Commit Graph

251 Commits

Author SHA1 Message Date
Florian Hahn b3e8ace198
Recommit "[VPlan] Introduce recipe to build scalar steps."
This reverts the revert commit ff93260bf6.

The underlying issue causing the PPC bot failures has been fixed in
cbaac14734 and a corresponding test case has been added in
ad2cad1c52.

Original message:

    This patch adds a new VPScalarIVStepsRecipe to handle building scalar
    steps.

    In the first patch, it only handles the case where there is no vector
    induction variable needed.

    Reviewed By: Ayal

    Differential Revision: https://reviews.llvm.org/D115953
2022-02-28 14:12:20 +00:00
Florian Hahn ff93260bf6
Revert "[VPlan] Introduce recipe to build scalar steps."
This reverts commit 49b23f451c.

This appears to break some PPC build bots. Revert while I investigate.
2022-02-27 17:51:19 +00:00
Florian Hahn 49b23f451c
[VPlan] Introduce recipe to build scalar steps.
This patch adds a new VPScalarIVStepsRecipe to handle building scalar
steps.

In the first patch, it only handles the case where there is no vector
induction variable needed.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D115953
2022-02-27 17:32:41 +00:00
Florian Hahn 9bc866cc6f
[VPlan] Add recipe to handle SCEV expansion (NFC).
This can be used to explicitly model VPValues that depend on SCEV
expansion, like the step for inductions.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D116288
2022-02-27 12:47:02 +00:00
Florian Hahn 5a72357697
[LV] Use IRBuilderBase in VPlan.h, remove IRBuilder.h include (NFC).
By using IRBuilderBase instead of IRBuilder<> a forward declaration can
be used instead of including IRBuilder.h
2022-02-07 17:46:16 +00:00
Florian Hahn 8f12175fed
[VPlan] Use VPlan to check if only the first lane is used.
This removes the remaining dependence on LoopVectorizationCostModel from
buildScalarSteps and is required so it can be moved out of ILV.

It also improves allows us to remove a few unneeded instructions.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D116554
2022-01-30 13:07:29 +00:00
Florian Hahn 96400f179f
[VPlan] Record whether scalar IVs are need in induction recipe. (NFC)
This explicitly records whether a scalar IV is needed in the
VPWidenIntOrFpInductionRecipe, to remove a dependence on the cost-model
during its ::execute.

It will also be used in D116123 to determine if a vector phi will be
generated.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D118167
2022-01-28 09:34:03 +00:00
Florian Hahn 5f2854f1da
[LV] Always create VPWidenCanonicalIVRecipe, optimize away later.
This patch updates createBlockInMask to always generate
VPWidenCanonicalIVRecipe and adds a transform to optimize it away later,
if it is not needed.

This is a step towards breaking up VPWidenIntOrFpInductionRecipe and
explicitly distinguishing between vector phis and scalarizing.

Split off from D116123.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D117140
2022-01-22 15:34:20 +00:00
Florian Hahn c0cf209076
[VPlan] Add VPWidenIntOrFpInductionRecipe::isCanonical, use it (NFCI).
This patch adds VPWidenIntOrFpInductionRecipe::isCanonical to check if
an induction recipe is canonical. The code is also updated to use it
instead of isCanonicalID.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D117551
2022-01-21 09:35:06 +00:00
Florian Hahn 165e36bf18
[VPlan] Assert can IV is only used by increments during epilogue vec.
After resetting the start value of the canonical IV, it might not be
canonical any more. Add an assertion to make sure it is only used by its
increment, to avoid potential mis-use. Suggested in D117140.
2022-01-19 10:10:05 +00:00
Florian Hahn 3f2fb767e3
[VPlan] Make IV operand explicit for VPWidenCanonicalIVRecipe (NFC).
This makes the def-use relationship between VPCanonicalIVPHIRecipe and
VPWidenCanonicalIVRecipe explicit. Needed for D117140.
2022-01-13 11:13:05 +00:00
Florian Hahn d4a8fc3a87
[VPlan] Introduce and use BranchOnCount VPInstruction.
This patch adds a new BranchOnCount VPInstruction opcode with 2
operands. It first compares its 2 operands (increment of canonical
induction and vector trip count), followed by a branch to either the
exit block or back to the vector header.

It must be the last recipe in the exit block of the topmost vector loop
region.

This extracts parts from D113224 and was discussed in D113223.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D116479
2022-01-12 13:42:13 +00:00
Kazu Hirata b932bdf59f [llvm] Remove redundant member initialization (NFC)
Identified with readability-redundant-member-init.
2022-01-07 17:45:09 -08:00
Florian Hahn 65c4d6191f
[VPlan] Add VPCanonicalIVPHIRecipe, partly retire createInductionVariable.
At the moment, the primary induction variable for the vector loop is
created as part of the skeleton creation. This is tied to creating the
vector loop latch outside of VPlan. This prevents from modeling the
*whole* vector loop in VPlan, which in turn is required to model
preheader and exit blocks in VPlan as well.

This patch introduces a new recipe VPCanonicalIVPHIRecipe to represent the
primary IV in VPlan and CanonicalIVIncrement{NUW} opcodes for
VPInstruction to model the increment.

