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llvm-mirror/include/llvm/InitializePasses.h

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//===- llvm/InitializePasses.h - Initialize All Passes ----------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the declarations for the pass initialization routines
// for the entire LLVM project.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_INITIALIZEPASSES_H
#define LLVM_INITIALIZEPASSES_H
namespace llvm {
class PassRegistry;
/// Initialize all passes linked into the TransformUtils library.
void initializeCore(PassRegistry&);
/// Initialize all passes linked into the TransformUtils library.
void initializeTransformUtils(PassRegistry&);
/// Initialize all passes linked into the ScalarOpts library.
void initializeScalarOpts(PassRegistry&);
/// Initialize all passes linked into the ObjCARCOpts library.
void initializeObjCARCOpts(PassRegistry&);
/// Initialize all passes linked into the Vectorize library.
void initializeVectorization(PassRegistry&);
/// Initialize all passes linked into the InstCombine library.
void initializeInstCombine(PassRegistry&);
/// Initialize all passes linked into the AggressiveInstCombine library.
void initializeAggressiveInstCombine(PassRegistry&);
/// Initialize all passes linked into the IPO library.
void initializeIPO(PassRegistry&);
/// Initialize all passes linked into the Instrumentation library.
void initializeInstrumentation(PassRegistry&);
/// Initialize all passes linked into the Analysis library.
void initializeAnalysis(PassRegistry&);
/// Initialize all passes linked into the Coroutines library.
void initializeCoroutines(PassRegistry&);
/// Initialize all passes linked into the CodeGen library.
void initializeCodeGen(PassRegistry&);
/// Initialize all passes linked into the GlobalISel library.
void initializeGlobalISel(PassRegistry&);
/// Initialize all passes linked into the CodeGen library.
void initializeTarget(PassRegistry&);
void initializeAAEvalLegacyPassPass(PassRegistry&);
void initializeAAResultsWrapperPassPass(PassRegistry&);
void initializeADCELegacyPassPass(PassRegistry&);
void initializeAddDiscriminatorsLegacyPassPass(PassRegistry&);
void initializeModuleAddressSanitizerLegacyPassPass(PassRegistry &);
void initializeASanGlobalsMetadataWrapperPassPass(PassRegistry &);
void initializeAddressSanitizerLegacyPassPass(PassRegistry &);
void initializeAggressiveInstCombinerLegacyPassPass(PassRegistry&);
void initializeAliasSetPrinterPass(PassRegistry&);
void initializeAlignmentFromAssumptionsPass(PassRegistry&);
[PM] Port the always inliner to the new pass manager in a much more minimal and boring form than the old pass manager's version. This pass does the very minimal amount of work necessary to inline functions declared as always-inline. It doesn't support a wide array of things that the legacy pass manager did support, but is alse ... about 20 lines of code. So it has that going for it. Notably things this doesn't support: - Array alloca merging - To support the above, bottom-up inlining with careful history tracking and call graph updates - DCE of the functions that become dead after this inlining. - Inlining through call instructions with the always_inline attribute. Instead, it focuses on inlining functions with that attribute. The first I've omitted because I'm hoping to just turn it off for the primary pass manager. If that doesn't pan out, I can add it here but it will be reasonably expensive to do so. The second should really be handled by running global-dce after the inliner. I don't want to re-implement the non-trivial logic necessary to do comdat-correct DCE of functions. This means the -O0 pipeline will have to be at least 'always-inline,global-dce', but that seems reasonable to me. If others are seriously worried about this I'd like to hear about it and understand why. Again, this is all solveable by factoring that logic into a utility and calling it here, but I'd like to wait to do that until there is a clear reason why the existing pass-based factoring won't work. The final point is a serious one. I can fairly easily add support for this, but it seems both costly and a confusing construct for the use case of the always inliner running at -O0. This attribute can of course still impact the normal inliner easily (although I find that a questionable re-use of the same attribute). I've started a discussion to sort out what semantics we want here and based on that can figure out if it makes sense ta have this complexity at O0 or not. One other advantage of this design is that it should be quite a bit faster due to checking for whether the function is a viable candidate for inlining exactly once per function instead of doing it for each call site. Anyways, hopefully a reasonable starting point for this pass. Differential Revision: https://reviews.llvm.org/D23299 llvm-svn: 278896
2016-08-17 04:56:20 +02:00
void initializeAlwaysInlinerLegacyPassPass(PassRegistry&);
void initializeAssumeSimplifyPassLegacyPassPass(PassRegistry &);
void initializeAssumeBuilderPassLegacyPassPass(PassRegistry &);
void initializeAnnotation2MetadataLegacyPass(PassRegistry &);
void initializeAnnotationRemarksLegacyPass(PassRegistry &);
void initializeOpenMPOptCGSCCLegacyPassPass(PassRegistry &);
void initializeArgPromotionPass(PassRegistry&);
void initializeAssumptionCacheTrackerPass(PassRegistry&);
void initializeAtomicExpandPass(PassRegistry&);
void initializeAttributorLegacyPassPass(PassRegistry&);
void initializeAttributorCGSCCLegacyPassPass(PassRegistry &);
void initializeBasicBlockSectionsPass(PassRegistry &);
void initializeBDCELegacyPassPass(PassRegistry&);
void initializeBarrierNoopPass(PassRegistry&);
[PM/AA] Rebuild LLVM's alias analysis infrastructure in a way compatible with the new pass manager, and no longer relying on analysis groups. This builds essentially a ground-up new AA infrastructure stack for LLVM. The core ideas are the same that are used throughout the new pass manager: type erased polymorphism and direct composition. The design is as follows: - FunctionAAResults is a type-erasing alias analysis results aggregation interface to walk a single query across a range of results from different alias analyses. Currently this is function-specific as we always assume that aliasing queries are *within* a function. - AAResultBase is a CRTP utility providing stub implementations of various parts of the alias analysis result concept, notably in several cases in terms of other more general parts of the interface. This can be used to implement only a narrow part of the interface rather than the entire interface. This isn't really ideal, this logic should be hoisted into FunctionAAResults as currently it will cause a significant amount of redundant work, but it faithfully models the behavior of the prior infrastructure. - All the alias analysis passes are ported to be wrapper passes for the legacy PM and new-style analysis passes for the new PM with a shared result object. In some cases (most notably CFL), this is an extremely naive approach that we should revisit when we can specialize for the new pass manager. - BasicAA has been restructured to reflect that it is much more fundamentally a function analysis because it uses dominator trees and loop info that need to be constructed for each function. All of the references to getting alias analysis results have been updated to use the new aggregation interface. All the preservation and other pass management code has been updated accordingly. The way the FunctionAAResultsWrapperPass works is to detect the available alias analyses when run, and add them to the results object. This means that we should be able to continue to respect when various passes are added to the pipeline, for example adding CFL or adding TBAA passes should just cause their results to be available and to get folded into this. The exception to this rule is BasicAA which really needs to be a function pass due to using dominator trees and loop info. As a consequence, the FunctionAAResultsWrapperPass directly depends on BasicAA and always includes it in the aggregation. This has significant implications for preserving analyses. Generally, most passes shouldn't bother preserving FunctionAAResultsWrapperPass because rebuilding the results just updates the set of known AA passes. The exception to this rule are LoopPass instances which need to preserve all the function analyses that the loop pass manager will end up needing. This means preserving both BasicAAWrapperPass and the aggregating FunctionAAResultsWrapperPass. Now, when preserving an alias analysis, you do so by directly preserving that analysis. This is only necessary for non-immutable-pass-provided alias analyses though, and there are only three of interest: BasicAA, GlobalsAA (formerly GlobalsModRef), and SCEVAA. Usually BasicAA is preserved when needed because it (like DominatorTree and LoopInfo) is marked as a CFG-only pass. I've expanded GlobalsAA into the preserved set everywhere we previously were preserving all of AliasAnalysis, and I've added SCEVAA in the intersection of that with where we preserve SCEV itself. One significant challenge to all of this is that the CGSCC passes were actually using the alias analysis implementations by taking advantage of a pretty amazing set of loop holes in the old pass manager's analysis management code which allowed analysis groups to slide through in many cases. Moving away from analysis groups makes this problem much more obvious. To fix it, I've leveraged the flexibility the design of the new PM components provides to just directly construct the relevant alias analyses for the relevant functions in the IPO passes that need them. This is a bit hacky, but should go away with the new pass manager, and is already in many ways cleaner than the prior state. Another significant challenge is that various facilities of the old alias analysis infrastructure just don't fit any more. The most significant of these is the alias analysis 'counter' pass. That pass relied on the ability to snoop on AA queries at different points in the analysis group chain. Instead, I'm planning to build printing functionality directly into the aggregation layer. I've not included that in this patch merely to keep it smaller. Note that all of this needs a nearly complete rewrite of the AA documentation. I'm planning to do that, but I'd like to make sure the new design settles, and to flesh out a bit more of what it looks like in the new pass manager first. Differential Revision: http://reviews.llvm.org/D12080 llvm-svn: 247167
2015-09-09 19:55:00 +02:00
void initializeBasicAAWrapperPassPass(PassRegistry&);
void initializeBlockExtractorLegacyPassPass(PassRegistry &);
void initializeBlockFrequencyInfoWrapperPassPass(PassRegistry&);
void initializeBoundsCheckingLegacyPassPass(PassRegistry&);
void initializeBranchFolderPassPass(PassRegistry&);
void initializeBranchProbabilityInfoWrapperPassPass(PassRegistry&);
void initializeBranchRelaxationPass(PassRegistry&);
void initializeBreakCriticalEdgesPass(PassRegistry&);
Separate ExecutionDepsFix into 4 parts: 1. ReachingDefsAnalysis - Allows to identify for each instruction what is the “closest” reaching def of a certain register. Used by BreakFalseDeps (for clearance calculation) and ExecutionDomainFix (for arbitrating conflicting domains). 2. ExecutionDomainFix - Changes the variant of the instructions in order to minimize domain crossings. 3. BreakFalseDeps - Breaks false dependencies. 4. LoopTraversal - Creatws a traversal order of the basic blocks that is optimal for loops (introduced in revision L293571). Both ExecutionDomainFix and ReachingDefsAnalysis use this to determine the order they will traverse the basic blocks. This also included the following changes to ExcecutionDepsFix original logic: 1. BreakFalseDeps and ReachingDefsAnalysis logic no longer restricted by a register class. 2. ReachingDefsAnalysis tracks liveness of reg units instead of reg indices into a given reg class. Additional changes in affected files: 1. X86 and ARM targets now inherit from ExecutionDomainFix instead of ExecutionDepsFix. BreakFalseDeps also was added to the passes they activate. 2. Comments and references to ExecutionDepsFix replaced with ExecutionDomainFix and BreakFalseDeps, as appropriate. Additional refactoring changes will follow. This commit is (almost) NFC. The only functional change is that now BreakFalseDeps will break dependency for all register classes. Since no additional instructions were added to the list of instructions that have false dependencies, there is no actual change yet. In a future commit several instructions (and tests) will be added. This is the first of multiple patches that fix bugzilla https://bugs.llvm.org/show_bug.cgi?id=33869 Most of the patches are intended at refactoring the existent code. Additional relevant reviews: https://reviews.llvm.org/D40331 https://reviews.llvm.org/D40332 https://reviews.llvm.org/D40333 https://reviews.llvm.org/D40334 Differential Revision: https://reviews.llvm.org/D40330 Change-Id: Icaeb75e014eff96a8f721377783f9a3e6c679275 llvm-svn: 323087
