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path: root/llvm/lib/Transforms/Scalar/LoopRotation.cpp
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2024-11-02[Scalar] Remove unused includes (NFC) (#114645)Kazu Hirata
Identified with misc-include-cleaner.
2024-07-16[LoopRotate] Don't rotate loops when the minsize attribute is presentAyke
The main use for this patch is LTO. It is not (yet?) possible to set the size level (-Os, -Oz) in the linker, which means loops are still rotated even if -Oz is specified on the command line. Therefore, look at the function attribute instead of only at the size level to determine whether to rotate loops for a given function. For discussion, see: https://reviews.llvm.org/D119342 An older version of this patch was already approved at https://reviews.llvm.org/D119342 but I never got around to committing it. The code changed so I had to make some minor updates to this patch and in the meantime I also lost commit access because I wasn't really using it. So here is an updated patch.
2024-06-27[IR] Add getDataLayout() helpers to BasicBlock and Instruction (#96902)Nikita Popov
This is a helper to avoid writing `getModule()->getDataLayout()`. I regularly try to use this method only to remember it doesn't exist... `getModule()->getDataLayout()` is also a common (the most common?) reason why code has to include the Module.h header.
2024-02-16[LegacyPM] Remove legacy LoopRotate passArthur Eubanks
2023-06-22[opt] Exposing the parameters of LoopRotate to the -passes interfaceYann Girsberger
There is a gap between running opt -Oz and running opt -passes="OZ_PASSES" where OZ_PASSES is taken from running opt -Oz -print-pipeline-passes. One of the reasons causing this is that -Oz uses non-default setting for LoopRotate but LoopRotate does not expose its settings when printing the pipeline. This commit fixes this by exposing LoopRotates parameters. Reviewed By: aeubanks Differential Revision: https://reviews.llvm.org/D153437
2022-11-26[Scalar] Use std::optional in LoopRotation.cpp (NFC)Kazu Hirata
This is part of an effort to migrate from llvm::Optional to std::optional: https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-11-21Don't use Optional::getPointer (NFC)Kazu Hirata
Since std::optional does not offer getPointer(), this patch replaces X.getPointer() with &*X to make the migration from llvm::Optional to std::optional easier. This is part of an effort to migrate from llvm::Optional to std::optional: https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716 Differential Revision: https://reviews.llvm.org/D138466
2022-06-26[llvm] Don't use Optional::hasValue (NFC)Kazu Hirata
This patch replaces Optional::hasValue with the implicit cast to bool in conditionals only.
2022-06-25Revert "Don't use Optional::hasValue (NFC)"Kazu Hirata
This reverts commit aa8feeefd3ac6c78ee8f67bf033976fc7d68bc6d.
2022-06-25Don't use Optional::hasValue (NFC)Kazu Hirata
2022-03-03Cleanup includes: Transform/Scalarserge-sans-paille
Estimated impact on preprocessor output line: before: 1062981579 after: 1062494547 Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup Differential Revision: https://reviews.llvm.org/D120817
2021-08-16[MemorySSA] Remove -enable-mssa-loop-dependency optionNikita Popov
This option has been enabled by default for quite a while now. The practical impact of removing the option is that MSSA use cannot be disabled in default pipelines (both LPM and NPM) and in manual LPM invocations. NPM can still choose to enable/disable MSSA using loop vs loop-mssa. The next step will be to require MSSA for LICM and drop the AST-based implementation entirely. Differential Revision: https://reviews.llvm.org/D108075
2021-04-08[LoopRotate] Don't split loop pass managerNikita Popov
After D99249 we use three different loop pass managers for LICM, LoopRotate and LICM+LoopUnswitch. This happens because LazyBFI and LazyBPI are not preserved by LoopRotate (note that D74640 is no longer needed). Avoid this by marking them as preserved. My understanding of D86156 is that it is okay to simply preserve them (which LoopUnswitch already does for the same reason) and rely on callbacks to deal with deleted blocks. Differential Revision: https://reviews.llvm.org/D99843
