Enforce that all VPInstructions set the correct OpType of the VPIRFlags.
Flag mis-matches (e.g. VPInstruction Add without `OverflowingBinOp`
being set) can cause crashes (e.g. in CSE) or potentially mis-compiles.
Add a few helpers in VPBuilder to create common instructions with
correct flags.
PR: https://github.com/llvm/llvm-project/pull/179138
Replace ComputeFindIVResult with ComputeReductionResult + explicit
compare + select, to more explicitly and simpler model computing finding
the first/last induction, which boils down to a min/max reduction +
compare and select of the sentinel value.
PR: https://github.com/llvm/llvm-project/pull/176672
Remove the artificial PhiR operand of ComputeReductionResult, which was
only used to look up recurrence kind, in-loop and ordered properties.
Instead, encode them as VPIRFlags as suggested by @ayalz in
https://github.com/llvm/llvm-project/pull/170223.
This addresses a TODO to make codegen for ComputeReductionResult
independent of looking up information from other recipes.
This is NFC w.r.t. codegen, the printing has been improved to include
the reduction type, and whether it is in-loop/ordered.
PR: https://github.com/llvm/llvm-project/pull/174026
This patch adds VPValue sub-classes for the different cases we currently
have:
* VPIRValue: A live-in VPValue that wraps an underlying IR value
* VPSymbolicValue: A symbolic VPValue not tied to an underlying value,
e.g. the vector trip count or VF VPValues
* VPRecipeValue: A VPValue defined by a VPDef/VPRecipeBase.
This has multiple benefits:
* clearer constructors for each kind of VPValue
* limited scope: for example allows moving VPDef member to VPRecipeValue,
reducing size of other VPValues.
* stricter type checking for member variables (e.g. using VPLiveIn in
the Value -> live-in map in VPlan, or using VPSymbolicValue for symbolic
member VPValues)
There probably are additional opportunities for cleanups as follow-ups.
PR: https://github.com/llvm/llvm-project/pull/172758
In an effort to get rid of VPUnrollPartAccessor and directly unroll
recipes, start by directly unrolling VectorPointerRecipe, allowing for
VPlan-based simplifications and simplification of the corresponding
execute.
ExtractLastLane is a no-op for scalar VFs. Update simplifyRecipe to
remove them. This also requires adjusting the code in VPlanUnroll.cpp to
split off handling of ExtractLastLane/ExtractPenultimateElement for
scalar VFs, which now needs to match ExtractLastPart.
PR: https://github.com/llvm/llvm-project/pull/171145
Replace ExtractLastElement and ExtractLastLanePerPart with more generic
and specific ExtractLastLane and ExtractLastPart, which model distinct
parts of extracting across parts and lanes. ExtractLastElement ==
ExtractLastLane(ExtractLastPart) and ExtractLastLanePerPart ==
ExtractLastLane, the latter clarifying the name of the opcode. A new
m_ExtractLastElement matcher is provided for convenience.
The patch should be NFC modulo printing changes.
PR: https://github.com/llvm/llvm-project/pull/164124
Flags are now passed on construction/cloning. Remove unnecessary
transferFlags call, and make code independent of VPRecipeWithIRFlags, to
support additional recipes in the future.
Update VPlan to populate VPIRFlags during VPInstruction construction and
use it when creating widened recipes, instead of constructing VPIRFlags
from the underlying IR instruction each time. The VPRecipeWithIRFlags
constructor taking an underlying instruction and setting the flags based
on it has been removed.
This centralizes initial VPIRFlags creation and ensures flags are
consistently available throughout VPlan transformations and makes sure
we don't accidentally re-add flags from the underlying instruction that
already got dropped during transformations.
Follow-up to https://github.com/llvm/llvm-project/pull/167253, which did
the same for VPIRMetadata.
Should be NFC w.r.t. to the generated IR.
PR: https://github.com/llvm/llvm-project/pull/168450
Extend replicateByVF added in #142433 (aa240293190) to also explicitly
unroll replicating VPInstructions.
Now the only remaining case where we replicate for all lanes is
VPReplicateRecipes in replicate regions.
PR: https://github.com/llvm/llvm-project/pull/155102
If we have entries in Def2LaneDefs, we always have to use it. Move the
check before.
Otherwise we may not pick the correct operand, e.g. if Op was a
replicate recipe that got single-scalar after replicating it.
Fixes https://github.com/llvm/llvm-project/issues/154330.
Materialze Build(Struct)Vectors explicitly for VPRecplicateRecipes, to
serve their users requiring a vector, instead of doing so when unrolling
by VF.
Now we only need to implicitly build vectors in VPTransformState::get
for VPInstructions. Once they are also unrolled by VF we can remove the
code-path alltogether.
PR: https://github.com/llvm/llvm-project/pull/151487
A lot of time getCanonicalIV() is used to get the canonical IV type,
e.g. to instantiate a VPTypeAnalysis or to get the LLVMContext.
However VPTypeAnalysis has a constructor that takes the VPlan directly
and there's a method on VPlan to get the LLVMContext directly, so use
those instead where possible.
This lets us remove a constructor on VPTypeAnalysis.
Also remove an unused LLVMContext argument in UnrollState whilst we're
here.
This is the VPWidenPointerInductionRecipe equivalent of #118638, with
the motivation of allowing us to use the EVL as the induction step.
There is a new VPInstruction added, WidePtrAdd to allow adding the step
vector to the induction phi, since VPInstruction::PtrAdd only handles
scalars or multiple scalar lanes.
