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 } 441