2021-01-19[LoopRotate] Add PrepareForLTO stage, avoid rotating with inline cands.Florian Hahn
D84108 exposed a bad interaction between inlining and loop-rotation during regular LTO, which is causing notable regressions in at least CINT2006/473.astar. The problem boils down to: we now rotate a loop just before the vectorizer which requires duplicating a function call in the preheader when compiling the individual files ('prepare for LTO'). But this then prevents further inlining of the function during LTO. This patch tries to resolve this issue by making LoopRotate more conservative with respect to rotating loops that have inline-able calls during the 'prepare for LTO' stage. I think this change intuitively improves the current situation in general. Loop-rotate tries hard to avoid creating headers that are 'too big'. At the moment, it assumes all inlining already happened and the cost of duplicating a call is equal to just doing the call. But with LTO, inlining also happens during full LTO and it is possible that a previously duplicated call is actually a huge function which gets inlined during LTO. From the perspective of LV, not much should change overall. Most loops calling user-provided functions won't get vectorized to start with (unless we can infer that the function does not touch memory, has no other side effects). If we do not inline the 'inline-able' call during the LTO stage, we merely delayed loop-rotation & vectorization. If we inline during LTO, chances should be very high that the inlined code is itself vectorizable or the user call was not vectorizable to start with. There could of course be scenarios where we inline a sufficiently large function with code not profitable to vectorize, which would have be vectorized earlier (by scalarzing the call). But even in that case, there probably is no big performance impact, because it should be mostly down to the cost-model to reject vectorization in that case. And then the version with scalarized calls should also not be beneficial. In a way, LV should have strictly more information after inlining and make more accurate decisions (barring cost-model issues). There is of course plenty of room for things to go wrong unexpectedly, so we need to keep a close look at actual performance and address any follow-up issues. I took a look at the impact on statistics for MultiSource/SPEC2000/SPEC2006. There are a few benchmarks with fewer loops rotated, but no change to the number of loops vectorized. Reviewed By: sanwou01 Differential Revision: https://reviews.llvm.org/D94232
2020-12-03[NFC] Reduce include files dependency.dfukalov
1. Removed #include "...AliasAnalysis.h" in other headers and modules. 2. Cleaned up includes in AliasAnalysis.h. Reviewed By: RKSimon Differential Revision: https://reviews.llvm.org/D92489
2020-10-27[LoopRotation] Allow loop header duplication if vectorization is forced.Florian Hahn
-Oz normally does not allow loop header duplication so this loop wouldn't be vectorized. However the vectorization pragma should override this and allow for loop rotation. rdar://problem/49281061 Original patch by Adam Nemet. Reviewed By: Meinersbur Differential Revision: https://reviews.llvm.org/D59832
2020-02-14[LoopRotate] Get and update MSSA only if available in legacy pass manager.Alina Sbirlea
Summary: Potential fix for: https://bugs.llvm.org/show_bug.cgi?id=44889 and https://bugs.llvm.org/show_bug.cgi?id=44408 In the legacy pass manager, loop rotate need not compute MemorySSA when not being in the same loop pass manager with other loop passes. There isn't currently a way to differentiate between the two cases, so this attempts to limit the usage in LoopRotate to only update MemorySSA when the analysis is already available. The side-effect of this is that it will split the Loop pipeline. This issue does not apply to the new pass manager, where we have a flag specifying if all loop passes in that loop pass manager preserve MemorySSA. Reviewers: dmgreen, fedor.sergeev, nikic Subscribers: Prazek, hiraditya, george.burgess.iv, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D74574