2018-01-22 11:05:23 +01:00
void initializeBreakFalseDepsPass(PassRegistry&);
void initializeCanonicalizeAliasesLegacyPassPass(PassRegistry &);
void initializeCanonicalizeFreezeInLoopsPass(PassRegistry &);
void initializeCFGOnlyPrinterLegacyPassPass(PassRegistry&);
void initializeCFGOnlyViewerLegacyPassPass(PassRegistry&);
void initializeCFGPrinterLegacyPassPass(PassRegistry&);
void initializeCFGSimplifyPassPass(PassRegistry&);
void initializeCFGuardPass(PassRegistry&);
void initializeCFGuardLongjmpPass(PassRegistry&);
void initializeCFGViewerLegacyPassPass(PassRegistry&);
Correct dwarf unwind information in function epilogue This patch aims to provide correct dwarf unwind information in function epilogue for X86. It consists of two parts. The first part inserts CFI instructions that set appropriate cfa offset and cfa register in emitEpilogue() in X86FrameLowering. This part is X86 specific. The second part is platform independent and ensures that: * CFI instructions do not affect code generation (they are not counted as instructions when tail duplicating or tail merging) * Unwind information remains correct when a function is modified by different passes. This is done in a late pass by analyzing information about cfa offset and cfa register in BBs and inserting additional CFI directives where necessary. Added CFIInstrInserter pass: * analyzes each basic block to determine cfa offset and register are valid at its entry and exit * verifies that outgoing cfa offset and register of predecessor blocks match incoming values of their successors * inserts additional CFI directives at basic block beginning to correct the rule for calculating CFA Having CFI instructions in function epilogue can cause incorrect CFA calculation rule for some basic blocks. This can happen if, due to basic block reordering, or the existence of multiple epilogue blocks, some of the blocks have wrong cfa offset and register values set by the epilogue block above them. CFIInstrInserter is currently run only on X86, but can be used by any target that implements support for adding CFI instructions in epilogue. Patch by Violeta Vukobrat. Differential Revision: https://reviews.llvm.org/D42848 llvm-svn: 330706
2018-04-24 12:32:08 +02:00
void initializeCFIInstrInserterPass(PassRegistry&);
void initializeCFLAndersAAWrapperPassPass(PassRegistry&);
void initializeCFLSteensAAWrapperPassPass(PassRegistry&);
void initializeCGProfileLegacyPassPass(PassRegistry &);
void initializeCallGraphDOTPrinterPass(PassRegistry&);
void initializeCallGraphPrinterLegacyPassPass(PassRegistry&);
void initializeCallGraphViewerPass(PassRegistry&);
void initializeCallGraphWrapperPassPass(PassRegistry&);
void initializeCallSiteSplittingLegacyPassPass(PassRegistry&);
void initializeCalledValuePropagationLegacyPassPass(PassRegistry &);
void initializeCheckDebugMachineModulePass(PassRegistry &);
void initializeCodeGenPreparePass(PassRegistry&);
void initializeConstantHoistingLegacyPassPass(PassRegistry&);
void initializeConstantMergeLegacyPassPass(PassRegistry&);
void initializeConstraintEliminationPass(PassRegistry &);
void initializeControlHeightReductionLegacyPassPass(PassRegistry&);
void initializeCorrelatedValuePropagationPass(PassRegistry&);
void initializeCostModelAnalysisPass(PassRegistry&);
void initializeCrossDSOCFIPass(PassRegistry&);
void initializeDAEPass(PassRegistry&);
void initializeDAHPass(PassRegistry&);
void initializeDCELegacyPassPass(PassRegistry&);
void initializeDSELegacyPassPass(PassRegistry&);
void initializeDataFlowSanitizerLegacyPassPass(PassRegistry &);
void initializeDeadMachineInstructionElimPass(PassRegistry&);
Add MIR-level debugify with only locations support for now Summary: Re-used the IR-level debugify for the most part. The MIR-level code then adds locations to the MachineInstrs afterwards based on the LLVM-IR debug info. It's worth mentioning that the resulting locations make little sense as the range of line numbers used in a Function at the MIR level exceeds that of the equivelent IR level function. As such, MachineInstrs can appear to originate from outside the subprogram scope (and from other subprogram scopes). However, it doesn't seem worth worrying about as the source is imaginary anyway. There's a few high level goals this pass works towards: * We should be able to debugify our .ll/.mir in the lit tests without changing the checks and still pass them. I.e. Debug info should not change codegen. Combining this with a strip-debug pass should enable this. The main issue I ran into without the strip-debug pass was instructions with MMO's and checks on both the instruction and the MMO as the debug-location is between them. I currently have a simple hack in the MIRPrinter to resolve that but the more general solution is a proper strip-debug pass. * We should be able to test that GlobalISel does not lose debug info. I recently found that the legalizer can be unexpectedly lossy in seemingly simple cases (e.g. expanding one instr into many). I have a verifier (will be posted separately) that can be integrated with passes that use the observer interface and will catch location loss (it does not verify correctness, just that there's zero lossage). It is a little conservative as the line-0 locations that arise from conflicts do not track the conflicting locations but it can still catch a fair bit. Depends on D77439, D77438 Reviewers: aprantl, bogner, vsk Subscribers: mgorny, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D77446
2020-04-04 01:18:45 +02:00
void initializeDebugifyMachineModulePass(PassRegistry &);
void initializeDelinearizationPass(PassRegistry&);
void initializeDemandedBitsWrapperPassPass(PassRegistry&);
void initializeDependenceAnalysisPass(PassRegistry&);
void initializeDependenceAnalysisWrapperPassPass(PassRegistry&);
void initializeDetectDeadLanesPass(PassRegistry&);
void initializeDivRemPairsLegacyPassPass(PassRegistry&);
void initializeDomOnlyPrinterPass(PassRegistry&);
void initializeDomOnlyViewerPass(PassRegistry&);
void initializeDomPrinterPass(PassRegistry&);
void initializeDomViewerPass(PassRegistry&);
void initializeDominanceFrontierWrapperPassPass(PassRegistry&);
void initializeDominatorTreeWrapperPassPass(PassRegistry&);
void initializeDwarfEHPrepareLegacyPassPass(PassRegistry &);
void initializeEarlyCSELegacyPassPass(PassRegistry&);
void initializeEarlyCSEMemSSALegacyPassPass(PassRegistry&);
void initializeEarlyIfConverterPass(PassRegistry&);
void initializeEarlyIfPredicatorPass(PassRegistry &);
void initializeEarlyMachineLICMPass(PassRegistry&);
void initializeEarlyTailDuplicatePass(PassRegistry&);
void initializeEdgeBundlesPass(PassRegistry&);
void initializeEHContGuardCatchretPass(PassRegistry &);
void initializeEliminateAvailableExternallyLegacyPassPass(PassRegistry&);
void initializeEntryExitInstrumenterPass(PassRegistry&);
void initializeExpandMemCmpPassPass(PassRegistry&);
void initializeExpandPostRAPass(PassRegistry&);
void initializeExpandReductionsPass(PassRegistry&);
void initializeExpandVectorPredicationPass(PassRegistry &);
Introduce llvm.experimental.widenable_condition intrinsic This patch introduces a new instinsic `@llvm.experimental.widenable_condition` that allows explicit representation for guards. It is an alternative to using `@llvm.experimental.guard` intrinsic that does not contain implicit control flow. We keep finding places where `@llvm.experimental.guard` is not supported or treated too conservatively, and there are 2 reasons to that: - `@llvm.experimental.guard` has memory write side effect to model implicit control flow, and this sometimes confuses passes and analyzes that work with memory; - Not all passes and analysis are aware of the semantics of guards. These passes treat them as regular throwing call and have no idea that the condition of guard may be used to prove something. One well-known place which had caused us troubles in the past is explicit loop iteration count calculation in SCEV. Another example is new loop unswitching which is not aware of guards. Whenever a new pass appears, we potentially have this problem there. Rather than go and fix all these places (and commit to keep track of them and add support in future), it seems more reasonable to leverage the existing optimizer's logic as much as possible. The only significant difference between guards and regular explicit branches is that guard's condition can be widened. It means that a guard contains (explicitly or implicitly) a `deopt` block successor, and it is always legal to go there no matter what the guard condition is. The other successor is a guarded block, and it is only legal to go there if the condition is true. This patch introduces a new explicit form of guards alternative to `@llvm.experimental.guard` intrinsic. Now a widenable guard can be represented in the CFG explicitly like this: %widenable_condition = call i1 @llvm.experimental.widenable.condition() %new_condition = and i1 %cond, %widenable_condition br i1 %new_condition, label %guarded, label %deopt guarded: ; Guarded instructions deopt: call type @llvm.experimental.deoptimize(<args...>) [ "deopt"(<deopt_args...>) ] The new intrinsic `@llvm.experimental.widenable.condition` has semantics of an `undef`, but the intrinsic prevents the optimizer from folding it early. This form should exploit all optimization boons provided to `br` instuction, and it still can be widened by replacing the result of `@llvm.experimental.widenable.condition()` with `and` with any arbitrary boolean value (as long as the branch that is taken when it is `false` has a deopt and has no side-effects). For more motivation, please check llvm-dev discussion "[llvm-dev] Giving up using implicit control flow in guards". This patch introduces this new intrinsic with respective LangRef changes and a pass that converts old-style guards (expressed as intrinsics) into the new form. The naming discussion is still ungoing. Merging this to unblock further items. We can later change the name of this intrinsic. Reviewed By: reames, fedor.sergeev, sanjoy Differential Revision: https://reviews.llvm.org/D51207 llvm-svn: 348593
2018-12-07 15:39:46 +01:00
void initializeMakeGuardsExplicitLegacyPassPass(PassRegistry&);
void initializeExternalAAWrapperPassPass(PassRegistry&);
void initializeFEntryInserterPass(PassRegistry&);
void initializeFinalizeISelPass(PassRegistry&);
void initializeFinalizeMachineBundlesPass(PassRegistry&);
void initializeFixIrreduciblePass(PassRegistry &);
void initializeFixupStatepointCallerSavedPass(PassRegistry&);
void initializeFlattenCFGPassPass(PassRegistry&);
void initializeFloat2IntLegacyPassPass(PassRegistry&);
void initializeForceFunctionAttrsLegacyPassPass(PassRegistry&);
void initializeForwardControlFlowIntegrityPass(PassRegistry&);
void initializeFuncletLayoutPass(PassRegistry&);
void initializeFunctionImportLegacyPassPass(PassRegistry&);
