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* [PM/AA] Rebuild LLVM's alias analysis infrastructure in a way compatibleChandler Carruth2015-09-091-62/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* [PM] Port ScalarEvolution to the new pass manager.Chandler Carruth2015-08-171-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* [PM/AA] Clean up the SCEV-AA comment formatting and typos.Chandler Carruth2015-08-141-2/+3
| | | | llvm-svn: 245015
* [PM/AA] Run clang-format over the SCEV-AA code to normalize theChandler Carruth2015-08-141-10/+10
| | | | | | formatting. llvm-svn: 245014
* [PM/AA] Hoist the SCEV-AA interface to its own header and pull theChandler Carruth2015-08-141-39/+1
| | | | | | creation function into that header. llvm-svn: 245013
* [PM/AA] Hoist the AliasResult enum out of the AliasAnalysis class.Chandler Carruth2015-06-221-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | This will allow classes to implement the AA interface without deriving from the class or referencing an internal enum of some other class as their return types. Also, to a pretty fundamental extent, concepts such as 'NoAlias', 'MayAlias', and 'MustAlias' are first class concepts in LLVM and we aren't saving anything by scoping them heavily. My mild preference would have been to use a scoped enum, but that feature is essentially completely broken AFAICT. I'm extremely disappointed. For example, we cannot through any reasonable[1] means construct an enum class (or analog) which has scoped names but converts to a boolean in order to test for the possibility of aliasing. [1]: Richard Smith came up with a "solution", but it requires class templates, and lots of boilerplate setting up the enumeration multiple times. Something like Boost.PP could potentially bundle this up, but even that would be quite painful and it doesn't seem realistically worth it. The enum class solution would probably work without the need for a bool conversion. Differential Revision: http://reviews.llvm.org/D10495 llvm-svn: 240255
* [PM/AA] Remove the UnknownSize static member from AliasAnalysis.Chandler Carruth2015-06-171-2/+4
| | | | | | | | This is now living in MemoryLocation, which is what it pertains to. It is also an enum there rather than a static data member which is left never defined. llvm-svn: 239886
* [PM/AA] Remove the Location typedef from the AliasAnalysis class nowChandler Carruth2015-06-171-9/+8
| | | | | | | | | | | | that it is its own entity in the form of MemoryLocation, and update all the callers. This is an entirely mechanical change. References to "Location" within AA subclases become "MemoryLocation", and elsewhere "AliasAnalysis::Location" becomes "MemoryLocation". Hope that helps out-of-tree folks update. llvm-svn: 239885
* Make DataLayout Non-Optional in the ModuleMehdi Amini2015-03-041-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: DataLayout keeps the string used for its creation. As a side effect it is no longer needed in the Module. This is "almost" NFC, the string is no longer canonicalized, you can't rely on two "equals" DataLayout having the same string returned by getStringRepresentation(). Get rid of DataLayoutPass: the DataLayout is in the Module The DataLayout is "per-module", let's enforce this by not duplicating it more than necessary. One more step toward non-optionality of the DataLayout in the module. Make DataLayout Non-Optional in the Module Module->getDataLayout() will never returns nullptr anymore. Reviewers: echristo Subscribers: resistor, llvm-commits, jholewinski Differential Revision: http://reviews.llvm.org/D7992 From: Mehdi Amini <mehdi.amini@apple.com> llvm-svn: 231270
* AA metadata refactoring (introduce AAMDNodes)Hal Finkel2014-07-241-2/+2
| | | | | | | | | | | | | | | | | | | | In order to enable the preservation of noalias function parameter information after inlining, and the representation of block-level __restrict__ pointer information (etc.), additional kinds of aliasing metadata will be introduced. This metadata needs to be carried around in AliasAnalysis::Location objects (and MMOs at the SDAG level), and so we need to generalize the current scheme (which is hard-coded to just one TBAA MDNode*). This commit introduces only the necessary refactoring to allow for the introduction of other aliasing metadata types, but does not actually introduce any (that will come in a follow-up commit). What it does introduce is a new AAMDNodes structure to hold all of the aliasing metadata nodes associated with a particular memory-accessing instruction, and uses that structure instead of the raw MDNode* in AliasAnalysis::Location, etc. No functionality change intended. llvm-svn: 213859
* [C++11] More 'nullptr' conversion. In some cases just using a boolean check ↵Craig Topper2014-04-151-4/+4
| | | | | | instead of comparing to nullptr. llvm-svn: 206243
* [C++11] Add 'override' keyword to virtual methods that override their base ↵Craig Topper2014-03-051-4/+4
| | | | | | class. llvm-svn: 202945
* Use the new script to sort the includes of every file under lib.Chandler Carruth2012-12-031-1/+1
| | | | | | | | | | | | | | | | | Sooooo many of these had incorrect or strange main module includes. I have manually inspected all of these, and fixed the main module include to be the nearest plausible thing I could find. If you own or care about any of these source files, I encourage you to take some time and check that these edits were sensible. I can't have broken anything (I strictly added headers, and reordered them, never removed), but they may not be the headers you'd really like to identify as containing the API being implemented. Many forward declarations and missing includes were added to a header files to allow them to parse cleanly when included first. The main module rule does in fact have its merits. =] llvm-svn: 169131