2020-02-04[NFCI] Update according to style.Alina Sbirlea
clang-tidy + clang-format
2019-11-14Add missing includes needed to prune LLVMContext.h include, NFCReid Kleckner
These are a pre-requisite to removing #include "llvm/Support/Options.h" from LLVMContext.h: https://reviews.llvm.org/D70280
2019-11-13Sink all InitializePasses.h includesReid Kleckner
This file lists every pass in LLVM, and is included by Pass.h, which is very popular. Every time we add, remove, or rename a pass in LLVM, it caused lots of recompilation. I found this fact by looking at this table, which is sorted by the number of times a file was changed over the last 100,000 git commits multiplied by the number of object files that depend on it in the current checkout: recompiles touches affected_files header 342380 95 3604 llvm/include/llvm/ADT/STLExtras.h 314730 234 1345 llvm/include/llvm/InitializePasses.h 307036 118 2602 llvm/include/llvm/ADT/APInt.h 213049 59 3611 llvm/include/llvm/Support/MathExtras.h 170422 47 3626 llvm/include/llvm/Support/Compiler.h 162225 45 3605 llvm/include/llvm/ADT/Optional.h 158319 63 2513 llvm/include/llvm/ADT/Triple.h 140322 39 3598 llvm/include/llvm/ADT/StringRef.h 137647 59 2333 llvm/include/llvm/Support/Error.h 131619 73 1803 llvm/include/llvm/Support/FileSystem.h Before this change, touching InitializePasses.h would cause 1345 files to recompile. After this change, touching it only causes 550 compiles in an incremental rebuild. Reviewers: bkramer, asbirlea, bollu, jdoerfert Differential Revision: https://reviews.llvm.org/D70211
2019-10-08[LoopRotate] Unconditionally get DomTree.Florian Hahn
LoopRotate is a loop pass and the DomTree should always be available. Similar to a70c5261436322a53187d67b8bdc0445d0463a9a llvm-svn: 374036
2019-10-08[LoopRotate] Unconditionally get ScalarEvolution.Florian Hahn
Summary: LoopRotate is a loop pass and SE should always be available. Reviewers: anemet, asbirlea Reviewed By: asbirlea Differential Revision: https://reviews.llvm.org/D68573 llvm-svn: 374026
2019-08-17[MemorySSA] Loop passes should mark MSSA preserved when available.Alina Sbirlea
This patch applies only to the new pass manager. Currently, when MSSA Analysis is available, and pass to each loop pass, it will be preserved by that loop pass. Hence, mark the analysis preserved based on that condition, vs the current `EnableMSSALoopDependency`. This leaves the global flag to affect only the entry point in the loop pass manager (in FunctionToLoopPassAdaptor). llvm-svn: 369181
2019-06-11Only passes that preserve MemorySSA must mark it as preserved.Alina Sbirlea
Summary: The method `getLoopPassPreservedAnalyses` should not mark MemorySSA as preserved, because it's being called in a lot of passes that do not preserve MemorySSA. Instead, mark the MemorySSA analysis as preserved by each pass that does preserve it. These changes only affect the new pass mananger. Reviewers: chandlerc Subscribers: mehdi_amini, jlebar, Prazek, george.burgess.iv, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D62536 llvm-svn: 363091
2019-01-19Update the file headers across all of the LLVM projects in the monorepoChandler Carruth
to reflect the new license. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351636
2018-10-24Update MemorySSA in LoopRotate.Alina Sbirlea
Summary: Teach LoopRotate to preserve MemorySSA. Enable tests for correctness, dependency disabled by default. Subscribers: sanjoy, jlebar, Prazek, george.burgess.iv, llvm-commits Differential Revision: https://reviews.llvm.org/D51718 llvm-svn: 345216
2018-04-19Refine the loop rotation's APIJin Lin
Summary: The following changes addresses the following two issues. 1) The existing loop rotation pass contains both loop latch simplification and loop rotation. So one flag RotationOnly is added to be passed to the loop rotation pass. 2) The threshold value is initialized with MAX_UINT since the loop rotation utility should not have threshold limit. Reviewers: dmgreen, efriedma Reviewed By: efriedma Differential Revision: https://reviews.llvm.org/D45582 llvm-svn: 330362
2018-03-29[LoopRotate] Restructuring LoopRotation.cpp to create Loop Rotation Pass ↵David Green
