diff options
Diffstat (limited to 'lib/Transforms/IPO/PassManagerBuilder.cpp')
| -rw-r--r-- | lib/Transforms/IPO/PassManagerBuilder.cpp | 165 |
1 files changed, 94 insertions, 71 deletions
diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp index 0b319f6a488b..3855e6245d8e 100644 --- a/lib/Transforms/IPO/PassManagerBuilder.cpp +++ b/lib/Transforms/IPO/PassManagerBuilder.cpp @@ -26,11 +26,9 @@ #include "llvm/Analysis/TypeBasedAliasAnalysis.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/LegacyPassManager.h" -#include "llvm/IR/ModuleSummaryIndex.h" #include "llvm/IR/Verifier.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/ManagedStatic.h" -#include "llvm/Target/TargetMachine.h" #include "llvm/Transforms/IPO.h" #include "llvm/Transforms/IPO/ForceFunctionAttrs.h" #include "llvm/Transforms/IPO/FunctionAttrs.h" @@ -94,15 +92,6 @@ static cl::opt<bool> EnableLoopInterchange( "enable-loopinterchange", cl::init(false), cl::Hidden, cl::desc("Enable the new, experimental LoopInterchange Pass")); -static cl::opt<bool> EnableNonLTOGlobalsModRef( - "enable-non-lto-gmr", cl::init(true), cl::Hidden, - cl::desc( - "Enable the GlobalsModRef AliasAnalysis outside of the LTO pipeline.")); - -static cl::opt<bool> EnableLoopLoadElim( - "enable-loop-load-elim", cl::init(true), cl::Hidden, - cl::desc("Enable the LoopLoadElimination Pass")); - static cl::opt<bool> EnablePrepareForThinLTO("prepare-for-thinlto", cl::init(false), cl::Hidden, cl::desc("Enable preparation for ThinLTO.")); @@ -160,7 +149,6 @@ PassManagerBuilder::PassManagerBuilder() { SizeLevel = 0; LibraryInfo = nullptr; Inliner = nullptr; - DisableUnitAtATime = false; DisableUnrollLoops = false; SLPVectorize = RunSLPVectorization; LoopVectorize = RunLoopVectorization; @@ -251,6 +239,7 @@ void PassManagerBuilder::addInstructionCombiningPass( void PassManagerBuilder::populateFunctionPassManager( legacy::FunctionPassManager &FPM) { addExtensionsToPM(EP_EarlyAsPossible, FPM); + FPM.add(createEntryExitInstrumenterPass()); // Add LibraryInfo if we have some. if (LibraryInfo) @@ -428,6 +417,14 @@ void PassManagerBuilder::populateModulePassManager( else if (GlobalExtensionsNotEmpty() || !Extensions.empty()) MPM.add(createBarrierNoopPass()); + if (PerformThinLTO) { + // Drop available_externally and unreferenced globals. This is necessary + // with ThinLTO in order to avoid leaving undefined references to dead + // globals in the object file. + MPM.add(createEliminateAvailableExternallyPass()); + MPM.add(createGlobalDCEPass()); + } + addExtensionsToPM(EP_EnabledOnOptLevel0, MPM); // Rename anon globals to be able to export them in the summary. @@ -464,23 +461,25 @@ void PassManagerBuilder::populateModulePassManager( if (PrepareForThinLTOUsingPGOSampleProfile) DisableUnrollLoops = true; - if (!DisableUnitAtATime) { - // Infer attributes about declarations if possible. - MPM.add(createInferFunctionAttrsLegacyPass()); + // Infer attributes about declarations if possible. + MPM.add(createInferFunctionAttrsLegacyPass()); - addExtensionsToPM(EP_ModuleOptimizerEarly, MPM); + addExtensionsToPM(EP_ModuleOptimizerEarly, MPM); - MPM.add(createIPSCCPPass()); // IP SCCP - MPM.add(createGlobalOptimizerPass()); // Optimize out global vars - // Promote any localized global vars. - MPM.add(createPromoteMemoryToRegisterPass()); + if (OptLevel > 2) + MPM.add(createCallSiteSplittingPass()); - MPM.add(createDeadArgEliminationPass()); // Dead argument elimination + MPM.add(createIPSCCPPass()); // IP SCCP + MPM.add(createCalledValuePropagationPass()); + MPM.add(createGlobalOptimizerPass()); // Optimize out global vars + // Promote any localized global vars. + MPM.add(createPromoteMemoryToRegisterPass()); - addInstructionCombiningPass(MPM); // Clean up after IPCP & DAE - addExtensionsToPM(EP_Peephole, MPM); - MPM.add(createCFGSimplificationPass()); // Clean up after IPCP & DAE - } + MPM.add(createDeadArgEliminationPass()); // Dead argument elimination + + addInstructionCombiningPass(MPM); // Clean up after IPCP & DAE + addExtensionsToPM(EP_Peephole, MPM); + MPM.add(createCFGSimplificationPass()); // Clean up after IPCP & DAE // For SamplePGO in ThinLTO compile phase, we do not want to do indirect // call promotion as it will change the CFG too much to make the 2nd @@ -490,21 +489,21 @@ void PassManagerBuilder::populateModulePassManager( if (!PerformThinLTO && !PrepareForThinLTOUsingPGOSampleProfile) addPGOInstrPasses(MPM); - if (EnableNonLTOGlobalsModRef) - // We add a module alias analysis pass here. In part due to bugs in the - // analysis infrastructure this "works" in that the analysis stays alive - // for the entire SCC pass run