Function Specialization Pass This adds a function specialization pass to LLVM. Constant parameters like function pointers and constant globals are propagated to the callee by specializing the function. This is a first version with a number of limitations: - The pass is off by default, so needs to be enabled on the command line, - It does not handle specialization of recursive functions, - It does not yet handle constants and constant ranges, - Only 1 argument per function is specialised, - The cost-model could be further looked into, and perhaps related, - We are not yet caching analysis results. This is based on earlier work by Matthew Simpson (D36432) and Vinay Madhusudan. More recently this was also discussed on the list, see: https://lists.llvm.org/pipermail/llvm-dev/2021-March/149380.html. The motivation for this work is that function specialisation often comes up as a reason for performance differences of generated code between LLVM and GCC, which has this enabled by default from optimisation level -O3 and up. And while this certainly helps a few cpu benchmark cases, this also triggers in real world codes and is thus a generally useful transformation to have in LLVM. Function specialisation has great potential to increase compile-times and code-size. The summary from some investigations with this patch is: - Compile-time increases for short compile jobs is high relatively, but the increase in absolute numbers still low. - For longer compile-jobs, the extra compile time is around 1%, and very much in line with GCC. - It is difficult to blame one thing for compile-time increases: it looks like everywhere a little bit more time is spent processing more functions and instructions. - But the function specialisation pass itself is not very expensive; it doesn't show up very high in the profile of the optimisation passes. The goal of this work is to reach parity with GCC which means that eventually we would like to get this enabled by default. But first we would like to address some of the limitations before that. Differential Revision: https://reviews.llvm.org/D93838
2021-05-04 16:12:44 +02:00
void initializeFunctionSpecializationLegacyPassPass(PassRegistry &);
void initializeGCMachineCodeAnalysisPass(PassRegistry&);
void initializeGCModuleInfoPass(PassRegistry&);
void initializeGCOVProfilerLegacyPassPass(PassRegistry&);
void initializeGVNHoistLegacyPassPass(PassRegistry&);
void initializeGVNLegacyPassPass(PassRegistry&);
void initializeGVNSinkLegacyPassPass(PassRegistry&);
void initializeGlobalDCELegacyPassPass(PassRegistry&);
void initializeGlobalMergePass(PassRegistry&);
void initializeGlobalOptLegacyPassPass(PassRegistry&);
void initializeGlobalSplitPass(PassRegistry&);
[PM/AA] Rebuild LLVM's alias analysis infrastructure in a way compatible with the new pass manager, and no longer relying on analysis groups. This builds essentially a ground-up new AA infrastructure stack for LLVM. The core ideas are the same that are used throughout the new pass manager: type erased polymorphism and direct composition. The design is as follows: - FunctionAAResults is a type-erasing alias analysis results aggregation interface to walk a single query across a range of results from different alias analyses. Currently this is function-specific as we always assume that aliasing queries are *within* a function. - AAResultBase is a CRTP utility providing stub implementations of various parts of the alias analysis result concept, notably in several cases in terms of other more general parts of the interface. This can be used to implement only a narrow part of the interface rather than the entire interface. This isn't really ideal, this logic should be hoisted into FunctionAAResults as currently it will cause a significant amount of redundant work, but it faithfully models the behavior of the prior infrastructure. - All the alias analysis passes are ported to be wrapper passes for the legacy PM and new-style analysis passes for the new PM with a shared result object. In some cases (most notably CFL), this is an extremely naive approach that we should revisit when we can specialize for the new pass manager. - BasicAA has been restructured to reflect that it is much more fundamentally a function analysis because it uses dominator trees and loop info that need to be constructed for each function. All of the references to getting alias analysis results have been updated to use the new aggregation interface. All the preservation and other pass management code has been updated accordingly. The way the FunctionAAResultsWrapperPass works is to detect the available alias analyses when run, and add them to the results object. This means that we should be able to continue to respect when various passes are added to the pipeline, for example adding CFL or adding TBAA passes should just cause their results to be available and to get folded into this. The exception to this rule is BasicAA which really needs to be a function pass due to using dominator trees and loop info. As a consequence, the FunctionAAResultsWrapperPass directly depends on BasicAA and always includes it in the aggregation. This has significant implications for preserving analyses. Generally, most passes shouldn't bother preserving FunctionAAResultsWrapperPass because rebuilding the results just updates the set of known AA passes. The exception to this rule are LoopPass instances which need to preserve all the function analyses that the loop pass manager will end up needing. This means preserving both BasicAAWrapperPass and the aggregating FunctionAAResultsWrapperPass. Now, when preserving an alias analysis, you do so by directly preserving that analysis. This is only necessary for non-immutable-pass-provided alias analyses though, and there are only three of interest: BasicAA, GlobalsAA (formerly GlobalsModRef), and SCEVAA. Usually BasicAA is preserved when needed because it (like DominatorTree and LoopInfo) is marked as a CFG-only pass. I've expanded GlobalsAA into the preserved set everywhere we previously were preserving all of AliasAnalysis, and I've added SCEVAA in the intersection of that with where we preserve SCEV itself. One significant challenge to all of this is that the CGSCC passes were actually using the alias analysis implementations by taking advantage of a pretty amazing set of loop holes in the old pass manager's analysis management code which allowed analysis groups to slide through in many cases. Moving away from analysis groups makes this problem much more obvious. To fix it, I've leveraged the flexibility the design of the new PM components provides to just directly construct the relevant alias analyses for the relevant functions in the IPO passes that need them. This is a bit hacky, but should go away with the new pass manager, and is already in many ways cleaner than the prior state. Another significant challenge is that various facilities of the old alias analysis infrastructure just don't fit any more. The most significant of these is the alias analysis 'counter' pass. That pass relied on the ability to snoop on AA queries at different points in the analysis group chain. Instead, I'm planning to build printing functionality directly into the aggregation layer. I've not included that in this patch merely to keep it smaller. Note that all of this needs a nearly complete rewrite of the AA documentation. I'm planning to do that, but I'd like to make sure the new design settles, and to flesh out a bit more of what it looks like in the new pass manager first. Differential Revision: http://reviews.llvm.org/D12080 llvm-svn: 247167
2015-09-09 19:55:00 +02:00
void initializeGlobalsAAWrapperPassPass(PassRegistry&);
void initializeGuardWideningLegacyPassPass(PassRegistry&);
void initializeHardwareLoopsPass(PassRegistry&);
void initializeMemProfilerLegacyPassPass(PassRegistry &);
void initializeHotColdSplittingLegacyPassPass(PassRegistry&);
void initializeHWAddressSanitizerLegacyPassPass(PassRegistry &);
void initializeIPSCCPLegacyPassPass(PassRegistry&);
void initializeIRCELegacyPassPass(PassRegistry&);
void initializeIROutlinerLegacyPassPass(PassRegistry&);
void initializeIRSimilarityIdentifierWrapperPassPass(PassRegistry&);
void initializeIRTranslatorPass(PassRegistry&);
void initializeIVUsersWrapperPassPass(PassRegistry&);
void initializeIfConverterPass(PassRegistry&);
void initializeImmutableModuleSummaryIndexWrapperPassPass(PassRegistry&);
void initializeImplicitNullChecksPass(PassRegistry&);
void initializeIndVarSimplifyLegacyPassPass(PassRegistry&);
Introduce the "retpoline" x86 mitigation technique for variant #2 of the speculative execution vulnerabilities disclosed today, specifically identified by CVE-2017-5715, "Branch Target Injection", and is one of the two halves to Spectre.. Summary: First, we need to explain the core of the vulnerability. Note that this is a very incomplete description, please see the Project Zero blog post for details: https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html The basis for branch target injection is to direct speculative execution of the processor to some "gadget" of executable code by poisoning the prediction of indirect branches with the address of that gadget. The gadget in turn contains an operation that provides a side channel for reading data. Most commonly, this will look like a load of secret data followed by a branch on the loaded value and then a load of some predictable cache line. The attacker then uses timing of the processors cache to determine which direction the branch took *in the speculative execution*, and in turn what one bit of the loaded value was. Due to the nature of these timing side channels and the branch predictor on Intel processors, this allows an attacker to leak data only accessible to a privileged domain (like the kernel) back into an unprivileged domain. The goal is simple: avoid generating code which contains an indirect branch that could have its prediction poisoned by an attacker. In many cases, the compiler can simply use directed conditional branches and a small search tree. LLVM already has support for lowering switches in this way and the first step of this patch is to disable jump-table lowering of switches and introduce a pass to rewrite explicit indirectbr sequences into a switch over integers. However, there is no fully general alternative to indirect calls. We introduce a new construct we call a "retpoline" to implement indirect calls in a non-speculatable way. It can be thought of loosely as a trampoline for indirect calls which uses the RET instruction on x86. Further, we arrange for a specific call->ret sequence which ensures the processor predicts the return to go to a controlled, known location. The retpoline then "smashes" the return address pushed onto the stack by the call with the desired target of the original indirect call. The result is a predicted return to the next instruction after a call (which can be used to trap speculative execution within an infinite loop) and an actual indirect branch to an arbitrary address. On 64-bit x86 ABIs, this is especially easily done in the compiler by using a guaranteed scratch register to pass the target into this device. For 32-bit ABIs there isn't a guaranteed scratch register and so several different retpoline variants are introduced to use a scratch register if one is available in the calling convention and to otherwise use direct stack push/pop sequences to pass the target address. This "retpoline" mitigation is fully described in the following blog post: https://support.google.com/faqs/answer/7625886 We also support a target feature that disables emission of the retpoline thunk by the compiler to allow for custom thunks if users want them. These are particularly useful in environments like kernels that routinely do hot-patching on boot and want to hot-patch their thunk to different code sequences. They can write this custom thunk and use `-mretpoline-external-thunk` *in addition* to `-mretpoline`. In this case, on x86-64 thu thunk names must be: ``` __llvm_external_retpoline_r11 ``` or on 32-bit: ``` __llvm_external_retpoline_eax __llvm_external_retpoline_ecx __llvm_external_retpoline_edx __llvm_external_retpoline_push ``` And the target of the retpoline is passed in the named register, or in the case of the `push` suffix on the top of the stack via a `pushl` instruction. There is one other important source of indirect branches in x86 ELF binaries: the PLT. These patches also include support for LLD to generate PLT entries that perform a retpoline-style indirection. The only other indirect branches remaining that we are aware of are from precompiled runtimes (such as crt0.o and similar). The ones we have found are not really attackable, and so we have not focused on them here, but eventually these runtimes should also be replicated for retpoline-ed configurations for completeness. For kernels or other freestanding or fully static executables, the compiler switch `-mretpoline` is sufficient to fully mitigate this particular attack. For dynamic executables, you must compile *all* libraries with `-mretpoline` and additionally link the dynamic executable and all shared libraries with LLD and pass `-z retpolineplt` (or use similar functionality from some other linker). We strongly recommend also using `-z now` as non-lazy binding allows the retpoline-mitigated PLT to be