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/Target/TargetLibraryInfo.h"
  25 #include "llvm/Transforms/Scalar.h"
  26 #include "llvm/Transforms/IPO.h"
  27 #include "llvm/ADT/SmallVector.h"
  28 #include "llvm/Support/ManagedStatic.h"
  29
  30 using namespace llvm;
  31
  32 PassManagerBuilder::PassManagerBuilder() {
  33     OptLevel = 2;
  34     SizeLevel = 0;
  35     LibraryInfo = 0;
  36     Inliner = 0;
  37     DisableSimplifyLibCalls = false;
  38     DisableUnitAtATime = false;
  39     DisableUnrollLoops = false;
  40 }
  41
  42 PassManagerBuilder::~PassManagerBuilder() {
  43   delete LibraryInfo;
  44   delete Inliner;
  45 }
  46
  47 /// Set of global extensions, automatically added as part of the standard set.
  48 static ManagedStatic<SmallVector<std::pair<PassManagerBuilder::ExtensionPointTy,
  49    PassManagerBuilder::ExtensionFn>, 8> > GlobalExtensions;
  50
  51 void PassManagerBuilder::addGlobalExtension(
  52     PassManagerBuilder::ExtensionPointTy Ty,
  53     PassManagerBuilder::ExtensionFn Fn) {
  54   GlobalExtensions->push_back(std::make_pair(Ty, Fn));
  55 }
  56
  57 void PassManagerBuilder::addExtension(ExtensionPointTy Ty, ExtensionFn Fn) {
  58   Extensions.push_back(std::make_pair(Ty, Fn));
  59 }
  60
  61 void PassManagerBuilder::addExtensionsToPM(ExtensionPointTy ETy,
  62                                            PassManagerBase &PM) const {
  63   for (unsigned i = 0, e = GlobalExtensions->size(); i != e; ++i)
  64     if ((*GlobalExtensions)[i].first == ETy)
  65       (*GlobalExtensions)[i].second(*this, PM);
  66   for (unsigned i = 0, e = Extensions.size(); i != e; ++i)
  67     if (Extensions[i].first == ETy)
  68       Extensions[i].second(*this, PM);
  69 }
  70
  71 void
  72 PassManagerBuilder::addInitialAliasAnalysisPasses(PassManagerBase &PM) const {
  73   // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that
  74   // BasicAliasAnalysis wins if they disagree. This is intended to help
  75   // support "obvious" type-punning idioms.
  76   PM.add(createTypeBasedAliasAnalysisPass());
  77   PM.add(createBasicAliasAnalysisPass());
  78 }
  79
  80 void PassManagerBuilder::populateFunctionPassManager(FunctionPassManager &FPM) {
  81   addExtensionsToPM(EP_EarlyAsPossible, FPM);
  82
  83   // Add LibraryInfo if we have some.
  84   if (LibraryInfo) FPM.add(new TargetLibraryInfo(*LibraryInfo));
  85
  86   if (OptLevel == 0) return;
  87
  88   addInitialAliasAnalysisPasses(FPM);
  89
  90   FPM.add(createCFGSimplificationPass());
  91   FPM.add(createScalarReplAggregatesPass());
  92   FPM.add(createEarlyCSEPass());
  93   FPM.add(createLowerExpectIntrinsicPass());
  94 }
  95
  96 void PassManagerBuilder::populateModulePassManager(PassManagerBase &MPM) {
  97   // If all optimizations are disabled, just run the always-inline pass.
  98   if (OptLevel == 0) {
  99     if (Inliner) {
 100       MPM.add(Inliner);
 101       Inliner = 0;
 102     }
 103     addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
 104     return;
 105   }
 106
 107   // Add LibraryInfo if we have some.
 108   if (LibraryInfo) MPM.add(new TargetLibraryInfo(*LibraryInfo));
 109
 110   addInitialAliasAnalysisPasses(MPM);
 111
 112   if (!DisableUnitAtATime) {
 113     addExtensionsToPM(EP_ModuleOptimizerEarly, MPM);
 114
 115     MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
 116
 117     MPM.add(createIPSCCPPass());              // IP SCCP
 118     MPM.add(createDeadArgEliminationPass());  // Dead argument elimination
 119
 120     MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE
 121     MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
 122   }
 123
 124   // Start of CallGraph SCC passes.