* Get rid of static constructors for pass registration. Instead, every pass ↵Owen Anderson2010-10-191-1/+4
| | | | | | | | | | | | | | | | | exposes an initializeMyPassFunction(), which must be called in the pass's constructor. This function uses static dependency declarations to recursively initialize the pass's dependencies. Clients that only create passes through the createFooPass() APIs will require no changes. Clients that want to use the CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h before parsing commandline arguments. I have tested this with all standard configurations of clang and llvm-gcc on Darwin. It is possible that there are problems with the static dependencies that will only be visible with non-standard options. If you encounter any crash in pass registration/creation, please send the testcase to me directly. llvm-svn: 116820
* Begin adding static dependence information to passes, which will allow us toOwen Anderson2010-10-121-1/+4
| | | | | | | | | perform initialization without static constructors AND without explicit initialization by the client. For the moment, passes are required to initialize both their (potential) dependencies and any passes they preserve. I hope to be able to relax the latter requirement in the future. llvm-svn: 116334
* Now with fewer extraneous semicolons!Owen Anderson2010-10-071-1/+1
| | | | llvm-svn: 115996
* Remove the experimental AliasAnalysis::getDependency interface, whichDan Gohman2010-09-141-13/+16
| | | | | | | | | | | isn't a good level of abstraction for memdep. Instead, generalize AliasAnalysis::alias and related interfaces with a new Location class for describing a memory location. For now, this is the same Pointer and Size as before, plus an additional field for a TBAA tag. Also, introduce a fixed MD_tbaa metadata tag kind. llvm-svn: 113858
* Reapply r110396, with fixes to appease the Linux buildbot gods.Owen Anderson2010-08-061-3/+3
| | | | llvm-svn: 110460
* Revert r110396 to fix buildbots.Owen Anderson2010-08-061-3/+3
| | | | llvm-svn: 110410
* Don't use PassInfo* as a type identifier for passes. Instead, use the ↵Owen Anderson2010-08-051-3/+3
| | | | | | | | address of the static ID member as the sole unique type identifier. Clean up APIs related to this change. llvm-svn: 110396
* Introduce a symbolic constant for ~0u for use with AliasAnalysis.Dan Gohman2010-08-031-2/+2
| | | | llvm-svn: 110091
* Add INSTANTIATE_AG_PASS, which combines RegisterPass<> with ↵Owen Anderson2010-07-211-5/+2
| | | | | | RegisterAnalysisGroup<> for pass registration. llvm-svn: 109058
* Speculatively revert r108813, in an attempt to get the self-host buildbots ↵Owen Anderson2010-07-201-1/+1
| | | | | | | | working again. I don't see why this patch would cause them to fail the way they are, but none of the other intervening patches seem likely either. llvm-svn: 108818
* Reapply r108794, a fix for the failing test from last time.Owen Anderson2010-07-201-1/+1
| | | | llvm-svn: 108813
* Revert r108794, "Separate PassInfo into two classes: a constructor-freeDaniel Dunbar2010-07-201-1/+1
| | | | | | | superclass (StaticPassInfo) and a constructor-ful subclass (PassInfo).", it is breaking teh everything. llvm-svn: 108805
* Separate PassInfo into two classes: a constructor-free superclass ↵Owen Anderson2010-07-201-1/+1
| | | | | | (StaticPassInfo) and a constructor-ful subclass (PassInfo). llvm-svn: 108794
* Rework scev-aa's basic computation so that it doesn't dependDan Gohman2010-06-301-7/+31
| | | | | | | | on ScalarEvolution successfully folding and preserving range information for both A-B and B-A. Now, if it gets either one, it's sufficient. llvm-svn: 107249
* Fix a typo in a comment.Dan Gohman2010-06-181-1/+1
| | | | llvm-svn: 106260
* Add a comment.Dan Gohman2010-03-011-1/+5
| | | | llvm-svn: 97459
* There are two ways of checking for a given type, for example isa<PointerType>(T)Duncan Sands2010-02-161-1/+1
| | | | | | | and T->isPointerTy(). Convert most instances of the first form to the second form. Requested by Chris. llvm-svn: 96344
* adopt getAdjustedAnalysisPointer in a few more passes.Chris Lattner2010-01-201-0/+10
| | | | llvm-svn: 94018
* Make ScalarEvolutionAliasAnalysis slightly more aggressive, by making anDan Gohman2009-10-311-13/+10
| | | | | | underlying alias call even for non-identified-object values. llvm-svn: 85656
* Remove includes of Support/Compiler.h that are no longer needed after theNick Lewycky2009-10-251-1/+0
| | | | | | VISIBILITY_HIDDEN removal. llvm-svn: 85043
* Remove VISIBILITY_HIDDEN from class/struct found inside anonymous namespaces.Nick Lewycky2009-10-251-2/+2
| | | | | | | Chris claims we should never have visibility_hidden inside any .cpp file but that's still not true even after this commit. llvm-svn: 85042
* Add some comments.Dan Gohman2009-08-291-0/+5
| | | | llvm-svn: 80452
* Create a ScalarEvolution-based AliasAnalysis implementation.Dan Gohman2009-08-261-0/+128
This is a simple AliasAnalysis implementation which works by making ScalarEvolution queries. ScalarEvolution has a more complete understanding of arithmetic than BasicAA's collection of ad-hoc checks, so it handles some cases that BasicAA misses, for example p[i] and p[i+1] within the same iteration of a loop. This is currently experimental. It may be that the main use for this pass will be to help find cases where BasicAA can be profitably extended, or to help in the development of the overall AliasAnalysis infrastructure, however it's also possible that it could grow up to become a directly useful pass. llvm-svn: 80098
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