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2024-07-17[TTI][WebAssembly] Pairwise reduction expansion (#93948)Sam Parker
WebAssembly doesn't support horizontal operations nor does it have a way of expressing fast-math or reassoc flags, so runtimes are currently unable to use pairwise operations when generating code from the existing shuffle patterns. This patch allows the backend to select which, arbitary, shuffle pattern to be used per reduction intrinsic. The default behaviour is the same as the existing, which is by splitting the vector into a top and bottom half. The other pattern introduced is for a pairwise shuffle. WebAssembly enables pairwise reductions for int/fp add/sub.
2024-02-16[Transforms][Utils] Add helpers to map between Reduction IntrinsicID and ↵Simon Pilgrim
Arithmetic Instruction Opcode and MinMax IntrinsicID / RecurKind Noticed on #81852
2023-04-05Update mentions of reduction intrinsics; NFCSven van Haastregt
The intrinsics have been out of experimental since 322d0afd875d ("[llvm][mlir] Promote the experimental reduction intrinsics to be first class intrinsics.", 2020-10-07); update some places that still referred to them as experimental.
2023-04-04[CodeGen] ExpandReductions - add reduce_and/or(<X x i1> V) -> icmp(iX ↵Simon Pilgrim
bitcast(<X x i1> V)) canonicalization This already exists in InstCombine but was missing from the late stage ExpandReductions pass Fixes #53419 Fixes #61923 Differential Revision: https://reviews.llvm.org/D147452
2022-03-16Cleanup codegen includesserge-sans-paille
This is a (fixed) recommit of https://reviews.llvm.org/D121169 after: 1061034926 before: 1063332844 Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup Differential Revision: https://reviews.llvm.org/D121681
2022-03-10Revert "Cleanup codegen includes"Nico Weber
This reverts commit 7f230feeeac8a67b335f52bd2e900a05c6098f20. Breaks CodeGenCUDA/link-device-bitcode.cu in check-clang, and many LLVM tests, see comments on https://reviews.llvm.org/D121169
2022-03-10Cleanup codegen includesserge-sans-paille
after: 1061034926 before: 1063332844 Differential Revision: https://reviews.llvm.org/D121169
2021-02-04[ExpandReductions] fix FMF requirement for fmin/fmaxSanjay Patel
The upstream callers (the vectorizers) were fixed with: bbed5f2f8a04 ( D95690 ) 77adbe6a8c71 We should remove this pass entirely now that reduction legalization/lowering is expected to work just as well, but we need to confirm that the shuffle ops do not regress (for x86 in particular). This should be the last step needed to close: https://llvm.org/PR23116
2021-01-01[Analysis] flatten enums for recurrence typesSanjay Patel
This is almost all mechanical search-and-replace and no-functional-change-intended (NFC). Having a single enum makes it easier to match/reason about the reduction cases. The goal is to remove `Opcode` from reduction matching code in the vectorizers because that makes it harder to adapt the code to handle intrinsics. The code in RecurrenceDescriptor::AddReductionVar() is the only place that required closer inspection. It uses a RecurrenceDescriptor and a second InstDesc to sometimes overwrite part of the struct. It seem like we should be able to simplify that logic, but it's not clear exactly which cmp+sel patterns that we are trying to handle/avoid.
