| Age | Commit message (Collapse) | Author |
|---|
|
Introduce a VPlan-level constant folder in simplifyRecipe that tries to
fold a recipe to a constant using TargetFolder.
|
|
Add a new convertToUniformRecipes transform which uses VPlan-based
uniformity analysis to determine if wide recipes and replicate recipes
can be converted to uniform recipes.
There are a few places where we ad-hoc convert recipes to uniform
recipes, which this transform will eventually replace. There are a few
more generalizations required to do so which I plan to do as follow-ups.
By converting the recipes to uniform recipes, we effectively materialize
the information from the VPlan-based analysis.
Note that there is one regression at the moment in SystemZ/pr47665.ll
due to trivial constant folding opportunities in the input IR. This will
be fixed by VPlan-based constant folding
(https://github.com/llvm/llvm-project/pull/125365/)
PR: https://github.com/llvm/llvm-project/pull/139150
|
|
Considering that "or disjoint" is the canonical for certain add
operations, then I think we want to support such "add like" operations
when doing ADD+GEP->GEP+GEP rewrites to make things more consistent.
Problem was found when improving ValueTracking, which turned an ADD into
OR, and then suddenly optimizations got worse due to these rewrites no
longer triggering.
|
|
Follow-up to 0f607f to actually use the captured operand X instead of Y.
|
|
Add additional OR simplification to fix a divergence between legacy and
VPlan-based cost model.
This adds a new m_AllOnes matcher by generalizing specific_intval to
int_pred_ty, which takes a predicate to check to support matching both
specific APInts and other APInt predices, like isAllOnes.
Fixes https://github.com/llvm/llvm-project/issues/131359.
|
|
Add an initial CFG simplification transform, which removes the dead
edges for blocks terminated with BranchOnCond true.
At the moment, this removes the edge between middle block and scalar
preheader when folding the tail.
PR: https://github.com/llvm/llvm-project/pull/106748
|
|
Optimize the IR generated for a VPWidenIntOrFpInductionRecipe to use the
narrowest type necessary, when the trip-count of a loop is known to be
constant and the only use of the recipe is the condition used by the
vector loop's backedge branch.
|
|
This PR removes the old `nocapture` attribute, replacing it with the new
`captures` attribute introduced in #116990. This change is
intended to be essentially NFC, replacing existing uses of `nocapture`
with `captures(none)` without adding any new analysis capabilities.
Making use of non-`none` values is left for a followup.
Some notes:
* `nocapture` will be upgraded to `captures(none)` by the bitcode
reader.
* `nocapture` will also be upgraded by the textual IR reader. This is to
make it easier to use old IR files and somewhat reduce the test churn in
this PR.
* Helper APIs like `doesNotCapture()` will check for `captures(none)`.
* MLIR import will convert `captures(none)` into an `llvm.nocapture`
attribute. The representation in the LLVM IR dialect should be updated
separately.
|
|
Update optimizeForVFAndUF to completely remove the vector loop region
when possible. At the moment, we cannot remove the region if it contains
* widened IVs: the recipe is needed to generate the step vector
* reductions: ComputeReductionResults requires the reduction phi recipe
for codegen.
Both cases can be addressed by more explicit modeling.
The patch also includes a number of updates to allow executing VPlans
without a vector loop region.
Depends on https://github.com/llvm/llvm-project/pull/110004
|
|
Use createDerivedIV to compute IV end values directly in VPlan, instead
of creating them up-front.
This allows updating IV users outside the loop as follow-up.
Depends on https://github.com/llvm/llvm-project/pull/110004 and
https://github.com/llvm/llvm-project/pull/109975.
PR: https://github.com/llvm/llvm-project/pull/112145
|
|
If IVUpdateMayOverflow is false, we proved that the induction increment
cannot overflow in the vector loop. This allows setting NUW in some
cases when folding the tail.
PR: https://github.com/llvm/llvm-project/pull/111758
|
|
Currently it's very difficult to improve the cost model for tail-folded
loops because as soon as you add a VPInstruction::computeCost function
that adds the costs of instructions such as
VPInstruction::ActiveLaneMask
and VPInstruction::ExplicitVectorLength the assert in
LoopVectorizationPlanner::computeBestVF fails for some tests. This is
because the VF chosen by the legacy cost model doesn't match the vplan
cost model. See PR #90191. This assert is currently making it difficult
to improve the cost model.
