Commit Graph

168 Commits

Author SHA1 Message Date
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
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 c8d73d939f.

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 a8e50f1c6e.

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 537829f2a7
[VPlan] Add isStore helper to VPWidenMemoryInstructionRecipe (NFC).
Move logic to check if the recipe is a store to a helper for easier
reuse.
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
Sander de Smalen 4a3bb9ea6c [VPlan] NFC: Change VFRange to take ElementCount
This patch changes the type of Start, End in VFRange to be an ElementCount
instead of `unsigned`. This is done as preparation to make VPlans for
scalable vectors, but is otherwise NFC.

Reviewed By: dmgreen, fhahn, vkmr

Differential Revision: https://reviews.llvm.org/D90715
2020-11-06 09:50:20 +00:00
Florian Hahn 93f6c6b79c Recommit "[VPlan] Use VPValue def for VPMemoryInstructionRecipe."
This reverts the revert commit 710aceb645
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 525b085a65.
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 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 d856365470 [VPlan] Change recipes to inherit from VPUser instead of a member var.
Now that VPUser is not inheriting from VPValue, we can take the next
step and turn the recipes that already manage their operands via VPUser
into VPUsers directly. This is another small step towards traversing
def-use chains in VPlan.

This is NFC with respect to the generated code, but makes the interface
more powerful.
2020-09-30 14:39:00 +01:00
Florian Hahn 31923f6b36 [VPlan] Disconnect VPValue and VPUser.
This refactors VPuser to not inherit from VPValue to facilitate
introducing operations that introduce multiple VPValues (e.g.
VPInterleaveRecipe).

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D84679
2020-09-23 14:44:31 +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
Simon Pilgrim 5ea9e655ef VPlan.h - remove unnecessary forward declarations. NFCI.
Already defined in includes.
2020-09-07 18:35:06 +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
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 c8d2b065b9.
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 e9761688e4. 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
David Green e9761688e4 [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
2020-08-05 18:14:05 +01:00
Florian Hahn c0cdba727a [VPlan] Add & use VPValue for VPWidenGEPRecipe operands (NFC).
This patch adds VPValue version of the GEP's operands to
VPWidenGEPRecipe and uses them during code-generation.

Reviewers: Ayal, gilr, rengolin

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D80220
2020-06-26 20:59:17 +01:00
Sjoerd Meijer e345d547a0 Recommit "[LV] Emit @llvm.get.active.lane.mask for tail-folded loops"
Fixed ARM regression test.

Please see the original commit message rG47650451738c for details.
2020-06-17 13:12:15 +01:00
Sjoerd Meijer d4e183f686 Revert "[LV] Emit @llvm.get.active.mask for tail-folded loops"
This reverts commit 4765045173
while I investigate the build bot failures.
2020-06-17 10:09:54 +01:00
Sjoerd Meijer 4765045173 [LV] Emit @llvm.get.active.mask for tail-folded loops
This emits new IR intrinsic @llvm.get.active.mask for tail-folded vectorised
loops if the intrinsic is supported by the backend, which is checked by
querying TargetTransform hook emitGetActiveLaneMask.

This intrinsic creates a mask representing active and inactive vector lanes,
which is used by the masked load/store instructions that are created for
tail-folded loops. The semantics of @llvm.get.active.mask are described here in
LangRef:

https://llvm.org/docs/LangRef.html#llvm-get-active-lane-mask-intrinsics

This intrinsic is also used to provide a hint to the backend. That is, the
second argument of the intrinsic represents the back-edge taken count of the
loop. For MVE, for example, we use that to set up tail-predication, which is a
new form of predication in MVE for vector loops that implicitely predicates the
last vector loop iteration by implicitely setting active/inactive lanes, i.e.
the tail loop is predicated. In order to set up a tail-predicated vector loop,
we need to know the number of data elements processed by the vector loop, which
corresponds the the tripcount of the scalar loop, which we can now reconstruct
using @llvm.get.active.mask.

Differential Revision: https://reviews.llvm.org/D79100
2020-06-17 09:53:58 +01:00
Florian Hahn 211596c94e [VPlan] Support extracting lanes for defs managed in VPTransformState.
Currently extracting a lane for a VPValue def is not supported, if it is
managed directly by VPTransformState (e.g. because it is created by a
VPInstruction or an external VPValue def).