This allows us to partly retire createInductionVariable. At the moment,
a bit of patching up is done after executing all blocks in the plan.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D113223
2022-01-05 10:46:06 +00:00
Kazu Hirata e5947760c2 Revert "[llvm] Remove redundant member initialization (NFC)"
This reverts commit fd4808887e.

This patch causes gcc to issue a lot of warnings like:

  warning: base class ‘class llvm::MCParsedAsmOperand’ should be
  explicitly initialized in the copy constructor [-Wextra]
2022-01-03 11:28:47 -08:00
Kazu Hirata fd4808887e [llvm] Remove redundant member initialization (NFC)
Identified with readability-redundant-member-init.
2022-01-01 16:18:18 -08:00
Florian Hahn 7305798049
[VPlan] Remove VPWidenPHIRecipe constructor without start value (NFC).
This was suggested as a separate cleanup in recent reviews.
2022-01-01 13:53:48 +00:00
Florian Hahn 9d297c7894
[VPlan] Add prepareToExecute to set up live-ins (NFC).
This patch adds a new prepareToExecute helper to set up live-ins, so
VPTransformState doesn't need to hold values like TripCount.

This also requires making the trip count operand for ActiveLaneMask
explicit in VPlan.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D116320
2021-12-28 17:49:47 +01:00
Florian Hahn c2275278c6
[VPlan] Add abstract base class for header phi recipes (NFC).
Not all header phis widen the phi, e.g. like the new
VPCanonicalIVPHIRecipe in D113223. To let those recipes also inherit
from a phi-like base class, add a more generic VPHeaderPHIRecipe
abstract base class.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D116304
2021-12-28 15:37:47 +01:00
Florian Hahn ede7c2438f
[VPlan] Create header & latch blocks for skeleton up front (NFC).
By creating the header and latch blocks up front and adding blocks and
recipes in between those 2 blocks we ensure that the entry and exits of
the plan remain valid throughout construction.

In order to avoid test changes and keep printing of the plans the same,
we use the new header block instead of creating a new block on the first
iteration of the loop traversing the original loop.

We also fold the latch into its predecessor.

This is a follow up to a post-commit suggestion in D114586.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D115793
2021-12-22 12:44:25 +00:00
Florian Hahn 5b362e4c7f
[VPlan] Add Debugloc to VPInstruction.
Upcoming changes require attaching debug locations to VPInstructions,
e.g. adding induction increment recipes in D113223.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D115123
2021-12-20 15:10:41 +00:00
Florian Hahn 3b35113ff0
[VPlan] Add VPBlockBase::successors() returning an iterator_range (NFC).
This will also be helpful for D115793.
2021-12-16 14:28:50 +00:00
Florian Hahn 505ad03c7d
[LV] Remove redundant IV casts using VPlan (NFCI).
This patch simplifies handling of redundant induction casts, by
removing dead cast instructions after initial VPlan construction.
This has the following benefits:

  1. fixes a crash
     (see @test_optimized_cast_induction_feeding_first_order_recurrence)
  2. Simplifies VPWidenIntOrFpInduction to a single-def recipes
  3. Retires recordVectorLoopValueForInductionCast.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D115112
2021-12-10 13:57:03 +00:00
Florian Hahn 978883d254
[VPlan] Add InductionDescriptor to VPWidenIntOrFpInduction. (NFC)
This allows easier access to the induction descriptor from VPlan,
without needing to go through Legal. VPReductionPHIRecipe already
contains a RecurrenceDescriptor in a similar fashion.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D115111
2021-12-10 09:55:09 +00:00
Florian Hahn d74a8a78ad
[LV] Mark various functions as const (NFC).
Make sure various accessors do not modify any state, in preparation for
D115111.
2021-12-09 10:51:29 +00:00
Florian Hahn 07276e49e3
[LV] Check VPValue operand instead of Cost::isUniformAfterVec (NFC).
ILV::scalarizeInstruction still uses the original IR operands to check
if an input value is uniform after vectorization.

There is no need to go back to the cost model to figure that out, as the
information is already explicit in the VPlan. Just check directly
whether the VPValue is defined outside the plan or is a uniform
VPReplicateRecipe.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D114253
2021-12-06 18:32:35 +00:00
Florian Hahn 7c3c352d82
[VPlan] Separate ctors for VPWidenIntOrFpInduction. (NFC)
VPWidenIntOrFpInductionRecipes can either be constructed with a PHI and
an optional cast or a PHI and a trunc instruction. Reflect this in 2
separate constructors. This also simplifies a follow-up change.
2021-12-05 12:15:18 +00:00
Florian Hahn 8b86752c60
[VPlan] Remove unused VPInstruction constructor. (NFC)
VPInstruction inherits from VPValue, so the constructor taking
ArrayRef<VPValue*> covers all cases that would be covered by the removed
constructor.
2021-11-24 14:06:50 +00:00
Rosie Sumpter 991074012a [LoopVectorize] Propagate fast-math flags for VPInstruction
In-loop vector reductions which use the llvm.fmuladd intrinsic involve
the creation of two recipes; a VPReductionRecipe for the fadd and a
VPInstruction for the fmul. If the call to llvm.fmuladd has fast-math flags
these should be propagated through to the fmul instruction, so an
interface setFastMathFlags has been added to the VPInstruction class to
enable this.

