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