
 215   if (BBVectorize) {
 216     MPM.add(createBBVectorizePass());
 217     MPM.add(createInstructionCombiningPass());
 218     if (OptLevel > 1 && UseGVNAfterVectorization)
 219       MPM.add(createGVNPass());                   // Remove redundancies
 220     else
 221       MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 222   }
 223
 224   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
 225   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 226   MPM.add(createInstructionCombiningPass());  // Clean up after everything.
 227
 228   if (!DisableUnitAtATime) {
 229     // FIXME: We shouldn't bother with this anymore.
 230     MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
 231
 232     // GlobalOpt already deletes dead functions and globals, at -O2 try a
 233     // late pass of GlobalDCE.  It is capable of deleting dead cycles.
 234     if (OptLevel > 1) {
 235       MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
 236       MPM.add(createConstantMergePass());     // Merge dup global constants
 237     }
 238   }
 239   addExtensionsToPM(EP_OptimizerLast, MPM);
 240 }
 241
 242 void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
 243                                                 bool Internalize,
 244                                                 bool RunInliner,
 245                                                 bool DisableGVNLoadPRE) {
 246   // Provide AliasAnalysis services for optimizations.
 247   addInitialAliasAnalysisPasses(PM);
 248
 249   // Now that composite has been compiled, scan through the module, looking
 250   // for a main function.  If main is defined, mark all other functions
 251   // internal.
 252   if (Internalize) {
 253     std::vector<const char*> E;
 254     E.push_back("main");
 255     PM.add(createInternalizePass(E));
 256   }
 257
 258   // Propagate constants at call sites into the functions they call.  This
 259   // opens opportunities for globalopt (and inlining) by substituting function
 260   // pointers passed as arguments to direct uses of functions.
 261   PM.add(createIPSCCPPass());
 262
 263   // Now that we internalized some globals, see if we can hack on them!
 264   PM.add(createGlobalOptimizerPass());
 265
 266   // Linking modules together can lead to duplicated global constants, only
 267   // keep one copy of each constant.
 268   PM.add(createConstantMergePass());
 269
 270   // Remove unused arguments from functions.
 271   PM.add(createDeadArgEliminationPass());
 272
 273   // Reduce the code after globalopt and ipsccp.  Both can open up significant
 274   // simplification opportunities, and both can propagate functions through
 275   // function pointers.  When this happens, we often have to resolve varargs
 276   // calls, etc, so let instcombine do this.
 277   PM.add(createInstructionCombiningPass());
 278
 279   // Inline small functions
 280   if (RunInliner)
 281     PM.add(createFunctionInliningPass());
 282
 283   PM.add(createPruneEHPass());   // Remove dead EH info.
 284
 285   // Optimize globals again if we ran the inliner.
 286   if (RunInliner)
 287     PM.add(createGlobalOptimizerPass());
 288   PM.add(createGlobalDCEPass()); // Remove dead functions.
 289
 290   // If we didn't decide to inline a function, check to see if we can
 291   // transform it to pass arguments by value instead of by reference.
 292   PM.add(createArgumentPromotionPass());
 293
 294   // The IPO passes may leave cruft around.  Clean up after them.
 295   PM.add(createInstructionCombiningPass());
 296   PM.add(createJumpThreadingPass());
 297   // Break up allocas
 298   if (UseNewSROA)
 299     PM.add(createSROAPass());
 300   else
 301     PM.add(createScalarReplAggregatesPass());
 302
 303   // Run a few AA driven optimizations here and now, to cleanup the code.
 304   PM.add(createFunctionAttrsPass()); // Add nocapture.
 305   PM.add(createGlobalsModRefPass()); // IP alias analysis.
 306
 307   PM.add(createLICMPass());                 // Hoist loop invariants.
 308   PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
 309   PM.add(createMemCpyOptPass());            // Remove dead memcpys.
 310   // Nuke dead stores.
 311   PM.add(createDeadStoreEliminationPass());
 312
 313   // Cleanup and simplify the code after the scalar optimizations.
 314   PM.add(createInstructionCombiningPass());
 315
 316   PM.add(createJumpThreadingPass());
 317
 318   // Delete basic blocks, which optimization passes may have killed.
 319   PM.add(createCFGSimplificationPass());
 320
 321   // Now that we have optimized the program, discard unreachable functions.
 322   PM.add(createGlobalDCEPass());
 323 }
 324
 325 LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate(void) {
 326   PassManagerBuilder *PMB = new PassManagerBuilder();
 327   return wrap(PMB);
 328 }
 329
 330 void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
 331   PassManagerBuilder *Builder = unwrap(PMB);
 332   delete Builder;
 333 }
 334
 335 void
 336 LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
 337                                   unsigned OptLevel) {
 338   PassManagerBuilder *Builder = unwrap(PMB);
 339   Builder->OptLevel = OptLevel;
 340 }
 341
 342 void
 343 LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
 344                                    unsigned SizeLevel) {
 345   PassManagerBuilder *Builder = unwrap(PMB);
 346   Builder->SizeLevel = SizeLevel;
 347 }
 348
 349 void
 350 LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
 351                                             LLVMBool Value) {
 352   PassManagerBuilder *Builder = unwrap(PMB);
 353   Builder->DisableUnitAtATime = Value;
 354 }
 355
 356 void
 357 LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
 358                                             LLVMBool Value) {
 359   PassManagerBuilder *Builder = unwrap(PMB);
 360   Builder->DisableUnrollLoops = Value;
 361 }
 362
 363 void
 364 LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
 365                                                  LLVMBool Value) {
 366   PassManagerBuilder *Builder = unwrap(PMB);
 367   Builder->DisableSimplifyLibCalls = Value;
 368 }
 369
 370 void
 371 LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
 372                                               unsigned Threshold) {
 373   PassManagerBuilder *Builder = unwrap(PMB);
 374   Builder->Inliner = createFunctionInliningPass(Threshold);
 375 }
 376
 377 void
 378 LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
 379                                                   LLVMPassManagerRef PM) {
 380   PassManagerBuilder *Builder = unwrap(PMB);
 381   FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
 382   Builder->populateFunctionPassManager(*FPM);
 383 }
 384
 385 void
 386 LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
 387                                                 LLVMPassManagerRef PM) {
 388   PassManagerBuilder *Builder = unwrap(PMB);
 389   PassManagerBase *MPM = unwrap(PM);
 390   Builder->populateModulePassManager(*MPM);
 391 }
 392
 393 void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
 394                                                   LLVMPassManagerRef PM,
 395                                                   bool Internalize,
 396                                                   bool RunInliner) {
 397   PassManagerBuilder *Builder = unwrap(PMB);
 398   PassManagerBase *LPM = unwrap(PM);
 399   Builder->populateLTOPassManager(*LPM, Internalize, RunInliner);
 400 }