207 Commits

Author SHA1 Message Date
Florian Hahn
c11fd0df64
[VPlan] Skip VPWidenPHIRecipe in VPInterleavedACcessInfo.
Update unit tests that did not expect VPWidenPHIRecipes after
15a74b64dfa9.
2021-02-22 10:35:09 +00:00
Benjamin Kramer
59f442e6bb [LV] Fold single-use variable into assert. NFC. 2021-02-19 18:11:39 +01:00
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
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
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
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
19aacdb715 [llvm] Construct SmallVector with iterator ranges (NFC) 2021-01-16 09:40:53 -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
a94497a342 [VPlan] Move initial quote emission from ::print to ::dumpBasicBlock.
This means there will be no stray " when printing individual recipes
using print()/dump() in a debugger, for example.
2021-01-11 12:22:15 +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
Sanjay Patel
36263a7ccc [LoopUtils] remove redundant opcode parameter; NFC
While here, rename the inaccurate getRecurrenceBinOp()
because that was also used to get CmpInst opcodes.

The recurrence/reduction kind should always refer to the
expected opcode for a reduction. SLP appears to be the
only direct caller of createSimpleTargetReduction(), and
that calling code ideally should not be carrying around
both an opcode and a reduction kind.

This should allow us to generalize reduction matching to
use intrinsics instead of only binops.
2021-01-04 17:05:28 -05:00
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
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
Florian Hahn
533f85767c
[VPlan] Use interleaveComma in printOperands() (NFC). 2020-12-13 16:29:16 +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
4bc9b909d7
[VPlan] Use VPValue and VPUser ops to print VPReplicateRecipe. 2020-11-29 18:28:27 +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
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
Florian Hahn
52f3714dae [VPlan] Add VPDef class.
This patch introduces a new VPDef class, which can be used to
manage VPValues defined by recipes/VPInstructions.

The idea here is to mirror VPUser for values defined by a recipe. A
VPDef can produce either zero (e.g. a store recipe), one (most recipes)
or multiple (VPInterleaveRecipe) result VPValues.

To traverse the def-use chain from a VPDef to its users, one has to
traverse the users of all values defined by a VPDef.

VPValues now contain a pointer to their corresponding VPDef, if one
exists. To traverse the def-use chain upwards from a VPValue, we first
need to check if the VPValue is defined by a VPDef. If it does not have
a VPDef, this means we have a VPValue that is not directly defined
iniside the plan and we are done.

If we have a VPDef, it is defined inside the region by a recipe, which
is a VPUser, and the upwards def-use chain traversal continues by
traversing all its operands.

Note that we need to add an additional field to to VPVAlue to link them
to their defs. The space increase is going to be offset by being able to
remove the SubclassID field in future patches.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D90558
2020-11-17 16:18:11 +00:00
Florian Hahn
0c119ba8a8 [VPlan] Use VPValue def for VPWidenGEPRecipe.
This patch turns VPWidenGEPRecipe into a VPValue and uses it
during VPlan construction and codegeneration instead of the plain IR
reference where possible.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D84683
2020-11-15 15:12:47 +00:00
Florian Hahn
a70b511e78 Recommit "[VPlan] Use VPValue def for VPWidenSelectRecipe."
This reverts the revert commit c8d73d939fa4fda9c87b3979225d02d63062bd68.

It includes a fix for cases where we missed inserting VPValues
for some selects, which should fix PR48142.
2020-11-14 20:00:25 +00:00
Florian Hahn
c8d73d939f Revert "[VPlan] Use VPValue def for VPWidenSelectRecipe."
This reverts commit a8e50f1c6e7b404aab8fedb972f003a4d6a6434e.

