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     MPM.add(createLICMPass());
 196   }
 197
 198   if (!DisableUnrollLoops)
 199     MPM.add(createLoopUnrollPass());          // Unroll small loops
 200   addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
 201
 202   if (OptLevel > 1)
 203     MPM.add(createGVNPass());                 // Remove redundancies
 204   MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
 205   MPM.add(createSCCPPass());                  // Constant prop with SCCP
 206
 207   // Run instcombine after redundancy elimination to exploit opportunities
 208   // opened up by them.
 209   MPM.add(createInstructionCombiningPass());
 210   MPM.add(createJumpThreadingPass());         // Thread jumps
 211   MPM.add(createCorrelatedValuePropagationPass());
 212   MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
 213
 214   addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
 215
 216   if (Vectorize) {
 217     MPM.add(createBBVectorizePass());
 218     MPM.add(createInstructionCombiningPass());
 219     if (OptLevel > 1 && UseGVNAfterVectorization)
 220       MPM.add(createGVNPass());                   // Remove redundancies
 221     else
 222       MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 223   }
 224
 225   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
 226   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 227   MPM.add(createInstructionCombiningPass());  // Clean up after everything.
 228
 229   if (!DisableUnitAtATime) {
 230     // FIXME: We shouldn't bother with this anymore.
 231     MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
 232
 233     // GlobalOpt already deletes dead functions and globals, at -O2 try a
 234     // late pass of GlobalDCE.  It is capable of deleting dead cycles.
 235     if (OptLevel > 1) {
 236       MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
 237       MPM.add(createConstantMergePass());     // Merge dup global constants
 238     }
 239   }
 240   addExtensionsToPM(EP_OptimizerLast, MPM);
 241 }
 242
 243 void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
 244                                                 bool Internalize,
 245                                                 bool RunInliner,
 246                                                 bool DisableGVNLoadPRE) {
 247   // Provide AliasAnalysis services for optimizations.
 248   addInitialAliasAnalysisPasses(PM);
 249
 250   // Now that composite has been compiled, scan through the module, looking
 251   // for a main function.  If main is defined, mark all other functions
 252   // internal.
 253   if (Internalize) {
 254     std::vector<const char*> E;
 255     E.push_back("main");
 256     PM.add(createInternalizePass(E));
 257   }
 258
 259   // Propagate constants at call sites into the functions they call.  This
 260   // opens opportunities for globalopt (and inlining) by substituting function
 261   // pointers passed as arguments to direct uses of functions.
 262   PM.add(createIPSCCPPass());
 263
 264   // Now that we internalized some globals, see if we can hack on them!
 265   PM.add(createGlobalOptimizerPass());
 266
 267   // Linking modules together can lead to duplicated global constants, only
 268   // keep one copy of each constant.
 269   PM.add(createConstantMergePass());
 270
 271   // Remove unused arguments from functions.
 272   PM.add(createDeadArgEliminationPass());
 273
 274   // Reduce the code after globalopt and ipsccp.  Both can open up significant
 275   // simplification opportunities, and both can propagate functions through
 276   // function pointers.  When this happens, we often have to resolve varargs
 277   // calls, etc, so let instcombine do this.
 278   PM.add(createInstructionCombiningPass());
 279
 280   // Inline small functions
 281   if (RunInliner)
 282     PM.add(createFunctionInliningPass());
 283
 284   PM.add(createPruneEHPass());   // Remove dead EH info.
 285
 286   // Optimize globals again if we ran the inliner.
 287   if (RunInliner)
 288     PM.add(createGlobalOptimizerPass());
 289   PM.add(createGlobalDCEPass()); // Remove dead functions.
 290
 291   // If we didn't decide to inline a function, check to see if we can
 292   // transform it to pass arguments by value instead of by reference.
 293   PM.add(createArgumentPromotionPass());
 294
 295   // The IPO passes may leave cruft around.  Clean up after them.
 296   PM.add(createInstructionCombiningPass());
 297   PM.add(createJumpThreadingPass());
 298   // Break up allocas
 299   if (UseNewSROA)
 300     PM.add(createSROAPass());
 301   else
 302     PM.add(createScalarReplAggregatesPass());
 303
 304   // Run a few AA driven optimizations here and now, to cleanup the code.
 305   PM.add(createFunctionAttrsPass()); // Add nocapture.
 306   PM.add(createGlobalsModRefPass()); // IP alias analysis.
 307
 308   PM.add(createLICMPass());                 // Hoist loop invariants.
 309   PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
 310   PM.add(createMemCpyOptPass());            // Remove dead memcpys.
 311   // Nuke dead stores.
 312   PM.add(createDeadStoreEliminationPass());
 313
 314   // Cleanup and simplify the code after the scalar optimizations.
 315   PM.add(createInstructionCombiningPass());
 316
 317   PM.add(createJumpThreadingPass());
 318
 319   // Delete basic blocks, which optimization passes may have killed.
 320   PM.add(createCFGSimplificationPass());
 321
 322   // Now that we have optimized the program, discard unreachable functions.
 323   PM.add(createGlobalDCEPass());
 324 }
 325
 326 LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate() {
 327   PassManagerBuilder *PMB = new PassManagerBuilder();
 328   return wrap(PMB);
 329 }
 330
 331 void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
 332   PassManagerBuilder *Builder = unwrap(PMB);
 333   delete Builder;
 334 }
 335
 336 void
 337 LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
 338                                   unsigned OptLevel) {
 339   PassManagerBuilder *Builder = unwrap(PMB);
 340   Builder->OptLevel = OptLevel;
 341 }
 342
 343 void
 344 LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
 345                                    unsigned SizeLevel) {
 346   PassManagerBuilder *Builder = unwrap(PMB);
 347   Builder->SizeLevel = SizeLevel;
 348 }
 349
 350 void
 351 LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
 352                                             LLVMBool Value) {
 353   PassManagerBuilder *Builder = unwrap(PMB);
 354   Builder->DisableUnitAtATime = Value;
 355 }
 356
 357 void
 358 LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
 359                                             LLVMBool Value) {
 360   PassManagerBuilder *Builder = unwrap(PMB);
 361   Builder->DisableUnrollLoops = Value;
 362 }
 363
 364 void
 365 LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
 366                                                  LLVMBool Value) {
 367   PassManagerBuilder *Builder = unwrap(PMB);
 368   Builder->DisableSimplifyLibCalls = Value;
 369 }
 370
 371 void
 372 LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
 373                                               unsigned Threshold) {
 374   PassManagerBuilder *Builder = unwrap(PMB);
 375   Builder->Inliner = createFunctionInliningPass(Threshold);
 376 }
 377
 378 void
 379 LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
 380                                                   LLVMPassManagerRef PM) {
 381   PassManagerBuilder *Builder = unwrap(PMB);
 382   FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
 383   Builder->populateFunctionPassManager(*FPM);
 384 }
 385
 386 void
 387 LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
 388                                                 LLVMPassManagerRef PM) {
 389   PassManagerBuilder *Builder = unwrap(PMB);
 390   PassManagerBase *MPM = unwrap(PM);
 391   Builder->populateModulePassManager(*MPM);
 392 }
 393
 394 void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
 395                                                   LLVMPassManagerRef PM,
 396                                                   bool Internalize,
 397                                                   bool RunInliner) {
 398   PassManagerBuilder *Builder = unwrap(PMB);
 399   PassManagerBase *LPM = unwrap(PM);
 400   Builder->populateLTOPassManager(*LPM, Internalize, RunInliner);
 401 }