with Loop Rotation Utility Interface The existing LoopRotation.cpp is implemented as one of loop passes instead of being a utility. The user cannot easily perform the loop rotation selectively (or on demand) under different optimization level. For example, the loop rotation is needed as part of the logic to convert a loop into a loop with bottom test for a transformation. If the loop rotation is simply added as a loop pass before the transformation, the pass is skipped if it is compiled at –O0 or if it is explicitly disabled by the user, causing the compiler to generate incorrect code. Furthermore, as a loop pass it will rotate all loops instead of just the relevant loops. We provide a utility interface for the loop rotation so that the loop rotation can be called on demand. The changeset is as follows: - Create a new file lib/Transforms/Utils/LoopRotationUtils.cpp and move the main implementation of class LoopRotate into this file. - Create a new file llvm/include/Transform/Utils/LoopRotationUtils.h with the interface LoopRotation(...). - Original LoopRotation.cpp is changed to use the utility function LoopRotation in LoopRotationUtils.cpp. This is done in the same way community did for mem-to-reg implementation. Patch by Jin Lin! Differential Revision: https://reviews.llvm.org/D44595 llvm-svn: 328766
2018-03-21Fix a couple of layering violations in TransformsDavid Blaikie
Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering. Transforms depends on Transforms/Utils, not the other way around. So remove the header and the "createStripGCRelocatesPass" function declaration (& definition) that is unused and motivated this dependency. Move Transforms/Utils/Local.h into Analysis because it's used by Analysis/MemoryBuiltins.cpp. llvm-svn: 328165
2018-01-25[Debug] Add a utility to propagate dbg.value to new PHIs, NFCVedant Kumar
This simply moves an existing utility to Utils for reuse. Split out of: https://reviews.llvm.org/D42551 Patch by Matt Davis! llvm-svn: 323471
2018-01-09[LoopRotate] Detect loops with indirect branches better (we're giving up on ↵Michael Zolotukhin
them). llvm-svn: 322137
2017-11-15[LoopRotate] processLoop should return true even if it just simplified the ↵Craig Topper
loop latch without making any other changes Simplifying a loop latch changes the IR and we need to make sure the pass manager knows to invalidate analysis passes if that happened. PR35210 discovered a case where we failed to invalidate the post dominator tree after this simplification because we no changes other than simplifying the loop latch. Fixes PR35210. Differential Revision: https://reviews.llvm.org/D40035 llvm-svn: 318237
2017-11-01loop-rotate: avoid duplicating dbg.value intrinsics in the entry block.Adrian Prantl
This fixes the second half of PR35113. This reapplies r317106 without modifications. llvm-svn: 317121
2017-11-01Revert r317106 to facilitate reverting r317105.Adrian Prantl
llvm-svn: 317109
2017-11-01loop-rotate: avoid duplicating dbg.value intrinsics in the entry block.Adrian Prantl
This fixes the second half of PR35113. llvm-svn: 317106
2017-10-31loop-rotate: simplify code by using llvm::findDbgValues(). (NFC)Adrian Prantl
llvm-svn: 317037
2017-08-17[LoopRotate][Dominators] Use the incremental API to update DomTreeJakub Kuderski
Summary: This patch teaches LoopRotate to use the new incremental API to update the DominatorTree. Reviewers: dberlin, davide, grosser, sanjoy Reviewed By: dberlin, davide Subscribers: hiraditya, llvm-commits, mzolotukhin Differential Revision: https://reviews.llvm.org/D35581 llvm-svn: 311125
2017-07-12[LoopRotate] Fix DomTree update logic for unreachable nodes. Fix PR33701.Jakub Kuderski
Summary: LoopRotate manually updates the DoomTree by iterating over all predecessors of a basic block and computing the Nearest Common Dominator. When a predecessor happens to be unreachable, `DT.findNearestCommonDominator` returns nullptr. This patch teaches LoopRotate to handle this case and fixes [[ https://bugs.llvm.org/show_bug.cgi?id=33701 | PR33701 ]]. In the future, LoopRotate should be taught to use the new incremental API for updating the DomTree. Reviewers: dberlin, davide, uabelho, grosser Subscribers: efriedma, mzolotukhin Differential Revision: https://reviews.llvm.org/D35074 llvm-svn: 307828