For now, simply extract the requested lane. In the future, we should
also cache the extracted scalar values, similar to LV.

Reviewers: Ayal, rengolin, gilr, SjoerdMeijer

Reviewed By: SjoerdMeijer

Differential Revision: https://reviews.llvm.org/D80787
2020-06-03 12:14:16 +01:00
Florian Hahn 15224408f0 [VPlan] Use VPUser for VPWidenSelectRecipe operands (NFC).
VPWidenSelectRecipe already contains a VPUser, but it is not used. This
patch updates the code related to VPWidenSelectRecipe to use VPUser for
its operands.

Reviewers: Ayal, gilr, rengolin

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D80219
2020-05-24 13:58:08 +01:00
Florian Hahn cff9399f6b [VPlan] Fix comment for User in VPWidenSelectRecipe (NFC).
The comment was referring the arguments of the call, but the recipe
widens a select.
2020-05-19 15:31:39 +01:00
Florian Hahn f828d75b46 [VPlan] Add & use VPValue operands for VPReplicateRecipe (NFC).
This patch adds VPValue version of the instruction operands to
VPReplicateRecipe and uses them during code-generation.

Reviewers: Ayal, gilr, rengolin

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D80114
2020-05-19 15:12:17 +01:00
Florian Hahn 66ad107452 [VPlan] Remove unique_ptr from VPBranchOnRecipeMask (NFC).
We can remove a dynamic memory allocation, by checking the number of
operands: no operands = all true, 1 operand = mask.

Reviewers: Ayal, gilr, rengolin

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D80110
2020-05-19 15:01:37 +01:00
Florian Hahn bbdfcf8f69 [VPlan] Remove unused & undefined print method (NFC). 2020-05-03 18:36:20 +01:00
Florian Hahn e89379856a Recommit "[VPlan] Add & use VPValue operands for VPWidenRecipe (NFC)."
The crash that caused the original revert has been fixed in
a3c964a278. I also added a reduced version of the crash reproducer.

This reverts the revert commit 2107af9ccf.
2020-04-29 11:40:39 +01:00
Ayal Zaks a3c964a278 [LV] Fix recording of BranchTakenCount for FoldTail
When folding tail, branch taken count is computed during initial VPlan execution
and recorded to be used by the compare computing the loop's mask. This recording
should directly set the State, instead of reusing Value2VPValue mapping which
serves original Values present prior to vectorization.
The branch taken count may be a constant Value, which may be used elsewhere in
the loop; trying to employ Value2VPValue for both leads to the issue reported in
https://reviews.llvm.org/D76992#inline-721028

Differential Revision: https://reviews.llvm.org/D78847
2020-04-26 20:13:10 +03:00
Mehdi Amini 2107af9ccf Revert "[VPlan] Add & use VPValue operands for VPWidenRecipe (NFC)."
This reverts commit 9245c7ac13.

This is triggering a segfault in XLA downstream, we'll follow-up with
a reproducer, it is likely influenced by TTI/TLI settings or other
options as a simple `opt -loop-vectorize` invocation on the IR
before the crash does not reproduce immediately.
2020-04-24 05:07:32 +00:00
Simon Pilgrim b108a457e1 [VPlan] Remove unused forward declarations. NFC.
Move VPlan.h include from VPlanVerifier.h down to VPlanVerifier.cpp
2020-04-23 12:34:20 +01:00
Florian Hahn 9245c7ac13 [VPlan] Add & use VPValue operands for VPWidenRecipe (NFC).
This patch adds VPValue version of the instruction operands to
VPWidenRecipe and uses them during code-generation.

Similar to D76373 this reduces ingredient def-use usage by ILV as
a step towards full VPlan-based def-use relations.

Reviewers: rengolin, Ayal, gilr

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D76992
2020-04-23 12:16:46 +01:00
Gil Rapaport b747d72c19 [LV] Fix PR45525: Incorrect assert in blend recipe
Fix an assert introduced in 41ed5d856c1: a phi with a single predecessor and a
mask is a valid case which is already supported by the code.