substantially smaller. When manually apply similar transformations to `-mretpoline` to the Linux kernel we observed very small performance hits to applications running typical workloads, and relatively minor hits (approximately 2%) even for extremely syscall-heavy applications. This is largely due to the small number of indirect branches that occur in performance sensitive paths of the kernel. When using these patches on statically linked applications, especially C++ applications, you should expect to see a much more dramatic performance hit. For microbenchmarks that are switch, indirect-, or virtual-call heavy we have seen overheads ranging from 10% to 50%. However, real-world workloads exhibit substantially lower performance impact. Notably, techniques such as PGO and ThinLTO dramatically reduce the impact of hot indirect calls (by speculatively promoting them to direct calls) and allow optimized search trees to be used to lower switches. If you need to deploy these techniques in C++ applications, we *strongly* recommend that you ensure all hot call targets are statically linked (avoiding PLT indirection) and use both PGO and ThinLTO. Well tuned servers using all of these techniques saw 5% - 10% overhead from the use of retpoline. We will add detailed documentation covering these components in subsequent patches, but wanted to make the core functionality available as soon as possible. Happy for more code review, but we'd really like to get these patches landed and backported ASAP for obvious reasons. We're planning to backport this to both 6.0 and 5.0 release streams and get a 5.0 release with just this cherry picked ASAP for distros and vendors. This patch is the work of a number of people over the past month: Eric, Reid, Rui, and myself. I'm mailing it out as a single commit due to the time sensitive nature of landing this and the need to backport it. Huge thanks to everyone who helped out here, and everyone at Intel who helped out in discussions about how to craft this. Also, credit goes to Paul Turner (at Google, but not an LLVM contributor) for much of the underlying retpoline design. Reviewers: echristo, rnk, ruiu, craig.topper, DavidKreitzer Subscribers: sanjoy, emaste, mcrosier, mgorny, mehdi_amini, hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D41723 llvm-svn: 323155
2018-01-22 23:05:25 +01:00
void initializeIndirectBrExpandPassPass(PassRegistry&);
void initializeInferAddressSpacesPass(PassRegistry&);
void initializeInferFunctionAttrsLegacyPassPass(PassRegistry&);
void initializeInjectTLIMappingsLegacyPass(PassRegistry &);
void initializeInlineCostAnalysisPass(PassRegistry&);
void initializeInstCountLegacyPassPass(PassRegistry &);
void initializeInstNamerPass(PassRegistry&);
void initializeInstSimplifyLegacyPassPass(PassRegistry &);
void initializeInstrProfilingLegacyPassPass(PassRegistry&);
void initializeInstrOrderFileLegacyPassPass(PassRegistry&);
void initializeInstructionCombiningPassPass(PassRegistry&);
void initializeInstructionSelectPass(PassRegistry&);
void initializeInterleavedAccessPass(PassRegistry&);
void initializeInterleavedLoadCombinePass(PassRegistry &);
void initializeInternalizeLegacyPassPass(PassRegistry&);
void initializeIntervalPartitionPass(PassRegistry&);
void initializeJumpThreadingPass(PassRegistry&);
void initializeLCSSAVerificationPassPass(PassRegistry&);
void initializeLCSSAWrapperPassPass(PassRegistry&);
void initializeLazyBlockFrequencyInfoPassPass(PassRegistry&);
void initializeLazyBranchProbabilityInfoPassPass(PassRegistry&);
void initializeLazyMachineBlockFrequencyInfoPassPass(PassRegistry&);
void initializeLazyValueInfoPrinterPass(PassRegistry&);
void initializeLazyValueInfoWrapperPassPass(PassRegistry&);
void initializeLegacyDivergenceAnalysisPass(PassRegistry&);
void initializeLegacyLICMPassPass(PassRegistry&);
void initializeLegacyLoopSinkPassPass(PassRegistry&);
void initializeLegalizerPass(PassRegistry&);
void initializeGISelCSEAnalysisWrapperPassPass(PassRegistry &);
void initializeGISelKnownBitsAnalysisPass(PassRegistry &);
void initializeLibCallsShrinkWrapLegacyPassPass(PassRegistry&);
void initializeLintLegacyPassPass(PassRegistry &);
void initializeLiveDebugValuesPass(PassRegistry&);
void initializeLiveDebugVariablesPass(PassRegistry&);
void initializeLiveIntervalsPass(PassRegistry&);
void initializeLiveRangeShrinkPass(PassRegistry&);
void initializeLiveRegMatrixPass(PassRegistry&);
void initializeLiveStacksPass(PassRegistry&);
void initializeLiveVariablesPass(PassRegistry&);
void initializeLoadStoreVectorizerLegacyPassPass(PassRegistry&);
void initializeLoaderPassPass(PassRegistry&);
void initializeLocalStackSlotPassPass(PassRegistry&);
void initializeLocalizerPass(PassRegistry&);
void initializeLoopAccessLegacyAnalysisPass(PassRegistry&);
void initializeLoopDataPrefetchLegacyPassPass(PassRegistry&);
void initializeLoopDeletionLegacyPassPass(PassRegistry&);
void initializeLoopDistributeLegacyPass(PassRegistry&);
void initializeLoopExtractorLegacyPassPass(PassRegistry &);
void initializeLoopGuardWideningLegacyPassPass(PassRegistry&);
void initializeLoopFuseLegacyPass(PassRegistry&);
void initializeLoopIdiomRecognizeLegacyPassPass(PassRegistry&);
void initializeLoopInfoWrapperPassPass(PassRegistry&);
void initializeLoopInstSimplifyLegacyPassPass(PassRegistry&);
void initializeLoopInterchangeLegacyPassPass(PassRegistry &);
void initializeLoopFlattenLegacyPassPass(PassRegistry&);
void initializeLoopLoadEliminationPass(PassRegistry&);
void initializeLoopPassPass(PassRegistry&);
void initializeLoopPredicationLegacyPassPass(PassRegistry&);
void initializeLoopRerollLegacyPassPass(PassRegistry &);
void initializeLoopRotateLegacyPassPass(PassRegistry&);
void initializeLoopSimplifyCFGLegacyPassPass(PassRegistry&);
void initializeLoopSimplifyPass(PassRegistry&);
void initializeLoopStrengthReducePass(PassRegistry&);
void initializeLoopUnrollAndJamPass(PassRegistry&);
void initializeLoopUnrollPass(PassRegistry&);
void initializeLoopUnswitchPass(PassRegistry&);
void initializeLoopVectorizePass(PassRegistry&);
void initializeLoopVersioningLICMLegacyPassPass(PassRegistry &);
void initializeLoopVersioningLegacyPassPass(PassRegistry &);
void initializeLowerAtomicLegacyPassPass(PassRegistry&);
void initializeLowerConstantIntrinsicsPass(PassRegistry&);
void initializeLowerEmuTLSPass(PassRegistry&);
void initializeLowerExpectIntrinsicPass(PassRegistry&);
void initializeLowerGuardIntrinsicLegacyPassPass(PassRegistry&);
void initializeLowerWidenableConditionLegacyPassPass(PassRegistry&);
void initializeLowerIntrinsicsPass(PassRegistry&);
void initializeLowerInvokeLegacyPassPass(PassRegistry&);
void initializeLowerSwitchLegacyPassPass(PassRegistry &);
IR: New representation for CFI and virtual call optimization pass metadata. The bitset metadata currently used in LLVM has a few problems: 1. It has the wrong name. The name "bitset" refers to an implementation detail of one use of the metadata (i.e. its original use case, CFI). This makes it harder to understand, as the name makes no sense in the context of virtual call optimization. 2. It is represented using a global named metadata node, rather than being directly associated with a global. This makes it harder to manipulate the metadata when rebuilding global variables, summarise it as part of ThinLTO and drop unused metadata when associated globals are dropped. For this reason, CFI does not currently work correctly when both CFI and vcall opt are enabled, as vcall opt needs to rebuild vtable globals, and fails to associate metadata with the rebuilt globals. As I understand it, the same problem could also affect ASan, which rebuilds globals with a red zone. This patch solves both of those problems in the following way: 1. Rename the metadata to "type metadata". This new name reflects how the metadata is currently being used (i.e. to represent type information for CFI and vtable opt). The new name is reflected in the name for the associated intrinsic (llvm.type.test) and pass (LowerTypeTests). 2. Attach metadata directly to the globals that it pertains to, rather than using the "llvm.bitsets" global metadata node as we are doing now. This is done using the newly introduced capability to attach metadata to global variables (r271348 and r271358). See also: http://lists.llvm.org/pipermail/llvm-dev/2016-June/100462.html Differential Revision: http://reviews.llvm.org/D21053 llvm-svn: 273729
2016-06-24 23:21:32 +02:00
void initializeLowerTypeTestsPass(PassRegistry&);
[Matrix] Add first set of matrix intrinsics and initial lowering pass. This is the first patch adding an initial set of matrix intrinsics and a corresponding lowering pass. This has been discussed on llvm-dev: http://lists.llvm.org/pipermail/llvm-dev/2019-October/136240.html The first patch introduces four new intrinsics (transpose, multiply, columnwise load and store) and a LowerMatrixIntrinsics pass, that lowers those intrinsics to vector operations. Matrixes are embedded in a 'flat' vector (e.g. a 4 x 4 float matrix embedded in a <16 x float> vector) and the intrinsics take the dimension information as parameters. Those parameters need to be ConstantInt. For the memory layout, we initially assume column-major, but in the RFC we also described how to extend the intrinsics to support row-major as well. For the initial lowering, we split the input of the intrinsics into a set of column vectors, transform those column vectors and concatenate the result columns to a flat result vector. This allows us to lower the intrinsics without any shape propagation, as mentioned in the RFC. In follow-up patches, we plan to submit the following improvements: * Shape propagation to eliminate the embedding/splitting for each intrinsic. * Fused & tiled lowering of multiply and other operations. * Optimization remarks highlighting matrix expressions and costs. * Generate loops for operations on large matrixes. * More general block processing for operation on large vectors, exploiting shape information. We would like to add dedicated transpose, columnwise load and store intrinsics, even though they are not strictly necessary. For example, we could instead emit a large shufflevector instruction instead of the transpose. But we expect that to (1) become unwieldy for larger matrixes (even for 16x16 matrixes, the resulting shufflevector masks would be huge), (2) risk instcombine making small changes, causing us to fail to detect the transpose, preventing better lowerings For the load/store, we are additionally planning on exploiting the intrinsics for better alias analysis. Reviewers: anemet, Gerolf, reames, hfinkel, andrew.w.kaylor, efriedma, rengolin Reviewed By: anemet Differential Revision: https://reviews.llvm.org/D70456
2019-12-12 16:27:28 +01:00
void initializeLowerMatrixIntrinsicsLegacyPassPass(PassRegistry &);
void initializeLowerMatrixIntrinsicsMinimalLegacyPassPass(PassRegistry &);
void initializeMIRAddFSDiscriminatorsPass(PassRegistry &);
void initializeMIRCanonicalizerPass(PassRegistry &);
void initializeMIRNamerPass(PassRegistry &);
void initializeMIRPrintingPassPass(PassRegistry&);
void initializeMachineBlockFrequencyInfoPass(PassRegistry&);
Implement a block placement pass based on the branch probability and block frequency analyses. This differs substantially from the existing block-placement pass in LLVM: 1) It operates on the Machine-IR in the CodeGen layer. This exposes much more (and more precise) information and opportunities. Also, the results are more stable due to fewer transforms ocurring after the pass runs. 2) It uses the generalized probability and frequency analyses. These can model static heuristics, code annotation derived heuristics as well as eventual profile loading. By basing the optimization on the analysis interface it can work from any (or a combination) of these inputs. 3) It uses a more aggressive algorithm, both building chains from tho bottom up to maximize benefit, and using an SCC-based walk to layout chains of blocks in a profitable ordering without O(N^2) iterations which the old pass involves. The pass is currently gated behind a flag, and not enabled by default because it still needs to grow some important features. Most notably, it needs to support loop aligning and careful layout of loop structures much as done by hand currently in CodePlacementOpt. Once it supports these, and has sufficient testing and quality tuning, it should replace both of these passes. Thanks to Nick Lewycky and Richard Smith for help authoring & debugging this, and to Jakob, Andy, Eric, Jim, and probably a few others I'm forgetting for reviewing and answering all my questions. Writing a backend pass is *sooo* much better now than it used to be. =D llvm-svn: 142641