This reportedly breaks building the Linux kernel.
  https://bugs.llvm.org/show_bug.cgi?id=48142
2020-11-10 22:50:46 +00:00
Florian Hahn
a8e50f1c6e
[VPlan] Use VPValue def for VPWidenSelectRecipe.
This patch turns VPWidenSelectRecipe into a VPValue and uses it
during VPlan construction and codegeneration instead of the plain IR
reference where possible.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D84682
2020-11-10 19:39:37 +00:00
Florian Hahn
f0d76275cb
[VPlan] Print result value for loads in VPWidenMemoryInst (NFC).
For loads, print the result value.
2020-11-09 14:01:29 +00:00
Florian Hahn
fec64de261
[VPlan] Use VPValue def for VPWidenCall.
This patch turns VPWidenCall into a VPValue and uses it
during VPlan construction and codegeneration instead of the plain IR
reference where possible.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D84681
2020-11-09 13:29:41 +00:00
Florian Hahn
091c5c9a18
[VPlan] Add printOperands helper to VPUser (NFC).
Factor out the code for printing operands of a VPUser so it can be
re-used when printing other recipes.
2020-11-09 12:30:57 +00:00
Florian Hahn
aa1a198a64 [VPlan] Use isa<> instead getVPRecipeID in getFirstNonPhi (NFC).
As per the comment in VPRecipeBase, clients should not rely on
getVPRecipeID, as it may change in the future. It should only be used in
classof implementations. Use isa instead in getFirstNonPhi.
2020-10-30 14:56:06 +00:00
Florian Hahn
93f6c6b79c Recommit "[VPlan] Use VPValue def for VPMemoryInstructionRecipe."
This reverts the revert commit 710aceb645e7dba4de7053eef2c616311b9163d4
and includes a fix for a memsan failure.

Original message:

    This patch turns VPMemoryInstructionRecipe into a VPValue and uses it
    during VPlan construction and codegeneration instead of the plain IR
    reference where possible.
2020-10-14 17:41:23 +01:00
Vitaly Buka
710aceb645 Revert "[VPlan] Use VPValue def for VPMemoryInstructionRecipe."
It introduced a memory leak.

This reverts commit 525b085a65d30a5f2ae2af38c0be252fe8d4781b.
2020-10-13 03:14:08 -07:00
Florian Hahn
525b085a65 [VPlan] Use VPValue def for VPMemoryInstructionRecipe.
This patch turns VPMemoryInstructionRecipe into a VPValue and uses it
during VPlan construction and codegeneration instead of the plain IR
reference where possible.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D84680
2020-10-12 18:02:33 +01:00
Florian Hahn
ea058d289c [VPlan] Use operands for printing of VPWidenMemoryInstructionRecipe.
Now that operands of the recipe are managed through VPUser, we can
simplify the printing by just using the operands.
2020-10-12 16:51:54 +01:00
David Sherwood
c5ba0d33cc [SVE] Make ElementCount and TypeSize use a new PolySize class
I have introduced a new template PolySize class, where the template
parameter determines the type of quantity, i.e. for an element
count this is just an unsigned value. The ElementCount class is
now just a simple derivation of PolySize<unsigned>, whereas TypeSize
is more complicated because it still needs to contain the uint64_t
cast operator, since there are still many places in the code that
rely upon this implicit cast. As such the class also still needs
some of it's own operators.

I've tried to minimise the amount of code in the base PolySize
class, which led to a couple of changes:

1. In some places we were relying on '==' operator comparisons
between ElementCounts and the scalar value 1. I didn't put this
operator in the new PolySize class, and thought it was actually
clearer to use the isScalar() function instead.
2. I removed the isByteSized function and replaced it with calls
to isKnownMultipleOf(8).

I've also renamed NextPowerOf2 to be coefficientNextPowerOf2 so
that it's more consistent with coefficientDivideBy.

Differential Revision: https://reviews.llvm.org/D88409
2020-10-12 08:23:38 +01:00
David Green
be6e8e50f4 [LV] Tail folded inloop reductions.
This expands upon the inloop reductions added in e9761688e41cb9e976,
allowing them to be inserted into tail folded loops. Reductions are
generates with the form:

  x = select(mask, vecop, zero)
  v = vecreduce.add(x)
  c = add chain, v

Where zero here is chosen as the identity value for add reductions. The
backend is then expected to fold the select and the vecreduce into a
single predicated instruction.

Most of the code is fairly straight forward, except for the creation of
blockmasks which need to ensure they are created in dominance order. The
order they are added is altered to be after any phis, keeping the
requirements for the underlying IR.

Differential Revision: https://reviews.llvm.org/D84451
2020-10-11 16:58:34 +01:00
Florian Hahn
348d85a6c7 [VPlan] Clean up uses/operands on VPBB deletion.
Update the code responsible for deleting VPBBs and recipes to properly
update users and release operands.

This is another preparation for D84680 & following patches towards
enabling modeling def-use chains in VPlan.
2020-10-05 14:43:52 +01:00
Florian Hahn
357bbaab66 [VPlan] Add VPRecipeBase::toVPUser helper (NFC).
This adds a helper to convert a VPRecipeBase pointer to a VPUser, for
recipes that inherit from VPUser. Once VPRecipeBase directly inherits
from VPUser this helper can be removed.
2020-10-04 19:43:27 +01:00
Florian Hahn
f5fe7abe8a [VPlan] Account for removed users in replaceAllUsesWith.
Make sure we do not iterate using an invalid iterator.