Differential Revision: https://reviews.llvm.org/D78115
2020-04-15 10:39:07 +03:00
Florian Hahn 18138e0252 [VPlan] Introduce VPWidenSelectRecipe (NFC).
Widening a selects depends on whether the condition is loop invariant or
not. Rather than checking during codegen-time, the information can be
recorded at the VPlan construction time.

This was suggested as part of D76992, to reduce the reliance on
accessing the original underlying IR values.

Reviewers: gilr, rengolin, Ayal, hsaito

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D77869
2020-04-13 08:35:28 +01:00
Florian Hahn 719846c469 [VPlan] Drop redundant private: at beginning of class defs (NFC).
Default visibility for classes is private, so the private: at the top of
various class definitions is redundant.

Reviewers: gilr, rengolin, Ayal, hsaito

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D77810
2020-04-11 13:27:10 +01:00
Gil Rapaport e2a1867880 [LV] Add VPValue operands to VPBlendRecipe (NFCI)
InnerLoopVectorizer's code called during VPlan execution still relies on
original IR's def-use relations to decide which vector code to generate,
limiting VPlan transformations ability to modify def-use relations and still
have ILV generate the vector code.
This commit introduces VPValues for VPBlendRecipe to use as the values to
blend. The recipe is generated with VPValues wrapping the phi's incoming values
of the scalar phi. This reduces ingredient def-use usage by ILV as a step
towards full VPlan-based def-use relations.

Differential Revision: https://reviews.llvm.org/D77539
2020-04-09 18:48:33 +03:00
Ayal Zaks 1678489234 [LV] FoldTail w/o Primary Induction
Introduce a new VPWidenCanonicalIVRecipe to generate a canonical vector
induction for use in fold-tail-with-masking, if a primary induction is absent.

The canonical scalar IV having start = 0 and step = VF*UF, created during code
-gen to control the vector loop, is widened into a canonical vector IV having
start = {<Part*VF, Part*VF+1, ..., Part*VF+VF-1> for 0 <= Part < UF} and
step = <VF*UF, VF*UF, ..., VF*UF>.

Differential Revision: https://reviews.llvm.org/D77635
2020-04-09 17:45:23 +03:00
Florian Hahn 9997ee23ed [VPlan] Add & use VPValue operands for VPWidenCallRecipe (NFC).
This patch adds VPValue versions for the arguments of the call to
VPWidenCallRecipe and uses them during code-generation.

Similar to D76373 this reduces ingredient def-use usage by ILV as
a step towards full VPlan-based def-use relations.

Reviewers: Ayal, gilr, rengolin

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D77655
2020-04-09 10:23:26 +01:00
Florian Hahn 90be3c24a7 [VPlan] Introduce new VPWidenCallRecipe (NFC).
This patch moves calls to their own recipe, to simplify the transition
to VPUser for operands of VPWidenRecipe, as discussed in D76992.

Subsequently additional information can be added to the recipe rather
than computing it during the execute step.

Reviewers: rengolin, Ayal, gilr, hsaito

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D77467
2020-04-06 16:07:37 +01:00
Florian Hahn 49d00824bb [VPlan] Use one VPWidenRecipe per original IR instruction. (NFC).
This patch changes VPWidenRecipe to only store a single original IR
instruction. This is the first required step towards modeling it's
operands as VPValues and also towards breaking it up into a
VPInstruction.

Discussed as part of D74695.

Reviewers: Ayal, gilr, rengolin

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D76988
2020-03-29 13:47:28 +01:00
Gil Rapaport 078c863305 [LV] Replace stored value with a VPValue (NFCI)
InnerLoopVectorizer's code called during VPlan execution still relies on
original IR's def-use relations to decide which vector code to generate,
limiting VPlan transformations ability to modify def-use relations and still
have ILV generate the vector code.
This commit introduces a VPValue for VPWidenMemoryInstructionRecipe to use as
the stored value. The recipe is generated with a VPValue wrapping the stored
value of the scalar store. This reduces ingredient def-use usage by ILV as a
step towards full VPlan-based def-use relations.