below. - MPM.add(createGlobalsAAWrapperPass()); + // We add a module alias analysis pass here. In part due to bugs in the + // analysis infrastructure this "works" in that the analysis stays alive + // for the entire SCC pass run below. + MPM.add(createGlobalsAAWrapperPass()); // Start of CallGraph SCC passes. - if (!DisableUnitAtATime) - MPM.add(createPruneEHPass()); // Remove dead EH info + MPM.add(createPruneEHPass()); // Remove dead EH info + bool RunInliner = false; if (Inliner) { MPM.add(Inliner); Inliner = nullptr; + RunInliner = true; } - if (!DisableUnitAtATime) - MPM.add(createPostOrderFunctionAttrsLegacyPass()); + + MPM.add(createPostOrderFunctionAttrsLegacyPass()); if (OptLevel > 2) MPM.add(createArgumentPromotionPass()); // Scalarize uninlined fn args @@ -515,11 +514,11 @@ void PassManagerBuilder::populateModulePassManager( // pass manager that we are specifically trying to avoid. To prevent this // we must insert a no-op module pass to reset the pass manager. MPM.add(createBarrierNoopPass()); + if (RunPartialInlining) MPM.add(createPartialInliningPass()); - if (!DisableUnitAtATime && OptLevel > 1 && !PrepareForLTO && - !PrepareForThinLTO) + if (OptLevel > 1 && !PrepareForLTO && !PrepareForThinLTO) // Remove avail extern fns and globals definitions if we aren't // compiling an object file for later LTO. For LTO we want to preserve // these so they are eligible for inlining at link-time. Note if they @@ -531,15 +530,26 @@ void PassManagerBuilder::populateModulePassManager( // and saves running remaining passes on the eliminated functions. MPM.add(createEliminateAvailableExternallyPass()); - if (!DisableUnitAtATime) - MPM.add(createReversePostOrderFunctionAttrsPass()); + MPM.add(createReversePostOrderFunctionAttrsPass()); + + // The inliner performs some kind of dead code elimination as it goes, + // but there are cases that are not really caught by it. We might + // at some point consider teaching the inliner about them, but it + // is OK for now to run GlobalOpt + GlobalDCE in tandem as their + // benefits generally outweight the cost, making the whole pipeline + // faster. + if (RunInliner) { + MPM.add(createGlobalOptimizerPass()); + MPM.add(createGlobalDCEPass()); + } // If we are planning to perform ThinLTO later, let's not bloat the code with // unrolling/vectorization/... now. We'll first run the inliner + CGSCC passes // during ThinLTO and perform the rest of the optimizations afterward. if (PrepareForThinLTO) { - // Reduce the size of the IR as much as possible. - MPM.add(createGlobalOptimizerPass()); + // Ensure we perform any last passes, but do so before renaming anonymous + // globals in case the passes add any. + addExtensionsToPM(EP_OptimizerLast, MPM); // Rename anon globals to be able to export them in the summary. MPM.add(createNameAnonGlobalPass()); return; @@ -560,23 +570,22 @@ void PassManagerBuilder::populateModulePassManager( MPM.add(createLICMPass()); // Hoist loop invariants } - if (EnableNonLTOGlobalsModRef) - // We add a fresh GlobalsModRef run at this point. This is particularly - // useful as the above will have inlined, DCE'ed, and function-attr - // propagated everything. We should at this point have a reasonably minimal - // and richly annotated call graph. By computing aliasing and mod/ref - // information for all local globals here, the late loop passes and notably - // the vectorizer will be able to use them to help recognize vectorizable - // memory operations. - // - // Note that this relies on a bug in the pass manager which preserves - // a module analysis into a function pass pipeline (and throughout it) so - // long as the first function pass doesn't invalidate the module analysis. - // Thus both Float2Int and LoopRotate have to preserve AliasAnalysis for - // this to work. Fortunately, it is trivial to preserve AliasAnalysis - // (doing nothing preserves it as it is required to be conservatively - // correct in the face of IR changes). - MPM.add(createGlobalsAAWrapperPass()); + // We add a fresh GlobalsModRef run at this point. This is particularly + // useful as the above will have inlined, DCE'ed, and function-attr + // propagated everything. We should at this point have a reasonably minimal + // and richly annotated call graph. By computing aliasing and mod/ref + // information for all local globals here, the late loop passes and notably + // the vectorizer will be able to use them to help recognize vectorizable + // memory operations. + // + // Note that this relies on a bug in the pass manager which preserves + // a module analysis into a function pass pipeline (and throughout it) so + // long as the first function pass doesn't invalidate the module