Differential Revision: https://reviews.llvm.org/D113125
2021-11-24 08:50:04 +00:00
Diego Caballero 4348cd42c3 [LV] Drop integer poison-generating flags from instructions that need predication
This patch fixes PR52111. The problem is that LV propagates poison-generating flags (`nuw`/`nsw`, `exact`
and `inbounds`) in instructions that contribute to the address computation of widen loads/stores that are
guarded by a condition. It may happen that when the code is vectorized and the control flow within the loop
is linearized, these flags may lead to generating a poison value that is effectively used as the base address
of the widen load/store. The fix drops all the integer poison-generating flags from instructions that
contribute to the address computation of a widen load/store whose original instruction was in a basic block
that needed predication and is not predicated after vectorization.

Reviewed By: fhahn, spatel, nlopes

Differential Revision: https://reviews.llvm.org/D111846
2021-11-22 10:57:29 +00:00
Florian Hahn 8e44bdd12a
[VPlan] Make VPWidenCanonicalIVRecipe a VPValue (NFC).
The recipe produces exactly one VPValue and can inherit directly from
it. This is in line with other recipes and avoids having to use
getVPSingleValue.
2021-11-03 14:11:01 +01:00
Gil Rapaport 1156bd4fc3 [LV] Record memory widening decisions (NFCI)
Record widening decisions for memory operations within the planned recipes and
use the recorded decisions in code-gen rather than querying the cost model.

Differential Revision: https://reviews.llvm.org/D110479
2021-10-18 18:03:35 +03:00
Florian Hahn abd36fe512
[VPlan] Introduce code to limit querying VPValues using IR references.
After applying VPlan-to-VPlan transformations, using IR references to
query VPlan values may be incorrect, as the IR is not in sync with the
VPlan any longer.

To better detect such mis-matches, this patch introduces a new flag to
VPlans to indicate whether it is safe to query VPValues using IR values.

getVPValue is updated to assert if it is called when the flag indicates
it is not safe any longer.

There is an escape hatch via an extra argument, because there are 3
places that need to be fixed first. Those are

1. truncateToMinimalBitwidths
2. clearReductionWrapFlags
3. fixLCSSAPHIs

As a first step, this flag will help preventing new code from violating
this property.

Any suggestions with respect to naming very welcome!

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D108573
2021-08-30 09:12:09 +02:00
Kazu Hirata 72661f337a [Transforms] Drop unnecessary const from return types (NFC)
Identified with readability-const-return-type.
2021-08-05 08:53:17 -07:00
Florian Hahn bb725c9803
[VPlan] Use defined and ops VPValues to print VPInterleaveRecipe.
This patch updates VPInterleaveRecipe::print to print the actual defined
VPValues for load groups and the store VPValue operands for store
groups.

The IR references may become outdated while transforming the VPlan and
the defined and stored VPValues always are up-to-date.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D107223
2021-08-02 18:36:36 +01:00
Florian Hahn 7a1e73f0b9
Recommit "[VPlan] Add recipe for first-order rec phis, make splicing explicit."
This reverts the revert commit b1777b04dc.

The patch originally got reverted due to a crash:
https://bugs.chromium.org/p/chromium/issues/detail?id=1232798#c2

The underlying issue was that we were not using the stored values from
the modified memory recipes, but the out-of-date values directly from
the IR (accessed via the VPlan). This should be fixed in d995d6376. A
reduced version of the reproducer has been added in 93664503be.
2021-07-26 15:50:30 +01:00
Nico Weber b1777b04dc Revert "[VPlan] Add recipe for first-order rec phis, make splicing explicit."
Makes clang crash: https://reviews.llvm.org/D105008#2903350
This reverts commit d2a73fb44e.

Also revert a minor formatting follow-up:
This reverts commit 82834a6732.
2021-07-25 17:39:28 -04:00
Florian Hahn 82834a6732
[VPlan] Fix formatting glitch from d2a73fb44e. 2021-07-20 16:16:30 +02:00
Florian Hahn d2a73fb44e
[VPlan] Add recipe for first-order rec phis, make splicing explicit.
This patch adds a VPFirstOrderRecurrencePHIRecipe, to further untangle
VPWidenPHIRecipe into distinct recipes for distinct use cases/lowering.
See D104989 for a new recipe for reduction phis.

This patch also introduces a new `FirstOrderRecurrenceSplice`
VPInstruction opcode, which is used to make the forming of the vector
recurrence value explicit in VPlan. This more accurately models def-uses
in VPlan and also simplifies code-generation. Now, the vector recurrence
values are created at the right place during VPlan-codegeneration,
rather than during post-VPlan fixups.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D105008
2021-07-20 16:14:17 +02:00
Florian Hahn ef0d147cdc
Recommit "[VPlan] Add VPReductionPHIRecipe (NFC)." and follow-ups.
This reverts commit 706bbfb35b.