2011-10-21 08:46:38 +02:00
void initializeMachineBlockPlacementPass(PassRegistry&);
void initializeMachineBlockPlacementStatsPass(PassRegistry&);
void initializeMachineBranchProbabilityInfoPass(PassRegistry&);
void initializeMachineCSEPass(PassRegistry&);
void initializeMachineCombinerPass(PassRegistry&);
void initializeMachineCopyPropagationPass(PassRegistry&);
void initializeMachineDominanceFrontierPass(PassRegistry&);
void initializeMachineDominatorTreePass(PassRegistry&);
void initializeMachineFunctionPrinterPassPass(PassRegistry&);
void initializeMachineFunctionSplitterPass(PassRegistry &);
void initializeMachineLICMPass(PassRegistry&);
void initializeMachineLoopInfoPass(PassRegistry&);
void initializeMachineModuleInfoWrapperPassPass(PassRegistry &);
void initializeMachineOptimizationRemarkEmitterPassPass(PassRegistry&);
void initializeMachineOutlinerPass(PassRegistry&);
void initializeMachinePipelinerPass(PassRegistry&);
void initializeMachinePostDominatorTreePass(PassRegistry&);
void initializeMachineRegionInfoPassPass(PassRegistry&);
void initializeMachineSchedulerPass(PassRegistry&);
void initializeMachineSinkingPass(PassRegistry&);
void initializeMachineTraceMetricsPass(PassRegistry&);
void initializeMachineVerifierPassPass(PassRegistry&);
void initializeMemCpyOptLegacyPassPass(PassRegistry&);
void initializeMemDepPrinterPass(PassRegistry&);
void initializeMemDerefPrinterPass(PassRegistry&);
void initializeMemoryDependenceWrapperPassPass(PassRegistry&);
void initializeMemorySSAPrinterLegacyPassPass(PassRegistry&);
void initializeMemorySSAWrapperPassPass(PassRegistry&);
void initializeMemorySanitizerLegacyPassPass(PassRegistry&);
void initializeMergeFunctionsLegacyPassPass(PassRegistry&);
void initializeMergeICmpsLegacyPassPass(PassRegistry &);
void initializeMergedLoadStoreMotionLegacyPassPass(PassRegistry&);
void initializeMetaRenamerPass(PassRegistry&);
void initializeModuleDebugInfoLegacyPrinterPass(PassRegistry &);
void initializeModuleMemProfilerLegacyPassPass(PassRegistry &);
void initializeModuleSummaryIndexWrapperPassPass(PassRegistry&);
void initializeModuloScheduleTestPass(PassRegistry&);
void initializeMustExecutePrinterPass(PassRegistry&);
void initializeMustBeExecutedContextPrinterPass(PassRegistry&);
void initializeNameAnonGlobalLegacyPassPass(PassRegistry&);
void initializeNaryReassociateLegacyPassPass(PassRegistry&);
void initializeNewGVNLegacyPassPass(PassRegistry&);
[PM/AA] Rebuild LLVM's alias analysis infrastructure in a way compatible with the new pass manager, and no longer relying on analysis groups. This builds essentially a ground-up new AA infrastructure stack for LLVM. The core ideas are the same that are used throughout the new pass manager: type erased polymorphism and direct composition. The design is as follows: - FunctionAAResults is a type-erasing alias analysis results aggregation interface to walk a single query across a range of results from different alias analyses. Currently this is function-specific as we always assume that aliasing queries are *within* a function. - AAResultBase is a CRTP utility providing stub implementations of various parts of the alias analysis result concept, notably in several cases in terms of other more general parts of the interface. This can be used to implement only a narrow part of the interface rather than the entire interface. This isn't really ideal, this logic should be hoisted into FunctionAAResults as currently it will cause a significant amount of redundant work, but it faithfully models the behavior of the prior infrastructure. - All the alias analysis passes are ported to be wrapper passes for the legacy PM and new-style analysis passes for the new PM with a shared result object. In some cases (most notably CFL), this is an extremely naive approach that we should revisit when we can specialize for the new pass manager. - BasicAA has been restructured to reflect that it is much more fundamentally a function analysis because it uses dominator trees and loop info that need to be constructed for each function. All of the references to getting alias analysis results have been updated to use the new aggregation interface. All the preservation and other pass management code has been updated accordingly. The way the FunctionAAResultsWrapperPass works is to detect the available alias analyses when run, and add them to the results object. This means that we should be able to continue to respect when various passes are added to the pipeline, for example adding CFL or adding TBAA passes should just cause their results to be available and to get folded into this. The exception to this rule is BasicAA which really needs to be a function pass due to using dominator trees and loop info. As a consequence, the FunctionAAResultsWrapperPass directly depends on BasicAA and always includes it in the aggregation. This has significant implications for preserving analyses. Generally, most passes shouldn't bother preserving FunctionAAResultsWrapperPass because rebuilding the results just updates the set of known AA passes. The exception to this rule are LoopPass instances which need to preserve all the function analyses that the loop pass manager will end up needing. This means preserving both BasicAAWrapperPass and the aggregating FunctionAAResultsWrapperPass. Now, when preserving an alias analysis, you do so by directly preserving that analysis. This is only necessary for non-immutable-pass-provided alias analyses though, and there are only three of interest: BasicAA, GlobalsAA (formerly GlobalsModRef), and SCEVAA. Usually BasicAA is preserved when needed because it (like DominatorTree and LoopInfo) is marked as a CFG-only pass. I've expanded GlobalsAA into the preserved set everywhere we previously were preserving all of AliasAnalysis, and I've added SCEVAA in the intersection of that with where we preserve SCEV itself. One significant challenge to all of this is that the CGSCC passes were actually using the alias analysis implementations by taking advantage of a pretty amazing set of loop holes in the old pass manager's analysis management code which allowed analysis groups to slide through in many cases. Moving away from analysis groups makes this problem much more obvious. To fix it, I've leveraged the flexibility the design of the new PM components provides to just directly construct the relevant alias analyses for the relevant functions in the IPO passes that need them. This is a bit hacky, but should go away with the new pass manager, and is already in many ways cleaner than the prior state. Another significant challenge is that various facilities of the old alias analysis infrastructure just don't fit any more. The most significant of these is the alias analysis 'counter' pass. That pass relied on the ability to snoop on AA queries at different points in the analysis group chain. Instead, I'm planning to build printing functionality directly into the aggregation layer. I've not included that in this patch merely to keep it smaller. Note that all of this needs a nearly complete rewrite of the AA documentation. I'm planning to do that, but I'd like to make sure the new design settles, and to flesh out a bit more of what it looks like in the new pass manager first. Differential Revision: http://reviews.llvm.org/D12080 llvm-svn: 247167
2015-09-09 19:55:00 +02:00
void initializeObjCARCAAWrapperPassPass(PassRegistry&);
void initializeObjCARCAPElimPass(PassRegistry&);
void initializeObjCARCContractLegacyPassPass(PassRegistry &);
void initializeObjCARCExpandPass(PassRegistry&);
void initializeObjCARCOptLegacyPassPass(PassRegistry &);
void initializeOptimizationRemarkEmitterWrapperPassPass(PassRegistry&);
void initializeOptimizePHIsPass(PassRegistry&);
void initializePAEvalPass(PassRegistry&);
void initializePEIPass(PassRegistry&);
void initializePGOIndirectCallPromotionLegacyPassPass(PassRegistry&);
void initializePGOInstrumentationGenLegacyPassPass(PassRegistry&);
void initializePGOInstrumentationUseLegacyPassPass(PassRegistry&);
void initializePGOInstrumentationGenCreateVarLegacyPassPass(PassRegistry&);
void initializePGOMemOPSizeOptLegacyPassPass(PassRegistry&);
void initializePHIEliminationPass(PassRegistry&);
void initializePartialInlinerLegacyPassPass(PassRegistry&);
void initializePartiallyInlineLibCallsLegacyPassPass(PassRegistry&);
void initializePatchableFunctionPass(PassRegistry&);
void initializePeepholeOptimizerPass(PassRegistry&);
void initializePhiValuesWrapperPassPass(PassRegistry&);
void initializePhysicalRegisterUsageInfoPass(PassRegistry&);
void initializePlaceBackedgeSafepointsImplPass(PassRegistry&);
void initializePlaceSafepointsPass(PassRegistry&);
void initializePostDomOnlyPrinterPass(PassRegistry&);
void initializePostDomOnlyViewerPass(PassRegistry&);
void initializePostDomPrinterPass(PassRegistry&);
void initializePostDomViewerPass(PassRegistry&);
void initializePostDominatorTreeWrapperPassPass(PassRegistry&);
void initializePostInlineEntryExitInstrumenterPass(PassRegistry&);
void initializePostMachineSchedulerPass(PassRegistry&);
void initializePostOrderFunctionAttrsLegacyPassPass(PassRegistry&);
void initializePostRAHazardRecognizerPass(PassRegistry&);
[CodeGen] Add a new pass for PostRA sink Summary: This pass sinks COPY instructions into a successor block, if the COPY is not used in the current block and the COPY is live-in to a single successor (i.e., doesn't require the COPY to be duplicated). This avoids executing the the copy on paths where their results aren't needed. This also exposes additional opportunites for dead copy elimination and shrink wrapping. These copies were either not handled by or are inserted after the MachineSink pass. As an example of the former case, the MachineSink pass cannot sink COPY instructions with allocatable source registers; for AArch64 these type of copy instructions are frequently used to move function parameters (PhyReg) into virtual registers in the entry block.. For the machine IR below, this pass will sink %w19 in the entry into its successor (%bb.1) because %w19 is only live-in in %bb.1. ``` %bb.0: %wzr = SUBSWri %w1, 1 %w19 = COPY %w0 Bcc 11, %bb.2 %bb.1: Live Ins: %w19 BL @fun %w0 = ADDWrr %w0, %w19 RET %w0 %bb.2: %w0 = COPY %wzr RET %w0 ``` As we sink %w19 (CSR in AArch64) into %bb.1, the shrink-wrapping pass will be able to see %bb.0 as a candidate. With this change I observed 12% more shrink-wrapping candidate and 13% more dead copies deleted in spec2000/2006/2017 on AArch64. Reviewers: qcolombet, MatzeB, thegameg, mcrosier, gberry, hfinkel, john.brawn, twoh, RKSimon, sebpop, kparzysz Reviewed By: sebpop Subscribers: evandro, sebpop, sfertile, aemerson, mgorny, javed.absar, kristof.beyls, llvm-commits Differential Revision: https://reviews.llvm.org/D41463 llvm-svn: 328237
2018-03-22 21:06:47 +01:00
void initializePostRAMachineSinkingPass(PassRegistry&);
void initializePostRASchedulerPass(PassRegistry&);
void initializePreISelIntrinsicLoweringLegacyPassPass(PassRegistry&);
void initializePredicateInfoPrinterLegacyPassPass(PassRegistry&);
void initializePrintFunctionPassWrapperPass(PassRegistry&);
void initializePrintModulePassWrapperPass(PassRegistry&);
void initializeProcessImplicitDefsPass(PassRegistry&);
void initializeProfileSummaryInfoWrapperPassPass(PassRegistry&);
void initializePromoteLegacyPassPass(PassRegistry&);
void initializePruneEHPass(PassRegistry&);
void initializeRABasicPass(PassRegistry&);