 125   if (!DisableUnitAtATime)
 126     MPM.add(createPruneEHPass());             // Remove dead EH info
 127   if (Inliner) {
 128     MPM.add(Inliner);
 129     Inliner = 0;
 130   }
 131   if (!DisableUnitAtATime)
 132     MPM.add(createFunctionAttrsPass());       // Set readonly/readnone attrs
 133   if (OptLevel > 2)
 134     MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
 135
 136   // Start of function pass.
 137   // Break up aggregate allocas, using SSAUpdater.
 138   MPM.add(createScalarReplAggregatesPass(-1, false));
 139   MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 140   if (!DisableSimplifyLibCalls)
 141     MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
 142   MPM.add(createJumpThreadingPass());         // Thread jumps.
 143   MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
 144   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 145   MPM.add(createInstructionCombiningPass());  // Combine silly seq's
 146
 147   MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
 148   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 149   MPM.add(createReassociatePass());           // Reassociate expressions
 150   MPM.add(createLoopRotatePass());            // Rotate Loop
 151   MPM.add(createLICMPass());                  // Hoist loop invariants
 152   MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
 153   MPM.add(createInstructionCombiningPass());
 154   MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
 155   MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
 156   MPM.add(createLoopDeletionPass());          // Delete dead loops
 157   if (!DisableUnrollLoops)
 158     MPM.add(createLoopUnrollPass());          // Unroll small loops
 159   addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
 160
 161   if (OptLevel > 1)
 162     MPM.add(createGVNPass());                 // Remove redundancies
 163   MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
 164   MPM.add(createSCCPPass());                  // Constant prop with SCCP
 165
 166   // Run instcombine after redundancy elimination to exploit opportunities
 167   // opened up by them.
 168   MPM.add(createInstructionCombiningPass());
 169   MPM.add(createJumpThreadingPass());         // Thread jumps
 170   MPM.add(createCorrelatedValuePropagationPass());
 171   MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
 172
 173   addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
 174
 175   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
 176   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 177   MPM.add(createInstructionCombiningPass());  // Clean up after everything.
 178
 179   if (!DisableUnitAtATime) {
 180     // FIXME: We shouldn't bother with this anymore.
 181     MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
 182
 183     // GlobalOpt already deletes dead functions and globals, at -O3 try a
 184     // late pass of GlobalDCE.  It is capable of deleting dead cycles.
 185     if (OptLevel > 2)
 186       MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
 187
 188     if (OptLevel > 1)
 189       MPM.add(createConstantMergePass());     // Merge dup global constants
 190   }
 191 }
 192
 193 void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
 194                                                 bool Internalize,
 195                                                 bool RunInliner) {
 196   // Provide AliasAnalysis services for optimizations.
 197   addInitialAliasAnalysisPasses(PM);
 198
 199   // Now that composite has been compiled, scan through the module, looking
 200   // for a main function.  If main is defined, mark all other functions
 201   // internal.
 202   if (Internalize)
 203     PM.add(createInternalizePass(true));
 204
 205   // Propagate constants at call sites into the functions they call.  This
 206   // opens opportunities for globalopt (and inlining) by substituting function
 207   // pointers passed as arguments to direct uses of functions.
 208   PM.add(createIPSCCPPass());
 209
 210   // Now that we internalized some globals, see if we can hack on them!
 211   PM.add(createGlobalOptimizerPass());
 212
 213   // Linking modules together can lead to duplicated global constants, only
 214   // keep one copy of each constant.
 215   PM.add(createConstantMergePass());
 216
 217   // Remove unused arguments from functions.
 218   PM.add(createDeadArgEliminationPass());
 219
 220   // Reduce the code after globalopt and ipsccp.  Both can open up significant
 221   // simplification opportunities, and both can propagate functions through
 222   // function pointers.  When this happens, we often have to resolve varargs
 223   // calls, etc, so let instcombine do this.
 224   PM.add(createInstructionCombiningPass());
 225
 226   // Inline small functions
 227   if (RunInliner)
 228     PM.add(createFunctionInliningPass());
 229
 230   PM.add(createPruneEHPass());   // Remove dead EH info.
 231
 232   // Optimize globals again if we ran the inliner.