The committed version moves the definition of VPReductionPHIRecipe out
of an ifdef only intended for ::print helpers. This should resolve the
build failures that caused the revert
2021-07-06 14:15:42 +01:00
Florian Hahn 706bbfb35b
Revert "[VPlan] Add VPReductionPHIRecipe (NFC)." and follow-ups
This reverts commit 3fed6d443f,
bbcbf21ae6 and
6c3451cd76.

The changes causing build failures with certain configurations, e.g.
https://lab.llvm.org/buildbot/#/builders/67/builds/3365/steps/6/logs/stdio

    lib/libLLVMVectorize.a(LoopVectorize.cpp.o): In function `llvm::VPRecipeBuilder::tryToCreateWidenRecipe(llvm::Instruction*, llvm::ArrayRef<llvm::VPValue*>, llvm::VFRange&, std::unique_ptr<llvm::VPlan, std::default_delete<llvm::VPlan> >&) [clone .localalias.8]':
    LoopVectorize.cpp:(.text._ZN4llvm15VPRecipeBuilder22tryToCreateWidenRecipeEPNS_11InstructionENS_8ArrayRefIPNS_7VPValueEEERNS_7VFRangeERSt10unique_ptrINS_5VPlanESt14default_deleteISA_EE+0x63b): undefined reference to `vtable for llvm::VPReductionPHIRecipe'
    collect2: error: ld returned 1 exit status
2021-07-06 12:10:03 +01:00
Florian Hahn 3fed6d443f
[VPlan] Mark overriden function in VPWidenPHIRecipe as virtual.
VPReductionRecipe overrides those implementations. Mark them as virtual
in the VPWidenPHIRecipe to unbreak build in certain configurations.
2021-07-06 12:00:41 +01:00
Florian Hahn bbcbf21ae6
[VPlan] Add destructor to VPReductionRecipe to unbreak build.
Attempt to unbreak
https://lab.llvm.org/buildbot/#/builders/67/builds/3363/steps/6/logs/stdio
2021-07-06 11:41:20 +01:00
Florian Hahn 6c3451cd76
[VPlan] Add VPReductionPHIRecipe (NFC).
This patch is a first step towards splitting up VPWidenPHIRecipe into
separate recipes for the 3 distinct cases they model:

    1. reduction phis,
    2. first-order recurrence phis,
    3. pointer induction phis.

This allows untangling the code generation and allows us to reduce the
reliance on LoopVectorizationCostModel during VPlan code generation.

Discussed/suggested in D100102, D100113, D104197.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D104989
2021-07-06 11:25:28 +01:00
Florian Hahn f1a6430272
[VPlan] Track both incoming values for first-order recurrence phis.
This patch updates VPWidenPHI recipes for first-order recurrences to
also track the incoming value from the back-edge. Similar to D99294,
which did the same for reductions.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D104197
2021-06-27 14:29:35 +01:00
Florian Hahn 1465e7770b
[VPlan] Print successors of VPRegionBlocks.
The non-DOT printing does not include the successors of VPregionBlocks.
This patch use the same style for printing successors as for
VPBasicBlock.

I think the printing of successors could be a bit improved further, as
at the moment it is hard to ensure a check line matches all successors.
But that can be done as follow-up.

Reviewed By: a.elovikov

Differential Revision: https://reviews.llvm.org/D103515
2021-06-07 17:57:21 +01:00
Florian Hahn e9d97d7d9d
[VPlan] Add mayReadOrWriteMemory & friends.
This patch adds initial implementation of mayReadOrWriteMemory,
mayReadFromMemory and mayWriteToMemory to VPRecipeBase.

Used by D100258.
2021-05-24 13:11:32 +01:00
Florian Hahn cc1a6361d3
[VPlan] Add VPUserID to distinguish between recipes and others.
This allows cast/dyn_cast'ing from VPUser to recipes. This is needed
because there are VPUsers that are not recipes.

Reviewed By: gilr, a.elovikov

Differential Revision: https://reviews.llvm.org/D100257
2021-05-18 09:17:28 +01:00
Florian Hahn ccebf7a109
[VPlan] Properly handle sinking of replicate regions.
This patch updates the code that sinks recipes required for first-order
recurrences to properly handle replicate-regions. At the moment, the
code would just move the replicate recipe out of its replicate-region,
producing an invalid VPlan.

When sinking a recipe in a replicate-region, we have to sink the whole
region. To do that, we first need to split the block at the target
recipe and move the region in between.

This patch also adds a splitAt helper to VPBasicBlock to split a
VPBasicBlock at a given iterator.

Fixes PR50009.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D100751
2021-05-04 22:36:01 +01:00
Florian Hahn 4ba8720f88
[VPlan] Representing backedge def-use feeding reduction phis.
This patch updates the code handling reduction recipes to also keep
track of the incoming value from the latch in the recipe. This is needed
to model the def-use chains completely in VPlan, so that it is possible
to replace the incoming value with an arbitrary VPValue.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D99294
2021-05-04 16:33:22 +01:00
Florian Hahn 2b7fa7f744 [LV] Iterate over recipes in VPlan to fix PHI (NFC).
As we gradually move more elements of LV to VPlan, we are trying to
reduce the number of places that still has to check IR of the original
loop.

