contrib/llvm/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/IR/Verifier.h"
  21 #include "llvm/PassManager.h"
  22 #include "llvm/Support/CommandLine.h"
  23 #include "llvm/Support/ManagedStatic.h"
  24 #include "llvm/Target/TargetLibraryInfo.h"
  25 #include "llvm/Transforms/IPO.h"
  26 #include "llvm/Transforms/Scalar.h"
  27 #include "llvm/Transforms/Vectorize.h"
  28
  29 using namespace llvm;
  30
  31 static cl::opt<bool>
  32 RunLoopVectorization("vectorize-loops", cl::Hidden,
  33                      cl::desc("Run the Loop vectorization passes"));
  34
  35 static cl::opt<bool>
  36 RunSLPVectorization("vectorize-slp", cl::Hidden,
  37                     cl::desc("Run the SLP vectorization passes"));
  38
  39 static cl::opt<bool>
  40 RunBBVectorization("vectorize-slp-aggressive", cl::Hidden,
  41                     cl::desc("Run the BB vectorization passes"));
  42
  43 static cl::opt<bool>
  44 UseGVNAfterVectorization("use-gvn-after-vectorization",
  45   cl::init(false), cl::Hidden,
  46   cl::desc("Run GVN instead of Early CSE after vectorization passes"));
  47
  48 static cl::opt<bool> UseNewSROA("use-new-sroa",
  49   cl::init(true), cl::Hidden,
  50   cl::desc("Enable the new, experimental SROA pass"));
  51
  52 static cl::opt<bool>
  53 RunLoopRerolling("reroll-loops", cl::Hidden,
  54                  cl::desc("Run the loop rerolling pass"));
  55
  56 static cl::opt<bool> RunLoadCombine("combine-loads", cl::init(false),
  57                                     cl::Hidden,
  58                                     cl::desc("Run the load combining pass"));
  59
  60 static cl::opt<bool> RunGVN("enable-gvn", cl::init(true),
  61                             cl::Hidden,
  62                             cl::desc("Run the global value numbering pass"));
  63
  64 PassManagerBuilder::PassManagerBuilder() {
  65     OptLevel = 2;
  66     SizeLevel = 0;
  67     LibraryInfo = nullptr;
  68     Inliner = nullptr;
  69     DisableTailCalls = false;
  70     DisableUnitAtATime = false;
  71     DisableUnrollLoops = false;
  72     BBVectorize = RunBBVectorization;
  73     SLPVectorize = RunSLPVectorization;
  74     LoopVectorize = RunLoopVectorization;
  75     RerollLoops = RunLoopRerolling;
  76     LoadCombine = RunLoadCombine;
  77 }
  78
  79 PassManagerBuilder::~PassManagerBuilder() {
  80   delete LibraryInfo;
  81   delete Inliner;
  82 }
  83
  84 /// Set of global extensions, automatically added as part of the standard set.
  85 static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
  86    PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
  87
  88 void PassManagerBuilder::addGlobalExtension(
  89     PassManagerBuilder::ExtensionPointTy Ty,
  90     PassManagerBuilder::ExtensionFn Fn) {
  91   GlobalExtensions->push_back(std::make_pair(Ty, Fn));
  92 }
  93
  94 void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
  95   Extensions.push_back(std::make_pair(Ty, Fn));
  96 }
  97
  98 void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
  99                                            PassManagerBase &PM) const {
 100   for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
 101     if ((*GlobalExtensions)[i].first == ETy)
 102       (*GlobalExtensions)[i].second(*this, PM);
 103   for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
 104     if (Extensions[i].first == ETy)
 105       Extensions[i].second(*this, PM);
 106 }
 107
 108 void
 109 PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
 110   // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
 111   // BasicAliasAnalysis wins if they disagree. This is intended to help
 112   // support "obvious" type-punning idioms.
 113   PM.add(createTypeBasedAliasAnalysisPass());
 114   PM.add(createBasicAliasAnalysisPass());
 115 }
 116
 117 void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
 118   addExtensionsToPM(EP_EarlyAsPossible, FPM);
 119
 120   // Add LibraryInfo if we have some.
 121   if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));
 122
 123   if (OptLevel == 0) return;
 124
 125   addInitialAliasAnalysisPasses(FPM);
 126
 127   FPM.add(createCFGSimplificationPass());
 128   if (UseNewSROA)
 129     FPM.add(createSROAPass());
 130   else
 131     FPM.add(createScalarReplAggregatesPass());
 132   FPM.add(createEarlyCSEPass());
 133   FPM.add(createLowerExpectIntrinsicPass());
 134 }
 135
 136 void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
 137   // If all optimizations are disabled, just run the always-inline pass.
