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llvm-mirror/include/llvm/InitializePasses.h

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//===- llvm/InitializePasses.h - Initialize All Passes ----------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// 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 initializeAddressSanitizerModulePass(PassRegistry&);
void initializeAddressSanitizerPass(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 initializeArgPromotionPass(PassRegistry&);
void initializeAssumptionCacheTrackerPass(PassRegistry&);
void initializeAtomicExpandPass(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 initializeBlockExtractorPass(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 initializeCFGOnlyPrinterLegacyPassPass(PassRegistry&);
void initializeCFGOnlyViewerLegacyPassPass(PassRegistry&);
void initializeCFGPrinterLegacyPassPass(PassRegistry&);
void initializeCFGSimplifyPassPass(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 initializeCallGraphDOTPrinterPass(PassRegistry&);
void initializeCallGraphPrinterLegacyPassPass(PassRegistry&);
void initializeCallGraphViewerPass(PassRegistry&);
void initializeCallGraphWrapperPassPass(PassRegistry&);
void initializeCallSiteSplittingLegacyPassPass(PassRegistry&);
void initializeCalledValuePropagationLegacyPassPass(PassRegistry &);
void initializeCodeGenPreparePass(PassRegistry&);
void initializeConstantHoistingLegacyPassPass(PassRegistry&);
void initializeConstantMergeLegacyPassPass(PassRegistry&);
void initializeConstantPropagationPass(PassRegistry&);
void initializeCorrelatedValuePropagationPass(PassRegistry&);
void initializeCostModelAnalysisPass(PassRegistry&);
void initializeCrossDSOCFIPass(PassRegistry&);
void initializeDAEPass(PassRegistry&);
void initializeDAHPass(PassRegistry&);
void initializeDCELegacyPassPass(PassRegistry&);
void initializeDSELegacyPassPass(PassRegistry&);
void initializeDataFlowSanitizerPass(PassRegistry&);
void initializeDeadInstEliminationPass(PassRegistry&);
void initializeDeadMachineInstructionElimPass(PassRegistry&);
void initializeDelinearizationPass(PassRegistry&);
void initializeDemandedBitsWrapperPassPass(PassRegistry&);
void initializeDependenceAnalysisPass(PassRegistry&);
void initializeDependenceAnalysisWrapperPassPass(PassRegistry&);
void initializeDetectDeadLanesPass(PassRegistry&);
void initializeDivRemPairsLegacyPassPass(PassRegistry&);
void initializeDivergenceAnalysisPass(PassRegistry&);
void initializeDomOnlyPrinterPass(PassRegistry&);
void initializeDomOnlyViewerPass(PassRegistry&);
void initializeDomPrinterPass(PassRegistry&);
void initializeDomViewerPass(PassRegistry&);
void initializeDominanceFrontierWrapperPassPass(PassRegistry&);
void initializeDominatorTreeWrapperPassPass(PassRegistry&);
void initializeDwarfEHPreparePass(PassRegistry&);
void initializeEarlyCSELegacyPassPass(PassRegistry&);
void initializeEarlyCSEMemSSALegacyPassPass(PassRegistry&);
void initializeEarlyIfConverterPass(PassRegistry&);
void initializeEarlyMachineLICMPass(PassRegistry&);
void initializeEarlyTailDuplicatePass(PassRegistry&);
void initializeEdgeBundlesPass(PassRegistry&);
void initializeEfficiencySanitizerPass(PassRegistry&);
void initializeEliminateAvailableExternallyLegacyPassPass(PassRegistry&);
void initializeEntryExitInstrumenterPass(PassRegistry&);
void initializeExpandISelPseudosPass(PassRegistry&);
void initializeExpandMemCmpPassPass(PassRegistry&);
void initializeExpandPostRAPass(PassRegistry&);
void initializeExpandReductionsPass(PassRegistry&);
void initializeExternalAAWrapperPassPass(PassRegistry&);
void initializeFEntryInserterPass(PassRegistry&);