Hopefully we will be in a position to remove the assert soon, however
in order to do that we have to fix up a whole bunch of tests that rely
upon the legacy cost model output. I've tried my best to update
these tests to use vplan output instead.
There is still work needed for the VF=1 case because the vplan cost
model is not printed out in this case. I've not attempted to fix those
in this patch.
|
|
|
|
Update isDefinedOutsideLoopRegions to check if a recipe is defined
outside any region. Split off already approved
https://github.com/llvm/llvm-project/pull/95842 now that this can be
tested separately after landing VPlan-based LICM
https://github.com/llvm/llvm-project/issues/107501
|
|
Add initial transform to move out loop-invariant recipes.
This also helps to fix a divergence between legacy and VPlan-based cost
model due to legacy using ScalarEvolution::isLoopInvariant in some
cases.
Fixes https://github.com/llvm/llvm-project/issues/107501.
PR: https://github.com/llvm/llvm-project/pull/107894
|
|
At the moment, the full cost of all interleave group members is assigned
to the instruction at the group's insert position, even if the decision
was to not form an interleave group.
This can lead to inaccurate cost estimates, e.g. if the instruction at
the insert position is dead. If the decision is to not vectorize but
scalarize or scather/gather, then the cost will be to total cost for all
members. In those cases, assign individual the cost per member, to more
closely reflect to choice per instruction.
This fixes a divergence between legacy and VPlan-based cost model.
Fixes https://github.com/llvm/llvm-project/issues/108098.
|
|
To match the behavior of the legacy cost model, only apply
-force-target-instruction-cost to recipes with underlying instructions
for now, as only original IR instructions are considered by the legacy
cost model.
This fixes a difference between legacy and VPlan based cost model,
triggering the verification assertion, reported by @JonPsson1.
|
|
Update existing tests with dead interleave groups by adding users. This
ensures the tests keep testing what they were intended to test with a
planned change to skip unused instructions in cost computations.
|
|
The current assertion VPTransformState::get when retrieving a single
scalar only does not account for cases where a def has multiple users,
some demanding all scalar lanes, some demanding only a single scalar.
For an example, see the modified test case. Relax the assertion by also
allowing requesting scalar lanes only when the Def doesn't have only its
first lane used.
Fixes https://github.com/llvm/llvm-project/issues/88849.
|
|
Add a test case where scalar steps are used by both a VPReplicateRecipe
(demands all scalar lanes) and a VPInstruction that only demands the
first lane.
Test case for https://github.com/llvm/llvm-project/issues/88849.
|
|
This patch introduces a new ResumePhi VPInstruction which creates a phi
in a leaf block of a VPlan. The first use is to create the phi node for
fixed-order recurrence resume values in the scalar preheader.
The VPInstruction takes 2 operands: 1) the incoming value from the
middle-block and a default value to be used for all other incoming
blocks.
In follow-up changes, it will also be used to create phis for reduction
and induction resume values.
Depends on https://github.com/llvm/llvm-project/pull/92651
PR: https://github.com/llvm/llvm-project/pull/94760
|
|
This patch moves the check if any vector instructions will be generated
from getInstructionCost to be based on VPlan. This simplifies
getInstructionCost, is more accurate as we check the final result and
also allows us to exit early once we visit a recipe that generates
vector instructions.
The helper can then be re-used by the VPlan-based cost model to match
the legacy selectVectorizationFactor behavior, this fixing a crash and
paving the way to recommit
https://github.com/llvm/llvm-project/pull/92555.
PR: https://github.com/llvm/llvm-project/pull/96622
|
|
Regenerate test checks to better show impact of
https://github.com/llvm/llvm-project/pull/96622.
|
|
This patch moves branch condition creation to enter the scalar epilogue
loop to VPlan. Modeling the branch in the middle block also requires
modeling the successor blocks. This is done using the recently
introduced VPIRBasicBlock.
Note that the middle.block is still created as part of the skeleton and
then patched in during VPlan execution. Unfortunately the skeleton needs
to create the middle.block early on, as it is also used for induction
resume value creation and is also needed to properly update the
dominator tree during skeleton creation.