 138   if (OptLevel == 0) {
 139     if (Inliner) {
 140       MPM.add(Inliner);
 141       Inliner = nullptr;
 142     }
 143
 144     // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
 145     // pass manager, but we don't want to add extensions into that pass manager.
 146     // To prevent this we must insert a no-op module pass to reset the pass
 147     // manager to get the same behavior as EP_OptimizerLast in non-O0 builds.
 148     if (!GlobalExtensions->empty() || !Extensions.empty())
 149       MPM.add(createBarrierNoopPass());
 150
 151     addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
 152     return;
 153   }
 154
 155   // Add LibraryInfo if we have some.
 156   if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));
 157
 158   addInitialAliasAnalysisPasses(MPM);
 159
 160   if (!DisableUnitAtATime) {
 161     addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
 162
 163     MPM.add(createIPSCCPPass());              // IP SCCP
 164     MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
 165
 166     MPM.add(createDeadArgEliminationPass());  // Dead argument elimination
 167
 168     MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
 169     addExtensionsToPM(EP_Peephole, MPM);
 170     MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
 171   }
 172
 173   // Start of CallGraph SCC passes.
 174   if (!DisableUnitAtATime)
 175     MPM.add(createPruneEHPass());             // Remove dead EH info
 176   if (Inliner) {
 177     MPM.add(Inliner);
 178     Inliner = nullptr;
 179   }
 180   if (!DisableUnitAtATime)
 181     MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
 182   if (OptLevel > 2)
 183     MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
 184
 185   // Start of function pass.
 186   // Break up aggregate allocas, using SSAUpdater.
 187   if (UseNewSROA)
 188     MPM.add(createSROAPass(/*RequiresDomTree*/ false));
 189   else
 190     MPM.add(createScalarReplAggregatesPass(-1, false));
 191   MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 192   MPM.add(createJumpThreadingPass());         // Thread jumps.
 193   MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
 194   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 195   MPM.add(createInstructionCombiningPass());  // Combine silly seq's
 196   addExtensionsToPM(EP_Peephole, MPM);
 197
 198   if (!DisableTailCalls)
 199     MPM.add(createTailCallEliminationPass()); // Eliminate tail calls
 200   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 201   MPM.add(createReassociatePass());           // Reassociate expressions
 202   // Rotate Loop - disable header duplication at -Oz
 203   MPM.add(createLoopRotatePass(SizeLevel == 2 ? 0 : -1));
 204   MPM.add(createLICMPass());                  // Hoist loop invariants
 205   MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
 206   MPM.add(createInstructionCombiningPass());
 207   MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
 208   MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
 209   MPM.add(createLoopDeletionPass());          // Delete dead loops
 210
 211   if (!DisableUnrollLoops)
 212     MPM.add(createSimpleLoopUnrollPass());    // Unroll small loops
 213   addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
 214
 215   if (OptLevel > 1) {
 216     MPM.add(createMergedLoadStoreMotionPass()); // Merge load/stores in diamond
 217     if (RunGVN)
 218       MPM.add(createGVNPass());                 // Remove redundancies
 219   }
 220   MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
 221   MPM.add(createSCCPPass());                  // Constant prop with SCCP
 222
 223   // Run instcombine after redundancy elimination to exploit opportunities
 224   // opened up by them.
 225   MPM.add(createInstructionCombiningPass());
 226   addExtensionsToPM(EP_Peephole, MPM);
 227   MPM.add(createJumpThreadingPass());         // Thread jumps
 228   MPM.add(createCorrelatedValuePropagationPass());
 229   MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
 230
 231   addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
 232
 233   if (RerollLoops)
 234     MPM.add(createLoopRerollPass());
 235   if (SLPVectorize)
 236     MPM.add(createSLPVectorizerPass());   // Vectorize parallel scalar chains.
 237
 238   if (BBVectorize) {
 239     MPM.add(createBBVectorizePass());
 240     MPM.add(createInstructionCombiningPass());
 241     addExtensionsToPM(EP_Peephole, MPM);
 242     if (OptLevel > 1 && UseGVNAfterVectorization)
 243       MPM.add(createGVNPass());           // Remove redundancies
 244     else
 245       MPM.add(createEarlyCSEPass());      // Catch trivial redundancies
 246
 247     // BBVectorize may have significantly shortened a loop body; unroll again.