void initializeFinalizeMachineBundlesPass(PassRegistry&);
void initializeFlattenCFGPassPass(PassRegistry&);
void initializeFloat2IntLegacyPassPass(PassRegistry&);
void initializeForceFunctionAttrsLegacyPassPass(PassRegistry&);
void initializeForwardControlFlowIntegrityPass(PassRegistry&);
void initializeFuncletLayoutPass(PassRegistry&);
void initializeFunctionImportLegacyPassPass(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 initializeHWAddressSanitizerPass(PassRegistry&);
void initializeIPCPPass(PassRegistry&);
void initializeIPSCCPLegacyPassPass(PassRegistry&);
void initializeIRCELegacyPassPass(PassRegistry&);
void initializeIRTranslatorPass(PassRegistry&);
void initializeIVUsersWrapperPassPass(PassRegistry&);
void initializeIfConverterPass(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 initializeInlineCostAnalysisPass(PassRegistry&);
void initializeInstCountPass(PassRegistry&);
void initializeInstNamerPass(PassRegistry&);
void initializeInstSimplifyLegacyPassPass(PassRegistry &);
void initializeInstrProfilingLegacyPassPass(PassRegistry&);
void initializeInstructionCombiningPassPass(PassRegistry&);
void initializeInstructionSelectPass(PassRegistry&);
void initializeInterleavedAccessPass(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 initializeLegacyLICMPassPass(PassRegistry&);
void initializeLegacyLoopSinkPassPass(PassRegistry&);
void initializeLegalizerPass(PassRegistry&);
void initializeLibCallsShrinkWrapLegacyPassPass(PassRegistry&);
void initializeLintPass(PassRegistry&);
void initializeLiveDebugValuesPass(PassRegistry&);
void initializeLiveDebugVariablesPass(PassRegistry&);
void initializeLiveIntervalsPass(PassRegistry&);
void initializeLiveRangeShrinkPass(PassRegistry&);
void initializeLiveRegMatrixPass(PassRegistry&);
void initializeLiveStacksPass(PassRegistry&);
void initializeLiveVariablesPass(PassRegistry&);
void initializeLoadStoreVectorizerPass(PassRegistry&);
void initializeLoaderPassPass(PassRegistry&);
void initializeLocalStackSlotPassPass(PassRegistry&);
void initializeLocalizerPass(PassRegistry&);
void initializeLoopAccessLegacyAnalysisPass(PassRegistry&);
void initializeLoopDataPrefetchLegacyPassPass(PassRegistry&);
void initializeLoopDeletionLegacyPassPass(PassRegistry&);
void initializeLoopDistributeLegacyPass(PassRegistry&);
void initializeLoopExtractorPass(PassRegistry&);
void initializeLoopGuardWideningLegacyPassPass(PassRegistry&);
void initializeLoopIdiomRecognizeLegacyPassPass(PassRegistry&);
void initializeLoopInfoWrapperPassPass(PassRegistry&);
void initializeLoopInstSimplifyLegacyPassPass(PassRegistry&);
void initializeLoopInterchangePass(PassRegistry&);
void initializeLoopLoadEliminationPass(PassRegistry&);
void initializeLoopPassPass(PassRegistry&);
void initializeLoopPredicationLegacyPassPass(PassRegistry&);
void initializeLoopRerollPass(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 initializeLoopVersioningLICMPass(PassRegistry&);
void initializeLoopVersioningPassPass(PassRegistry&);
void initializeLowerAtomicLegacyPassPass(PassRegistry&);
void initializeLowerEmuTLSPass(PassRegistry&);
void initializeLowerExpectIntrinsicPass(PassRegistry&);
void initializeLowerGuardIntrinsicLegacyPassPass(PassRegistry&);
void initializeLowerIntrinsicsPass(PassRegistry&);
void initializeLowerInvokeLegacyPassPass(PassRegistry&);
void initializeLowerSwitchPass(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&);
void initializeMIRCanonicalizerPass(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 initializeMachineLICMPass(PassRegistry&);
void initializeMachineLoopInfoPass(PassRegistry&);
void initializeMachineModuleInfoPass(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 initializeMemorySanitizerPass(PassRegistry&);