This patch adjusts the code to fix cross iteration phis to get the PHIs
to fix directly from the VPlan that is executed. We still need the
original PHI to check for first-order recurrences, but we can get rid of
that once we model that explicitly in VPlan as well.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D99293
2021-05-03 14:09:46 +01:00
Florian Hahn 942e068d7a [VPlan] Add VPBasicBlock::phis() helper (NFC).
This patch introduces a helper to obtain an iterator range for the
PHI-like recipes in a block.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D100101
2021-05-02 19:20:13 +01:00
Florian Hahn a0e1313c23
[VPlan] Add getVPSingleValue helper.
As suggested in D99294, this adds a getVPSingleValue helper to use for
recipes that are guaranteed to define a single value. This replaces uses
of getVPValue() which used to default to I = 0.
2021-04-29 13:37:38 +01:00
Florian Hahn 7302fe4328
[VPlan] Make blocksOnly work properly with ranges over const pointers.
When iterating over const blocks, the base type in the lambdas needs
to use const VPBlockBase *, otherwise it cannot be used with input
iterators over const VPBlockBase.

Also adjust the type of the input iterator range to const &, as it
does not take ownership of the input range.
2021-04-26 10:52:35 +01:00
Florian Hahn 4b9be5ac08
[VPlan] Add VPBlockUtils::blocksOnly helper.
This patch adds a blocksOnly helpers which take an iterator range
over VPBlockBase * or const VPBlockBase * and returns an interator
range that only include BlockTy blocks. The accesses are casted to
BlockTy.

Reviewed By: a.elovikov

Differential Revision: https://reviews.llvm.org/D101093
2021-04-25 17:38:09 +01:00
Florian Hahn 89c4dda076
[VPlan] Add GraphTraits impl to traverse through VPRegionBlock.
This patch adds a new iterator to traverse through VPRegionBlocks and a
GraphTraits specialization using the iterator to traverse through
VPRegionBlocks.

Because there is already a GraphTraits specialization for VPBlockBase *
and co, a new VPBlockRecursiveTraversalWrapper helper is introduced.
This allows us to provide a new GraphTraits specialization for that
type. Users can use the new recursive traversal by using this wrapper.

The graph trait visits both the entry block of a region, as well as all
its successors. Exit blocks of a region implicitly have their parent
region's successors. This ensures all blocks in a region are visited
before any blocks in a successor region when doing a reverse post-order
traversal of the graph.

Reviewed By: a.elovikov

Differential Revision: https://reviews.llvm.org/D100175
2021-04-23 17:26:47 +01:00
Sander de Smalen 86729538bd [LV] Let selectVectorizationFactor reason directly on VectorizationFactor.
Rather than maintaining two separate values, a `float` for the per-lane
cost and a Width for the VF, maintain a single VectorizationFactor which
comprises the two and also removes the need for converting an integer value
to float.

This simplifies the query when asking if one VF is more profitable than
another when we want to extend this for scalable vectors (which may
require additional options to determine if e.g. a scalable VF of the
some cost, is more profitable than a fixed VF of the same cost).

The patch isn't entirely NFC because it also fixes an issue in
selectEpilogueVectorizationFactor, where the cost passed to ProfitableVFs
no longer truncates the floating-point cost from `float` to `unsigned` to
then perform the calculation on the truncated cost. It now does
a cost comparison with the correct precision.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D100121
2021-04-20 09:54:45 +01:00
Florian Hahn 6adebe3fd2 [VPlan] Add VPRecipeBase::mayHaveSideEffects.
Add an initial version of a helper to determine whether a recipe may
have side-effects.

Reviewed By: a.elovikov

Differential Revision: https://reviews.llvm.org/D100259
2021-04-15 11:49:40 +01:00
Huihui Zhang d857a81437 [VPlan] Use SetVector for VPExternalDefs to prevent non-determinism.
Use SetVector instead of SmallPtrSet for external definitions created for VPlan.
Doing this can help avoid non-determinism caused by iterating over unordered containers.

This bug was found with reverse iteration turning on,
 --extra-llvm-cmake-variables="-DLLVM_REVERSE_ITERATION=ON".
Failing LLVM-Unit test VPRecipeTest.dump.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D99544
2021-03-30 12:10:56 -07:00
Andrei Elovikov 92205cb27f [NFC][VPlan] Guard print routines with "#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)"
Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D98897
2021-03-19 10:50:12 -07:00
Andrei Elovikov 93a9d2de8f [VPlan] Add plain text (not DOT's digraph) dumps
I foresee two uses for this:
1) It's easier to use those in debugger.
2) Once we start implementing more VPlan-to-VPlan transformations (especially
   inner loop massaging stuff), using the vectorized LLVM IR as CHECK targets in
   LIT test would become too obscure. I can imagine that we'd want to CHECK
   against VPlan dumps after multiple transformations instead. That would be
   easier with plain text dumps than with DOT format.

