Commit Graph

216 Commits

Author SHA1 Message Date
Florian Hahn d1d3563278
[LV] Move code to place pointer induction increment to VPlan post-processing.
This patch moves the code to set the correct incoming block for the
backedge value to VPlan::execute.

When generating the phi node, the backedge value is temporarily added
using the pre-header as incoming block. The invalid phi node will be
fixed up during VPlan::execute after main VPlan code generation.
At the same time, the backedge value is also moved to the latch.

This change removes the requirement to create the latch block up-front
for VPWidenInductionPHIRecipe::execute, which in turn will enable
modeling the pre-header in VPlan.

Depends on D121617.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D121618
2022-03-29 20:27:59 +01:00
Florian Hahn e7bf2ea934
[LV] Move code to place induction increment to VPlan post-processing.
This patch moves the code to set the correct incoming block for the
backedge value to VPlan::execute.

When generating the phi node, the backedge value is temporarily added
using the pre-header as incoming block. The invalid phi node will be
fixed up during VPlan::execute after main VPlan code generation.
At the same time, the backedge value is also moved to the latch.

This change removes the requirement to create the latch block up-front
for VPWidenIntOrFpInductionRecipe::execute, which in turn will enable
modeling the pre-header in VPlan.

As an alternative, the increment could be modeled as separate recipe,
but that would require more work and a bit of redundant code, as we need
to create the step-vector during VPWidenIntOrFpInductionRecipe::execute
anyways, to create the values for different parts.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D121617
2022-03-28 16:20:02 +01:00
Florian Hahn e47d220230
[LV] Use getVectorLoopRegion to retrieve header. (NFC)
Update all places that currently assume the entry block to the plan is
also the vector loop header to use getVectorLoopRegion instead.

getVectorLoopRegion will keep doing the right thing when the pre-header
is modeled explicitly (and becomes the new entry block in the plan).
2022-03-25 16:57:12 +00:00
Florian Hahn 46432a0088
[VPlan] Add VPWidenPointerInductionRecipe.
This patch moves pointer induction handling from VPWidenPHIRecipe to its
own recipe. In the process, it adds all information required to generate
code for pointer inductions without relying on Legal to access the list
of induction phis.

Alternatively VPWidenPHIRecipe could also take an optional pointer to InductionDescriptor.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D121615
2022-03-24 14:58:45 +00:00
serge-sans-paille 1b89c83254 Cleanup includes: Transforms/Instrumentation & Transforms/Vectorize
Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D122181
2022-03-23 11:06:13 +01:00
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 55689904d2
[VPlan] Move ::isCanonical outside ifdef.
This fixes a build failure with assertions disabled.
2022-01-21 09:44:31 +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
David Sherwood e781620dee [LoopVectorize][AArch64] Use get.active.lane.mask intrinsic when SVE is enabled
When SVE is enabled for AArch64 targets it makes more sense to use the
get.active.lane.mask intrinsic, because SVE has an exact 1-1 mapping
from the intrinsic to the 'whilelo' instruction for legal vector types.
This instruction neatly takes overflow into account as well. This patch
fixes an issue in VPInstruction::generateInstruction that assumed we are
only dealing with fixed-width vectors.

Differential Revision: https://reviews.llvm.org/D117109
2022-01-18 11:59:30 +00:00
Florian Hahn 500fe60957
[VPlan] Drop unnecessary uses of getVPSingleValue (NFC). 2022-01-17 13:27:33 +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
David Sherwood b0922a9dcd [LoopVectorize] Make VPWidenCanonicalIVRecipe::execute work for scalable vectors
The code in VPWidenCanonicalIVRecipe::execute only worked for fixed-width
vectors due to the way we generate the values per lane. This patch changes
the code to use a combination of vector splats and step vectors to get
the same result. This then works for both fixed-width and scalable vectors.

Tests that exercise this code path for scalable vectors have been added here:

  Transforms/LoopVectorize/AArch64/sve-tail-folding.ll

Differential Revision: https://reviews.llvm.org/D113180
2022-01-10 14:12:32 +00:00
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
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 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
Rosie Sumpter 2d33327f9d [LoopVectorize] Print fast-math flags for VPReductionRecipe 2021-11-24 08:50:05 +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
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
Florian Hahn ab33427c86
[VPlan] Print live-in backedge taken count as part of plan.
At the moment, a VPValue is created for the backedge-taken count, which
is used by some recipes. To make it easier to identify the operands of
recipes using the backedge-taken count, print it at the beginning of the
VPlan if it is used.

Reviewed By: a.elovikov

Differential Revision: https://reviews.llvm.org/D111298
2021-10-11 20:13:01 +01:00
David Sherwood 26b7d9d622 [LoopVectorize] Permit vectorisation of more select(cmp(), X, Y) reduction patterns
This patch adds further support for vectorisation of loops that involve
selecting an integer value based on a previous comparison. Consider the
following C++ loop:

  int r = a;
  for (int i = 0; i < n; i++) {
    if (src[i] > 3) {
      r = b;
    }
    src[i] += 2;
  }

We should be able to vectorise this loop because all we are doing is
selecting between two states - 'a' and 'b' - both of which are loop
invariant. This just involves building a vector of values that contain
either 'a' or 'b', where the final reduced value will be 'b' if any lane
contains 'b'.

