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