 248     if (!DisableUnrollLoops)
 249       MPM.add(createLoopUnrollPass());
 250   }
 251
 252   if (LoadCombine)
 253     MPM.add(createLoadCombinePass());
 254
 255   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
 256   MPM.add(createCFGSimplificationPass()); // Merge & remove BBs
 257   MPM.add(createInstructionCombiningPass());  // Clean up after everything.
 258   addExtensionsToPM(EP_Peephole, MPM);
 259
 260   // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
 261   // pass manager that we are specifically trying to avoid. To prevent this
 262   // we must insert a no-op module pass to reset the pass manager.
 263   MPM.add(createBarrierNoopPass());
 264   MPM.add(createLoopVectorizePass(DisableUnrollLoops, LoopVectorize));
 265   // FIXME: Because of #pragma vectorize enable, the passes below are always
 266   // inserted in the pipeline, even when the vectorizer doesn't run (ex. when
 267   // on -O1 and no #pragma is found). Would be good to have these two passes
 268   // as function calls, so that we can only pass them when the vectorizer
 269   // changed the code.
 270   MPM.add(createInstructionCombiningPass());
 271   addExtensionsToPM(EP_Peephole, MPM);
 272   MPM.add(createCFGSimplificationPass());
 273
 274   if (!DisableUnrollLoops)
 275     MPM.add(createLoopUnrollPass());    // Unroll small loops
 276
 277   if (!DisableUnitAtATime) {
 278     // FIXME: We shouldn't bother with this anymore.
 279     MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
 280
 281     // GlobalOpt already deletes dead functions and globals, at -O2 try a
 282     // late pass of GlobalDCE.  It is capable of deleting dead cycles.
 283     if (OptLevel > 1) {
 284       MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
 285       MPM.add(createConstantMergePass());     // Merge dup global constants
 286     }
 287   }
 288   addExtensionsToPM(EP_OptimizerLast, MPM);
 289 }
 290
 291 void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
 292                                                 bool Internalize,
 293                                                 bool RunInliner,
 294                                                 bool DisableGVNLoadPRE) {
 295   // Provide AliasAnalysis services for optimizations.
 296   addInitialAliasAnalysisPasses(PM);
 297
 298   // Now that composite has been compiled, scan through the module, looking
 299   // for a main function.  If main is defined, mark all other functions
 300   // internal.
 301   if (Internalize)
 302     PM.add(createInternalizePass("main"));
 303
 304   // Propagate constants at call sites into the functions they call.  This
 305   // opens opportunities for globalopt (and inlining) by substituting function
 306   // pointers passed as arguments to direct uses of functions.
 307   PM.add(createIPSCCPPass());
 308
 309   // Now that we internalized some globals, see if we can hack on them!
 310   PM.add(createGlobalOptimizerPass());
 311
 312   // Linking modules together can lead to duplicated global constants, only
 313   // keep one copy of each constant.
 314   PM.add(createConstantMergePass());
 315
 316   // Remove unused arguments from functions.
 317   PM.add(createDeadArgEliminationPass());
 318
 319   // Reduce the code after globalopt and ipsccp.  Both can open up significant
 320   // simplification opportunities, and both can propagate functions through
 321   // function pointers.  When this happens, we often have to resolve varargs
 322   // calls, etc, so let instcombine do this.
 323   PM.add(createInstructionCombiningPass());
 324   addExtensionsToPM(EP_Peephole, PM);
 325
 326   // Inline small functions
 327   if (RunInliner)
 328     PM.add(createFunctionInliningPass());
 329
 330   PM.add(createPruneEHPass());   // Remove dead EH info.
 331
 332   // Optimize globals again if we ran the inliner.
 333   if (RunInliner)
 334     PM.add(createGlobalOptimizerPass());
 335   PM.add(createGlobalDCEPass()); // Remove dead functions.
 336
 337   // If we didn't decide to inline a function, check to see if we can
 338   // transform it to pass arguments by value instead of by reference.
 339   PM.add(createArgumentPromotionPass());
 340
 341   // The IPO passes may leave cruft around.  Clean up after them.
 342   PM.add(createInstructionCombiningPass());
 343   addExtensionsToPM(EP_Peephole, PM);
 344   PM.add(createJumpThreadingPass());
 345
 346   // Break up allocas
 347   if (UseNewSROA)
 348     PM.add(createSROAPass());
 349   else
 350     PM.add(createScalarReplAggregatesPass());
 351
 352   // Run a few AA driven optimizations here and now, to cleanup the code.
