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 RunVectorization("vectorize", cl::desc("Run vectorization passes"));
  37
  38 static cl::opt<bool>
  39 UseGVNAfterVectorization("use-gvn-after-vectorization",
  40   cl::init(false), cl::Hidden,
  41   cl::desc("Run GVN instead of Early CSE after vectorization passes"));
  42
  43 static cl::opt<bool> UseNewSROA("use-new-sroa",
  44   cl::init(true), cl::Hidden,
  45   cl::desc("Enable the new, experimental SROA pass"));
  46
  47 PassManagerBuilder::PassManagerBuilder() {
  48     OptLevel = 2;
  49     SizeLevel = 0;
  50     LibraryInfo = 0;
  51     Inliner = 0;
  52     DisableSimplifyLibCalls = false;
  53     DisableUnitAtATime = false;
  54     DisableUnrollLoops = false;
  55     Vectorize = RunVectorization;
  56 }
  57
  58 PassManagerBuilder::~PassManagerBuilder() {
  59   delete LibraryInfo;
  60   delete Inliner;
  61 }
  62
  63 /// Set of global extensions, automatically added as part of the standard set.
  64 static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
  65    PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
  66
  67 void PassManagerBuilder::addGlobalExtension(
  68     PassManagerBuilder::ExtensionPointTy Ty,
  69     PassManagerBuilder::ExtensionFn Fn) {
  70   GlobalExtensions->push_back(std::make_pair(Ty, Fn));
  71 }
  72
  73 void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
  74   Extensions.push_back(std::make_pair(Ty, Fn));
  75 }
  76
  77 void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
  78                                            PassManagerBase &PM) const {
  79   for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
  80     if ((*GlobalExtensions)[i].first == ETy)
  81       (*GlobalExtensions)[i].second(*this, PM);
  82   for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
  83     if (Extensions[i].first == ETy)
  84       Extensions[i].second(*this, PM);
  85 }
  86
  87 void
  88 PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
  89   // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
  90   // BasicAliasAnalysis wins if they disagree. This is intended to help
  91   // support "obvious" type-punning idioms.
  92   PM.add(createTypeBasedAliasAnalysisPass());
  93   PM.add(createBasicAliasAnalysisPass());
  94 }
  95
  96 void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
  97   addExtensionsToPM(EP_EarlyAsPossible, FPM);
  98
  99   // Add LibraryInfo if we have some.
 100   if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));
 101
 102   if (OptLevel == 0) return;
 103
 104   addInitialAliasAnalysisPasses(FPM);
 105
 106   FPM.add(createCFGSimplificationPass());
 107   if (UseNewSROA)
 108     FPM.add(createSROAPass());
 109   else
 110     FPM.add(createScalarReplAggregatesPass());
 111   FPM.add(createEarlyCSEPass());
 112   FPM.add(createLowerExpectIntrinsicPass());
 113 }
 114
 115 void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
 116   // If all optimizations are disabled, just run the always-inline pass.
 117   if (OptLevel == 0) {
 118     if (Inliner) {
 119       MPM.add(Inliner);
 120       Inliner = 0;
 121     }
 122     addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
 123     return;
 124   }
 125
 126   // Add LibraryInfo if we have some.
 127   if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));
 128
 129   addInitialAliasAnalysisPasses(MPM);
 130
 131   if (!DisableUnitAtATime) {
 132     addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
 133
 134     MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
 135
 136     MPM.add(createIPSCCPPass());              // IP SCCP
 137     MPM.add(createDeadArgEliminationPass());  // Dead argument elimination
 138
 139     MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
 140     MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
 141   }
 142
 143   // Start of CallGraph SCC passes.
 144   if (!DisableUnitAtATime)
 145     MPM.add(createPruneEHPass());             // Remove dead EH info
 146   if (Inliner) {
 147     MPM.add(Inliner);
 148     Inliner = 0;
 149   }
 150   if (!DisableUnitAtATime)
 151     MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
 152   if (OptLevel > 2)
 153     MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
 154
 155   // Start of function pass.
 156   // Break up aggregate allocas, using SSAUpdater.