analysis. + // Thus both Float2Int and LoopRotate have to preserve AliasAnalysis for + // this to work. Fortunately, it is trivial to preserve AliasAnalysis + // (doing nothing preserves it as it is required to be conservatively + // correct in the face of IR changes). + MPM.add(createGlobalsAAWrapperPass()); MPM.add(createFloat2IntPass()); @@ -597,8 +606,7 @@ void PassManagerBuilder::populateModulePassManager( // Eliminate loads by forwarding stores from the previous iteration to loads // of the current iteration. - if (EnableLoopLoadElim) - MPM.add(createLoopLoadEliminationPass()); + MPM.add(createLoopLoadEliminationPass()); // FIXME: Because of #pragma vectorize enable, the passes below are always // inserted in the pipeline, even when the vectorizer doesn't run (ex. when @@ -622,6 +630,13 @@ void PassManagerBuilder::populateModulePassManager( addInstructionCombiningPass(MPM); } + // Cleanup after loop vectorization, etc. Simplification passes like CVP and + // GVN, loop transforms, and others have already run, so it's now better to + // convert to more optimized IR using more aggressive simplify CFG options. + // The extra sinking transform can create larger basic blocks, so do this + // before SLP vectorization. + MPM.add(createCFGSimplificationPass(1, true, true, false, true)); + if (RunSLPAfterLoopVectorization && SLPVectorize) { MPM.add(createSLPVectorizerPass()); // Vectorize parallel scalar chains. if (OptLevel > 1 && ExtraVectorizerPasses) { @@ -630,7 +645,6 @@ void PassManagerBuilder::populateModulePassManager( } addExtensionsToPM(EP_Peephole, MPM); - MPM.add(createLateCFGSimplificationPass()); // Switches to lookup tables addInstructionCombiningPass(MPM); if (!DisableUnrollLoops) { @@ -650,16 +664,14 @@ void PassManagerBuilder::populateModulePassManager( // about pointer alignments. MPM.add(createAlignmentFromAssumptionsPass()); - if (!DisableUnitAtATime) { - // FIXME: We shouldn't bother with this anymore. - MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes + // FIXME: We shouldn't bother with this anymore. + MPM.add(createStripDeadPrototypesPass()); // Get rid of dead prototypes - // GlobalOpt already deletes dead functions and globals, at -O2 try a - // late pass of GlobalDCE. It is capable of deleting dead cycles. - if (OptLevel > 1) { - MPM.add(createGlobalDCEPass()); // Remove dead fns and globals. - MPM.add(createConstantMergePass()); // Merge dup global constants - } + // GlobalOpt already deletes dead functions and globals, at -O2 try a + // late pass of GlobalDCE. It is capable of deleting dead cycles. + if (OptLevel > 1) { + MPM.add(createGlobalDCEPass()); // Remove dead fns and globals. + MPM.add(createConstantMergePass()); // Merge dup global constants } if (MergeFunctions) @@ -673,6 +685,11 @@ void PassManagerBuilder::populateModulePassManager( // Get rid of LCSSA nodes. MPM.add(createInstructionSimplifierPass()); + // This hoists/decomposes div/rem ops. It should run after other sink/hoist + // passes to avoid re-sinking, but before SimplifyCFG because it can allow + // flattening of blocks. + MPM.add(createDivRemPairsPass()); + // LoopSink (and other loop passes since the last simplifyCFG) might have // resulted in single-entry-single-exit or empty blocks. Clean up the CFG. MPM.add(createCFGSimplificationPass()); @@ -695,6 +712,9 @@ void PassManagerBuilder::addLTOOptimizationPasses(legacy::PassManagerBase &PM) { PM.add(createInferFunctionAttrsLegacyPass()); if (OptLevel > 1) { + // Split call-site with more constrained arguments. + PM.add(createCallSiteSplittingPass()); + // Indirect call promotion. This should promote all the targets that are // left by the earlier promotion pass that promotes intra-module targets. // This two-step promotion is to save the compile time. For LTO, it should @@ -706,6 +726,10 @@ void PassManagerBuilder::addLTOOptimizationPasses(legacy::PassManagerBase &PM) { // opens opportunities for globalopt (and inlining) by substituting function // pointers passed as arguments to direct uses of functions. PM.add(createIPSCCPPass()); + + // Attach metadata to indirect call sites indicating the set of functions + // they may target at run-time. This should follow IPSCCP. + PM.add(createCalledValuePropagationPass()); } // Infer attributes about definitions. The readnone attribute in particular is @@ -936,8 +960,7 @@ LLVMPassManagerBuilderSetSizeLevel(LLVMPassManagerBuilderRef PMB, void LLVMPassManagerBuilderSetDisableUnitAtATime(LLVMPassManagerBuilderRef PMB, LLVMBool Value) { - PassManagerBuilder *Builder = unwrap(PMB); - Builder->DisableUnitAtATime = Value; + // NOTE: The DisableUnitAtATime switch has been removed. } void |