2017-05-18[IR] De-virtualize ~Value to save a vptrReid Kleckner
Summary: Implements PR889 Removing the virtual table pointer from Value saves 1% of RSS when doing LTO of llc on Linux. The impact on time was positive, but too noisy to conclusively say that performance improved. Here is a link to the spreadsheet with the original data: https://docs.google.com/spreadsheets/d/1F4FHir0qYnV0MEp2sYYp_BuvnJgWlWPhWOwZ6LbW7W4/edit?usp=sharing This change makes it invalid to directly delete a Value, User, or Instruction pointer. Instead, such code can be rewritten to a null check and a call Value::deleteValue(). Value objects tend to have their lifetimes managed through iplist, so for the most part, this isn't a big deal. However, there are some places where LLVM deletes values, and those places had to be migrated to deleteValue. I have also created llvm::unique_value, which has a custom deleter, so it can be used in place of std::unique_ptr<Value>. I had to add the "DerivedUser" Deleter escape hatch for MemorySSA, which derives from User outside of lib/IR. Code in IR cannot include MemorySSA headers or call the MemoryAccess object destructors without introducing a circular dependency, so we need some level of indirection. Unfortunately, no class derived from User may have any virtual methods, because adding a virtual method would break User::getHungOffOperands(), which assumes that it can find the use list immediately prior to the User object. I've added a static_assert to the appropriate OperandTraits templates to help people avoid this trap. Reviewers: chandlerc, mehdi_amini, pete, dberlin, george.burgess.iv Reviewed By: chandlerc Subscribers: krytarowski, eraman, george.burgess.iv, mzolotukhin, Prazek, nlewycky, hans, inglorion, pcc, tejohnson, dberlin, llvm-commits Differential Revision: https://reviews.llvm.org/D31261 llvm-svn: 303362
2017-04-28LoopRotate: Fix use after scope bugDaniel Berlin
llvm-svn: 301702
2017-04-28Kill off the old SimplifyInstruction API by converting remaining users.Daniel Berlin
llvm-svn: 301673
2017-04-26Fix unused-variable warning caused by r301407.Haojian Wu
llvm-svn: 301411
2017-04-26Convert LoopRotation to use SimplifyQuery version of SimplifyInstruction. ↵Daniel Berlin
Add AssumptionCache, DominatorTree, TLI if available. llvm-svn: 301407
2017-03-08[LoopRotate] Propagate dbg.value intrinsicsSam Parker
Recommitting patch which was previously reverted in r297159. These changes should address the casting issues. The original patch enables dbg.value intrinsics to be attached to newly inserted PHI nodes. Differential Review: https://reviews.llvm.org/D30701 llvm-svn: 297269
2017-03-07Revert r297132, it caused PR32171Nico Weber
llvm-svn: 297159
2017-03-07[LoopRotate] Update dbg.value intrinsicsSam Parker
Propagate debug info through the newly inserted PHI nodes. Differential Revision: https://reviews.llvm.org/D30190 llvm-svn: 297132
2017-01-15[PM] Introduce an analysis set used to preserve all analyses overChandler Carruth
a function's CFG when that CFG is unchanged. This allows transformation passes to simply claim they preserve the CFG and analysis passes to check for the CFG being preserved to remove the fanout of all analyses being listed in all passes. I've gone through and removed or cleaned up as many of the comments reminding us to do this as I could. Differential Revision: https://reviews.llvm.org/D28627 llvm-svn: 292054
2017-01-11[PM] Separate the LoopAnalysisManager from the LoopPassManager and moveChandler Carruth
the latter to the Transforms library. While the loop PM uses an analysis to form the IR units, the current plan is to have the PM itself establish and enforce both loop simplified form and LCSSA. This would be a layering violation in the analysis library. Fundamentally, the idea behind the loop PM is to *transform* loops in addition to running passes over them, so it really seemed like the most natural place to sink this was into the transforms library. We can't just move *everything* because we also have loop analyses that rely on a subset of the invariants. So this patch splits the the loop infrastructure into the analysis management that has to be part of the analysis library, and the transform-aware pass manager. This also required splitting the loop analyses' printer passes out to the transforms library, which makes sense to me as running these will transform the code into LCSSA in theory. I haven't split the unittest though because testing one component without the other seems nearly intractable. Differential Revision: https://reviews.llvm.org/D28452 llvm-svn: 291662