void initializeMergeFunctionsPass(PassRegistry&);
void initializeMergeICmpsPass(PassRegistry&);
void initializeMergedLoadStoreMotionLegacyPassPass(PassRegistry&);
void initializeMetaRenamerPass(PassRegistry&);
void initializeModuleDebugInfoPrinterPass(PassRegistry&);
void initializeModuleSummaryIndexWrapperPassPass(PassRegistry&);
void initializeMustExecutePrinterPass(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 initializeObjCARCContractPass(PassRegistry&);
void initializeObjCARCExpandPass(PassRegistry&);
void initializeObjCARCOptPass(PassRegistry&);
void initializeOptimizationRemarkEmitterWrapperPassPass(PassRegistry&);
void initializeOptimizePHIsPass(PassRegistry&);
void initializePAEvalPass(PassRegistry&);
void initializePEIPass(PassRegistry&);
void initializePGOIndirectCallPromotionLegacyPassPass(PassRegistry&);
void initializePGOInstrumentationGenLegacyPassPass(PassRegistry&);
void initializePGOInstrumentationUseLegacyPassPass(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 initializePrintBasicBlockPassPass(PassRegistry&);
void initializePrintFunctionPassWrapperPass(PassRegistry&);
void initializePrintModulePassWrapperPass(PassRegistry&);
void initializeProcessImplicitDefsPass(PassRegistry&);
void initializeProfileSummaryInfoWrapperPassPass(PassRegistry&);
void initializePromoteLegacyPassPass(PassRegistry&);
void initializePruneEHPass(PassRegistry&);
void initializeRABasicPass(PassRegistry&);
void initializeRAGreedyPass(PassRegistry&);
void initializeReachingDefAnalysisPass(PassRegistry&);
void initializeReassociateLegacyPassPass(PassRegistry&);
void initializeRegAllocFastPass(PassRegistry&);
void initializeRegBankSelectPass(PassRegistry&);
void initializeRegToMemPass(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&);
void initializeRenameIndependentSubregsPass(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 initializeSanitizerCoverageModulePass(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 initializeScalarizeMaskedMemIntrinPass(PassRegistry&);
void initializeScalarizerPass(PassRegistry&);
void initializeScavengerTestPass(PassRegistry&);
void initializeScopedNoAliasAAWrapperPassPass(PassRegistry&);
void initializeSeparateConstOffsetFromGEPPass(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 initializeStackSlotColoringPass(PassRegistry&);
void initializeStraightLineStrengthReducePass(PassRegistry&);
void initializeStripDeadDebugInfoPass(PassRegistry&);
void initializeStripDeadPrototypesLegacyPassPass(PassRegistry&);
void initializeStripDebugDeclarePass(PassRegistry&);
void initializeStripGCRelocatesPass(PassRegistry&);
void initializeStripNonDebugSymbolsPass(PassRegistry&);
void initializeStripNonLineTableDebugInfoPass(PassRegistry&);
void initializeStripSymbolsPass(PassRegistry&);
void initializeStructurizeCFGPass(PassRegistry&);
void initializeTailCallElimPass(PassRegistry&);
void initializeTailDuplicatePass(PassRegistry&);
void initializeTargetLibraryInfoWrapperPassPass(PassRegistry&);
void initializeTargetPassConfigPass(PassRegistry&);
void initializeTargetTransformInfoWrapperPassPass(PassRegistry&);
void initializeThreadSanitizerPass(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 initializeUnifyFunctionExitNodesPass(PassRegistry&);
void initializeUnpackMachineBundlesPass(PassRegistry&);
void initializeUnreachableBlockElimLegacyPassPass(PassRegistry&);
void initializeUnreachableMachineBlockElimPass(PassRegistry&);
void initializeVerifierLegacyPassPass(PassRegistry&);
void initializeVirtRegMapPass(PassRegistry&);
void initializeVirtRegRewriterPass(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