Commit Graph

3283 Commits

Author SHA1 Message Date
Florian Hahn 0dddf04cab
[LV] Don't optimize exit cond during epilogue vectorization.
At the moment, the same VPlan can be used code generation of both the
main vector and epilogue vector loop. This can lead to wrong results, if
the plan is optimized based on the VF of the main vector loop and then
re-used for the epilogue loop.

One example where this is problematic is if the scalar loops need to
execute at least one iteration, e.g. due to interleave groups.

To prevent mis-compiles in the short-term, disable optimizing exit
conditions for VPlans when using epilogue vectorization. The proper fix
is to avoid re-using the same plan for both loops, which will require
support for cloning plans first.

Fixes #56319.
2022-07-01 13:48:38 +01:00
Florian Hahn 583abd0e36
[VPlan] Move addMetadata to VPTransformState (NFC).
The moved helpers are only used for codegen. It will allow moving the
remaining ::execute implementations out of LoopVectorize.cpp.

Depends on D127966.
Depends on D127965.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D127968
2022-07-01 12:03:25 +01:00
Alexey Bataev 4be3fc35aa [SLP][NFC]Cleanup up operands of the removed insertelements, NFC.
Replace all operands of the insertelement instruction, replaced by
shuffles, by poisons to avoid false-positive reports about incorrect function.
2022-06-30 17:51:43 -07:00
Florian Hahn 68884dde70
[LV] Move LoopVersioning creation to LVP::execute.
At the moment LoopVersioning is only created for inner-loop
vectorization. This patch moves it to LVP::execute, which means it will
also be added for epilogue vectorization. As a consequence, the proper
noalias metadata is now also added to epilogue vector loops.

LVer will be moved to VPTransformState as follow-up.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D127966
2022-06-30 12:14:32 +01:00
Florian Hahn 24b5f8e0d0
[VPlan] Make sure optimizeInductions removes wide ind from scalar plan.
In some cases, there may be widened users of inductions even though the
plan includes the scalar VF. In those cases, make sure we still replace
the VPWidenIntOrFpInductionRecipe with scalar steps, as otherwise we may
try to execute a VPWidenIntOrFpInductionRecipe with a scalar VF.

Alternatively the patch could also split the range if needed.

This fixes a crash exposed by D123720.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D128755
2022-06-30 09:11:48 +01:00
Nikita Popov bdba8278d9 [VectorCombine] Avoid ConstantExpr::get() (NFC)
Use IRBuilder APIs instead, which will still constant fold.
2022-06-29 17:17:52 +02:00
Alexey Bataev bf4dcbd2df [SLP]Fix PR56251: Do not remove the reordering from the root node, being used as an operand.
If the root order itself does not require reordering, we can just
remove its reorder mask safely (e.g., if the root node is a vector of
phis). But if this node is used as an operand in the graph, we cannot
delete the reordering, need to keep it. Otherwise the graph nodes are
not synchronized with the operands. It may cause an extra gather
instruction(s) or a compiler crash.
Also, need to be very careful when selecting the gather nodes for
reordering since there might several gather nodes with the same scalars
and we can try to reorder just the same node many times instead of
different nodes.

Differential Revision: https://reviews.llvm.org/D128680
2022-06-28 13:42:05 -07:00
Florian Hahn 03975b7f0e
[VPlan] Move recipe implementations to separate file (NFC).
This patch moves the code for recipe implementations to a separate file.

The benefits are:
 * Keep VPlan.cpp smaller => faster compile-time during parallel builds.
 * Keep code for logical units together

As a follow-up I am also planning on moving all ::execute
implemetnations from LoopVectorize.cpp over to the new file, which
should help to reduce the size of the file a bit.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D127965
2022-06-28 10:34:30 +01:00
Guillaume Chatelet 3c126d5fe4 [Alignment] Replace commonAlignment with std::min
`commonAlignment` is a shortcut to pick the smallest of two `Align`
objects. As-is it doesn't bring much value compared to `std::min`.

Differential Revision: https://reviews.llvm.org/D128345
2022-06-28 07:15:02 +00:00
Philip Reames 20dd3297b1 [LV] Allow scalable vectorization with vscale = 1
This change is a bit subtle. If we have a type like <vscale x 1 x i64>, the vectorizer will currently reject vectorization. The reason is that a type like <1 x i64> is likely to get simply rescalarized, and the vectorizer doesn't want to be in the game of simple unrolling.

(I've given the example in terms of 1 x types which use a single register, but the same issue exists for any N x types which use N registers. e.g. RISCV LMULs.)

This change distinguishes scalable types from fixed types under the reasoning that converting to a scalable type isn't unrolling. Because the actual vscale isn't known until runtime, using a vscale type is potentially very profitable.

This makes an important, but unchecked, assumption. Specifically, the scalable type is assumed to only be legal per the cost model if there's actually a scalable register class which is distinct from the scalar domain. This is, to my knowledge, true for all targets which return non-invalid costs for scalable vector ops today, but in theory, we could have a target decide to lower scalable to fixed length vector or even scalar registers. If that ever happens, we'd need to revisit this code.

In practice, this patch unblocks scalable vectorization for ELEN types on RISCV.

Let me sketch one alternate implementation I considered. We could have restricted this to when we know a minimum value for vscale. Specifically, for the default +v extension for RISCV, we actually know that vscale >= 2 for ELEN types. However, doing it this way means we can't generate scalable vectors when using the various embedded vector extensions which have a minimum vscale of 1.