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D96628
2021-03-19 10:50:12 -07:00
Mehdi Amini 3614df3537 Revert "[VPlan] Add plain text (not DOT's digraph) dumps"
This reverts commit 6b053c9867.
The build is broken:

ld.lld: error: undefined symbol: llvm::VPlan::printDOT(llvm::raw_ostream&) const
>>> referenced by LoopVectorize.cpp
>>>               LoopVectorize.cpp.o:(llvm::LoopVectorizationPlanner::printPlans(llvm::raw_ostream&)) in archive lib/libLLVMVectorize.a
2021-03-18 19:20:39 +00:00
Andrei Elovikov 6b053c9867 [VPlan] Add plain text (not DOT's digraph) dumps
I foresee two uses for this:
1) It's easier to use those in debugger.
2) Once we start implementing more VPlan-to-VPlan transformations (especially
   inner loop massaging stuff), using the vectorized LLVM IR as CHECK targets in
   LIT test would become too obscure. I can imagine that we'd want to CHECK
   against VPlan dumps after multiple transformations instead. That would be
   easier with plain text dumps than with DOT format.

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D96628
2021-03-18 11:33:39 -07:00
Florian Hahn f586de8459
[VPlan] Remove PredInst2Recipe, use VP operands instead. (NFC)
Instead of maintaining a separate map from predicated instructions to
recipes, we can instead directly look at the VP operands. If the operand
comes from a predicated instruction, the operand will be a
VPPredInstPHIRecipe with a VPReplicateRecipe as its operand.
2021-03-16 17:40:35 +00:00
David Sherwood fec0a0adac [SVE][LoopVectorize] Add support for extracting the last lane of a scalable vector
There are certain loops like this below:

  for (int i = 0; i < n; i++) {
    a[i] = b[i] + 1;
    *inv = a[i];
  }

that can only be vectorised if we are able to extract the last lane of the
vectorised form of 'a[i]'. For fixed width vectors this already works since
we know at compile time what the final lane is, however for scalable vectors
this is a different story. This patch adds support for extracting the last
lane from a scalable vector using a runtime determined lane value. I have
added support to VPIteration for runtime-determined lanes that still permit
the caching of values. I did this by introducing a new class called VPLane,
which describes the lane we're dealing with and provides interfaces to get
both the compile-time known lane and the runtime determined value. Whilst
doing this work I couldn't find any explicit tests for extracting the last
lane values of fixed width vectors so I added tests for both scalable and
fixed width vectors.

Differential Revision: https://reviews.llvm.org/D95139
2021-03-05 09:57:56 +00:00
Florian Hahn a6c81d3366
[VPlan] Remove recipes from back to front.
Update the deletion order when destroying VPBasicBlocks. This ensures
recipes that depend on earlier ones in the block are removed first.
Otherwise this may cause issues when recipes have remaining users later
in the block.
2021-03-01 16:06:30 +00:00
Andrei Elovikov 3605b873f6 [NFC][VPlan] Use VPUser to store block's predicate
Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D96529
2021-02-23 11:08:27 -08:00
Florian Hahn 15a74b64df
[VPlan] Manage pairs of incoming (VPValue, VPBB) in VPWidenPHIRecipe.
This patch extends VPWidenPHIRecipe to manage pairs of incoming
(VPValue, VPBasicBlock) in the VPlan native path. This is made possible
because we now directly manage defined VPValues for recipes.

By keeping both the incoming value and block in the recipe directly,
code-generation in the VPlan native path becomes independent of the
predecessor ordering when fixing up non-induction phis, which currently
can cause crashes in the VPlan native path.

This fixes PR45958.

Reviewed By: sguggill

Differential Revision: https://reviews.llvm.org/D96773
2021-02-22 09:44:25 +00:00
Florian Hahn edc92a1c42
[LV] Remove VPCallback.
Now that all state for generated instructions is managed directly in
VPTransformState, VPCallBack is no longer needed. This patch updates the
last use of `getOrCreateScalarValue` to instead manage the value
directly in VPTransformState and removes VPCallback.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D95383
2021-02-19 12:50:41 +00:00
Florian Hahn f64c626069
[VPlan] Remove unused Phi member from VPWidenPHIRecipe (NFC).
The member is not needed any longer after recent changes.
2021-02-16 13:53:06 +00:00
Florian Hahn 54a14c264a
[VPlan] Manage scalarized values using VPValues.
This patch updates codegen to use VPValues to manage the generated
scalarized instructions.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D92285
2021-02-16 09:04:10 +00:00
Florian Hahn 85fe5c9345
[VPlan] Make VPRecipeBase inherit from VPUser directly (NFC).
The individual recipes have been updated to manage their operands using
VPUser a while back. Now that the transition is done, we can instead
make VPRecipeBase a VPUser and get rid of the toVPUser helper.
2021-02-12 13:06:58 +00:00
Florian Hahn fd8afa41eb
[VPlan] Use VPUser to manage CondBit
VP blocks keep track of a condition, which is a VPValue. This patch
updates VPBlockBase to manage the value using VPUser, so
replaceAllUsesWith properly updates the condition bit as well.

This is required to enable VP2VP transformations and it helps with
simplifying some of the code required to manage condition bits.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D95382
2021-02-09 21:53:50 +00:00
Florian Hahn 3bb6dc0b26
[LV] Replace some uses of VectorLoopValueMap with VPTransformState (NFC)
This patch updates some places where VectorLoopValueMap is accessed
directly to instead go through VPTransformState.