Another small fix/step towards traversing the def-use chains in VPlan.
2020-10-04 18:18:58 +01:00
Florian Hahn
c671e34bf2 [VPlan] Add dump() helper to VPValue & VPRecipeBase.
This provides a convenient way to print VPValues and recipes in a
debugger. In particular it saves the user from instantiating
VPSlotTracker to print recipes or values.
2020-09-22 15:55:16 +01:00
David Sherwood
f4257c5832 [SVE] Make ElementCount members private
This patch changes ElementCount so that the Min and Scalable
members are now private and can only be accessed via the get
functions getKnownMinValue() and isScalable(). In addition I've
added some other member functions for more commonly used operations.
Hopefully this makes the class more useful and will reduce the
need for calling getKnownMinValue().

Differential Revision: https://reviews.llvm.org/D86065
2020-08-28 14:43:53 +01:00
Sjoerd Meijer
ae366479e8 [LV] get.active.lane.mask consuming tripcount instead of backedge-taken count
This adapts LV to the new semantics of get.active.lane.mask as discussed in
D86147, which means that the LV now emits intrinsic get.active.lane.mask with
the loop tripcount instead of the backedge-taken count as its second argument.
The motivation for this is described in D86147.

Differential Revision: https://reviews.llvm.org/D86304
2020-08-25 13:49:19 +01:00
Francesco Petrogalli
5a34b3ab95 [llvm][LV] Replace unsigned VF with ElementCount VF [NFCI]
Changes:

* Change `ToVectorTy` to deal directly with `ElementCount` instances.
* `VF == 1` replaced with `VF.isScalar()`.
* `VF > 1` and `VF >=2` replaced with `VF.isVector()`.
* `VF <=1` is replaced with `VF.isZero() || VF.isScalar()`.
* Replaced the uses of `llvm::SmallSet<ElementCount, ...>` with
   `llvm::SmallSetVector<ElementCount, ...>`. This avoids the need of an
   ordering function for the `ElementCount` class.
* Bits and pieces around printing the `ElementCount` to string streams.

To guarantee that this change is a NFC, `VF.Min` and asserts are used
in the following places:

1. When it doesn't make sense to deal with the scalable property, for
example:
   a. When computing unrolling factors.
   b. When shuffle masks are built for fixed width vector types
In this cases, an
assert(!VF.Scalable && "<mgs>") has been added to make sure we don't
enter coepaths that don't make sense for scalable vectors.
2. When there is a conscious decision to use `FixedVectorType`. These
uses of `FixedVectorType` will likely be removed in favour of
`VectorType` once the vectorizer is generic enough to deal with both
fixed vector types and scalable vector types.
3. When dealing with building constants out of the value of VF, for
example when computing the vectorization `step`, or building vectors
of indices. These operation _make sense_ for scalable vectors too,
but changing the code in these places to be generic and make it work
for scalable vectors is to be submitted in a separate patch, as it is
a functional change.
4. When building the potential VFs in VPlan. Making the VPlan generic
enough to handle scalable vectorization factors is a functional change
that needs a separate patch. See for example `void
LoopVectorizationPlanner::buildVPlans(unsigned MinVF, unsigned
MaxVF)`.
5. The class `IntrinsicCostAttribute`: this class still uses `unsigned
VF` as updating the field to use `ElementCount` woudl require changes
that could result in changing the behavior of the compiler. Will be done
in a separate patch.
7. When dealing with user input for forcing the vectorization
factor. In this case, adding support for scalable vectorization is a
functional change that migh require changes at command line.

Note that in some places the idiom

```
unsigned VF = ...
auto VTy = FixedVectorType::get(ScalarTy, VF)
```

has been replaced with

```
ElementCount VF = ...
assert(!VF.Scalable && ...);
auto VTy = VectorType::get(ScalarTy, VF)
```

The assertion guarantees that the new code is (at least in debug mode)
functionally equivalent to the old version. Notice that this change had been
possible because none of the methods that are specific to `FixedVectorType`
were used after the instantiation of `VTy`.

