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path: root/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
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* Preserve CFG in MergedLoadStoreMotion. This fixes PR24426.Jakub Staszak2015-10-181-0/+1
| | | | llvm-svn: 250660
* Scalar: Remove remaining ilist iterator implicit conversionsDuncan P. N. Exon Smith2015-10-131-6/+5
| | | | | | | | | | | | | | | | | | | Remove remaining `ilist_iterator` implicit conversions from LLVMScalarOpts. This change exposed some scary behaviour in lib/Transforms/Scalar/SCCP.cpp around line 1770. This patch changes a call from `Function::begin()` to `&Function::front()`, since the return was immediately being passed into another function that takes a `Function*`. `Function::front()` started to assert, since the function was empty. Note that `Function::end()` does not point at a legal `Function*` -- it points at an `ilist_half_node` -- so the other function was getting garbage before. (I added the missing check for `Function::isDeclaration()`.) Otherwise, no functionality change intended. llvm-svn: 250211
* Fix Clang-tidy modernize-use-nullptr warnings in source directories and ↵Hans Wennborg2015-10-061-3/+3
| | | | | | | | | | generated files; other minor cleanups. Patch by Eugene Zelenko! Differential Revision: http://reviews.llvm.org/D13321 llvm-svn: 249482
* [PM/AA] Rebuild LLVM's alias analysis infrastructure in a way compatibleChandler Carruth2015-09-091-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Rename Instruction::dropUnknownMetadata() to dropUnknownNonDebugMetadata()Adrian Prantl2015-08-201-2/+2
| | | | | | | | | | | and make it always preserve debug locations, since all callers wanted this behavior anyway. This is addressing a post-commit review feedback for r245589. NFC (inside the LLVM tree). llvm-svn: 245622
* Fix a bug that caused SimplifyCFG to drop DebugLocs.Adrian Prantl2015-08-201-2/+2
| | | | | | | | | | | Instruction::dropUnknownMetadata(KnownSet) is supposed to preserve all metadata in KnownSet, but the condition for DebugLocs was inverted. Most users of dropUnknownMetadata() actually worked around this by not adding LLVMContext::MD_dbg to their list of KnowIDs. This is now made explicit. llvm-svn: 245589
* [PM/AA] Extract the ModRef enums from the AliasAnalysis class inChandler Carruth2015-07-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | preparation for de-coupling the AA implementations. In order to do this, they had to become fake-scoped using the traditional LLVM pattern of a leading initialism. These can't be actual scoped enumerations because they're bitfields and thus inherently we use them as integers. I've also renamed the behavior enums that are specific to reasoning about the mod/ref behavior of functions when called. This makes it more clear that they have a very narrow domain of applicability. I think there is a significantly cleaner API for all of this, but I don't want to try to do really substantive changes for now, I just want to refactor the things away from analysis groups so I'm preserving the exact original design and just cleaning up the names, style, and lifting out of the class. Differential Revision: http://reviews.llvm.org/D10564 llvm-svn: 242963
* [PM/AA] Remove the addEscapingUse update API that won't be easy toChandler Carruth2015-07-181-9/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | directly model in the new PM. This also was an incredibly brittle and expensive update API that was never fully utilized by all the passes that claimed to preserve AA, nor could it reasonably have been extended to all of them. Any number of places add uses of values. If we ever wanted to reliably instrument this, we would want a callback hook much like we have with ValueHandles, but doing this for every use addition seems *extremely* expensive in terms of compile time. The only user of this update mechanism is GlobalsModRef. The idea of using this to keep it up to date doesn't really work anyways as its analysis requires a symmetric analysis of two different memory locations. It would be very hard to make updates be sufficiently rigorous to *guarantee* symmetric analysis in this way, and it pretty certainly isn't true today. However, folks have been using GMR with this update for a long time and seem to not be hitting the issues. The reported issue that the update hook fixes isn't even a problem any more as other changes to GetUnderlyingObject worked around it, and that issue stemmed from *many* years ago. As a consequence, a prior patch provided a flag to control the unsafe behavior of GMR, and this patch removes the update mechanism that has questionable compile-time tradeoffs and is causing problems with moving to the new pass manager. Note the lack of test updates -- not one test in tree actually requires this update, even for a contrived case. All of this was extensively discussed on the dev list, this patch will just enact what that discussion decides on. I'm sending it for review in part to show what I'm planning, and in part to show the *amazing* amount of work this avoids. Every call to the AA here is something like three to six indirect function calls, which in the non-LTO pipeline never do any work! =[ Differential Revision: http://reviews.llvm.org/D11214 llvm-svn: 242605
* [PM/AA] Completely remove the AliasAnalysis::copyValue interface.Chandler Carruth2015-07-111-8/+0