Differential Revision: https://reviews.llvm.org/D128542
2022-06-27 13:38:57 -07:00
Kazu Hirata a7938c74f1 [llvm] Don't use Optional::hasValue (NFC)
This patch replaces Optional::hasValue with the implicit cast to bool
in conditionals only.
2022-06-25 21:42:52 -07:00
Kazu Hirata 3b7c3a654c Revert "Don't use Optional::hasValue (NFC)"
This reverts commit aa8feeefd3.
2022-06-25 11:56:50 -07:00
Kazu Hirata aa8feeefd3 Don't use Optional::hasValue (NFC) 2022-06-25 11:55:57 -07:00
Alexey Bataev 2faacf61a5 [SLP]Improve shuffles cost estimation where possible.
Improved/fixed cost modeling for shuffles by providing masks, improved
cost model for non-identity insertelements.

Differential Revision: https://reviews.llvm.org/D115462
2022-06-24 09:28:01 -07:00
Florian Hahn cb69ba4faa
[LV] Create RT checks once VF/IC are selected, track scalar cost.
This patch updates LV to generate runtime after the VF & IC are selected. It
allows deciding whether to vectorize with runtime checks or not based on
their cost compared to the vector loop.

It also updates VectorizationFactor to include the scalar cost.

Reviewed By: lebedev.ri, dmgreen

Differential Revision: https://reviews.llvm.org/D75981
2022-06-24 17:42:11 +02:00
Florian Hahn b18141a8f2
[VPlan] Set VFs included in plan before last set of VPTransforms (NFC).
This allows VPlanTransforms to query the VFs included in the plan in the
future.
2022-06-24 10:16:56 +02:00
Philip Reames 46ea4b5ea1 [LV] Avoid a crash when costing a uniform store which doesn't correspond to a legal scatter
If we have an unaligned uniform store, then when costing a scalable VF we can't emit code to scalarize it.  (Well, we could, but we haven't implemented that case.)  This change replaces an assert with a cost-model bailout such that we reject vectorization with the scalable VF instead of crashing.
2022-06-23 12:41:09 -07:00
Alexey Bataev 3b6edef15d [SLP]Fix a crash when reorder masked gather nodes with reused scalars.
If the masked gather nodes must be reordered, we can just reorder
scalars, just like for gather nodes. But if the node contains reused
scalars, it must be handled same way as a regular vectorizable node,
since need to reorder reused mask, not the scalars directly.

Differential Revision: https://reviews.llvm.org/D128360
2022-06-23 11:32:30 -07:00
Florian Hahn 569d84fe99
[VPlan] Remove dead recipes across whole plan.
This extends removeDeadRecipe to remove recipes across the whole plan.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D127580
2022-06-23 13:36:02 +02:00
Fangrui Song 1ffd2d99c2 Revert D115462 "[SLP]Improve shuffles cost estimation where possible."
This reverts commit cac60940b7.

Caused -Os -fsanitize=memory -march=haswell miscompile to pytorch/cpuinfo.
See my latest comment (may update) on D115462.
2022-06-22 23:16:31 -07:00
Fangrui Song a411bc11d6 Revert "[SLP]Fix a crash when insert subvector is out of range."
This reverts commit f1ee2738b3.

Revert due to the revert of a dependent commit `[SLP]Improve shuffles cost estimation where possible.`
2022-06-22 23:16:25 -07:00
Guillaume Chatelet 57ffff6db0 Revert "[NFC] Remove dead code"
This reverts commit 8ba2cbff70.
2022-06-22 14:55:47 +00:00
Guillaume Chatelet 8ba2cbff70 [NFC] Remove dead code 2022-06-22 13:33:58 +00:00
Serguei Katkov 8f891b7c39 [LoopVectorize] Uninitialized phi node leads to a crash in SSAUpdater.
createInductionResumeValues creates a phi node placeholder
without filling incoming values. Then it generates the incoming values.

It includes triggering of SCEV expander which may invoke SSAUpdater.
SSAUpdater has an optimization to detect number of predecessors
basing on incoming values if there is phi node.
In case phi node is not filled with incoming values - the number of predecessors
is detected as 0 and this leads to segmentation fault.

In other words SSAUpdater expects that phi is in good shape while
LoopVectorizer breaks this requirement.

The fix is just prepare all incoming values first and then build a phi node.

Reviewed By: fhahn
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D128033
2022-06-22 10:49:27 +07:00
Vasileios Porpodas 7a9ad25769 Recommit "[SLP][X86] Improve reordering to consider alternate instruction bundles"
This reverts commit 6d6268dcbf.

Review: https://reviews.llvm.org/D125712
2022-06-21 18:35:29 -07:00
Vasileios Porpodas 6d6268dcbf Revert "[SLP][X86] Improve reordering to consider alternate instruction bundles"
This reverts commit 6f88acf410.
2022-06-21 17:07:21 -07:00
Vasileios Porpodas 6f88acf410 [SLP][X86] Improve reordering to consider alternate instruction bundles
During the reordering transformation we should try to avoid reordering bundles
like fadd,fsub because this may block them being matched into a single vector
instruction in x86.
We do this by checking if a TreeEntry is such a pattern and adding it to the
list of TreeEntries with orders that need to be considered.

Differential Revision: https://reviews.llvm.org/D125712
2022-06-21 16:44:48 -07:00
Florian Hahn 88ce403c6a
[LV] Add new block to place recurrence splice, if needed.
In some cases, a recurrence splice instructions needs to be inserted
between to regions, for example if the regions get re-arranged during
sinking.

Fixes #56146.
2022-06-21 21:54:37 +02:00
Alexey Bataev d4ee43153d [SLP][NFC]Fix a warning in a comparison, NFC.
Fixed signedness warning.
2022-06-21 10:19:47 -07:00
Alexey Bataev f1ee2738b3 [SLP]Fix a crash when insert subvector is out of range.
If the OffsetBeg + InsertVecSz is greater than VecSz, need to estimate
the cost as shuffle of 2 vector, not as insert of subvector. Otherwise,
the inserted subvector is out of range and compiler may crash.