 157   MPM.add(createScalarReplAggregatesPass(-1, false));
 158   MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 159   if (!DisableSimplifyLibCalls)
 160     MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
 161   MPM.add(createJumpThreadingPass());         // Thread jumps.
 162   MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
 163   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 164   MPM.add(createInstructionCombiningPass());  // Combine silly seq's
 165
 166   MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
 167   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 168   MPM.add(createReassociatePass());           // Reassociate expressions
 169   MPM.add(createLoopRotatePass());            // Rotate Loop
 170   MPM.add(createLICMPass());                  // Hoist loop invariants
 171   MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
 172   MPM.add(createInstructionCombiningPass());
 173   MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
 174   MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
 175   MPM.add(createLoopDeletionPass());          // Delete dead loops
 176   if (!DisableUnrollLoops)
 177     MPM.add(createLoopUnrollPass());          // Unroll small loops
 178   addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
 179
 180   if (OptLevel > 1)
 181     MPM.add(createGVNPass());                 // Remove redundancies
 182   MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
 183   MPM.add(createSCCPPass());                  // Constant prop with SCCP
 184
 185   // Run instcombine after redundancy elimination to exploit opportunities
 186   // opened up by them.
 187   MPM.add(createInstructionCombiningPass());
 188   MPM.add(createJumpThreadingPass());         // Thread jumps
 189   MPM.add(createCorrelatedValuePropagationPass());
 190   MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
 191
 192   addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
 193
 194   if (Vectorize) {
 195     MPM.add(createBBVectorizePass());
 196     MPM.add(createInstructionCombiningPass());
 197     if (OptLevel > 1 && UseGVNAfterVectorization)
 198       MPM.add(createGVNPass());                   // Remove redundancies
 199     else
 200       MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 201   }
 202
 203   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
 204   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 205   MPM.add(createInstructionCombiningPass());  // Clean up after everything.
 206
 207   if (!DisableUnitAtATime) {
 208     // FIXME: We shouldn't bother with this anymore.
 209     MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
 210
 211     // GlobalOpt already deletes dead functions and globals, at -O3 try a
 212     // late pass of GlobalDCE.  It is capable of deleting dead cycles.
 213     if (OptLevel > 2)
 214       MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
 215
 216     if (OptLevel > 1)
 217       MPM.add(createConstantMergePass());     // Merge dup global constants
 218   }
 219   addExtensionsToPM(EP_OptimizerLast, MPM);
 220 }
 221
 222 void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
 223                                                 bool Internalize,
 224                                                 bool RunInliner,
 225                                                 bool DisableGVNLoadPRE) {
 226   // Provide AliasAnalysis services for optimizations.
 227   addInitialAliasAnalysisPasses(PM);
 228
 229   // Now that composite has been compiled, scan through the module, looking
 230   // for a main function.  If main is defined, mark all other functions
 231   // internal.
 232   if (Internalize)
 233     PM.add(createInternalizePass(true));
 234
 235   // Propagate constants at call sites into the functions they call.  This
 236   // opens opportunities for globalopt (and inlining) by substituting function
 237   // pointers passed as arguments to direct uses of functions.
 238   PM.add(createIPSCCPPass());
 239
 240   // Now that we internalized some globals, see if we can hack on them!
 241   PM.add(createGlobalOptimizerPass());
 242
 243   // Linking modules together can lead to duplicated global constants, only
 244   // keep one copy of each constant.
 245   PM.add(createConstantMergePass());
 246
 247   // Remove unused arguments from functions.
 248   PM.add(createDeadArgEliminationPass());
 249
 250   // Reduce the code after globalopt and ipsccp.  Both can open up significant
 251   // simplification opportunities, and both can propagate functions through
 252   // function pointers.  When this happens, we often have to resolve varargs
 253   // calls, etc, so let instcombine do this.
 254   PM.add(createInstructionCombiningPass());
 255
 256   // Inline small functions
 257   if (RunInliner)
 258     PM.add(createFunctionInliningPass());
 259
 260   PM.add(createPruneEHPass());   // Remove dead EH info.
 261
 262   // Optimize globals again if we ran the inliner.