[CSSPGO] Pseudo probes for function calls. An indirect call site needs to be probed for its potential call targets. With CSSPGO a direct call also needs a probe so that a calling context can be represented by a stack of callsite probes. Unlike pseudo probes for basic blocks that are in form of standalone intrinsic call instructions, pseudo probes for callsites have to be attached to the call instruction, thus a separate instruction would not work. One possible way of attaching a probe to a call instruction is to use a special metadata that carries information about the probe. The special metadata will have to make its way through the optimization pipeline down to object emission. This requires additional efforts to maintain the metadata in various places. Given that the `!dbg` metadata is a first-class metadata and has all essential support in place , leveraging the `!dbg` metadata as a channel to encode pseudo probe information is probably the easiest solution. With the requirement of not inflating `!dbg` metadata that is allocated for almost every instruction, we found that the 32-bit DWARF discriminator field which mainly serves AutoFDO can be reused for pseudo probes. DWARF discriminators distinguish identical source locations between instructions and with pseudo probes such support is not required. In this change we are using the discriminator field to encode the ID and type of a callsite probe and the encoded value will be unpacked and consumed right before object emission. When a callsite is inlined, the callsite discriminator field will go with the inlined instructions. The `!dbg` metadata of an inlined instruction is in form of a scope stack. The top of the stack is the instruction's original `!dbg` metadata and the bottom of the stack is for the original callsite of the top-level inliner. Except for the top of the stack, all other elements of the stack actually refer to the nested inlined callsites whose discriminator field (which actually represents a calliste probe) can be used together to represent the inline context of an inlined PseudoProbeInst or CallInst. To avoid collision with the baseline AutoFDO in various places that handles dwarf discriminators where a check against the `-pseudo-probe-for-profiling` switch is not available, a special encoding scheme is used to tell apart a pseudo probe discriminator from a regular discriminator. For the regular discriminator, if all lowest 3 bits are non-zero, it means the discriminator is basically empty and all higher 29 bits can be reversed for pseudo probe use. Callsite pseudo probes are inserted in `SampleProfileProbePass` and a target-independent MIR pass `PseudoProbeInserter` is added to unpack the probe ID/type from `!dbg`. Note that with this work the switch -debug-info-for-profiling will not work with -pseudo-probe-for-profiling anymore. They cannot be used at the same time. Reviewed By: wmi Differential Revision: https://reviews.llvm.org/D91756
2020-12-02 06:44:06 +01:00
void initializePseudoProbeInserterPass(PassRegistry &);
void initializeRAGreedyPass(PassRegistry&);
void initializeReachingDefAnalysisPass(PassRegistry&);
void initializeReassociateLegacyPassPass(PassRegistry&);
[BasicBlockUtils] Add utility to remove redundant dbg.value instrs Summary: Add a RemoveRedundantDbgInstrs to BasicBlockUtils with the goal to remove redundant dbg intrinsics from a basic block. This can be useful after various transforms, as it might be simpler to do a filtering of dbg intrinsics after the transform than during the transform. One primary use case would be to replace a too aggressive removal done by MergeBlockIntoPredecessor, seen at loop rotate (not done in this patch). The elimination algorithm currently focuses on dbg.value intrinsics and is doing two iterations over the BB. First we iterate backward starting at the last instruction in the BB. Whenever a consecutive sequence of dbg.value instructions are found we keep the last dbg.value for each variable found (variable fragments are identified using the {DILocalVariable, FragmentInfo, inlinedAt} triple as given by the DebugVariable helper class). Next we iterate forward starting at the first instruction in the BB. Whenever we find a dbg.value describing a DebugVariable (identified by {DILocalVariable, inlinedAt}) we save the {DIValue, DIExpression} that describes that variables value. But if the variable already was mapped to the same {DIValue, DIExpression} pair we instead drop the second dbg.value. To ease the process of making lit tests for this utility a new pass is introduced called RedundantDbgInstElimination. It can be executed by opt using -redundant-dbg-inst-elim. Reviewers: aprantl, jmorse, vsk Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D71478
2019-12-12 20:51:13 +01:00
void initializeRedundantDbgInstEliminationPass(PassRegistry&);
void initializeRegAllocFastPass(PassRegistry&);
void initializeRegBankSelectPass(PassRegistry&);
void initializeRegToMemLegacyPass(PassRegistry&);
void initializeRegUsageInfoCollectorPass(PassRegistry&);
void initializeRegUsageInfoPropagationPass(PassRegistry&);
void initializeRegionInfoPassPass(PassRegistry&);
void initializeRegionOnlyPrinterPass(PassRegistry&);
void initializeRegionOnlyViewerPass(PassRegistry&);
void initializeRegionPrinterPass(PassRegistry&);
void initializeRegionViewerPass(PassRegistry&);
void initializeRegisterCoalescerPass(PassRegistry&);
[RemoveRedundantDebugValues] Add a Pass that removes redundant DBG_VALUEs This new MIR pass removes redundant DBG_VALUEs. After the register allocator is done, more precisely, after the Virtual Register Rewriter, we end up having duplicated DBG_VALUEs, since some virtual registers are being rewritten into the same physical register as some of existing DBG_VALUEs. Each DBG_VALUE should indicate (at least before the LiveDebugValues) variables assignment, but it is being clobbered for function parameters during the SelectionDAG since it generates new DBG_VALUEs after COPY instructions, even though the parameter has no assignment. For example, if we had a DBG_VALUE $regX as an entry debug value representing the parameter, and a COPY and after the COPY, DBG_VALUE $virt_reg, and after the virtregrewrite the $virt_reg gets rewritten into $regX, we'd end up having redundant DBG_VALUE. This breaks the definition of the DBG_VALUE since some analysis passes might be built on top of that premise..., and this patch tries to fix the MIR with the respect to that. This first patch performs bacward scan, by trying to detect a sequence of consecutive DBG_VALUEs, and to remove all DBG_VALUEs describing one variable but the last one: For example: (1) DBG_VALUE $edi, !"var1", ... (2) DBG_VALUE $esi, !"var2", ... (3) DBG_VALUE $edi, !"var1", ... ... in this case, we can remove (1). By combining the forward scan that will be introduced in the next patch (from this stack), by inspecting the statistics, the RemoveRedundantDebugValues removes 15032 instructions by using gdb-7.11 as a testbed. Differential Revision: https://reviews.llvm.org/D105279
2021-06-28 14:15:31 +02:00
void initializeRemoveRedundantDebugValuesPass(PassRegistry&);
void initializeRenameIndependentSubregsPass(PassRegistry&);
void initializeReplaceWithVeclibLegacyPass(PassRegistry &);
void initializeResetMachineFunctionPass(PassRegistry&);
[PM] Port ReversePostOrderFunctionAttrs to the new PM Below are my super rough notes when porting. They can probably serve as a basic guide for porting other passes to the new PM. As I port more passes I'll expand and generalize this and make a proper docs/HowToPortToNewPassManager.rst document. There is also missing documentation for general concepts and API's in the new PM which will require some documentation. Once there is proper documentation in place we can put up a list of passes that have to be ported and game-ify/crowdsource the rest of the porting (at least of the middle end; the backend is still unclear). I will however be taking personal responsibility for ensuring that the LLD/ELF LTO pipeline is ported in a timely fashion. The remaining passes to be ported are (do something like `git grep "<the string in the bullet point below>"` to find the pass): General Scalar: [ ] Simplify the CFG [ ] Jump Threading [ ] MemCpy Optimization [ ] Promote Memory to Register [ ] MergedLoadStoreMotion [ ] Lazy Value Information Analysis General IPO: [ ] Dead Argument Elimination [ ] Deduce function attributes in RPO Loop stuff / vectorization stuff: [ ] Alignment from assumptions [ ] Canonicalize natural loops [ ] Delete dead loops [ ] Loop Access Analysis [ ] Loop Invariant Code Motion [ ] Loop Vectorization [ ] SLP Vectorizer [ ] Unroll loops Devirtualization / CFI: [ ] Cross-DSO CFI [ ] Whole program devirtualization [ ] Lower bitset metadata CGSCC passes: [ ] Function Integration/Inlining [ ] Remove unused exception handling info [ ] Promote 'by reference' arguments to scalars Please let me know if you are interested in working on any of the passes in the above list (e.g. reply to the post-commit thread for this patch). I'll probably be tackling "General Scalar" and "General IPO" first FWIW. Steps as I port "Deduce function attributes in RPO" --------------------------------------------------- (note: if you are doing any work based on these notes, please leave a note in the post-commit review thread for this commit with any improvements / suggestions / incompleteness you ran into!) Note: "Deduce function attributes in RPO" is a module pass. 1. Do preparatory refactoring. Do preparatory factoring. In this case all I had to do was to pull out a static helper (r272503). (TODO: give more advice here e.g. if pass holds state or something) 2. Rename the old pass class. llvm/lib/Transforms/IPO/FunctionAttrs.cpp Rename class ReversePostOrderFunctionAttrs -> ReversePostOrderFunctionAttrsLegacyPass in preparation for adding a class ReversePostOrderFunctionAttrs as the pass in the new PM. (edit: actually wait what? The new class name will be ReversePostOrderFunctionAttrsPass, so it doesn't conflict. So this step is sort of useless churn). llvm/include/llvm/InitializePasses.h llvm/lib/LTO/LTOCodeGenerator.cpp llvm/lib/Transforms/IPO/IPO.cpp llvm/lib/Transforms/IPO/FunctionAttrs.cpp Rename initializeReversePostOrderFunctionAttrsPass -> initializeReversePostOrderFunctionAttrsLegacyPassPass (note that the "PassPass" thing falls out of `s/ReversePostOrderFunctionAttrs/ReversePostOrderFunctionAttrsLegacyPass/`) Note that the INITIALIZE_PASS macro is what creates this identifier name, so renaming the class requires this renaming too. Note that createReversePostOrderFunctionAttrsPass does not need to be renamed since its name is not generated from the class name. 3. Add the new PM pass class. In the new PM all passes need to have their declaration in a header somewhere, so you will often need to add a header. In this case llvm/include/llvm/Transforms/IPO/FunctionAttrs.h is already there because PostOrderFunctionAttrsPass was already ported. The file-level comment from the .cpp file can be used as the file-level comment for the new header. You may want to tweak the wording slightly from "this file implements" to "this file provides" or similar. Add declaration for the new PM pass in this header: class ReversePostOrderFunctionAttrsPass : public PassInfoMixin<ReversePostOrderFunctionAttrsPass> { public: PreservedAnalyses run(Module &M, AnalysisManager<Module> &AM); }; Its name should end with `Pass` for consistency (note that this doesn't collide with the names of most old PM passes). E.g. call it `<name of the old PM pass>Pass`. Also, move the doxygen comment from the old PM pass to the declaration of this class in the header. Also, include the declaration for the new PM class `llvm/Transforms/IPO/FunctionAttrs.h` at the top of the file (in this case, it was already done when the other pass in this file was ported). Now define the `run` method for the new class. The main things here are: a) Use AM.getResult<...>(M) to get results instead of `getAnalysis<...>()` b) If the old PM pass would have returned "false" (i.e. `Changed == false`), then you should return PreservedAnalyses::all(); c) In the old PM getAnalysisUsage method, observe the calls `AU.addPreserved<...>();`. In the case `Changed == true`, for each preserved analysis you should do call `PA.preserve<...>()` on a PreservedAnalyses object and return it. E.g.: PreservedAnalyses PA; PA.preserve<CallGraphAnalysis>(); return PA; Note that calls to skipModule/skipFunction are not supported in the new PM currently, so optnone and optimization bisect support do not work. You can just drop those calls for now. 4. Add the pass to the new PM pass registry to make it available in opt. In llvm/lib/Passes/PassBuilder.cpp add a #include for your header. `#include "llvm/Transforms/IPO/FunctionAttrs.h"` In this case there is already an include (from when PostOrderFunctionAttrsPass was ported). Add your pass to llvm/lib/Passes/PassRegistry.def In this case, I added `MODULE_PASS("rpo-functionattrs", ReversePostOrderFunctionAttrsPass())` The string is from the `INITIALIZE_PASS*` macros used in the old pass manager. Then choose a test that uses the pass and use the new PM `-passes=...` to run it. E.g. in this case there is a test that does: ; RUN: opt < %s -basicaa -functionattrs -rpo-functionattrs -S | FileCheck %s I have added the line: ; RUN: opt < %s -aa-pipeline=basic-aa -passes='require<targetlibinfo>,cgscc(function-attrs),rpo-functionattrs' -S | FileCheck %s The `-aa-pipeline=basic-aa` and `require<targetlibinfo>,cgscc(function-attrs)` are what is needed to run functionattrs in the new PM (note that in the new PM "functionattrs" becomes "function-attrs" for some reason). This is just pulled from `readattrs.ll` which contains the change from when functionattrs was ported to the new PM. Adding rpo-functionattrs causes the pass that was just ported to run. llvm-svn: 272505