Reviewed By: rengolin, ctetreau

Differential Revision: https://reviews.llvm.org/D85794
2020-08-24 13:54:03 +00:00
Francesco Petrogalli
bad7d6b373 Revert "[llvm][LV] Replace unsigned VF with ElementCount VF [NFCI]"
Reverting because the commit message doesn't reflect the one agreed on
phabricator at https://reviews.llvm.org/D85794.

This reverts commit c8d2b065b98fa91139cc7bb1fd1407f032ef252e.
2020-08-24 13:50:55 +00:00
Francesco Petrogalli
c8d2b065b9 [llvm][LV] Replace unsigned VF with ElementCount VF [NFCI]
Changes:

* Change `ToVectorTy` to deal directly with `ElementCount` instances.
* `VF == 1` replaced with `VF.isScalar()`.
* `VF > 1` and `VF >=2` replaced with `VF.isVector()`.
* `VF <=1` is replaced with `VF.isZero() || VF.isScalar()`.
* Add `<` operator to `ElementCount` to be able to use
`llvm::SmallSetVector<ElementCount, ...>`.
* Bits and pieces around printing the ElementCount to string streams.
* Added a static method to `ElementCount` to represent a scalar.

To guarantee that this change is a NFC, `VF.Min` and asserts are used
in the following places:

1. When it doesn't make sense to deal with the scalable property, for
example:
   a. When computing unrolling factors.
   b. When shuffle masks are built for fixed width vector types
In this cases, an
assert(!VF.Scalable && "<mgs>") has been added to make sure we don't
enter coepaths that don't make sense for scalable vectors.
2. When there is a conscious decision to use `FixedVectorType`. These
uses of `FixedVectorType` will likely be removed in favour of
`VectorType` once the vectorizer is generic enough to deal with both
fixed vector types and scalable vector types.
3. When dealing with building constants out of the value of VF, for
example when computing the vectorization `step`, or building vectors
of indices. These operation _make sense_ for scalable vectors too,
but changing the code in these places to be generic and make it work
for scalable vectors is to be submitted in a separate patch, as it is
a functional change.
4. When building the potential VFs in VPlan. Making the VPlan generic
enough to handle scalable vectorization factors is a functional change
that needs a separate patch. See for example `void
LoopVectorizationPlanner::buildVPlans(unsigned MinVF, unsigned
MaxVF)`.
5. The class `IntrinsicCostAttribute`: this class still uses `unsigned
VF` as updating the field to use `ElementCount` woudl require changes
that could result in changing the behavior of the compiler. Will be done
in a separate patch.
7. When dealing with user input for forcing the vectorization
factor. In this case, adding support for scalable vectorization is a
functional change that migh require changes at command line.

Differential Revision: https://reviews.llvm.org/D85794
2020-08-24 13:39:42 +00:00
David Green
745bf6cf44 [LoopVectorizer] Inloop vector reductions
Arm MVE has multiple instructions such as VMLAVA.s8, which (in this
case) can take two 128bit vectors, sign extend the inputs to i32,
multiplying them together and sum the result into a 32bit general
purpose register. So taking 16 i8's as inputs, they can multiply and
accumulate the result into a single i32 without any rounding/truncating
along the way. There are also reduction instructions for plain integer
add and min/max, and operations that sum into a pair of 32bit registers
together treated as a 64bit integer (even though MVE does not have a
plain 64bit addition instruction). So giving the vectorizer the ability
to use these instructions both enables us to vectorize at higher
bitwidths, and to vectorize things we previously could not.

In order to do that we need a way to represent that the reduction
operation, specified with a llvm.experimental.vector.reduce when
vectorizing for Arm, occurs inside the loop not after it like most
reductions. This patch attempts to do that, teaching the vectorizer
about in-loop reductions. It does this through a vplan recipe
representing the reductions that the original chain of reduction
operations is replaced by. Cost modelling is currently just done through
a prefersInloopReduction TTI hook (which follows in a later patch).

Differential Revision: https://reviews.llvm.org/D75069
2020-08-06 10:10:50 +01:00
Jordan Rupprecht
3c39db0c44 Revert "[LoopVectorizer] Inloop vector reductions"
This reverts commit e9761688e41cb979a1fa6a79eb18145a75104933. It breaks the build:

```
~/src/llvm-project/llvm/lib/Analysis/IVDescriptors.cpp:868:10: error: no viable conversion from returned value of type 'SmallVector<[...], 8>' to function return type 'SmallVector<[...], 4>'
  return ReductionOperations;
```
2020-08-05 10:24:15 -07:00