As we move towards managing created values exclusively in VPTransformState,
this ensures the use always can fetch the correct value.

This is in preparation for D92285, which switches to managing scalarized
values through VPValues.

In the future, the various fix* functions should be moved directly into
the VPlan codegen stage.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D95757
2021-02-07 18:28:21 +00:00
Florian Hahn daaa0e3501
[VPlan] Manage induction value creation using VPValues.
This patch updates the induction value creation to use VPValues of
recipes to map the created values. This should bring is one step closer
to being able to optimize induction recipes directly in VPlan.

Currently widenIntOrFpInduction also generates vector values for a cast
of the induction, if it exists. Make this explicit by adding the cast
instruction to the values defined by the recipe.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D92284
2021-02-03 17:45:03 +00:00
David Sherwood d4626eb0bd [VPlan][NFC] Introduce constructors for VPIteration
This patch adds constructors to VPIteration as a cleaner way of
initialising the struct and replaces existing constructions of
the form:

  {Part, Lane}

with

  VPIteration(Part, Lane)

I have also added a default constructor, which is used by VPlan.cpp
when deciding whether to replicate a block or not.

This refactoring will be required in a later patch that adds more
members and functions to VPIteration.

Differential Revision: https://reviews.llvm.org/D95676
2021-02-03 08:52:27 +00:00
Sanjay Patel ab93c18c12 [LoopVectorize] use IR fast-math-flags exclusively (not FP function attributes)
I am trying to untangle the fast-math-flags propagation logic
in the vectorizers (see a6f022127 for SLP).

The loop vectorizer has a mix of checking FP function attributes,
IR-level FMF, and just wrong assumptions.

I am trying to avoid regressions while fixing this, and I think
the IR-level logic is good enough for that, but it's hard to say
for sure. This would be the 1st step in the clean-up.

The existing test that I changed to include 'fast' actually shows
a miscompile: the function only had the equivalent of nnan, but we
created new instructions that had fast (all FMF set). This is
similar to the example in https://llvm.org/PR35538

Differential Revision: https://reviews.llvm.org/D95452
2021-01-27 14:17:11 -05:00
Florian Hahn 3201274dea
[VPlan] Handle scalarized values in VPTransformState.
This patch adds plumbing to handle scalarized values directly in
VPTransformState.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D92282
2021-01-25 14:21:56 +00:00
Kazu Hirata 8857202489 [llvm] Use llvm::find (NFC) 2021-01-19 20:19:14 -08:00
Florian Hahn eb0371e403 [VPlan] Unify value/recipe printing after VPDef transition.
This patch unifies the way recipes and VPValues are printed after the
transition to VPDef.

VPSlotTracker has been updated to iterate over all recipes and all
their defined values to number those. There is no need to number
values in Value2VPValue.

It also updates a few places that only used slot numbers for
VPInstruction. All recipes now can produce numbered VPValues.
2021-01-11 14:42:46 +00:00
Florian Hahn 65f578fc0e [VPlan] Keep start value of VPWidenPHIRecipe as VPValue.
Similar to D92129, update VPWidenPHIRecipe  to manage the start value as
VPValue. This allows adjusting the start value as a VPlan transform,
which will be used in a follow-up patch to support reductions during
epilogue vectorization.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D93975
2021-01-09 16:34:15 +00:00
Florian Hahn c493e9216b [VPlan] Move reduction start value creation to widenPHIRecipe.
This was suggested to prepare for D93975.

By moving the start value creation to widenPHInstruction, we set the
stage to manage the start value directly in VPWidenPHIRecipe, which be
used subsequently to set the 'resume' value for reductions during
epilogue vectorization.

It also moves RdxDesc to the recipe, so we do not have to rely on Legal
to look it up later.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D94175
2021-01-08 17:49:43 +00:00
David Green 72fb5ba079 [LV] Don't sink into replication regions
The new test case here contains a first order recurrences and an
instruction that is replicated. The first order recurrence forces an
instruction to be sunk _into_, as opposed to after the replication
region. That causes several things to go wrong including registering
vector instructions multiple times and failing to create dominance
relations correctly.

Instead we should be sinking to after the replication region, which is
what this patch makes sure happens.

Differential Revision: https://reviews.llvm.org/D93629
2021-01-08 09:50:10 +00:00
Florian Hahn 816dba48af
[VPlan] Keep start value in VPWidenIntOrFpInductionRecipe (NFC).
This patch updates VPWidenIntOrFpInductionRecipe to hold the start value
for the induction variable. This makes the start value explicit and
allows for adjusting the start value for a VPlan.