2016-06-12 09:48:51 +02:00
void initializeReversePostOrderFunctionAttrsLegacyPassPass(PassRegistry&);
void initializeRewriteStatepointsForGCLegacyPassPass(PassRegistry &);
void initializeRewriteSymbolsLegacyPassPass(PassRegistry&);
void initializeSCCPLegacyPassPass(PassRegistry&);
void initializeSCEVAAWrapperPassPass(PassRegistry&);
void initializeSLPVectorizerPass(PassRegistry&);
[PM] Port SROA to the new pass manager. In some ways this is a very boring port to the new pass manager as there are no interesting analyses or dependencies or other oddities. However, this does introduce the first good example of a transformation pass with non-trivial state porting to the new pass manager. I've tried to carve out patterns here to replicate elsewhere, and would appreciate comments on whether folks like these patterns: - A common need in the new pass manager is to effectively lift the pass class and some of its state into a public header file. Prior to this, LLVM used anonymous namespaces to provide "module private" types and utilities, but that doesn't scale to cases where a public header file is needed and the new pass manager will exacerbate that. The pattern I've adopted here is to use the namespace-cased-name of the core pass (what would be a module if we had them) as a module-private namespace. Then utility and other code can be declared and defined in this namespace. At some point in the future, we could even have (conditionally compiled) code that used modules features when available to do the same basic thing. - I've split the actual pass run method in two in order to expose a private method usable by the old pass manager to wrap the new class with a minimum of duplicated code. I actually looked at a bunch of ways to automate or generate these, but they are all quite terrible IMO. The fundamental need is to extract the set of analyses which need to cross this interface boundary, and that will end up being too unpredictable to effectively encapsulate IMO. This is also a relatively small amount of boiler plate that will live a relatively short time, so I'm not too worried about the fact that it is boiler plate. The rest of the patch is totally boring but results in a massive diff (sorry). It just moves code around and removes or adds qualifiers to reflect the new name and nesting structure. Differential Revision: http://reviews.llvm.org/D12773 llvm-svn: 247501
2015-09-12 11:09:14 +02:00
void initializeSROALegacyPassPass(PassRegistry&);
void initializeSafeStackLegacyPassPass(PassRegistry&);
void initializeSafepointIRVerifierPass(PassRegistry&);
void initializeSampleProfileLoaderLegacyPassPass(PassRegistry&);
void initializeModuleSanitizerCoverageLegacyPassPass(PassRegistry &);
[PM] Port ScalarEvolution to the new pass manager. This change makes ScalarEvolution a stand-alone object and just produces one from a pass as needed. Making this work well requires making the object movable, using references instead of overwritten pointers in a number of places, and other refactorings. I've also wired it up to the new pass manager and added a RUN line to a test to exercise it under the new pass manager. This includes basic printing support much like with other analyses. But there is a big and somewhat scary change here. Prior to this patch ScalarEvolution was never *actually* invalidated!!! Re-running the pass just re-wired up the various other analyses and didn't remove any of the existing entries in the SCEV caches or clear out anything at all. This might seem OK as everything in SCEV that can uses ValueHandles to track updates to the values that serve as SCEV keys. However, this still means that as we ran SCEV over each function in the module, we kept accumulating more and more SCEVs into the cache. At the end, we would have a SCEV cache with every value that we ever needed a SCEV for in the entire module!!! Yowzers. The releaseMemory routine would dump all of this, but that isn't realy called during normal runs of the pipeline as far as I can see. To make matters worse, there *is* actually a key that we don't update with value handles -- there is a map keyed off of Loop*s. Because LoopInfo *does* release its memory from run to run, it is entirely possible to run SCEV over one function, then over another function, and then lookup a Loop* from the second function but find an entry inserted for the first function! Ouch. To make matters still worse, there are plenty of updates that *don't* trip a value handle. It seems incredibly unlikely that today GVN or another pass that invalidates SCEV can update values in *just* such a way that a subsequent run of SCEV will incorrectly find lookups in a cache, but it is theoretically possible and would be a nightmare to debug. With this refactoring, I've fixed all this by actually destroying and recreating the ScalarEvolution object from run to run. Technically, this could increase the amount of malloc traffic we see, but then again it is also technically correct. ;] I don't actually think we're suffering from tons of malloc traffic from SCEV because if we were, the fact that we never clear the memory would seem more likely to have come up as an actual problem before now. So, I've made the simple fix here. If in fact there are serious issues with too much allocation and deallocation, I can work on a clever fix that preserves the allocations (while clearing the data) between each run, but I'd prefer to do that kind of optimization with a test case / benchmark that shows why we need such cleverness (and that can test that we actually make it faster). It's possible that this will make some things faster by making the SCEV caches have higher locality (due to being significantly smaller) so until there is a clear benchmark, I think the simple change is best. Differential Revision: http://reviews.llvm.org/D12063 llvm-svn: 245193
2015-08-17 04:08:17 +02:00
void initializeScalarEvolutionWrapperPassPass(PassRegistry&);
void initializeScalarizeMaskedMemIntrinLegacyPassPass(PassRegistry &);
void initializeScalarizerLegacyPassPass(PassRegistry&);
void initializeScavengerTestPass(PassRegistry&);
void initializeScopedNoAliasAAWrapperPassPass(PassRegistry&);
void initializeSeparateConstOffsetFromGEPLegacyPassPass(PassRegistry &);
void initializeShadowStackGCLoweringPass(PassRegistry&);
void initializeShrinkWrapPass(PassRegistry&);
void initializeSimpleInlinerPass(PassRegistry&);
[PM/LoopUnswitch] Introduce a new, simpler loop unswitch pass. Currently, this pass only focuses on *trivial* loop unswitching. At that reduced problem it remains significantly better than the current loop unswitch: - Old pass is worse than cubic complexity. New pass is (I think) linear. - New pass is much simpler in its design by focusing on full unswitching. (See below for details on this). - New pass doesn't carry state for thresholds between pass iterations. - New pass doesn't carry state for correctness (both miscompile and infloop) between pass iterations. - New pass produces substantially better code after unswitching. - New pass can handle more trivial unswitch cases. - New pass doesn't recompute the dominator tree for the entire function and instead incrementally updates it. I've ported all of the trivial unswitching test cases from the old pass to the new one to make sure that major functionality isn't lost in the process. For several of the test cases I've worked to improve the precision and rigor of the CHECKs, but for many I've just updated them to handle the new IR produced. My initial motivation was the fact that the old pass carried state in very unreliable ways between pass iterations, and these mechansims were incompatible with the new pass manager. However, I discovered many more improvements to make along the way. This pass makes two very significant assumptions that enable most of these improvements: 1) Focus on *full* unswitching -- that is, completely removing whatever control flow construct is being unswitched from the loop. In the case of trivial unswitching, this means removing the trivial (exiting) edge. In non-trivial unswitching, this means removing the branch or switch itself. This is in opposition to *partial* unswitching where some part of the unswitched control flow remains in the loop. Partial unswitching only really applies to switches and to folded branches. These are very similar to full unrolling and partial unrolling. The full form is an effective canonicalization, the partial form needs a complex cost model, cannot be iterated, isn't canonicalizing, and should be a separate pass that runs very late (much like unrolling). 2) Leverage LLVM's Loop machinery to the fullest. The original unswitch dates from a time when a great deal of LLVM's loop infrastructure was missing, ineffective, and/or unreliable. As a consequence, a lot of complexity was added which we no longer need. With these two overarching principles, I think we can build a fast and effective unswitcher that fits in well in the new PM and in the canonicalization pipeline. Some of the remaining functionality around partial unswitching may not be relevant today (not many test cases or benchmarks I can find) but if they are I'd like to add support for them as a separate layer that runs very late in the pipeline. Purely to make reviewing and introducing this code more manageable, I've split this into first a trivial-unswitch-only pass and in the next patch I'll add support for full non-trivial unswitching against a *fixed* threshold, exactly like full unrolling. I even plan to re-use the unrolling thresholds, as these are incredibly similar cost tradeoffs: we're cloning a loop body in order to end up with simplified control flow. We should only do that when the total growth is reasonably small. One of the biggest changes with this pass compared to the previous one is that previously, each individual trivial exiting edge from a switch was unswitched separately as a branch. Now, we unswitch the entire switch at once, with cases going to the various destinations. This lets us unswitch multiple exiting edges in a single operation and also avoids numerous extremely bad behaviors, where we would introduce 1000s of branches to test for thousands of possible values, all of which would take the exact same exit path bypassing the loop. Now we will use a switch with 1000s of cases that can be efficiently lowered into a jumptable. This avoids relying on somehow forming a switch out of the branches or getting horrible code if that fails for any reason. Another significant change is that this pass actively updates the CFG based on unswitching. For trivial unswitching, this is actually very easy because of the definition of loop simplified form. Doing this makes the code coming out of loop unswitch dramatically more friendly. We still should run loop-simplifycfg (at the least) after this to clean up, but it will have to do a lot less work. Finally, this pass makes much fewer attempts to simplify instructions based on the unswitch. Something like loop-instsimplify, instcombine, or GVN can be used to do increasingly powerful simplifications based on the now dominating predicate. The old simplifications are things that something like loop-instsimplify should get today or a very, very basic loop-instcombine could get. Keeping that logic separate is a big simplifying technique. Most of the code in this pass that isn't in the old one has to do with achieving specific goals: - Updating the dominator tree as we go - Unswitching all cases in a switch in a single step. I think it is still shorter than just the trivial unswitching code in the old pass despite having this functionality. Differential Revision: https://reviews.llvm.org/D32409 llvm-svn: 301576
2017-04-27 20:45:20 +02:00
void initializeSimpleLoopUnswitchLegacyPassPass(PassRegistry&);