The IR generated by clang typically looks like this:

  %phi = phi i32 [ %a, %entry ], [ %phi.update, %for.body ]
  ...
  %pred = icmp ugt i32 %val, i32 3
  %phi.update = select i1 %pred, i32 %b, i32 %phi

We already detect min/max patterns, which also involve a select + cmp.
However, with the min/max patterns we are selecting loaded values (and
hence loop variant) in the loop. In addition we only support certain
cmp predicates. This patch adds a new pattern matching function
(isSelectCmpPattern) and new RecurKind enums - SelectICmp & SelectFCmp.
We only support selecting values that are integer and loop invariant,
however we can support any kind of compare - integer or float.

Tests have been added here:

  Transforms/LoopVectorize/AArch64/sve-select-cmp.ll
  Transforms/LoopVectorize/select-cmp-predicated.ll
  Transforms/LoopVectorize/select-cmp.ll

Differential Revision: https://reviews.llvm.org/D108136
2021-10-11 09:41:38 +01:00
Krasimir Georgiev 685f1bfd0a Revert "[LoopVectorize] Permit vectorisation of more select(cmp(), X, Y) reduction patterns"
It appears to cause stage2 clang build failures, e.g.,
https://lab.llvm.org/buildbot/#/builders/74/builds/7145.

This reverts commit 1fb37334bd.
2021-10-01 11:39:43 +02:00
David Sherwood 1fb37334bd [LoopVectorize] Permit vectorisation of more select(cmp(), X, Y) reduction patterns
This patch adds further support for vectorisation of loops that involve
selecting an integer value based on a previous comparison. Consider the
following C++ loop:

  int r = a;
  for (int i = 0; i < n; i++) {
    if (src[i] > 3) {
      r = b;
    }
    src[i] += 2;
  }

We should be able to vectorise this loop because all we are doing is
selecting between two states - 'a' and 'b' - both of which are loop
invariant. This just involves building a vector of values that contain
either 'a' or 'b', where the final reduced value will be 'b' if any lane
contains 'b'.

The IR generated by clang typically looks like this:

  %phi = phi i32 [ %a, %entry ], [ %phi.update, %for.body ]
  ...
  %pred = icmp ugt i32 %val, i32 3
  %phi.update = select i1 %pred, i32 %b, i32 %phi

We already detect min/max patterns, which also involve a select + cmp.
However, with the min/max patterns we are selecting loaded values (and
hence loop variant) in the loop. In addition we only support certain
cmp predicates. This patch adds a new pattern matching function
(isSelectCmpPattern) and new RecurKind enums - SelectICmp & SelectFCmp.
We only support selecting values that are integer and loop invariant,
however we can support any kind of compare - integer or float.

Tests have been added here:

  Transforms/LoopVectorize/AArch64/sve-select-cmp.ll
  Transforms/LoopVectorize/select-cmp-predicated.ll
  Transforms/LoopVectorize/select-cmp.ll

Differential Revision: https://reviews.llvm.org/D108136
2021-10-01 08:41:03 +01:00
Florian Hahn 3e58dd19df
[LV] Move reduction PHI node fixup to VPlan::execute (NFC).
All information to fix-up the reduction phi nodes in the vectorized loop
is available in VPlan now. This patch moves the code to do so, to make
this clearer. Fixing up the loop exit value still relies on other
information and remains outside of VPlan for now.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D100113
2021-08-06 08:29:20 +01:00
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 c07dd2b885
[LV] Move recurrence backedge fixup code to VPlan::execute (NFC).
As suggested in D105008, move the code that fixes up the backedge value
for first order recurrences to VPlan::execute.

Now all that remains in fixFirstOrderRecurrences is the code responsible
for creating the exit values in the middle block.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D106244
2021-07-28 13:32:40 +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 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 c6e4c1fbd8
[VPlan] Remove default arg from getVPValue (NFC).
The const version of VPValue::getVPValue still had a default value for
the value index. Remove the default value and use getVPSingleValue
instead, which is the proper function.
2021-07-11 22:03:09 +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 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 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 bdada7546e
[VPlan] Adjust assert in splitBlock to allow splitting at end.
SplitAt should only be dereferenced in the assert if it does not point
to the end of the block. This fixes a crash in the added test case.
2021-05-13 13:36:35 +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 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 160e729cf0
[VPlan] Use recursive traversal iterator in VPSlotTracker.
This patch simplifies VPSlotTracker by using the recursive traversal
iterator to traverse all blocks in a VPlan in reverse post-order when
numbering VPValues in a plan.

This depends on a fix to RPOT (D100169). It also extends the traversal
unit tests to check RPOT.

Reviewed By: a.elovikov

Differential Revision: https://reviews.llvm.org/D100176
2021-04-27 12:39:06 +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
Florian Hahn a6b06b785c [VPlan] Print VPValue operands for VPWidenPHI if possible.
For VPWidenPHIRecipes that model all incoming values as VPValue
operands, print those operands instead of printing the original PHI.

D99294 updates recipes of reduction PHIs to use the VPValue for the
incoming value from the loop backedge, making use of this new printing.
2021-04-06 12:11:21 +01:00
Florian Hahn f759d512c8
[VPlan] Include name when printing after 93a9d2de8f.
The name is included when printing in DOT mode. Also print it in non-DOT
mode after 93a9d2de8f.

This will become more important to distinguish different plans once
VPlans are gradually refined.
2021-03-23 09:50:14 +00:00
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
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
Andrei Elovikov b24afec8ae [NFCI][VPlan] Modify Recipes' print methods to honor Indent parameter
Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D97787
2021-03-02 15:32:10 -08:00
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 c11fd0df64
[VPlan] Skip VPWidenPHIRecipe in VPInterleavedACcessInfo.
Update unit tests that did not expect VPWidenPHIRecipes after
15a74b64df.
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 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 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 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 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