Differential Revision: https://reviews.llvm.org/D128071
2022-06-21 07:16:35 -07:00
Kazu Hirata 7a47ee51a1 [llvm] Don't use Optional::getValue (NFC) 2022-06-20 22:45:45 -07:00
Kazu Hirata e0e687a615 [llvm] Don't use Optional::hasValue (NFC) 2022-06-20 10:38:12 -07:00
Kazu Hirata 129b531c9c [llvm] Use value_or instead of getValueOr (NFC) 2022-06-18 23:07:11 -07:00
Kazu Hirata c399b3a608 [Vectorize] Use llvm::is_contained (NFC) 2022-06-18 15:49:15 -07:00
Malhar Jajoo 6bb40552f2 [LoopVectorize] Add support for invariant stores of ordered reductions
Reviewed By: david-arm

Differential Revision: https://reviews.llvm.org/D126772
2022-06-17 14:56:21 +01:00
Alexey Bataev 76782a65ee [SLP]Use original vector if need to shuffle truncated root.
If the root scalar is mapped to to the smallest bit width, the vector is
truncated and the types between original buildvector and extracted value
mismatched. For extract, we emit sext/zext instructions, for shuffles we
can reuse oringal vector instead of the truncated one.

Differential Revision: https://reviews.llvm.org/D127974
2022-06-16 10:41:18 -07:00
Florian Hahn 949c13649c
[LV] Remove widenPHIInstruction dependence on underlying instr (NFC).
Instead of using the underlying instruction and VF to get the type, use
the type of the incoming value. This removes an unnecessary dependence
on the underlying instruction and enables using the recipe without an
underlying instruction.
2022-06-16 16:03:01 +02:00
Alexey Bataev 7236d49fd5 [SLP]Extend vectorization for scatter vectorize nodes.
Currently scatter vectorize nodes can be emitted only for GEPs with
constant indices. But we can also emit such nodes for GEPs with the same
ptr and non-constant vectorizable/gathered indices, if profitable. Patch
adds support for such nodes and tries to improve handling of GEPs with
non-const indeces for such nodes.

Metric: SLP.NumVectorInstructions

Program                                                                                       SLP.NumVectorInstructions
                                                                                              results                   results0 diff
                    test-suite :: External/SPEC/CFP2017speed/638.imagick_s/638.imagick_s.test  5243.00                   5240.00  -0.1%
                     test-suite :: External/SPEC/CFP2017rate/538.imagick_r/538.imagick_r.test  5243.00                   5240.00  -0.1%
                     test-suite :: External/SPEC/CFP2017rate/526.blender_r/526.blender_r.test 27550.00                  27507.00  -0.2%
                               test-suite :: External/SPEC/CFP2006/453.povray/453.povray.test  5395.00                   5380.00  -0.3%
                       test-suite :: External/SPEC/CFP2017rate/511.povray_r/511.povray_r.test  5389.00                   5374.00  -0.3%
                    test-suite :: External/SPEC/CINT2017rate/520.omnetpp_r/520.omnetpp_r.test   961.00                    958.00  -0.3%
                   test-suite :: External/SPEC/CINT2017speed/620.omnetpp_s/620.omnetpp_s.test   961.00                    958.00  -0.3%
                               test-suite :: External/SPEC/CFP2006/447.dealII/447.dealII.test  5664.00                   5643.00  -0.4%
                       test-suite :: External/SPEC/CFP2017rate/510.parest_r/510.parest_r.test 13202.00                  13127.00  -0.6%
                                test-suite :: External/SPEC/CINT2006/445.gobmk/445.gobmk.test   212.00                    207.00  -2.4%
                                test-suite :: MultiSource/Benchmarks/7zip/7zip-benchmark.test   890.00                    850.00  -4.5%
                            test-suite :: External/SPEC/CINT2006/464.h264ref/464.h264ref.test  1695.00                   1581.00  -6.7%
                                 test-suite :: MultiSource/Applications/JM/lencod/lencod.test  2338.00                   2140.00  -8.5%
                                  test-suite :: SingleSource/UnitTests/matrix-types-spec.test    63.00                     55.00 -12.7%
                             test-suite :: SingleSource/Benchmarks/Adobe-C++/loop_unroll.test   468.00                    356.00 -23.9%
                                                                           Geomean difference                                     -0.3%

All numbers show increased number of generated vector instructions.

Diff:
SingleSource/Benchmarks/Adobe-C++/loop_unroll - better without LTO, but
need an extra analysis with LTO (with LTO compiler generates
masked_gather, while before regular loads were emitted because of extra
data, availbale at LTO time).
SingleSource/UnitTests/matrix-types-spec - more vector code.
MultiSource/Applications/JM/lencod/lencod - same.
External/SPEC/CINT2006/464.h264ref/464.h264ref - same.
MultiSource/Benchmarks/7zip/7zip-benchmark - same.
External/SPEC/CINT2006/445.gobmk/445.gobmk - no changes.
External/SPEC/CFP2017rate/510.parest_r/510.parest_r - more vector code.
External/SPEC/CFP2006/447.dealII/447.dealII - same
External/SPEC/CINT2017speed/620.omnetpp_s/620.omnetpp_s - same
External/SPEC/CINT2017rate/520.omnetpp_r/520.omnetpp - same
External/SPEC/CFP2017rate/511.povray_r/511.povray - same
External/SPEC/CFP2006/453.povray/453.povray - same
External/SPEC/CFP2017rate/526.blender_r/526.blender_r - same
External/SPEC/CFP2017rate/538.imagick_r/538.imagick_r - same
External/SPEC/CFP2017speed/638.imagick_s/638.imagick_s - same

Differential Revision: https://reviews.llvm.org/D127219
2022-06-16 06:05:48 -07:00
Florian Hahn 5ff5b460d9
[LV] Remove unneeded CustomBuilder arg from setDebugLocFromInst (NFC).
The only user that passed in a custom builder was passing in
VPTransformState::Builder, which is the same as ILV::Builder.
2022-06-15 18:48:02 +01:00
Alexey Bataev c60c13f7eb [SLP] Improve reordering in presence of constant only nodes.
We can skip the analysis of the constant nodes, their order should not
affect the ordering of the trees/subtrees.