Originally this transformation was copied from the original recipe's
execute code, but it's since been simplifed by teaching
`unrollWidenInductionByUF` to unroll the recipe, which brings it inline
with VPWidenIntOrFpInductionRecipe.
This patch adds a new ExtractLane VPInstruction which extracts across
multiple parts using a wide index, to be used in combination with
FirstActiveLane.
The patch updates early-exit codegen to use it instead ExtractElement,
which is only per-part. With this change, interleaving should work
correctly with early-exit loops.
The patch removes the restrictions added in 6f43754e9 (#145877), but
does not yet automatically select interleave counts > 1 for early-exit
loops.
I'll share a patch as follow-up. The cost of extracting a lane adds
non-trivial overhead in the exit block, so that should be considered
when picking the interleave count.
PR: https://github.com/llvm/llvm-project/pull/148817
This fixes a bug introduced by aa2402931908317f5cc19b164ef17c5a74f2ae67,
"[VPlan] Unroll VPReplicateRecipe by VF", which cloned a
VPReplicateRecipe without transferring the flags from the original.
That can cause incorrect nsw/nuw flags to be emitted on the new
instructions, which may result in miscompiles.
It turns out there were no test-cases in the repo which end up hitting
the situation where the recipe requires instruction clones to have
different flags from the underlying instruction. The existing tests
covered the flags being correct when the replacement instruction is a
vectorized version of the initial instruction, but not when it required
clones. A new test is added covering this.
Similar to FindLastIV, add FindFirstIVSMin to support select (icmp(), x, y)
reductions where one of x or y is a decreasing induction, producing a SMin
reduction. It uses signed max as sentinel value.
PR: https://github.com/llvm/llvm-project/pull/140451
Make sure all VPBBs outside the top-level loop region and directly
inside the region are visited; all those blocks may contain
VPReplicateRecipes that need unrolling.
This makes sure we unroll VPRepicateRecipes by VF if they are hoisted
out of the loop, but cannot be converted to single scalar recipes yet.
Currently FirstActiveLane is not handled correctly during
unrolling. This is currently causing mis-compiles when
vectorizing early-exit loops with interleaving forced.
This patch updates handling of FirstActiveLane to be analogous to
computing final reduction results: during unrolling, the created copies
for its original operand are added as additional operands, and
FirstActiveLane will always produce the index of the first active lane
across all unrolled iterations.
Note that some of the generated code is still incorrect, as we also need
to handle ExtractElement with FirstActiveLane operands. I will share
patches for those soon as well.
PR: https://github.com/llvm/llvm-project/pull/145394
Currently AnyOf is not handled correctly during unrolling. This is
currently causing mis-compiles when vectorizing early-exit loops with
interleaving forced (even though selectInterleaveCount will currently
only pick IC = 1, unless forced by the user).
This patch updates handling of AnyOf to be analogous to computing final
reduction results: during unrolling, the created copies for its original
operand are added as additional operands, and AnyOf will always produce
the reduced value across all unrolled iterations.
Note that the generated code is still incorrect, as we also need to
handle FirstActiveLane and ExtractElement with FirstActiveLane operands.
I will share patches for those soon as well.
PR: https://github.com/llvm/llvm-project/pull/145340
Explicitly unroll VPReplicateRecipes outside replicate regions by VF,
replacing them by VF single-scalar recipes. Extracts for operands are
added as needed and the scalar results are combined to a vector using a
new BuildVector VPInstruction.
It also adds a few folds to simplify unnecessary extracts/BuildVectors.
It also adds a BuildStructVector opcode for handling of calls that have
struct return types.
VPReplicateRecipe in replicate regions can will be unrolled as follow
up, turing non-single-scalar VPReplicateRecipes into 'abstract', i.e.
not executable.
PR: https://github.com/llvm/llvm-project/pull/142433
Update handling of ReductionStartVector in VPlanUnroll for partial
reductions. The new code makes sure all parts are properly set to the
cloned ReductionStartVector.
Fixes a mis-compile reported for
https://github.com/llvm/llvm-project/pull/142290.
Similar to modeling the start value as operand, also model the sentinel
value as operand explicitly. This makes all require information for
code-gen available directly in VPlan.
PR: https://github.com/llvm/llvm-project/pull/142291
Add a new VPInstruction::ReductionStartVector opcode to create the start
values for wide reductions. This more accurately models the start value
creation in VPlan and simplifies VPReductionPHIRecipe::execute. Down the
line it also allows removing VPReductionPHIRecipe::RdxDesc.
PR: https://github.com/llvm/llvm-project/pull/142290
This patch moves the logic to manage IR flags to a separate VPIRFlags
class. For now, VPRecipeWithIRFlags is the only class that inherits
VPIRFlags. The new class allows for simpler passing of flags when
constructing recipes, simplifying the constructors for various recipes
(VPInstruction in particular, which now just has 2 constructors, one
taking an extra VPIRFlags argument.
This mirrors the approach taken for VPIRMetadata and makes it easier to
extend in the future. The patch also adds a unified flagsValidForOpcode
to check if the flags in a VPIRFlags match the provided opcode.
PR: https://github.com/llvm/llvm-project/pull/140621
ExtractFromEnd only has 2 uses, extracting the last and penultimate
elements. Replace it with 2 separate opcodes, removing the need to
materialize and handle a constant argument.
PR: https://github.com/llvm/llvm-project/pull/137030