 353   PM.add(createFunctionAttrsPass()); // Add nocapture.
 354   PM.add(createGlobalsModRefPass()); // IP alias analysis.
 355
 356   PM.add(createLICMPass());                 // Hoist loop invariants.
 357   PM.add(createMergedLoadStoreMotionPass()); // Merge load/stores in diamonds
 358   PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
 359   PM.add(createMemCpyOptPass());            // Remove dead memcpys.
 360
 361   // Nuke dead stores.
 362   PM.add(createDeadStoreEliminationPass());
 363
 364   // More loops are countable; try to optimize them.
 365   PM.add(createIndVarSimplifyPass());
 366   PM.add(createLoopDeletionPass());
 367   PM.add(createLoopVectorizePass(true, true));
 368
 369   // More scalar chains could be vectorized due to more alias information
 370   PM.add(createSLPVectorizerPass()); // Vectorize parallel scalar chains.
 371
 372   if (LoadCombine)
 373     PM.add(createLoadCombinePass());
 374
 375   // Cleanup and simplify the code after the scalar optimizations.
 376   PM.add(createInstructionCombiningPass());
 377   addExtensionsToPM(EP_Peephole, PM);
 378
 379   PM.add(createJumpThreadingPass());
 380
 381   // Delete basic blocks, which optimization passes may have killed.
 382   PM.add(createCFGSimplificationPass());
 383
 384   // Now that we have optimized the program, discard unreachable functions.
 385   PM.add(createGlobalDCEPass());
 386 }
 387
 388 inline PassManagerBuilder *unwrap(LLVMPassManagerBuilderRef P) {
 389     return reinterpret_cast<PassManagerBuilder*>(P);
 390 }
 391
 392 inline LLVMPassManagerBuilderRef wrap(PassManagerBuilder *P) {
 393   return reinterpret_cast<LLVMPassManagerBuilderRef>(P);
 394 }
 395
 396 LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate() {
 397   PassManagerBuilder *PMB = new PassManagerBuilder();
 398   return wrap(PMB);
 399 }
 400
 401 void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
 402   PassManagerBuilder *Builder = unwrap(PMB);
 403   delete Builder;
 404 }
 405
 406 void
 407 LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
 408                                   unsigned OptLevel) {
 409   PassManagerBuilder *Builder = unwrap(PMB);
 410   Builder->OptLevel = OptLevel;
 411 }
 412
 413 void
 414 LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
 415                                    unsigned SizeLevel) {
 416   PassManagerBuilder *Builder = unwrap(PMB);
 417   Builder->SizeLevel = SizeLevel;
 418 }
 419
 420 void
 421 LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
 422                                             LLVMBool Value) {
 423   PassManagerBuilder *Builder = unwrap(PMB);
 424   Builder->DisableUnitAtATime = Value;
 425 }
 426
 427 void
 428 LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
 429                                             LLVMBool Value) {
 430   PassManagerBuilder *Builder = unwrap(PMB);
 431   Builder->DisableUnrollLoops = Value;
 432 }
 433
 434 void
 435 LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
 436                                                  LLVMBool Value) {
 437   // NOTE: The simplify-libcalls pass has been removed.
 438 }
 439
 440 void
 441 LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
 442                                               unsigned Threshold) {
 443   PassManagerBuilder *Builder = unwrap(PMB);
 444   Builder->Inliner = createFunctionInliningPass(Threshold);
 445 }
 446
 447 void
 448 LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
 449                                                   LLVMPassManagerRef PM) {
 450   PassManagerBuilder *Builder = unwrap(PMB);
 451   FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
 452   Builder->populateFunctionPassManager(*FPM);
 453 }
 454
 455 void
 456 LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
 457                                                 LLVMPassManagerRef PM) {
 458   PassManagerBuilder *Builder = unwrap(PMB);
 459   PassManagerBase *MPM = unwrap(PM);
 460   Builder->populateModulePassManager(*MPM);
 461 }
 462
 463 void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
 464                                                   LLVMPassManagerRef PM,
 465                                                   LLVMBool Internalize,
 466                                                   LLVMBool RunInliner) {
 467   PassManagerBuilder *Builder = unwrap(PMB);
 468   PassManagerBase *LPM = unwrap(PM);
 469   Builder->populateLTOPassManager(*LPM, Internalize != 0, RunInliner != 0);
 470 }