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/IR/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 RunSLPVectorization("vectorize-slp", cl::Hidden, 37 cl::desc("Run the SLP vectorization passes")); 38 39 static cl::opt<bool> 40 RunBBVectorization("vectorize-slp-aggressive", cl::Hidden, 41 cl::desc("Run the BB vectorization passes")); 42 43 static cl::opt<bool> 44 UseGVNAfterVectorization("use-gvn-after-vectorization", 45 cl::init(false), cl::Hidden, 46 cl::desc("Run GVN instead of Early CSE after vectorization passes")); 47 48 static cl::opt<bool> UseNewSROA("use-new-sroa", 49 cl::init(true), cl::Hidden, 50 cl::desc("Enable the new, experimental SROA pass")); 51 52 static cl::opt<bool> 53 RunLoopRerolling("reroll-loops", cl::Hidden, 54 cl::desc("Run the loop rerolling pass")); 55 56 static cl::opt<bool> RunLoadCombine("combine-loads", cl::init(false), 57 cl::Hidden, 58 cl::desc("Run the load combining pass")); 59 60 PassManagerBuilder::PassManagerBuilder() { 61 OptLevel = 2; 62 SizeLevel = 0; 63 LibraryInfo = nullptr; 64 Inliner = nullptr; 65 DisableTailCalls = false; 66 DisableUnitAtATime = false; 67 DisableUnrollLoops = false; 68 BBVectorize = RunBBVectorization; 69 SLPVectorize = RunSLPVectorization; 70 LoopVectorize = RunLoopVectorization; 71 RerollLoops = RunLoopRerolling; 72 LoadCombine = RunLoadCombine; 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 = nullptr; 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(createIPSCCPPass()); // IP SCCP 160 MPM.add(createGlobalOptimizerPass()); // Optimize out global vars 161 162 MPM.add(createDeadArgEliminationPass()); // Dead argument elimination 163 164 MPM.add(createInstructionCombiningPass());// Clean up after IPCP & DAE 165 addExtensionsToPM(EP_Peephole, MPM); 166 MPM.add(createCFGSimplificationPass()); // Clean up after IPCP & DAE 167 } 168 169 // Start of CallGraph SCC passes. 170 if (!DisableUnitAtATime) 171 MPM.add(createPruneEHPass()); // Remove dead EH info 172 if (Inliner) { 173 MPM.add(Inliner); 174 Inliner = nullptr; 175 } 176 if (!DisableUnitAtATime) 177 MPM.add(createFunctionAttrsPass()); // Set readonly/readnone attrs 178 if (OptLevel > 2) 179 MPM.add(createArgumentPromotionPass()); // Scalarize uninlined fn args 180 181 // Start of function pass. 182 // Break up aggregate allocas, using SSAUpdater. 183 if (UseNewSROA) 184 MPM.add(createSROAPass(/*RequiresDomTree*/ false)); 185 else 186 MPM.add(createScalarReplAggregatesPass(-1, false)); 187 MPM.add(createEarlyCSEPass()); // Catch trivial redundancies 188 MPM.add(createJumpThreadingPass()); // Thread jumps. 189 MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals 190 MPM.add(createCFGSimplificationPass()); // Merge & remove BBs 191 MPM.add(createInstructionCombiningPass()); // Combine silly seq's 192 addExtensionsToPM(EP_Peephole, MPM); 193 194 if (!DisableTailCalls) 195 MPM.add(createTailCallEliminationPass()); // Eliminate tail calls 196 MPM.add(createCFGSimplificationPass()); // Merge & remove BBs 197 MPM.add(createReassociatePass()); // Reassociate expressions 198 MPM.add(createLoopRotatePass()); // Rotate Loop 199 MPM.add(createLICMPass()); // Hoist loop invariants 200 MPM.add(createLoopUnswitchPass(SizeLevel || OptLevel < 3)); 201 MPM.add(createInstructionCombiningPass()); 202 MPM.add(createIndVarSimplifyPass()); // Canonicalize indvars 203 MPM.add(createLoopIdiomPass()); // Recognize idioms like memset. 204 MPM.add(createLoopDeletionPass()); // Delete dead loops 205 206 if (!DisableUnrollLoops) 207 MPM.add(createSimpleLoopUnrollPass()); // 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 addExtensionsToPM(EP_Peephole, MPM); 219 MPM.add(createJumpThreadingPass()); // Thread jumps 220 MPM.add(createCorrelatedValuePropagationPass()); 221 MPM.add(createDeadStoreEliminationPass()); // Delete dead stores 222 223 addExtensionsToPM(EP_ScalarOptimizerLate, MPM); 224 225 if (RerollLoops) 226 MPM.add(createLoopRerollPass()); 227 if (SLPVectorize) 228 MPM.add(createSLPVectorizerPass()); // Vectorize parallel scalar chains. 