Differential Revision: https://reviews.llvm.org/D127775
2022-06-15 06:17:34 -07:00
Florian Hahn 9129e7bb54
[LV] Replace OrigPHIsToFix in native with VPlan traversal. (NFC)
OrigPHIsToFix is only used in the native path. Collecting phis can be
replaced by iterating over the plan. This also removes another
unnecessary use of a late getVPValue.

This also reduces the coupling between ILV and the VPlan utilities.
2022-06-13 22:20:58 +01:00
Hubert Tong 5efb380c26 [NFC] Undo AIX build compiler workaround
Removes the workaround from https://reviews.llvm.org/D98509#2732628 for
an AIX build compiler issue.

The AIX build compiler product that caused the issue has since been
fixed. Also, the AIX build compiler has been changed to one based on
LLVM.
2022-06-13 17:00:33 -04:00
Florian Hahn 763f2bdba5
[VPlan] Remove dead OrigLoop argument from removeDeadRecipes (NFC).
The use of the argument has been remove a while ago. Remove the dead
argument.
2022-06-11 23:36:47 +01:00
Florian Hahn 85983ca42e
[VPlan] Replace remaining use of needsScalarIV.
All information is already available in VPlan. Note that there are some
test changes, because we now can correctly look through instructions
like truncates to analyze the actual users.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D123541
2022-06-09 12:05:37 +01:00
Florian Hahn cedfd7a2e5
Recommit "[VPlan] Remove uneeded needsVectorIV check."
This reverts commit 266ea446ab.

The reasons for the revert have been addressed by cleaning up condition
handling in VPlan and properly marking VPBranchOnMaskRecipe as using
scalars.

The test case for the revert from D123720 has been added in 3d663308a5.
2022-06-08 14:06:45 +01:00
Florian Hahn b0c9a71be0
[VPlan] Handle VPInst without underlying instr in VPInterleavedAccess.
This violation is hidden while `cast` is missing an isa assertion after
D123901.
2022-06-07 21:00:49 +01:00
David Sherwood 997ecb0036 [LoopVectorize] Add FastMathFlags to the select used for reductions with tail-folding
Based on reviewer comments on https://reviews.llvm.org/D126692 I've
added FastMathFlags to the select instruction used when tail-folding
with reductions. These flags can then be used by InstCombine to
decide upon the most optimal floating point identity value for
fadd/fsub. Doing so unlocks further optimisations, such as folding
selects into masked loads.

Differential Revision: https://reviews.llvm.org/D126778
2022-06-07 10:21:31 +01:00
Florian Hahn eaf48dd9b0
[VPlan] Replace BranchOnCount with BranchOnCond if TC <= UF * VF.
Try to simplify BranchOnCount to `BranchOnCond true` if TC <= UF * VF.

This is an alternative to D121899 which simplifies the VPlan directly
instead of doing so late in code-gen.

The potential benefit of doing this in VPlan is that this may help
cost-modeling in the future. The reason this is done in prepareToExecute
at the moment is that a single plan may be used for multiple VFs/UFs.

There are further simplifications that can be applied as follow ups:

1. Replace inductions with constants
2. Replace vector region with regular block.

Fixes #55354.

Depends on D126679.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D126680
2022-06-06 09:38:53 +01:00
Florian Hahn 416a5080d8
[VPlan] Update vector latch terminator edge to exit block after execution.
Instead of setting the successor to the exit using CFG.ExitBB, set it to
nullptr initially. The successor to the exit block is later set either
through createEmptyBasicBlock or after VPlan execution (because at the
moment, no block is created by VPlan for the exit block, the existing
one is reused).

This also enables BranchOnCond to be used as terminator for the exiting
block of the topmost vector region.

Depends on D126618.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D126679
2022-06-04 21:22:32 +01:00
Alexey Bataev cac60940b7 [SLP]Improve shuffles cost estimation where possible.
Improved/fixed cost modeling for shuffles by providing masks, improved
cost model for non-identity insertelements.

Differential Revision: https://reviews.llvm.org/D115462
2022-06-03 08:06:22 -07:00
Benjamin Kramer a8d2a381a2 [VPlan] Silence another unused variable warning in release builds 2022-06-03 14:07:56 +02:00
Benjamin Kramer 6b7c186390 [VPlan] Inline variable into assertion. NFC.
Avoids a warning in release builds
llvm/lib/Transforms/Vectorize/VPlanHCFGBuilder.cpp:311:14: warning: unused variable 'BrCond' [-Wunused-variable]
      Value *BrCond = Br->getCondition();
2022-06-03 13:59:48 +02:00
Florian Hahn a5bb4a3b4d
[VPlan] Replace CondBit with BranchOnCond VPInstruction.
This patch removes CondBit and Predicate from VPBasicBlock. To do so,
the patch introduces a new branch-on-cond VPInstruction opcode to model
a branch on a condition explicitly.