Differential Revision: https://reviews.llvm.org/D76373
2020-03-25 19:36:55 +02:00
Florian Hahn 00c1cd1934 [VPlan] Record underlying value for VPValues created by addVPValue (NFC).
Now that printing VPValues uses the underlying IR value name, if
available, recording the underlying value here improves printing.

Reviewers: rengolin, hsaito, Ayal, gilr

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D76374
2020-03-18 21:30:58 +00:00
Florian Hahn e6a74803d4 [VPlan] Use underlying value for printing, if available.
When the an underlying value is available, we can use its name for
printing, as discussed in D73078.

Reviewers: rengolin, hsaito, Ayal, gilr

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D76200
2020-03-18 17:46:57 +00:00
Florian Hahn 40e7bfc424 [VPlan] Use consecutive numbers to print VPValues instead of addresses.
Currently when printing VPValues we use the object address, which makes
it hard to distinguish VPValues as they usually are large numbers with
varying distance between them.

This patch adds a simple slot tracker, similar to the ModuleSlotTracker
used for IR values. In order to dump a VPValue or anything containing a
VPValue, a slot tracker for the enclosing VPlan needs to be created. The
existing VPlanPrinter can take care of that for the existing code. We
assign consecutive numbers to each VPValue we encounter in a reverse
post order traversal of the VPlan.

Reviewers: rengolin, hsaito, fhahn, Ayal, dorit, gilr

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D73078
2020-03-05 14:55:15 +00:00
Florian Hahn 05afa55521 [VPlan] Add getPlan() to VPBlockBase.
This patch adds a getPlan accessor to VPBlockBase, which finds the entry
block of the plan containing the block and returns the plan set for this
block.

VPBlockBase contains a VPlan pointer, but it should only be set for
the entry block of a plan. This allows moving blocks without updating
the pointer for each moved block and in the future we might introduce a
parent relationship between plans and blocks, similar to the one in LLVM IR.

Reviewers: rengolin, hsaito, fhahn, Ayal, dorit, gilr

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D74445
2020-03-03 13:20:13 +00:00
Gil Rapaport 8647a72c4a [LV] VPValues for memory operation pointers (NFCI)
Memory instruction widening recipes use the pointer operand of their load/store
ingredient for generating the needed GEPs, making it difficult to feed these
recipes with pointers based on other ingredients or none at all.
This patch modifies these recipes to use a VPValue for the pointer instead, in
order to reduce ingredient def-use usage by ILV as a step towards full
VPlan-based def-use relations. The recipes are constructed with VPValues bound
to these ingredients, maintaining current behavior.

Differential revision: https://reviews.llvm.org/D70865
2020-01-10 09:24:59 +02:00
Evgeniy Brevnov 948e745270 [LV][NFC] Keep dominator tree up to date during vectorization. 2019-12-30 18:38:41 +07:00
Gil Rapaport d62bf16131 [LV] Use getMask() when printing recipe [NFCI]
Use dedicated API for getting the mask instead of duplicating it.

Differential Revision: https://reviews.llvm.org/D71964
2019-12-29 08:50:40 +02:00
Florian Hahn e60b36cf92 [VPlan] Rename VPlanHCFGTransforms to VPlanTransforms (NFC).
The file is intended to gather various VPlan transformations, not only
CFG related transforms. Actually, the only transformation there is not
CFG related.

Reviewers: Ayal, gilr, hsaito, rengolin

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D70732
2019-12-07 08:56:35 +00:00
Gil Rapaport 39ccc099c9 [LV] Record GEP widening decisions in recipe (NFCI)
InnerLoopVectorizer's code called during VPlan execution still relies on
original IR's def-use relations to decide which vector code to generate,
limiting VPlan transformations ability to modify def-use relations and still
have ILV generate the vector code.
This commit moves GEP operand queries controlling how GEPs are widened to a
dedicated recipe and extracts GEP widening code to its own ILV method taking
those recorded decisions as arguments. This reduces ingredient def-use usage by
ILV as a step towards full VPlan-based def-use relations.

Differential revision: https://reviews.llvm.org/D69067
2019-12-06 13:41:19 +02:00
Florian Hahn e9c68422de [VPlan] Add dump function to VPlan class.
This adds a dump() function to VPlan, which uses the existing
operator<<.