| | | | | | | | | | | | | | | | | | | | | No in-tree alias analysis used this facility, and it was not called in any particularly rigorous way, so it seems unlikely to be correct. Note that one of the only stateful AA implementations in-tree, GlobalsModRef is completely broken currently (and any AA passes like it are equally broken) because Module AA passes are not effectively invalidated when a function pass that fails to update the AA stack runs. Ultimately, it doesn't seem like we know how we want to build stateful AA, and until then trying to support and maintain correctness for an untested API is essentially impossible. To that end, I'm planning to rip out all of the update API. It can return if and when we need it and know how to build it on top of the new pass manager and as part of *tested* stateful AA implementations in the tree. Differential Revision: http://reviews.llvm.org/D10889 llvm-svn: 241975
* Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)Alexander Kornienko2015-06-231-1/+1
| | | | | | Apparently, the style needs to be agreed upon first. llvm-svn: 240390
* Fixed/added namespace ending comments using clang-tidy. NFCAlexander Kornienko2015-06-191-1/+1
| | | | | | | | | | | | | The patch is generated using this command: tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \ -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \ llvm/lib/ Thanks to Eugene Kosov for the original patch! llvm-svn: 240137
* [PM/AA] Remove the Location typedef from the AliasAnalysis class nowChandler Carruth2015-06-171-12/+10
| | | | | | | | | | | | 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
* [PM/AA] Start refactoring AliasAnalysis to remove the analysis group andChandler Carruth2015-06-041-5/+5
| | | | | | | | | | | | | | | | | | | | | port it to the new pass manager. All this does is extract the inner "location" class used by AA into its own full fledged type. This seems *much* cleaner as MemoryDependence and soon MemorySSA also use this heavily, and it doesn't make much sense being inside the AA infrastructure. This will also make it much easier to break apart the AA infrastructure into something that stands on its own rather than using the analysis group design. There are a few places where this makes APIs not make sense -- they were taking an AliasAnalysis pointer just to build locations. I'll try to clean those up in follow-up commits. Differential Revision: http://reviews.llvm.org/D10228 llvm-svn: 239003
* MergedLoadStoreMotion preserves MemoryDependenceAnalysis, it does not ↵Daniel Berlin2015-05-221-2/+2
| | | | | | | | require it. (It already was coded assuming it can sometimes be null, so no other changes are necessary) llvm-svn: 237978
* Another set of missing raw_ostream.h. Still no functional change.Benjamin Kramer2015-03-231-1/+2
| | | | llvm-svn: 232993
* Fixed a bug in store sinking.Elena Demikhovsky2015-02-171-4/+6
| | | | | | | | | | The problem was in store-sink barrier check. Store sink barrier should be checked for ModRef (read-write) mode. http://llvm.org/bugs/show_bug.cgi?id=22613 llvm-svn: 229495
* [PM] Separate the TargetLibraryInfo object from the immutable pass.Chandler Carruth2015-01-151-2/+2
| | | | | | | | | | | | | | The pass is really just a means of accessing a cached instance of the TargetLibraryInfo object, and this way we can re-use that object for the new pass manager as its result. Lots of delta, but nothing interesting happening here. This is the common pattern that is developing to allow analyses to live in both the old and new pass manager -- a wrapper pass in the old pass manager emulates the separation intrinsic to the new pass manager between the result and pass for analyses. llvm-svn: 226157
* [PM] Move TargetLibraryInfo into the Analysis library.Chandler Carruth2015-01-151-1/+1
| | | | | | | | | | | | | | | | While the term "Target" is in the name, it doesn't really have to do with the LLVM Target library -- this isn't an abstraction which LLVM targets generally need to implement or extend. It has much more to do with modeling the various runtime libraries on different OSes and with different runtime environments. The "target" in this sense is the more general sense of a target of cross compilation. This is in preparation for porting this analysis to the new pass manager. No functionality changed, and updates inbound for Clang and Polly. llvm-svn: 226078
* Sink store based on alias analysisElena Demikhovsky2014-12-151-40/+35
| | | | | | | | | | | | - by Ella Bolshinsky The alias analysis is used define whether the given instruction is a barrier for store sinking. For 2 identical stores, following instructions are checked in the both basic blocks, to determine whether they are sinking barriers. http://reviews.llvm.org/D6420 llvm-svn: 224247
* Use Alias Analysis to hoist 2 loads from diamond to the common predecessor ↵Elena Demikhovsky2014-11-021-47/+25
| | | | | | | | | | basic block. Alias Analysis allows to detect real barriers for load hoisting. Review in http://reviews.llvm.org/D5991 llvm-svn: 221091
* [MergedLoadStoreMotion] Move pass enabling option to PassManagerBuilderGerolf Hoflehner2014-09-101-5/+0
| | | | llvm-svn: 217538
* Removed misleading comment.Gerolf Hoflehner2014-09-101-1/+0
| | | | llvm-svn: 217527
* Fix for multi-line comment warningGerolf Hoflehner2014-08-071-12/+12
| | | | llvm-svn: 215169
* Fix for regression: [Bug 20369] wrong code at -O3 on x86_64-linux-gnu in ↵Gerolf Hoflehner2014-07-211-1/+9
| | | | | | | | | 64-bit mode Prevents hoisting of loads above stores and sinking of stores below loads in MergedLoadStoreMotion.cpp (rdar://15991737) llvm-svn: 213497
* MergedLoadStoreMotion.cpp: Fix msc17 build. Member initializer is unavailable.NAKAMURA Takumi2014-07-191-2/+3
| | | | llvm-svn: 213448
* MergedLoadStoreMotion passGerolf Hoflehner2014-07-181-0/+623
Merges equivalent loads on both sides of a hammock/diamond and hoists into into the header. Merges equivalent stores on both sides of a hammock/diamond and sinks it to the footer. Can enable if conversion and tolerate better load misses and store operand latencies. llvm-svn: 213396
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