This addresses a long-standing TODO/FIXME that blocks shouldn't be users
of VPValues. Those extra users can cause issues for VPValue-based
analyses that don't expect blocks. Addressing this fixme should allow us
to re-introduce 266ea446ab.

The generic branch opcode can also be used in follow-up patches.

Depends on D123005.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D126618
2022-06-03 11:48:31 +01:00
Fangrui Song df0f30dc36 Revert "[SLP]Improve shuffles cost estimation where possible."
This reverts commit 9980c99718.

Caused assertion failures: https://reviews.llvm.org/D115462#3555350
2022-06-03 00:30:34 -07:00
Alexey Bataev 9980c99718 [SLP]Improve shuffles cost estimation where possible.
Improved/fixed cost modeling for shuffles by providing masks, improved
cost model for non-identity insertelements.

Differential Revision: https://reviews.llvm.org/D115462
2022-06-02 11:18:14 -07:00
Florian Hahn 4f1c86e3d5
[VPlan] Remove dead VPlan-native special case from BranchOnCount (NFC).
After 05776122b6 this special case doesn't exist any longer.
2022-06-02 12:07:54 +01:00
Alexey Bataev 73020b4540 Revert "[SLP]Improve shuffles cost estimation where possible."
This reverts commit fd5a6ce9dc to fix
a crash detected by a buildbot
https://lab.llvm.org/buildbot/#/builders/179/builds/3805/steps/11/logs/stdio.
2022-06-01 15:44:51 -07:00
Florian Hahn 08482830eb
[LV] Update var name to Exiting, in line with terminology (NFC)
Recently the terminology used has been changed from Exit->Exiting in
line with common LLVM loop terminology. Update a remaining use of the
old terminology.
2022-06-01 22:13:29 +01:00
Alexey Bataev fd5a6ce9dc [SLP]Improve shuffles cost estimation where possible.
Improved/fixed cost modeling for shuffles by providing masks, improved
cost model for non-identity insertelements.

Differential Revision: https://reviews.llvm.org/D115462
2022-06-01 11:01:37 -07:00
Alexey Bataev fe4949942d [SLP]Fix PR55796: insert point for extractelements from different basic blocks.
Extractelement instructions may come from different basic blocks, need
to take it into account when looking for a last instruction in the
bundle to prevent compiler crash.

Differential Revision: https://reviews.llvm.org/D126777
2022-06-01 09:44:53 -07:00
Florian Hahn 05776122b6
[VPlan] Use region for each loop in native path.
This patch updates the VPlan native path to use VPRegionBlocks for all
loops in a loop nest. Up to now, only the outermost loop used a region.

This is a step towards unifying both paths and keep things consistent
between them. It also prepares various code-gen parts for modeling the
pre-header in the inner loop vectorizer (D121624).

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D123005
2022-06-01 10:41:05 +01:00
Florian Hahn d157019482
[VPlan] Remove unused native utilities incompatible with nested regions.
The implementations of VPlanDominatorTree, VPlanLoopInfo and VPlanPredicator
are all incompatible with modeling loops in VPlans as region without
explicit back-edges.

Those pieces are not actively used and only exercised by a few gtest
unit tests. They are at the moment blocking progress towards unifying
the native and inner-loop vectorizer paths in D121624 and D123005.

I think we should not block forward progress on unused pieces of code,
so this patch removes the utilities for now. The plan is to re-introduce
them as needed in a way that is compatible with the unified VPlan scheme
used in both the inner loop vectorizer and the native path.

Reviewed By: sguggill

Differential Revision: https://reviews.llvm.org/D123017
2022-06-01 09:32:59 +01:00
Mel Chen b0fc765350 [NFC] Change LoopVectorizationCostModel::useOrderedReductions() to be a const function.
Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D126200
2022-05-31 05:39:13 -07:00
Florian Hahn 6abce17fc2
[VPlan] Use Exiting-block instead of Exit-block terminology (NFC).
In LLVM's common loop terminology, an exit block is a block outside a
loop with a predecessor inside the loop. An exiting block is a block
inside the loop which branches to an exit block outside the loop.

This patch updates a few places where VPlan was using ExitBlock for a
block exiting a region. Those instances have been updated to use
ExitingBlock.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D126173
2022-05-28 21:16:05 +01:00
Alexey Bataev 7b809c30b9 [SLP]Improve compile time, NFC.
Patch improves compile time. For function calls, which cannot be
vectorized, create a unique group for each such a call instead of
subgroup. It prevents them from being grouped by a subgroups and
attempts for their vectorization.

Also, looks through casts operand to try to check their
groups/subgroups.

Reduces number of vectorization attempts. No changes in the statistics
for SPEC2017/2006/llvm-test-suite.

Differential Revision: https://reviews.llvm.org/D126476
2022-05-26 08:40:59 -07:00
Alexey Bataev 120d52b0ef [SLP]Fix PR55653: emit undefs where required, not poison.
Need to handle a corner case correctly, if all elements are Undefs/Poisons,
need to emit actual values, not just poisons.

Differential Revision: https://reviews.llvm.org/D126298
2022-05-26 08:38:50 -07:00
Simon Pilgrim 14258d6fb5 [SLP] Move canVectorizeLoads implementation to simplify the diff in D105986. NFC. 2022-05-26 15:23:58 +01:00
Alexey Bataev 9139d484d4 [SLP]Fix crash on reordering of ScatterVectorize nodes.
ScatterVectorize nodes should be handled same way as gathers in
reorderBottomToTop function, since we can simple reorder the loads in
this node. Because of that need to include such nodes to the list of
gathered nodes to fix compiler crash.