This method provides a convenient way to dump a VPlan while debugging,
e.g. from lldb.

Reviewers: hsaito, Ayal, gilr, rengolin

Reviewed By: hsaito

Differential Revision: https://reviews.llvm.org/D70920
2019-12-03 11:59:10 +00:00
Florian Hahn fe459ce65a [VPlan] Move graph traits (NFC).
By defining the graph traits right after the VPBlockBase definitions, we
can make use of them earlier in the file.

Reviewers: hsaito, Ayal, gilr

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D70733
2019-12-02 18:23:11 +00:00
Gil Rapaport 7f152543e4 [LV] Apply sink-after & interleave-groups as VPlan transformations (NFCI)
This recommits 11ed1c0239 (reverted in
9f08ce0d21 for failing an assert) with a fix:
tryToWidenMemory() now first checks if the widening decision is to interleave,
thus maintaining previous behavior where tryToInterleaveMemory() was called
first, giving priority to interleave decisions over widening/scalarization. This
commit adds the test case that exposed this bug as a LIT.
2019-11-09 20:52:25 +02:00
Gil Rapaport 9f08ce0d21 Revert "[LV] Apply sink-after & interleave-groups as VPlan transformations (NFCI)"
This reverts commit 11ed1c0239 - causes an assert failure.
2019-11-08 22:17:11 +02:00
Gil Rapaport 11ed1c0239 [LV] Apply sink-after & interleave-groups as VPlan transformations (NFCI)
This recommits 100e797adb (reverted in
009e032634 for failing an assert). While the
root cause was independently reverted in eaff300401,
this commit includes a LIT to make sure IVDescriptor's SinkAfter logic does not
try to sink branch instructions.
2019-11-08 15:25:14 +02:00
Eric Christopher 009e032634 Temporarily Revert "[LV] Apply sink-after & interleave-groups as VPlan transformations (NFC)"
as it's causing assert failures.

This reverts commit 100e797adb.
2019-11-06 21:58:28 -08:00
Gil Rapaport 100e797adb [LV] Apply sink-after & interleave-groups as VPlan transformations (NFC)
This recommits 2be17087f8 (reverted in
d3ec06d219 for heap-use-after-free) with a fix
in IAI's reset() which was not clearing the set of interleave groups after
deleting them.
2019-11-05 17:29:13 +02:00
Benjamin Kramer d3ec06d219 Revert "[LV] Apply sink-after & interleave-groups as VPlan transformations (NFC)"
This reverts commit 2be17087f8. Fails ASAN.
2019-11-04 15:04:42 +01:00
Gil Rapaport 2be17087f8 [LV] Apply sink-after & interleave-groups as VPlan transformations (NFC)
The sink-after and interleave-group vectorization decisions were so far applied to
VPlan during initial VPlan construction, which complicates VPlan construction – also because of
their inter-dependence. This patch refactors buildVPlanWithRecipes() to construct a simpler
initial VPlan and later apply both these vectorization decisions, in order, as VPlan-to-VPlan
transformations.

Differential Revision: https://reviews.llvm.org/D68577
2019-11-04 10:37:39 +02:00
Simon Pilgrim 81ba611e88 Ensure VPlanPrinter::Depth is initialized to fix static analyzer warning. NFCI. 2019-11-03 11:17:05 +00:00
Florian Hahn 39d4c9fd56 [VPlan] Add moveAfter to VPRecipeBase.
This patch adds a moveAfter method to VPRecipeBase, which can be used to
move elements after other elements, across VPBasicBlocks, if necessary.

Reviewers: dcaballe, hsaito, rengolin, hfinkel

Reviewed By: dcaballe

Differential Revision: https://reviews.llvm.org/D46825

llvm-svn: 374565
2019-10-11 15:36:55 +00:00
Hideki Saito 4e4ecae028 [LV][VPlan] Change to implement VPlan based predication for
VPlan-native path

Context: Patch Series #2 for outer loop vectorization support in LV
using VPlan. (RFC:
http://lists.llvm.org/pipermail/llvm-dev/2017-December/119523.html).

Patch series #2 checks that inner loops are still trivially lock-step
among all vector elements. Non-loop branches are blindly assumed as
divergent.