The flexibility will be used in further patches.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D92129
2021-01-06 11:47:33 +00:00
Florian Hahn f73c09caa2
[VPlan] Use public VPValue constructor in VPPRedInstPHIRecipe (NFC).
VPPredInstPHIRecipe does not need access to VPValue via friendship. It
can just use the public constructor,

Discussed as part of D92281.
2021-01-06 10:47:09 +00:00
Kazu Hirata 789d250613 [CodeGen, Transforms] Use *Map::lookup (NFC) 2020-12-27 09:57:27 -08:00
Florian Hahn c0c0ae16c3
[VPlan] Make VPInstruction a VPDef
This patch turns updates VPInstruction to manage the value it defines
using VPDef. The VPValue is used  during VPlan construction and
codegeneration instead of the plain IR reference where possible.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D90565
2020-12-22 09:53:47 +00:00
Florian Hahn f250892373
[VPlan] Make VPRecipeBase inherit from VPDef.
This patch makes VPRecipeBase a direct subclass of VPDef, moving the
SubclassID to VPDef.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D90564
2020-12-21 13:34:00 +00:00
Florian Hahn cd608dc8d3
[VPlan] Use VPDef for VPInterleaveRecipe.
This patch turns updates VPInterleaveRecipe to manage the values it defines
using VPDef. The VPValue is used  during VPlan construction and
codegeneration instead of the plain IR reference where possible.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D90562
2020-12-21 10:56:53 +00:00
Florian Hahn 7186a3965a
[VPlan] Use VPDef for VPWidenSelectRecipe.
This patch turns updates VPWidenSelectRecipe to manage the value
it defines using VPDef.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D90560
2020-12-15 14:15:01 +00:00
Florian Hahn 318f5798d8
[VPlan] Use VPDef for VPWidenGEPRecipe.
This patch turns updates VPWidenGEPRecipe to manage the value it defines
using VPDef. The VPValue is used  during VPlan construction and
codegeneration instead of the plain IR reference where possible.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D90561
2020-12-15 09:30:14 +00:00
Florian Hahn ad1161f9b5
[VPlan] Use VPdef for VPWidenCall.
This patch turns updates VPWidenREcipe to manage the value it defines
using VPDef.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D90559
2020-12-15 09:20:07 +00:00
Florian Hahn e42e5263bd
[VPlan] Make VPWidenMemoryInstructionRecipe a VPDef.
This patch updates VPWidenMemoryInstructionRecipe to use VPDef
to manage the value it produces instead of inheriting from VPValue.

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D90563
2020-12-14 14:13:59 +00:00
Sander de Smalen d568cff696 [LoopVectorizer][SVE] Vectorize a simple loop with with a scalable VF.
* Steps are scaled by `vscale`, a runtime value.
* Changes to circumvent the cost-model for now (temporary)
  so that the cost-model can be implemented separately.

This can vectorize the following loop [1]:

   void loop(int N, double *a, double *b) {
     #pragma clang loop vectorize_width(4, scalable)
     for (int i = 0; i < N; i++) {
       a[i] = b[i] + 1.0;
     }
   }

[1] This source-level example is based on the pragma proposed
separately in D89031. This patch only implements the LLVM part.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D91077
2020-12-09 11:25:21 +00:00
Florian Hahn fe83adb05a
[VPlan] Use VPUser to manage VPPredInstPHIRecipe operand (NFC).
VPPredInstPHIRecipe is one of the recipes that was missed during the
initial conversion. This patch adjusts the recipe to also manage its
operand using VPUser.
2020-11-30 13:09:58 +00:00
Florian Hahn a813090072
[VPlan] Manage stored values of interleave groups using VPUser (NFC)
Interleave groups also depend on the values they store. Manage the
stored values as VPUser operands. This is currently a NFC, but is
required to allow VPlan transforms and to manage generated vector values
exclusively in VPTransformState.
2020-11-29 17:24:36 +00:00
Florian Hahn bd0b1311db
[VPlan] Turn VPReplicateRecipe into a VPValue.
Update VPReplicateRecipe to inherit from VPValue. This still does not
update scalarizeInstruction to set the result for the VPValue of
VPReplicateRecipe, because this first requires tracking scalar values in
VPTransformState.

Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D91500
2020-11-26 13:50:24 +00:00
Florian Hahn ad5b83ddcf
[VPlan] Add VPReductionSC to VPUser::classof, unify VPValue IDs.
This is a follow-up to 00a6601136 to make
isa<VPReductionRecipe> work and unifies the VPValue ID names, by making
sure they all consistently start with VPV*.
2020-11-25 11:08:25 +00:00
David Green e0c479cd0e [VPlan] Switch VPWidenRecipe to be a VPValue
Similar to other patches, this makes VPWidenRecipe a VPValue. Because of
the way it interacts with the reduction code it also slightly alters the
way that VPValues are registered, removing the up front NeedDef and
using getOrAddVPValue to create them on-demand if needed instead.

Differential Revision: https://reviews.llvm.org/D88447
2020-11-25 08:25:06 +00:00
David Green 00a6601136 [VPlan] Turn VPReductionRecipe into a VPValue
This converts the VPReductionRecipe into a VPValue, like other
VPRecipe's in preparation for traversing def-use chains. It also makes
it a VPUser, now storing the used VPValues as operands.

It doesn't yet change how the VPReductionRecipes are created. It will
need to call replaceAllUsesWith from the original recipe they replace,
but that is not done yet as VPWidenRecipe need to be created first.

Differential Revision: https://reviews.llvm.org/D88382
2020-11-25 08:25:05 +00:00