 263   if (RunInliner)
 264     PM.add(createGlobalOptimizerPass());
 265   PM.add(createGlobalDCEPass()); // Remove dead functions.
 266
 267   // If we didn't decide to inline a function, check to see if we can
 268   // transform it to pass arguments by value instead of by reference.
 269   PM.add(createArgumentPromotionPass());
 270
 271   // The IPO passes may leave cruft around.  Clean up after them.
 272   PM.add(createInstructionCombiningPass());
 273   PM.add(createJumpThreadingPass());
 274   // Break up allocas
 275   if (UseNewSROA)
 276     PM.add(createSROAPass());
 277   else
 278     PM.add(createScalarReplAggregatesPass());
 279
 280   // Run a few AA driven optimizations here and now, to cleanup the code.
 281   PM.add(createFunctionAttrsPass()); // Add nocapture.
 282   PM.add(createGlobalsModRefPass()); // IP alias analysis.
 283
 284   PM.add(createLICMPass());                 // Hoist loop invariants.
 285   PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
 286   PM.add(createMemCpyOptPass());            // Remove dead memcpys.
 287   // Nuke dead stores.
 288   PM.add(createDeadStoreEliminationPass());
 289
 290   // Cleanup and simplify the code after the scalar optimizations.
 291   PM.add(createInstructionCombiningPass());
 292
 293   PM.add(createJumpThreadingPass());
 294
 295   // Delete basic blocks, which optimization passes may have killed.
 296   PM.add(createCFGSimplificationPass());
 297
 298   // Now that we have optimized the program, discard unreachable functions.
 299   PM.add(createGlobalDCEPass());
 300 }
 301
 302 LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate(void) {
 303   PassManagerBuilder *PMB = new PassManagerBuilder();
 304   return wrap(PMB);
 305 }
 306
 307 void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
 308   PassManagerBuilder *Builder = unwrap(PMB);
 309   delete Builder;
 310 }
 311
 312 void
 313 LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
 314                                   unsigned OptLevel) {
 315   PassManagerBuilder *Builder = unwrap(PMB);
 316   Builder->OptLevel = OptLevel;
 317 }
 318
 319 void
 320 LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
 321                                    unsigned SizeLevel) {
 322   PassManagerBuilder *Builder = unwrap(PMB);
 323   Builder->SizeLevel = SizeLevel;
 324 }
 325
 326 void
 327 LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
 328                                             LLVMBool Value) {
 329   PassManagerBuilder *Builder = unwrap(PMB);
 330   Builder->DisableUnitAtATime = Value;
 331 }
 332
 333 void
 334 LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
 335                                             LLVMBool Value) {
 336   PassManagerBuilder *Builder = unwrap(PMB);
 337   Builder->DisableUnrollLoops = Value;
 338 }
 339
 340 void
 341 LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
 342                                                  LLVMBool Value) {
 343   PassManagerBuilder *Builder = unwrap(PMB);
 344   Builder->DisableSimplifyLibCalls = Value;
 345 }
 346
 347 void
 348 LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
 349                                               unsigned Threshold) {
 350   PassManagerBuilder *Builder = unwrap(PMB);
 351   Builder->Inliner = createFunctionInliningPass(Threshold);
 352 }
 353
 354 void
 355 LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
 356                                                   LLVMPassManagerRef PM) {
 357   PassManagerBuilder *Builder = unwrap(PMB);
 358   FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
 359   Builder->populateFunctionPassManager(*FPM);
 360 }
 361
 362 void
 363 LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
 364                                                 LLVMPassManagerRef PM) {
 365   PassManagerBuilder *Builder = unwrap(PMB);
 366   PassManagerBase *MPM = unwrap(PM);
 367   Builder->populateModulePassManager(*MPM);
 368 }
 369
 370 void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
 371                                                   LLVMPassManagerRef PM,
 372                                                   bool Internalize,
 373                                                   bool RunInliner) {
 374   PassManagerBuilder *Builder = unwrap(PMB);
 375   PassManagerBase *LPM = unwrap(PM);
 376   Builder->populateLTOPassManager(*LPM, Internalize, RunInliner);
 377 }