229 230 if (BBVectorize) { 231 MPM.add(createBBVectorizePass()); 232 MPM.add(createInstructionCombiningPass()); 233 addExtensionsToPM(EP_Peephole, MPM); 234 if (OptLevel > 1 && UseGVNAfterVectorization) 235 MPM.add(createGVNPass()); // Remove redundancies 236 else 237 MPM.add(createEarlyCSEPass()); // Catch trivial redundancies 238 239 // BBVectorize may have significantly shortened a loop body; unroll again. 240 if (!DisableUnrollLoops) 241 MPM.add(createLoopUnrollPass()); 242 } 243 244 if (LoadCombine) 245 MPM.add(createLoadCombinePass()); 246 247 MPM.add(createAggressiveDCEPass()); // Delete dead instructions 248 MPM.add(createCFGSimplificationPass()); // Merge & remove BBs 249 MPM.add(createInstructionCombiningPass()); // Clean up after everything. 250 addExtensionsToPM(EP_Peephole, MPM); 251 252 // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC 253 // pass manager that we are specifically trying to avoid. To prevent this 254 // we must insert a no-op module pass to reset the pass manager. 255 MPM.add(createBarrierNoopPass()); 256 MPM.add(createLoopVectorizePass(DisableUnrollLoops, LoopVectorize)); 257 // FIXME: Because of #pragma vectorize enable, the passes below are always 258 // inserted in the pipeline, even when the vectorizer doesn't run (ex. when 259 // on -O1 and no #pragma is found). Would be good to have these two passes 260 // as function calls, so that we can only pass them when the vectorizer 261 // changed the code. 262 MPM.add(createInstructionCombiningPass()); 263 addExtensionsToPM(EP_Peephole, MPM); 264 MPM.add(createCFGSimplificationPass()); 265 266 if (!DisableUnrollLoops) 267 MPM.add(createLoopUnrollPass()); // Unroll small loops 268 269 if (!DisableUnitAtATime) { 270 // FIXME: We shouldn't bother with this anymore. 271 MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes 272 273 // GlobalOpt already deletes dead functions and globals, at -O2 try a 274 // late pass of GlobalDCE. It is capable of deleting dead cycles. 275 if (OptLevel > 1) { 276 MPM.add(createGlobalDCEPass()); // Remove dead fns and globals. 277 MPM.add(createConstantMergePass()); // Merge dup global constants 278 } 279 } 280 addExtensionsToPM(EP_OptimizerLast, MPM); 281 } 282 283 void PassManagerBuilder::populateLTOPassManager(PassManagerBase &PM, 284 bool Internalize, 285 bool RunInliner, 286 bool DisableGVNLoadPRE) { 287 // Provide AliasAnalysis services for optimizations. 288 addInitialAliasAnalysisPasses(PM); 289 290 // Now that composite has been compiled, scan through the module, looking 291 // for a main function. If main is defined, mark all other functions 292 // internal. 293 if (Internalize) 294 PM.add(createInternalizePass("main")); 295 296 // Propagate constants at call sites into the functions they call. This 297 // opens opportunities for globalopt (and inlining) by substituting function 298 // pointers passed as arguments to direct uses of functions. 299 PM.add(createIPSCCPPass()); 300 301 // Now that we internalized some globals, see if we can hack on them! 302 PM.add(createGlobalOptimizerPass()); 303 304 // Linking modules together can lead to duplicated global constants, only 305 // keep one copy of each constant. 306 PM.add(createConstantMergePass()); 307 308 // Remove unused arguments from functions. 309 PM.add(createDeadArgEliminationPass()); 310 311 // Reduce the code after globalopt and ipsccp. Both can open up significant 312 // simplification opportunities, and both can propagate functions through 313 // function pointers. When this happens, we often have to resolve varargs 314 // calls, etc, so let instcombine do this. 315 PM.add(createInstructionCombiningPass()); 316 addExtensionsToPM(EP_Peephole, PM); 317 318 // Inline small functions 319 if (RunInliner) 320 PM.add(createFunctionInliningPass()); 321 322 PM.add(createPruneEHPass()); // Remove dead EH info. 323 324 // Optimize globals again if we ran the inliner. 325 if (RunInliner) 326 PM.add(createGlobalOptimizerPass()); 327 PM.add(createGlobalDCEPass()); // Remove dead functions. 328 329 // If we didn't decide to inline a function, check to see if we can 330 // transform it to pass arguments by value instead of by reference. 