Changes here implement VPlan based predication algorithm to compute
predicates for blocks that need predication. Predicates are computed
for the VPLoop region in reverse post order. A block's predicate is
computed as OR of the masks of all incoming edges. The mask for an
incoming edge is computed as AND of predecessor block's predicate and
either predecessor's Condition bit or NOT(Condition bit) depending on
whether the edge from predecessor block to the current block is true
or false edge.

Reviewers: fhahn, rengolin, hsaito, dcaballe

Reviewed By: fhahn

Patch by Satish Guggilla, thanks!

Differential Revision: https://reviews.llvm.org/D53349

llvm-svn: 351990
2019-01-23 22:43:12 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Florian Hahn 6df11868b5 [VPlan, SLP] Use SmallPtrSet for Candidates.
This slightly improves the candidate handling in getBest().

llvm-svn: 346870
2018-11-14 15:58:40 +00:00
Florian Hahn 09e516c54b [VPlan, SLP] Add simple SLP analysis on top of VPlan.
This patch adds an initial implementation of the look-ahead SLP tree
construction described in 'Look-Ahead SLP: Auto-vectorization in the Presence
of Commutative Operations, CGO 2018 by Vasileios Porpodas, Rodrigo C. O. Rocha,
Luís F. W. Góes'.

It returns an SLP tree represented as VPInstructions, with combined
instructions represented as a single, wider VPInstruction.

This initial version does not support instructions with multiple
different users (either inside or outside the SLP tree) or
non-instruction operands; it won't generate any shuffles or
insertelement instructions.

It also just adds the analysis that builds an SLP tree rooted in a set
of stores. It does not include any cost modeling or memory legality
checks. The plan is to integrate it with VPlan based cost modeling, once
available and to only apply it to operations that can be widened.

A follow-up patch will add a support for replacing instructions in a
VPlan with their SLP counter parts.

Reviewers: Ayal, mssimpso, rengolin, mkuper, hfinkel, hsaito, dcaballe, vporpo, RKSimon, ABataev

Reviewed By: rengolin

Differential Revision: https://reviews.llvm.org/D4949

llvm-svn: 346857
2018-11-14 13:11:49 +00:00
Florian Hahn a4dc7feeea [VPlan] VPlan version of InterleavedAccessInfo.
This patch turns InterleaveGroup into a template with the instruction type
being a template parameter. It also adds a VPInterleavedAccessInfo class, which
only contains a mapping from VPInstructions to their respective InterleaveGroup.
As we do not have access to scalar evolution in VPlan, we can re-use
convert InterleavedAccessInfo to VPInterleavedAccess info.


Reviewers: Ayal, mssimpso, hfinkel, dcaballe, rengolin, mkuper, hsaito

Reviewed By: rengolin

Differential Revision: https://reviews.llvm.org/D49489

llvm-svn: 346758
2018-11-13 15:58:18 +00:00
Ayal Zaks b0b5312e67 [LV] Fold tail by masking to vectorize loops of arbitrary trip count under opt for size
When optimizing for size, a loop is vectorized only if the resulting vector loop
completely replaces the original scalar loop. This holds if no runtime guards
are needed, if the original trip-count TC does not overflow, and if TC is a
known constant that is a multiple of the VF. The last two TC-related conditions
can be overcome by
1. rounding the trip-count of the vector loop up from TC to a multiple of VF;
2. masking the vector body under a newly introduced "if (i <= TC-1)" condition.

The patch allows loops with arbitrary trip counts to be vectorized under -Os,
subject to the existing cost model considerations. It also applies to loops with
small trip counts (under -O2) which are currently handled as if under -Os.

The patch does not handle loops with reductions, live-outs, or w/o a primary
induction variable, and disallows interleave groups.