2017-01-11[PM] Rewrite the loop pass manager to use a worklist and augmented runChandler Carruth
arguments much like the CGSCC pass manager. This is a major redesign following the pattern establish for the CGSCC layer to support updates to the set of loops during the traversal of the loop nest and to support invalidation of analyses. An additional significant burden in the loop PM is that so many passes require access to a large number of function analyses. Manually ensuring these are cached, available, and preserved has been a long-standing burden in LLVM even with the help of the automatic scheduling in the old pass manager. And it made the new pass manager extremely unweildy. With this design, we can package the common analyses up while in a function pass and make them immediately available to all the loop passes. While in some cases this is unnecessary, I think the simplicity afforded is worth it. This does not (yet) address loop simplified form or LCSSA form, but those are the next things on my radar and I have a clear plan for them. While the patch is very large, most of it is either mechanically updating loop passes to the new API or the new testing for the loop PM. The code for it is reasonably compact. I have not yet updated all of the loop passes to correctly leverage the update mechanisms demonstrated in the unittests. I'll do that in follow-up patches along with improved FileCheck tests for those passes that ensure things work in more realistic scenarios. In many cases, there isn't much we can do with these until the loop simplified form and LCSSA form are in place. Differential Revision: https://reviews.llvm.org/D28292 llvm-svn: 291651
2016-12-22[PM] Introduce a reasonable port of the main per-module pass pipelineChandler Carruth
from the old pass manager in the new one. I'm not trying to support (initially) the numerous options that are currently available to customize the pass pipeline. If we end up really wanting them, we can add them later, but I suspect many are no longer interesting. The simplicity of omitting them will help a lot as we sort out what the pipeline should look like in the new PM. I've also documented to the best of my ability *why* each pass or group of passes is used so that reading the pipeline is more helpful. In many cases I think we have some questionable choices of ordering and I've left FIXME comments in place so we know what to come back and revisit going forward. But for now, I've left it as similar to the current pipeline as I could. Lastly, I've had to comment out several places where passes are not ported to the new pass manager or where the loop pass infrastructure is not yet ready. I did at least fix a few bugs in the loop pass infrastructure uncovered by running the full pipeline, but I didn't want to go too far in this patch -- I'll come back and re-enable these as the infrastructure comes online. But I'd like to keep the comments in place because I don't want to lose track of which passes need to be enabled and where they go. One thing that seemed like a significant API improvement was to require that we don't build pipelines for O0. It seems to have no real benefit. I've also switched back to returning pass managers by value as at this API layer it feels much more natural to me for composition. But if others disagree, I'm happy to go back to an output parameter. I'm not 100% happy with the testing strategy currently, but it seems at least OK. I may come back and try to refactor or otherwise improve this in subsequent patches but I wanted to at least get a good starting point in place. Differential Revision: https://reviews.llvm.org/D28042 llvm-svn: 290325