 233   if (RunInliner)
 234     PM.add(createGlobalOptimizerPass());
 235   PM.add(createGlobalDCEPass()); // Remove dead functions.
 236
 237   // If we didn't decide to inline a function, check to see if we can
 238   // transform it to pass arguments by value instead of by reference.
 239   PM.add(createArgumentPromotionPass());
 240
 241   // The IPO passes may leave cruft around.  Clean up after them.
 242   PM.add(createInstructionCombiningPass());
 243   PM.add(createJumpThreadingPass());
 244   // Break up allocas
 245   PM.add(createScalarReplAggregatesPass());
 246
 247   // Run a few AA driven optimizations here and now, to cleanup the code.
 248   PM.add(createFunctionAttrsPass()); // Add nocapture.
 249   PM.add(createGlobalsModRefPass()); // IP alias analysis.
 250
 251   PM.add(createLICMPass());      // Hoist loop invariants.
 252   PM.add(createGVNPass());       // Remove redundancies.
 253   PM.add(createMemCpyOptPass()); // Remove dead memcpys.
 254   // Nuke dead stores.
 255   PM.add(createDeadStoreEliminationPass());
 256
 257   // Cleanup and simplify the code after the scalar optimizations.
 258   PM.add(createInstructionCombiningPass());
 259
 260   PM.add(createJumpThreadingPass());
 261
 262   // Delete basic blocks, which optimization passes may have killed.
 263   PM.add(createCFGSimplificationPass());
 264
 265   // Now that we have optimized the program, discard unreachable functions.
 266   PM.add(createGlobalDCEPass());
 267 }
 268
 269 LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate(void) {
 270   PassManagerBuilder *PMB = new PassManagerBuilder();
 271   return wrap(PMB);
 272 }
 273
 274 void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
 275   PassManagerBuilder *Builder = unwrap(PMB);
 276   delete Builder;
 277 }
 278
 279 void
 280 LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
 281                                   unsigned OptLevel) {
 282   PassManagerBuilder *Builder = unwrap(PMB);
 283   Builder->OptLevel = OptLevel;
 284 }
 285
 286 void
 287 LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
 288                                    unsigned SizeLevel) {
 289   PassManagerBuilder *Builder = unwrap(PMB);
 290   Builder->SizeLevel = SizeLevel;
 291 }
 292
 293 void
 294 LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
 295                                             LLVMBool Value) {
 296   PassManagerBuilder *Builder = unwrap(PMB);
 297   Builder->DisableUnitAtATime = Value;
 298 }
 299
 300 void
 301 LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
 302                                             LLVMBool Value) {
 303   PassManagerBuilder *Builder = unwrap(PMB);
 304   Builder->DisableUnrollLoops = Value;
 305 }
 306
 307 void
 308 LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
 309                                                  LLVMBool Value) {
 310   PassManagerBuilder *Builder = unwrap(PMB);
 311   Builder->DisableSimplifyLibCalls = Value;
 312 }
 313
 314 void
 315 LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
 316                                               unsigned Threshold) {
 317   PassManagerBuilder *Builder = unwrap(PMB);
 318   Builder->Inliner = createFunctionInliningPass(Threshold);
 319 }
 320
 321 void
 322 LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
 323                                                   LLVMPassManagerRef PM) {
 324   PassManagerBuilder *Builder = unwrap(PMB);
 325   FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
 326   Builder->populateFunctionPassManager(*FPM);
 327 }
 328
 329 void
 330 LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
 331                                                 LLVMPassManagerRef PM) {
 332   PassManagerBuilder *Builder = unwrap(PMB);
 333   PassManagerBase *MPM = unwrap(PM);
 334   Builder->populateModulePassManager(*MPM);
 335 }
 336
 337 void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
 338                                                   LLVMPassManagerRef PM,
 339                                                   bool Internalize,
 340                                                   bool RunInliner) {
 341   PassManagerBuilder *Builder = unwrap(PMB);
 342   PassManagerBase *LPM = unwrap(PM);
 343   Builder->populateLTOPassManager(*LPM, Internalize, RunInliner);
 344 }