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   if (UseNewSROA)
 158     MPM.add(createSROAPass(/*RequiresDomTree*/ false));
 159   else
 160     MPM.add(createScalarReplAggregatesPass(-1, false));
 161   MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 162   if (!DisableSimplifyLibCalls)
 163     MPM.add(createSimplifyLibCallsPass());    // Library Call Optimizations
 164   MPM.add(createJumpThreadingPass());         // Thread jumps.
 165   MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
 166   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 167   MPM.add(createInstructionCombiningPass());  // Combine silly seq's
 168
 169   MPM.add(createTailCallEliminationPass());   // Eliminate tail calls
 170   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 171   MPM.add(createReassociatePass());           // Reassociate expressions
 172   MPM.add(createLoopRotatePass());            // Rotate Loop
 173   MPM.add(createLICMPass());                  // Hoist loop invariants
 174   MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3));
 175   MPM.add(createInstructionCombiningPass());
 176   MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
 177   MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
 178   MPM.add(createLoopDeletionPass());          // Delete dead loops
 179
 180   if (Vectorize) {
 181     MPM.add(createLoopVectorizePass());
 182     MPM.add(createLICMPass());
 183   }
 184
 185   if (!DisableUnrollLoops)
 186     MPM.add(createLoopUnrollPass());          // Unroll small loops
 187   addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
 188
 189   if (OptLevel > 1)
 190     MPM.add(createGVNPass());                 // Remove redundancies
 191   MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
 192   MPM.add(createSCCPPass());                  // Constant prop with SCCP
 193
 194   // Run instcombine after redundancy elimination to exploit opportunities
 195   // opened up by them.
 196   MPM.add(createInstructionCombiningPass());
 197   MPM.add(createJumpThreadingPass());         // Thread jumps
 198   MPM.add(createCorrelatedValuePropagationPass());
 199   MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
 200
 201   addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
 202
 203   if (Vectorize) {
 204     MPM.add(createBBVectorizePass());
 205     MPM.add(createInstructionCombiningPass());
 206     if (OptLevel > 1 && UseGVNAfterVectorization)
 207       MPM.add(createGVNPass());                   // Remove redundancies
 208     else
 209       MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
 210   }
 211
 212   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
 213   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
 214   MPM.add(createInstructionCombiningPass());  // Clean up after everything.
 215
 216   if (!DisableUnitAtATime) {
 217     // FIXME: We shouldn't bother with this anymore.
 218     MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes
 219
 220     // GlobalOpt already deletes dead functions and globals, at -O2 try a
 221     // late pass of GlobalDCE.  It is capable of deleting dead cycles.
 222     if (OptLevel > 1) {
 223       MPM.add(createGlobalDCEPass());         // Remove dead fns and globals.
 224       MPM.add(createConstantMergePass());     // Merge dup global constants
 225     }
 226   }
 227   addExtensionsToPM(EP_OptimizerLast, MPM);
 228 }
 229
 230 void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM,
 231                                                 bool Internalize,
 232                                                 bool RunInliner,
 233                                                 bool DisableGVNLoadPRE) {
 234   // Provide AliasAnalysis services for optimizations.
 235   addInitialAliasAnalysisPasses(PM);
 236
 237   // Now that composite has been compiled, scan through the module, looking
 238   // for a main function.  If main is defined, mark all other functions
 239   // internal.
 240   if (Internalize)
 241     PM.add(createInternalizePass(true));
 242
 243   // Propagate constants at call sites into the functions they call.  This
 244   // opens opportunities for globalopt (and inlining) by substituting function
 245   // pointers passed as arguments to direct uses of functions.
 246   PM.add(createIPSCCPPass());
 247
 248   // Now that we internalized some globals, see if we can hack on them!
 249   PM.add(createGlobalOptimizerPass());
 250
 251   // Linking modules together can lead to duplicated global constants, only
 252   // keep one copy of each constant.
 253   PM.add(createConstantMergePass());
 254
 255   // Remove unused arguments from functions.
 256   PM.add(createDeadArgEliminationPass());
 257
 258   // Reduce the code after globalopt and ipsccp.  Both can open up significant
 259   // simplification opportunities, and both can propagate functions through
 260   // function pointers.  When this happens, we often have to resolve varargs
 261   // calls, etc, so let instcombine do this.