void initializeSingleLoopExtractorPass(PassRegistry&);
void initializeSinkingLegacyPassPass(PassRegistry&);
void initializeSjLjEHPreparePass(PassRegistry&);
void initializeSlotIndexesPass(PassRegistry&);
void initializeSpeculativeExecutionLegacyPassPass(PassRegistry&);
void initializeSpillPlacementPass(PassRegistry&);
void initializeStackColoringPass(PassRegistry&);
void initializeStackMapLivenessPass(PassRegistry&);
void initializeStackProtectorPass(PassRegistry&);
void initializeStackSafetyGlobalInfoWrapperPassPass(PassRegistry &);
void initializeStackSafetyInfoWrapperPassPass(PassRegistry &);
void initializeStackSlotColoringPass(PassRegistry&);
void initializeStraightLineStrengthReduceLegacyPassPass(PassRegistry &);
void initializeStripDeadDebugInfoPass(PassRegistry&);
void initializeStripDeadPrototypesLegacyPassPass(PassRegistry&);
void initializeStripDebugDeclarePass(PassRegistry&);
void initializeStripDebugMachineModulePass(PassRegistry &);
void initializeStripGCRelocatesLegacyPass(PassRegistry &);
void initializeStripNonDebugSymbolsPass(PassRegistry&);
void initializeStripNonLineTableDebugLegacyPassPass(PassRegistry &);
void initializeStripSymbolsPass(PassRegistry&);
void initializeStructurizeCFGLegacyPassPass(PassRegistry &);
void initializeTailCallElimPass(PassRegistry&);
void initializeTailDuplicatePass(PassRegistry&);
void initializeTargetLibraryInfoWrapperPassPass(PassRegistry&);
void initializeTargetPassConfigPass(PassRegistry&);
void initializeTargetTransformInfoWrapperPassPass(PassRegistry&);
void initializeThreadSanitizerLegacyPassPass(PassRegistry&);
void initializeTwoAddressInstructionPassPass(PassRegistry&);
[PM/AA] Rebuild LLVM's alias analysis infrastructure in a way compatible with the new pass manager, and no longer relying on analysis groups. This builds essentially a ground-up new AA infrastructure stack for LLVM. The core ideas are the same that are used throughout the new pass manager: type erased polymorphism and direct composition. The design is as follows: - FunctionAAResults is a type-erasing alias analysis results aggregation interface to walk a single query across a range of results from different alias analyses. Currently this is function-specific as we always assume that aliasing queries are *within* a function. - AAResultBase is a CRTP utility providing stub implementations of various parts of the alias analysis result concept, notably in several cases in terms of other more general parts of the interface. This can be used to implement only a narrow part of the interface rather than the entire interface. This isn't really ideal, this logic should be hoisted into FunctionAAResults as currently it will cause a significant amount of redundant work, but it faithfully models the behavior of the prior infrastructure. - All the alias analysis passes are ported to be wrapper passes for the legacy PM and new-style analysis passes for the new PM with a shared result object. In some cases (most notably CFL), this is an extremely naive approach that we should revisit when we can specialize for the new pass manager. - BasicAA has been restructured to reflect that it is much more fundamentally a function analysis because it uses dominator trees and loop info that need to be constructed for each function. All of the references to getting alias analysis results have been updated to use the new aggregation interface. All the preservation and other pass management code has been updated accordingly. The way the FunctionAAResultsWrapperPass works is to detect the available alias analyses when run, and add them to the results object. This means that we should be able to continue to respect when various passes are added to the pipeline, for example adding CFL or adding TBAA passes should just cause their results to be available and to get folded into this. The exception to this rule is BasicAA which really needs to be a function pass due to using dominator trees and loop info. As a consequence, the FunctionAAResultsWrapperPass directly depends on BasicAA and always includes it in the aggregation. This has significant implications for preserving analyses. Generally, most passes shouldn't bother preserving FunctionAAResultsWrapperPass because rebuilding the results just updates the set of known AA passes. The exception to this rule are LoopPass instances which need to preserve all the function analyses that the loop pass manager will end up needing. This means preserving both BasicAAWrapperPass and the aggregating FunctionAAResultsWrapperPass. Now, when preserving an alias analysis, you do so by directly preserving that analysis. This is only necessary for non-immutable-pass-provided alias analyses though, and there are only three of interest: BasicAA, GlobalsAA (formerly GlobalsModRef), and SCEVAA. Usually BasicAA is preserved when needed because it (like DominatorTree and LoopInfo) is marked as a CFG-only pass. I've expanded GlobalsAA into the preserved set everywhere we previously were preserving all of AliasAnalysis, and I've added SCEVAA in the intersection of that with where we preserve SCEV itself. One significant challenge to all of this is that the CGSCC passes were actually using the alias analysis implementations by taking advantage of a pretty amazing set of loop holes in the old pass manager's analysis management code which allowed analysis groups to slide through in many cases. Moving away from analysis groups makes this problem much more obvious. To fix it, I've leveraged the flexibility the design of the new PM components provides to just directly construct the relevant alias analyses for the relevant functions in the IPO passes that need them. This is a bit hacky, but should go away with the new pass manager, and is already in many ways cleaner than the prior state. Another significant challenge is that various facilities of the old alias analysis infrastructure just don't fit any more. The most significant of these is the alias analysis 'counter' pass. That pass relied on the ability to snoop on AA queries at different points in the analysis group chain. Instead, I'm planning to build printing functionality directly into the aggregation layer. I've not included that in this patch merely to keep it smaller. Note that all of this needs a nearly complete rewrite of the AA documentation. I'm planning to do that, but I'd like to make sure the new design settles, and to flesh out a bit more of what it looks like in the new pass manager first. Differential Revision: http://reviews.llvm.org/D12080 llvm-svn: 247167
2015-09-09 19:55:00 +02:00
void initializeTypeBasedAAWrapperPassPass(PassRegistry&);
void initializeTypePromotionPass(PassRegistry&);
void initializeUnifyFunctionExitNodesLegacyPassPass(PassRegistry &);
void initializeUnifyLoopExitsLegacyPassPass(PassRegistry &);
void initializeUnpackMachineBundlesPass(PassRegistry&);
void initializeUnreachableBlockElimLegacyPassPass(PassRegistry&);
void initializeUnreachableMachineBlockElimPass(PassRegistry&);
[VectorCombine] new IR transform pass for partial vector ops We have several bug reports that could be characterized as "reducing scalarization", and this topic was also raised on llvm-dev recently: http://lists.llvm.org/pipermail/llvm-dev/2020-January/138157.html ...so I'm proposing that we deal with these patterns in a new, lightweight IR vector pass that runs before/after other vectorization passes. There are 4 alternate options that I can think of to deal with this kind of problem (and we've seen various attempts at all of these), but they all have flaws: InstCombine - can't happen without TTI, but we don't want target-specific folds there. SDAG - too late to assist other vectorization passes; TLI is not equipped for these kind of cost queries; limited to a single basic block. CGP - too late to assist other vectorization passes; would need to re-implement basic cleanups like CSE/instcombine. SLP - doesn't fit with existing transforms; limited to a single basic block. This initial patch/transform is based on existing code in AggressiveInstCombine: we walk backwards through the function looking for a pattern match. But we diverge from that cost-independent IR canonicalization pass by using TTI to decide if the vector alternative is profitable. We probably have at least 10 similar bug reports/patterns (binops, constants, inserts, cheap shuffles, etc) that would fit in this pass as follow-up enhancements. It's possible that we could iterate on a worklist to fix-point like InstCombine does, but it's safer to start with a most basic case and evolve from there, so I didn't try to do anything fancy with this initial implementation. Differential Revision: https://reviews.llvm.org/D73480
2020-02-09 16:04:41 +01:00
void initializeVectorCombineLegacyPassPass(PassRegistry&);
void initializeVerifierLegacyPassPass(PassRegistry&);
void initializeVirtRegMapPass(PassRegistry&);
void initializeVirtRegRewriterPass(PassRegistry&);
[Unroll/UnrollAndJam/Vectorizer/Distribute] Add followup loop attributes. When multiple loop transformation are defined in a loop's metadata, their order of execution is defined by the order of their respective passes in the pass pipeline. For instance, e.g. #pragma clang loop unroll_and_jam(enable) #pragma clang loop distribute(enable) is the same as #pragma clang loop distribute(enable) #pragma clang loop unroll_and_jam(enable) and will try to loop-distribute before Unroll-And-Jam because the LoopDistribute pass is scheduled after UnrollAndJam pass. UnrollAndJamPass only supports one inner loop, i.e. it will necessarily fail after loop distribution. It is not possible to specify another execution order. Also,t the order of passes in the pipeline is subject to change between versions of LLVM, optimization options and which pass manager is used. This patch adds 'followup' attributes to various loop transformation passes. These attributes define which attributes the resulting loop of a transformation should have. For instance, !0 = !{!0, !1, !2} !1 = !{!"llvm.loop.unroll_and_jam.enable"} !2 = !{!"llvm.loop.unroll_and_jam.followup_inner", !3} !3 = !{!"llvm.loop.distribute.enable"} defines a loop ID (!0) to be unrolled-and-jammed (!1) and then the attribute !3 to be added to the jammed inner loop, which contains the instruction to distribute the inner loop. Currently, in both pass managers, pass execution is in a fixed order and UnrollAndJamPass will not execute again after LoopDistribute. We hope to fix this in the future by allowing pass managers to run passes until a fixpoint is reached, use Polly to perform these transformations, or add a loop transformation pass which takes the order issue into account. For mandatory/forced transformations (e.g. by having been declared by #pragma omp simd), the user must be notified when a transformation could not be performed. It is not possible that the responsible pass emits such a warning because the transformation might be 'hidden' in a followup attribute when it is executed, or it is not present in the pipeline at all. For this reason, this patche introduces a WarnMissedTransformations pass, to warn about orphaned transformations. Since this changes the user-visible diagnostic message when a transformation is applied, two test cases in the clang repository need to be updated. To ensure that no other transformation is executed before the intended one, the attribute `llvm.loop.disable_nonforced` can be added which should disable transformation heuristics before the intended transformation is applied. E.g. it would be surprising if a loop is distributed before a #pragma unroll_and_jam is applied. With more supported code transformations (loop fusion, interchange, stripmining, offloading, etc.), transformations can be used as building blocks for more complex transformations (e.g. stripmining+stripmining+interchange -> tiling). Reviewed By: hfinkel, dmgreen Differential Revision: https://reviews.llvm.org/D49281 Differential Revision: https://reviews.llvm.org/D55288 llvm-svn: 348944
2018-12-12 18:32:52 +01:00
void initializeWarnMissedTransformationsLegacyPass(PassRegistry &);
void initializeWasmEHPreparePass(PassRegistry&);
void initializeWholeProgramDevirtPass(PassRegistry&);
void initializeWinEHPreparePass(PassRegistry&);
void initializeWriteBitcodePassPass(PassRegistry&);
void initializeWriteThinLTOBitcodePass(PassRegistry&);
void initializeXRayInstrumentationPass(PassRegistry&);
} // end namespace llvm
#endif // LLVM_INITIALIZEPASSES_H