Differential Revision: https://reviews.llvm.org/D126378
2022-05-26 06:25:58 -07:00
Florian Hahn 390c0ac28d
[LV] Fix indentation in tryToCreateWidenRecipe (NFC). 2022-05-26 08:53:34 +01:00
Alexey Bataev 3bf5c2c8ec [SLP]Do not try to generate ScatterVectorize if it will be scalarized.
SLP should build ScatterVectorize nodes only if they actually end up
with masked gather rather than with scalarization. In the second
scenario better to build a gather node.

Differential Revision: https://reviews.llvm.org/D126379
2022-05-25 14:25:07 -07:00
Alexey Bataev 10f41a2147 [SLP]Fix PR55688: Miscompile due to incorrect nuw/nsw handling.
Need to use all ReductionOps when propagating flags for the reduction
ops, otherwise transformation is not correct. Plus, need to drop nuw/nsw
flags.

Differential Revision: https://reviews.llvm.org/D126371
2022-05-25 13:59:06 -07:00
David Sherwood 87936c7b13 [LoopVectorize] Fix assertion failure in fixReduction when tail-folding
When compiling the attached new test in scalable-reductions-tf.ll we
were hitting this assertion in fixReduction:

  Assertion `isa<PHINode>(U) && "Reduction exit must feed Phi's or select"

The loop contains a reduction and an intermediate store of the reduction
value. When vectorising with tail-folding the contains of 'U' in the
assertion above happened to be a scatter_store. It turns out that we
were still creating a widen recipe for the invariant store, despite
knowing that we can actually sink it. The simplest fix is to change
buildVPlanWithVPRecipes so that we look for invariant stores before
attempting to widen it.

Differential Revision: https://reviews.llvm.org/D126295
2022-05-25 11:46:32 +01:00
Florian Hahn c6e45ea074
[VPlan] Exit earlier when trying to widen with scalar VFs.
This simplifies the code a bit, suggested in D124718.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D125029
2022-05-25 11:05:23 +01:00
Florian Hahn 1ba42dd04b
[VPlan] Use MapVector for LiveOuts for deterministic iteration.
During code-gen, we iterate over the LiveOuts and the differences in
iteration order can cause slightly different outputs.
2022-05-25 09:30:02 +01:00
Vasileios Porpodas 9df0568b07 [SLP] Fix crash caused by reorderBottomToTop().
The crash is caused by incorrect order set by reorderBottomToTop(), which
happens when it is reordering a TreeEntry which has a user that has already been
reordered earlier. Please see the detailed description in the lit test.

Differential Revision: https://reviews.llvm.org/D126099
2022-05-24 12:24:19 -07:00
Alexey Bataev f9c806ae5c [SLP][NFC]Make isFirstInsertElement a weak strict ordering comparator.
To be used correctly in a sort-like function, isFirstInsertElement
function must follow weak strict ordering rule, i.e.
isFirstInsertElement(IE1, IE1) should return false.
2022-05-24 06:02:42 -07:00
Alexey Bataev 319a722f6f [SLP][NFC]Improve compile time, NFC.
Builds UserIgnore list only once as a SmallDenseSet without rebuilding
it between the runs, iterate over gathers instead list of reduction ops,
do some checks in the buildTree_rec only if the corresponding containers
  are not empty.
2022-05-23 12:15:27 -07:00
Benjamin Kramer 2f2ca30d0a Fix an unused variable warning in no-asserts build mode 2022-05-23 19:53:40 +02:00
Jingu Kang bb82f74612 Revert "Revert "[AArch64] Set maximum VF with shouldMaximizeVectorBandwidth""
This reverts commit 42ebfa8269.

The commmit from https://reviews.llvm.org/D125918 has fixed the stage 2 build
failure.

Differential Revision: https://reviews.llvm.org/D118979
2022-05-23 16:15:45 +01:00
Alexey Bataev 2ac5ebedea [SLP]Do not emit extract elements for insertelements users, replace with shuffles directly.
SLP vectorizer emits extracts for externally used vectorized scalars and
estimates the cost for each such extract. But in many cases these
scalars are input for insertelement instructions, forming buildvector,
and instead of extractelement/insertelement pair we can emit/cost
estimate shuffle(s) cost and generate series of shuffles, which can be
further optimized.

Tested using test-suite (+SPEC2017), the tests passed, SLP was able to
generate/vectorize more instructions in many cases and it allowed to reduce
number of re-vectorization attempts (where we could try to vectorize
buildector insertelements again and again).

Differential Revision: https://reviews.llvm.org/D107966
2022-05-23 07:06:45 -07:00
Peter Waller ade47bdc31 [LV] Improve register pressure estimate at high VFs
Previously, `getRegUsageForType` was implemented using
`getTypeLegalizationCost`.  `getRegUsageForType` is used by the loop
vectorizer to estimate the register pressure caused by using a vector
type.  However, `getTypeLegalizationCost` currently only appears to
understand splitting and not scalarization, so significantly
underestimates the register requirements.

Instead, use `getNumRegisters`, which understands when scalarization
can occur (via computeRegisterProperties).

This was discovered while investigating D118979 (Set maximum VF with
shouldMaximizeVectorBandwidth), where under fixed-length 512-bit SVE the
loop vectorizer previously ends up costing an v128i1 as 2 v64i*
registers where it actually occupies 128 i32 registers.

I'm sending this patch early for comment, I'm still doing some sanity checking
with LNT.  I note that getRegisterClassForType appears to return VectorRC even
though the type in question (large vNi1 types) end up occupying scalar
registers. That might be worth fixing too.