2020-10-07[llvm][mlir] Promote the experimental reduction intrinsics to be first class ↵Amara Emerson
intrinsics. This change renames the intrinsics to not have "experimental" in the name. The autoupgrader will handle legacy intrinsics. Relevant ML thread: http://lists.llvm.org/pipermail/llvm-dev/2020-April/140729.html Differential Revision: https://reviews.llvm.org/D88787
2020-09-12[Intrinsics] define semantics for experimental fmax/fmin vector reductionsSanjay Patel
As discussed on llvm-dev: http://lists.llvm.org/pipermail/llvm-dev/2020-April/140729.html This is hopefully the final remaining showstopper before we can remove the 'experimental' from the reduction intrinsics. No behavior was specified for the FP min/max reductions, so we have a mess of different interpretations. There are a few potential options for the semantics of these max/min ops. I think this is the simplest based on current behavior/implementation: make the reductions inherit from the existing llvm.maxnum/minnum intrinsics. These correspond to libm fmax/fmin, and those are similar to the (now deprecated?) IEEE-754 maxNum/minNum functions (NaNs are treated as missing data). So the default expansion creates calls to libm functions. Another option would be to inherit from llvm.maximum/minimum (NaNs propagate), but most targets just crash in codegen when given those nodes because no default expansion was ever implemented AFAICT. We could also just assume 'nnan' semantics by default (we are already assuming 'nsz' semantics in the maxnum/minnum intrinsics), but some targets (AArch64, PowerPC) support the more defined behavior, so it doesn't make much sense to not allow a tighter spec. Fast-math-flags (nnan) can be used to loosen the semantics. (Note that D67507 was proposed to update the LangRef to acknowledge the more recent IEEE-754 2019 standard, but that patch seems to have stalled. If we do update based on the new standard, the reduction instructions can seamlessly inherit from whatever updates are made to the max/min intrinsics.) x86 sees a regression here on 'nnan' tests because we have underlying, longstanding bugs in FMF creation/propagation. Those need to be fixed apart from this change (for example: https://llvm.org/PR35538). The expansion sequence before this patch may not have been correct. Differential Revision: https://reviews.llvm.org/D87391
2020-07-09[SVE] Remove calls to VectorType::getNumElements from CodeGenChristopher Tetreault
Reviewers: efriedma, fpetrogalli, sdesmalen, RKSimon, arsenm Reviewed By: RKSimon Subscribers: wdng, tschuett, hiraditya, rkruppe, psnobl, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D82210
2020-04-10Clean up usages of asserting vector getters in TypeChristopher Tetreault
Summary: Remove usages of asserting vector getters in Type in preparation for the VectorType refactor. The existence of these functions complicates the refactor while adding little value. Reviewers: stoklund, sdesmalen, efriedma Reviewed By: sdesmalen Subscribers: hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D77272
2019-11-14[ExpandReductions] Don't push all intrinsics to the worklist. Just push ↵Craig Topper
reductions. We were previously pushing all intrinsics used in a function to the worklist. This is wasteful for memory in a function with a lot of intrinsics. We also ask TTI if we should expand every intrinsic, but we only have expansion support for the reduction intrinsics. This just wastes time for the non-reduction intrinsics. This patch only pushes reduction intrinsics into the worklist and skips other intrinsics. Differential Revision: https://reviews.llvm.org/D69470
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
2019-11-02[CodeGen] [ExpandReduction] Fix the bug for ExpandReduction() when vector ↵shkzhang
size isn't power of 2 Summary: For below test case, we will get assert error except for AArch64 and ARM: declare i8 @llvm.experimental.vector.reduce.and.i8.v3i8(<3 x i8> %a) define i8 @test_v3i8(<3 x i8> %a) nounwind { %b = call i8 @llvm.experimental.vector.reduce.and.i8.v3i8(<3 x i8> %a) ret i8 %b } In the function getShuffleReduction (), we can see it needs the vector size must be power of 2. This patch is fix below error when the number of element is not power of 2 for those llvm.experimental.vector.reduce.* function. Reviewed By: jsji Differential Revision: https://reviews.llvm.org/D68625
2019-06-11Change semantics of fadd/fmul vector reductions.Sander de Smalen
This patch changes how LLVM handles the accumulator/start value in the reduction, by never ignoring it regardless of the presence of fast-math flags on callsites. This change introduces the following new intrinsics to replace the existing ones: llvm.experimental.vector.reduce.fadd -> llvm.experimental.vector.reduce.v2.fadd llvm.experimental.vector.reduce.fmul -> llvm.experimental.vector.reduce.v2.fmul and adds functionality to auto-upgrade existing LLVM IR and bitcode. Reviewers: RKSimon, greened, dmgreen, nikic, simoll, aemerson Reviewed By: nikic Differential Revision: https://reviews.llvm.org/D60261 llvm-svn: 363035
2019-06-05[LoopUtils][SLPVectorizer] clean up management of fast-math-flagsSanjay Patel
