Commit Graph

3199 Commits

Author SHA1 Message Date
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