(Third, final and main part of -)
Differential Revision: https://reviews.llvm.org/D50480

llvm-svn: 344743
2018-10-18 15:03:15 +00:00
Dorit Nuzman 38bbf81ade recommit 344472 after fixing build failure on ARM and PPC.
llvm-svn: 344475
2018-10-14 08:50:06 +00:00
Dorit Nuzman 5118c68cde revert 344472 due to failures.
llvm-svn: 344473
2018-10-14 07:21:20 +00:00
Dorit Nuzman 8174368955 [IAI,LV] Add support for vectorizing predicated strided accesses using masked
interleave-group

The vectorizer currently does not attempt to create interleave-groups that
contain predicated loads/stores; predicated strided accesses can currently be
vectorized only using masked gather/scatter or scalarization. This patch makes
predicated loads/stores candidates for forming interleave-groups during the
Loop-Vectorizer's analysis, and adds the proper support for masked-interleave-
groups to the Loop-Vectorizer's planning and transformation stages. The patch
also extends the TTI API to allow querying the cost of masked interleave groups
(which each target can control); Targets that support masked vector loads/
stores may choose to enable this feature and allow vectorizing predicated
strided loads/stores using masked wide loads/stores and shuffles.

Reviewers: Ayal, hsaito, dcaballe, fhahn, javed.absar

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D53011

llvm-svn: 344472
2018-10-14 07:06:16 +00:00
Hideki Saito d19851ac7e Fix for the buildbot failure http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/23635
from the commit (r342197) of https://reviews.llvm.org/D50820.

llvm-svn: 342201
2018-09-14 02:02:57 +00:00
Hideki Saito ea7f3035a0 [VPlan] Implement initial vector code generation support for simple outer loops.
Summary:
[VPlan] Implement vector code generation support for simple outer loops.

Context: Patch Series #1 for outer loop vectorization support in LV  using VPlan. (RFC: http://lists.llvm.org/pipermail/llvm-dev/2017-December/119523.html).
                                                          
This patch introduces vector code generation support for simple outer loops that are currently supported in the VPlanNativePath. Changes here essentially do the following:

  - force vector code generation using explicit vectorize_width

  - add conservative early returns in cost model and other places for VPlanNativePath

  - add code for setting up outer loop inductions 

  - support for widening non-induction PHIs that can result from inner loops and uniform conditional branches

  - support for generating uniform inner branches

We plan to add a handful C outer loop executable tests once the initial code generation support is committed. This patch is expected to be NFC for the inner loop vectorizer path. Since we are moving in the direction of supporting outer loop vectorization in LV, it may also be time to rename classes such as InnerLoopVectorizer. 

Reviewers: fhahn, rengolin, hsaito, dcaballe, mkuper, hfinkel, Ayal

Reviewed By: fhahn, hsaito

Subscribers: dmgreen, bollu, tschuett, rkruppe, rogfer01, llvm-commits

Differential Revision: https://reviews.llvm.org/D50820

llvm-svn: 342197
2018-09-14 00:36:00 +00:00
Diego Caballero 3587150fcb [VPlan] Introduce VPLoopInfo analysis.
The patch introduces loop analysis (VPLoopInfo/VPLoop) for VPBlockBases.
This analysis will be necessary to perform some H-CFG transformations and
detect and introduce regions representing a loop in the H-CFG.

Reviewers: fhahn, rengolin, mkuper, hfinkel, mssimpso

Reviewed By: fhahn 

Differential Revision: https://reviews.llvm.org/D48816

llvm-svn: 338346
2018-07-31 01:57:29 +00:00
Diego Caballero 2a34ac86d3 [VPlan] Introduce VPlan-based dominator analysis.
The patch introduces dominator analysis for VPBlockBases and extend
VPlan's GraphTraits specialization with the required interfaces. Dominator
analysis will be necessary to perform some H-CFG transformations and
to introduce VPLoopInfo (LoopInfo analysis on top of the VPlan representation).

Reviewers: fhahn, rengolin, mkuper, hfinkel, mssimpso

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D48815

llvm-svn: 338310
2018-07-30 21:33:31 +00:00
Diego Caballero d09530144a [VPlan][LV] Introduce condition bit in VPBlockBase
This patch introduces a VPValue in VPBlockBase to represent the condition
bit that is used as successor selector when a block has multiple successors.
This information wasn't necessary until now, when we are about to introduce
outer loop vectorization support in VPlan code gen.

Reviewers: fhahn, rengolin, mkuper, hfinkel, mssimpso

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D48814

llvm-svn: 336554
2018-07-09 15:57:09 +00:00