Instead of passing around fast-math-flags as a parameter, we can set those using an IRBuilder guard object. This is no-functional-change-intended. The motivation is to eventually fix the vectorizers to use and set the correct fast-math-flags for reductions. Examples of that not behaving as expected are: https://bugs.llvm.org/show_bug.cgi?id=23116 (should be able to reduce with less than 'fast') https://bugs.llvm.org/show_bug.cgi?id=35538 (possible miscompile for -0.0) D61802 (should be able to reduce with IR-level FMF) Differential Revision: https://reviews.llvm.org/D62272 llvm-svn: 362612
2019-03-12Reland "Relax constraints for reduction vectorization"Sanjoy Das
Change from original commit: move test (that uses an X86 triple) into the X86 subdirectory. Original description: Gating vectorizing reductions on *all* fastmath flags seems unnecessary; `reassoc` should be sufficient. Reviewers: tvvikram, mkuper, kristof.beyls, sdesmalen, Ayal Reviewed By: sdesmalen Subscribers: dcaballe, huntergr, jmolloy, mcrosier, jlebar, bixia, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D57728 llvm-svn: 355889
2019-03-11Revert "Relax constraints for reduction vectorization"Sanjoy Das
This reverts commit r355868. Breaks hexagon. llvm-svn: 355873
2019-03-11Relax constraints for reduction vectorizationSanjoy Das
Summary: Gating vectorizing reductions on *all* fastmath flags seems unnecessary; `reassoc` should be sufficient. Reviewers: tvvikram, mkuper, kristof.beyls, sdesmalen, Ayal Reviewed By: sdesmalen Subscribers: dcaballe, huntergr, jmolloy, mcrosier, jlebar, bixia, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D57728 llvm-svn: 355868
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
2018-04-09Support generic expansion of ordered vector reduction (PR36732)Simon Pilgrim
Without the fast math flags, the llvm.experimental.vector.reduce.fadd/fmul intrinsic expansions must be expanded in order. This patch scalarizes the reduction, applying the accumulator at the start of the sequence: ((((Acc + Scl[0]) + Scl[1]) + Scl[2]) + ) ... + Scl[NumElts-1] Differential Revision: https://reviews.llvm.org/D45366 llvm-svn: 329585
2017-11-06[IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' ↵Sanjay Patel
fast-math-flag As discussed on llvm-dev: http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html and again more recently: http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html ...this is a step in cleaning up our fast-math-flags implementation in IR to better match the capabilities of both clang's user-visible flags and the backend's flags for SDNode. As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic reassociation - 'AllowReassoc'. We're also adding a bit to allow approximations for library functions called 'ApproxFunc' (this was initially proposed as 'libm' or similar). ...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), but that's apparently already used for other purposes. Also, I don't think we can just add a field to FPMathOperator because Operator is not intended to be instantiated. We'll defer movement of FMF to another day. We keep the 'fast' keyword. I thought about removing that, but seeing IR like this: %f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2 ...made me think we want to keep the shortcut synonym. Finally, this change is binary incompatible with existing IR as seen in the compatibility tests. This statement: "Newer releases can ignore features from older releases, but they cannot miscompile them. For example, if nsw is ever replaced with something else, dropping it would be a valid way to upgrade the IR." ( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility ) ...provides the flexibility we want to make this change without requiring a new IR version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will fail to optimize some previously 'fast' code because it's no longer recognized as 'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'. Note: an inter-dependent clang commit to use the new API name should closely follow commit. Differential Revision: https://reviews.llvm.org/D39304 llvm-svn: 317488
2017-06-06Sort the remaining #include lines in include/... and lib/....Chandler Carruth
I did this a long time ago with a janky python script, but now clang-format has built-in support for this. I fed clang-format every line with a #include and let it re-sort things according to the precise LLVM rules for include ordering baked into clang-format these days. I've reverted a number of files where the results of sorting includes isn't healthy. Either places where we have legacy code relying on particular include ordering (where possible, I'll fix these separately) or where we have particular formatting around #include lines that I didn't want to disturb in this patch. This patch is *entirely* mechanical. If you get merge conflicts or anything, just ignore the changes in this patch and run clang-format over your #include lines in the files. Sorry for any noise here, but it is important to keep these things stable. I was seeing an increasing number of patches with irrelevant re-ordering of #include lines because clang-format was used. This patch at least isolates that churn, makes it easy to skip when resolving conflicts, and gets us to a clean baseline (again). llvm-svn: 304787
2017-05-10Add a late IR expansion pass for the experimental reduction intrinsics.Amara Emerson
This pass uses a new target hook to decide whether or not to expand a particular intrinsic to the shuffevector sequence. Differential Revision: https://reviews.llvm.org/D32245 llvm-svn: 302631