Differential Revision: https://reviews.llvm.org/D125918
2022-05-23 07:57:45 +00:00
Florian Hahn 145fe57106
[LV] Use exiting block instead of latch in addUsersInExitBlock.
The latch may not be the exiting block. Use the exiting block instead
when looking up the incoming value of the LCSSA phi node. This fixes a
crash with early-exit loops.
2022-05-22 18:27:41 +01:00
Florian Hahn 97590baead
[LV] Widen ptr-inductions with scalar uses for scalable VFs.
Current codegen only supports scalarization of pointer inductions for
scalable VFs if they are uniform. After 3bebec659 we now may enter the
scalarization code path in VPWidenPointerInductionRecipe::execute for
scalable vectors.

Fall back to widening for scalable vectors if necessary.

This should fix a build failure when bootstrapping LLVM with SVE, e.g.
https://lab.llvm.org/buildbot/#/builders/176/builds/1723
2022-05-22 16:24:13 +01:00
Florian Hahn aeb19817d6
Revert "[SLP]Do not emit extract elements for insertelements users, replace with shuffles directly."
This reverts commit fc9c59c355.

The patch triggers an assertion when building SPEC on X86. Reduced
reproducer shared at D107966.

Also reverts follow-up commit 11a09af76d.
2022-05-21 21:00:01 +01:00
Florian Hahn 3bebec6592
[VPlan] Model first exit values using VPLiveOut.
This patch introduces a new VPLiveOut subclass of VPUser  to model
 exit values explicitly. The initial version handles exit values that
are neither part of induction or reduction chains nor first order
recurrence phis.

Fixes #51366, #54867, #55167, #55459

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D123537
2022-05-21 16:01:38 +01:00
Dmitri Gribenko 11a09af76d Fix an unused variable warning in no-asserts build mode 2022-05-20 17:11:58 +02:00
Alexey Bataev fc9c59c355 [SLP]Do not emit extract elements for insertelements users, replace with shuffles directly.
SLP vectorizer emits extracts for externally used vectorized scalars and
estimates the cost for each such extract. But in many cases these
scalars are input for insertelement instructions, forming buildvector,
and instead of extractelement/insertelement pair we can emit/cost
estimate shuffle(s) cost and generate series of shuffles, which can be
further optimized.

Tested using test-suite (+SPEC2017), the tests passed, SLP was able to
generate/vectorize more instructions in many cases and it allowed to reduce
number of re-vectorization attempts (where we could try to vectorize
buildector insertelements again and again).

Differential Revision: https://reviews.llvm.org/D107966
2022-05-20 05:58:09 -07:00
Alexey Bataev 4e271fc495 [SLP][NFC]Use SmallPtrSet to avoid n*m complexity, NFC. 2022-05-20 05:56:43 -07:00
Florian Hahn cd61d4bd2f
[LV] Do not LoopSimplify/LCSSA after generating main vector loop.
At the moment LV runs LoopSimplify and reconstructs LCSSA form after
generating the main vector loop and before generating the epilogue
vector loop.

In practice, this adds a new exit block for the scalar loop because the
middle block now also branches to the original exit block of the scalar
loop. It also requires adding a new LCSSA phi in the newly created exit
block.

This complicates things when modeling exit values in VPlan, because we
would need to update the VPlan for the epilogue loop to update the newly
created LCSSA phi node.

But none of that should be necessary, as all analysis requiring
loop-simplify form is already done at this point and LCSSA form of the
original loop is not broken.

Reviewed By: bmahjour

Differential Revision: https://reviews.llvm.org/D125810
2022-05-20 09:58:40 +01:00
Florian Hahn c90235f0ef
[LV] Drop wrap flags for reductions using VP def-use chain.
Update clearReductionWrapFlags to use the VPlan def-use chain from the
reduction phi recipe to drop reduction wrap flags.

This addresses an existing FIXME and fixes a crash when instructions in
the reduction chain are not used and have been removed before VPlan
codegeneration.

Fixes #55540.
2022-05-19 20:36:46 +01:00
Tiehu Zhang 3ed9f603fd [LoopVectorize] Don't interleave when the number of runtime checks exceeds the threshold
The runtime check threshold should also restrict interleave count.
Otherwise, too many runtime checks will be generated for some cases.

Reviewed By: fhahn, dmgreen

Differential Revision: https://reviews.llvm.org/D122126
2022-05-19 23:29:00 +08:00
Florian Hahn df56fb44f5
[VPlan] Update VPWidenMemoryInstruction to not inherit from VPValue.
VPWidenMemoryInstruction also models stores which may not produce a value.
This can trip over analyses. Improve the modeling by only adding
VPValues for VPWidenMemoryInstructionRecipes modeling loads.
2022-05-19 16:24:58 +01:00
Jay Foad 6bec3e9303 [APInt] Remove all uses of zextOrSelf, sextOrSelf and truncOrSelf
Most clients only used these methods because they wanted to be able to
extend or truncate to the same bit width (which is a no-op). Now that
the standard zext, sext and trunc allow this, there is no reason to use
the OrSelf versions.

The OrSelf versions additionally have the strange behaviour of allowing
extending to a *smaller* width, or truncating to a *larger* width, which
are also treated as no-ops. A small amount of client code relied on this
(ConstantRange::castOp and MicrosoftCXXNameMangler::mangleNumber) and
needed rewriting.

Differential Revision: https://reviews.llvm.org/D125557
2022-05-19 11:23:13 +01:00
lizhijin 90ea81fcb2 [LV] Widen freeze instead of scalarizing it
This patch changes the strategy for vectorizing freeze instrucion, from
replicating multiple times to widening according to selected VF.

Fixes #54992

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D125016
2022-05-19 12:28:01 +08:00
Alexey Bataev 7d8060bc19 [SLP]Improve reductions vectorization.
The pattern matching and vectgorization for reductions was not very
effective. Some of of the possible reduction values were marked as
external arguments, SLP could not find some reduction patterns because
of too early attempt to vectorize pair of binops arguments, the cost of
consts reductions was not correct. Patch addresses these issues and
improves the analysis/cost estimation and vectorization of the
reductions.