 262   PM.add(createInstructionCombiningPass());
 263
 264   // Inline small functions
 265   if (RunInliner)
 266     PM.add(createFunctionInliningPass());
 267
 268   PM.add(createPruneEHPass());   // Remove dead EH info.
 269
 270   // Optimize globals again if we ran the inliner.
 271   if (RunInliner)
 272     PM.add(createGlobalOptimizerPass());
 273   PM.add(createGlobalDCEPass()); // Remove dead functions.
 274
 275   // If we didn't decide to inline a function, check to see if we can
 276   // transform it to pass arguments by value instead of by reference.
 277   PM.add(createArgumentPromotionPass());
 278
 279   // The IPO passes may leave cruft around.  Clean up after them.
 280   PM.add(createInstructionCombiningPass());
 281   PM.add(createJumpThreadingPass());
 282   // Break up allocas
 283   if (UseNewSROA)
 284     PM.add(createSROAPass());
 285   else
 286     PM.add(createScalarReplAggregatesPass());
 287
 288   // Run a few AA driven optimizations here and now, to cleanup the code.
 289   PM.add(createFunctionAttrsPass()); // Add nocapture.
 290   PM.add(createGlobalsModRefPass()); // IP alias analysis.
 291
 292   PM.add(createLICMPass());                 // Hoist loop invariants.
 293   PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
 294   PM.add(createMemCpyOptPass());            // Remove dead memcpys.
 295   // Nuke dead stores.
 296   PM.add(createDeadStoreEliminationPass());
 297
 298   // Cleanup and simplify the code after the scalar optimizations.
 299   PM.add(createInstructionCombiningPass());
 300
 301   PM.add(createJumpThreadingPass());
 302
 303   // Delete basic blocks, which optimization passes may have killed.
 304   PM.add(createCFGSimplificationPass());
 305
 306   // Now that we have optimized the program, discard unreachable functions.
 307   PM.add(createGlobalDCEPass());
 308 }
 309
 310 LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate(void) {
 311   PassManagerBuilder *PMB = new PassManagerBuilder();
 312   return wrap(PMB);
 313 }
 314
 315 void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
 316   PassManagerBuilder *Builder = unwrap(PMB);
 317   delete Builder;
 318 }
 319
 320 void
 321 LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB,
 322                                   unsigned OptLevel) {
 323   PassManagerBuilder *Builder = unwrap(PMB);
 324   Builder->OptLevel = OptLevel;
 325 }
 326
 327 void
 328 LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB,
 329                                    unsigned SizeLevel) {
 330   PassManagerBuilder *Builder = unwrap(PMB);
 331   Builder->SizeLevel = SizeLevel;
 332 }
 333
 334 void
 335 LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB,
 336                                             LLVMBool Value) {
 337   PassManagerBuilder *Builder = unwrap(PMB);
 338   Builder->DisableUnitAtATime = Value;
 339 }
 340
 341 void
 342 LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB,
 343                                             LLVMBool Value) {
 344   PassManagerBuilder *Builder = unwrap(PMB);
 345   Builder->DisableUnrollLoops = Value;
 346 }
 347
 348 void
 349 LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB,
 350                                                  LLVMBool Value) {
 351   PassManagerBuilder *Builder = unwrap(PMB);
 352   Builder->DisableSimplifyLibCalls = Value;
 353 }
 354
 355 void
 356 LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB,
 357                                               unsigned Threshold) {
 358   PassManagerBuilder *Builder = unwrap(PMB);
 359   Builder->Inliner = createFunctionInliningPass(Threshold);
 360 }
 361
 362 void
 363 LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB,
 364                                                   LLVMPassManagerRef PM) {
 365   PassManagerBuilder *Builder = unwrap(PMB);
 366   FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM);
 367   Builder->populateFunctionPassManager(*FPM);
 368 }
 369
 370 void
 371 LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB,
 372                                                 LLVMPassManagerRef PM) {
 373   PassManagerBuilder *Builder = unwrap(PMB);
 374   PassManagerBase *MPM = unwrap(PM);
 375   Builder->populateModulePassManager(*MPM);
 376 }
 377
 378 void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB,
 379                                                   LLVMPassManagerRef PM,
 380                                                   bool Internalize,
 381                                                   bool RunInliner) {
 382   PassManagerBuilder *Builder = unwrap(PMB);
 383   PassManagerBase *LPM = unwrap(PM);
 384   Builder->populateLTOPassManager(*LPM, Internalize, RunInliner);
 385 }