331 PM.add(createArgumentPromotionPass()); 332 333 // The IPO passes may leave cruft around. Clean up after them. 334 PM.add(createInstructionCombiningPass()); 335 addExtensionsToPM(EP_Peephole, PM); 336 PM.add(createJumpThreadingPass()); 337 338 // Break up allocas 339 if (UseNewSROA) 340 PM.add(createSROAPass()); 341 else 342 PM.add(createScalarReplAggregatesPass()); 343 344 // Run a few AA driven optimizations here and now, to cleanup the code. 345 PM.add(createFunctionAttrsPass()); // Add nocapture. 346 PM.add(createGlobalsModRefPass()); // IP alias analysis. 347 348 PM.add(createLICMPass()); // Hoist loop invariants. 349 PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies. 350 PM.add(createMemCpyOptPass()); // Remove dead memcpys. 351 352 // Nuke dead stores. 353 PM.add(createDeadStoreEliminationPass()); 354 355 // More loops are countable; try to optimize them. 356 PM.add(createIndVarSimplifyPass()); 357 PM.add(createLoopDeletionPass()); 358 PM.add(createLoopVectorizePass(true, true)); 359 360 // More scalar chains could be vectorized due to more alias information 361 PM.add(createSLPVectorizerPass()); // Vectorize parallel scalar chains. 362 363 if (LoadCombine) 364 PM.add(createLoadCombinePass()); 365 366 // Cleanup and simplify the code after the scalar optimizations. 367 PM.add(createInstructionCombiningPass()); 368 addExtensionsToPM(EP_Peephole, PM); 369 370 PM.add(createJumpThreadingPass()); 371 372 // Delete basic blocks, which optimization passes may have killed. 373 PM.add(createCFGSimplificationPass()); 374 375 // Now that we have optimized the program, discard unreachable functions. 376 PM.add(createGlobalDCEPass()); 377 } 378 379 inline PassManagerBuilder *unwrap(LLVMPassManagerBuilderRef P) { 380 return reinterpret_cast<PassManagerBuilder*>(P); 381 } 382 383 inline LLVMPassManagerBuilderRef wrap(PassManagerBuilder *P) { 384 return reinterpret_cast<LLVMPassManagerBuilderRef>(P); 385 } 386 387 LLVMPassManagerBuilderRef LLVMPassManagerBuilderCreate() { 388 PassManagerBuilder *PMB = new PassManagerBuilder(); 389 return wrap(PMB); 390 } 391 392 void LLVMPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) { 393 PassManagerBuilder *Builder = unwrap(PMB); 394 delete Builder; 395 } 396 397 void 398 LLVMPassManagerBuilderSetOptLevel(LLVMPassManagerBuilderRef PMB, 399 unsigned OptLevel) { 400 PassManagerBuilder *Builder = unwrap(PMB); 401 Builder->OptLevel = OptLevel; 402 } 403 404 void 405 LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB, 406 unsigned SizeLevel) { 407 PassManagerBuilder *Builder = unwrap(PMB); 408 Builder->SizeLevel = SizeLevel; 409 } 410 411 void 412 LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB, 413 LLVMBool Value) { 414 PassManagerBuilder *Builder = unwrap(PMB); 415 Builder->DisableUnitAtATime = Value; 416 } 417 418 void 419 LLVMPassManagerBuilderSetDisableUnrollLoops(LLVMPassManagerBuilderRef PMB, 420 LLVMBool Value) { 421 PassManagerBuilder *Builder = unwrap(PMB); 422 Builder->DisableUnrollLoops = Value; 423 } 424 425 void 426 LLVMPassManagerBuilderSetDisableSimplifyLibCalls(LLVMPassManagerBuilderRef PMB, 427 LLVMBool Value) { 428 // NOTE: The simplify-libcalls pass has been removed. 429 } 430 431 void 432 LLVMPassManagerBuilderUseInlinerWithThreshold(LLVMPassManagerBuilderRef PMB, 433 unsigned Threshold) { 434 PassManagerBuilder *Builder = unwrap(PMB); 435 Builder->Inliner = createFunctionInliningPass(Threshold); 436 } 437 438 void 439 LLVMPassManagerBuilderPopulateFunctionPassManager(LLVMPassManagerBuilderRef PMB, 440 LLVMPassManagerRef PM) { 441 PassManagerBuilder *Builder = unwrap(PMB); 442 FunctionPassManager *FPM = unwrap<FunctionPassManager>(PM); 443 Builder->populateFunctionPassManager(*FPM); 444 } 445 446 void 447 LLVMPassManagerBuilderPopulateModulePassManager(LLVMPassManagerBuilderRef PMB, 448 LLVMPassManagerRef PM) { 449 PassManagerBuilder *Builder = unwrap(PMB); 450 PassManagerBase *MPM = unwrap(PM); 451 Builder->populateModulePassManager(*MPM); 452 } 453 454 void LLVMPassManagerBuilderPopulateLTOPassManager(LLVMPassManagerBuilderRef PMB, 455 LLVMPassManagerRef PM, 456 LLVMBool Internalize, 457 LLVMBool RunInliner) { 458 PassManagerBuilder *Builder = unwrap(PMB); 459 PassManagerBase *LPM = unwrap(PM); 460 Builder->populateLTOPassManager(*LPM, Internalize != 0, RunInliner != 0); 461 } 462