The most significant changes in SLP.NumVectorInstructions:

Metric: SLP.NumVectorInstructions                                                                                                                                                                                                 [140/14396]

Program                                                                                        results  results0 diff
               test-suite :: SingleSource/Benchmarks/Adobe-C++/loop_unroll.test   920.00  3548.00 285.7%
                test-suite :: SingleSource/Benchmarks/BenchmarkGame/n-body.test    66.00   122.00  84.8%
      test-suite :: MultiSource/Benchmarks/DOE-ProxyApps-C/miniGMG/miniGMG.test   100.00   128.00  28.0%
 test-suite :: MultiSource/Benchmarks/Prolangs-C/TimberWolfMC/timberwolfmc.test   664.00   810.00  22.0%
                 test-suite :: MultiSource/Benchmarks/mafft/pairlocalalign.test   592.00   687.00  16.0%
  test-suite :: MultiSource/Benchmarks/MiBench/consumer-lame/consumer-lame.test   402.00   426.00   6.0%
                   test-suite :: MultiSource/Applications/JM/lencod/lencod.test  1665.00  1745.00   4.8%
  test-suite :: External/SPEC/CINT2017rate/500.perlbench_r/500.perlbench_r.test   135.00   139.00   3.0%
 test-suite :: External/SPEC/CINT2017speed/600.perlbench_s/600.perlbench_s.test   135.00   139.00   3.0%
                  test-suite :: MultiSource/Benchmarks/7zip/7zip-benchmark.test   388.00   397.00   2.3%
                   test-suite :: MultiSource/Applications/JM/ldecod/ldecod.test   895.00   914.00   2.1%
    test-suite :: MultiSource/Benchmarks/MiBench/telecomm-gsm/telecomm-gsm.test   240.00   244.00   1.7%
           test-suite :: MultiSource/Benchmarks/mediabench/gsm/toast/toast.test   240.00   244.00   1.7%
             test-suite :: External/SPEC/CINT2017speed/602.gcc_s/602.gcc_s.test   820.00   832.00   1.5%
              test-suite :: External/SPEC/CINT2017rate/502.gcc_r/502.gcc_r.test   820.00   832.00   1.5%
       test-suite :: External/SPEC/CFP2017rate/526.blender_r/526.blender_r.test 14804.00 14914.00   0.7%
                        test-suite :: MultiSource/Benchmarks/Bullet/bullet.test  8125.00  8183.00   0.7%
           test-suite :: External/SPEC/CINT2017speed/625.x264_s/625.x264_s.test  1330.00  1338.00   0.6%
            test-suite :: External/SPEC/CINT2017rate/525.x264_r/525.x264_r.test  1330.00  1338.00   0.6%
         test-suite :: External/SPEC/CFP2017rate/510.parest_r/510.parest_r.test  9832.00  9880.00   0.5%
         test-suite :: External/SPEC/CFP2017rate/511.povray_r/511.povray_r.test  5267.00  5291.00   0.5%
       test-suite :: External/SPEC/CFP2017rate/538.imagick_r/538.imagick_r.test  4018.00  4024.00   0.1%
      test-suite :: External/SPEC/CFP2017speed/638.imagick_s/638.imagick_s.test  4018.00  4024.00   0.1%
              test-suite :: External/SPEC/CFP2017speed/644.nab_s/644.nab_s.test   426.00   424.00  -0.5%
               test-suite :: External/SPEC/CFP2017rate/544.nab_r/544.nab_r.test   426.00   424.00  -0.5%
          test-suite :: External/SPEC/CINT2017rate/541.leela_r/541.leela_r.test   201.00   192.00  -4.5%
         test-suite :: External/SPEC/CINT2017speed/641.leela_s/641.leela_s.test   201.00   192.00  -4.5%

644.nab_s and 544.nab_r - reduced number of shuffles but increased number
of useful vectorized instructions.

641.leela_s and 541.leela_r - the function
`@_ZN9FastBoard25get_pattern3_augment_specEiib` is not inlined anymore
but its body gets vectorized successfully. Before, the function was
inlined twice and vectorized just after inlining, currently it is not
required. The vector code looks pretty similar, just like as it was before.

Differential Revision: https://reviews.llvm.org/D111574
2022-05-18 13:22:18 -07:00
Florian Hahn fcfb86483b
[LV] set Header earlier, use variable instead of repeated access (NFC). 2022-05-18 09:29:59 +01:00
Florian Hahn 5b00d13c00
[LV] Fetch vector loop region once and remember it (NFC).
This avoids an unnecessary lookup and makes the code slightly more
compact.
2022-05-17 15:57:23 +01:00
Alexey Bataev b0f0313feb [SLP]Add an extra check for select minmax reduction to avoid crash.
Need to check if the reduction is still (not)cmp-select pattern min/max
reduction to avoid compiler crash during building list of reduction
operations. cmp-sel pattern provides 2 reduction operations, while
intrinsics - just one.
2022-05-17 06:05:52 -07:00
Florian Hahn c1a9d14982
[VPlan] Move usesScalars/onlyFirstLaneUsed to VPUser.
Those helpers model properties of a user and they should also be
available to non-recipe users. This will be used in D123537 for a new
exit value user.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D124936
2022-05-17 11:20:06 +01:00
Alexey Bataev 152072801e [SLP]Check if the root of the buildvector has one use only.
The root of the buildvector can have only one use, otherwise it can be
treated only as a final element of the previous buildvector sequence.
2022-05-16 07:30:36 -07:00