After this patch lands, I plan to move induction resume value and phi
node creation in the scalar preheader to VPlan. Once that is done, we
should be able to create the middle.block in VPlan directly.
This is a re-worked version based on the earlier
https://reviews.llvm.org/D150398 and the main change is the use of
VPIRBasicBlock.
Depends on https://github.com/llvm/llvm-project/pull/92525
PR: https://github.com/llvm/llvm-project/pull/92651
|
|
This is a small canonicalization for `gep i32, p, (mul x, C)` -> `gep
i8, p, (mul x, C*4)`, so that the mul can combine both of the constant
multiplications, and we take a small step towards canonicalizing more
geps to i8.
It currently doesn't attempt to check for multiple uses on the mul, but
that should be possible if it sounds better. Let me know what you think
of the idea in general.
|
|
In LoopVectorizationCostModel::getInstructionCost(), when the condition
canTruncateToMinimalBitwidth() is satisfied, for a trunc, the source
type is computed as the smallest type of the source vector and the
destination vector, and the destination type is computed as the largest
type of the instruction and destination type. This is clearly a logical
error, as the original source vector type could be smaller than the
original destination vector type, and the trunc semantics are broken
because we're attempting to widen.
Fixes #47665.
|
|
|
|
loop (#67725)
A set of microbenchmarks (https://github.com/llvm/llvm-test-suite/pull/26) showed that loop interleaving can be beneficial for loops with low trip count as well. Loop interleaving count computation is updated accordingly in prior patches while this patch removes the loop trip count threshold for interleaving.
|
|
This assert does not seem justified given that the LoopVectorizer can
form interleave groups containing i128 elements where the number of
elements per vector is indeed just one.
|
|
The disjoint flag was recently added to IR in #72583
We already set it when we turn an add into an or. This patch sets it on Ors that weren't converted from an Add.
|
|
The disjoint flag was recently added to IR in #72583
|
|
I'm keeping the bitcast in the input here, because without it
we end up introducing a stride 1 assumption and end up testing
a different case.
|
|
This is a follow-up to b71edfaa4ec3c998aadb35255ce2f60bba2940b0
since I forgot the lit.local.cfg files in that one.
Reformatting is done with `black`.
If you end up having problems merging this commit because you
have made changes to a python file, the best way to handle that
is to run git checkout --ours <yourfile> and then reformat it
with black.
If you run into any problems, post to discourse about it and
we will try to help.
RFC Thread below:
https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style
Reviewed By: barannikov88, kwk
Differential Revision: https://reviews.llvm.org/D150762
|
|
Move the code to collect live-out earlier and only generate extracts for
exit values if there are any live-outs that use them.
Depends on D147472.
Reviewed By: Ayal
Differential Revision: https://reviews.llvm.org/D147567
|
|
IR is now always parsed in opaque pointer mode, unless
-opaque-pointers=0 is explicitly given. There is no automatic
detection of typed pointers anymore.
The -opaque-pointers=0 option is added to any remaining IR tests
that haven't been migrated yet.
Differential Revision: https://reviews.llvm.org/D141912
|
|
Check lines for some of these tests were regenerated. The difference
is that with opaque pointers SCEVExpander always emits i8 GEPs,
making the address calculation explicit. This is a known problem
that will be solved long term by making all address calculations
explicit.
|
|
|
|
|
|
|
|
|
|
This reverts commit 14e3450fb57305aa9ff3e9e60687b458e43835c9.
|
|
|
|
The analysis passes output function name encapsulated in `'` braces,
but LV uses `"`. Harmonizing this may help in creating an update script
for the LV costmodel test checks.
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D121105
|
|
extractelement/insertelement
The basic idea to this is that a) having a single canonical type makes CSE easier, and b) many of our transforms are inconsistent about which types we end up with based on visit order.
I'm restricting this to constants as for non-constants, we'd have to decide whether the simplicity was worth extra instructions. For constants, there are no extra instructions.
We chose the canonical type as i64 arbitrarily. We might consider changing this to something else in the future if we have cause.
Differential Revision: https://reviews.llvm.org/D115387
|
|
Done in advance of D115387. These are all the ones which my local script could handle, there's a couple more which need manual updates.
|
|
This reverts commit 0d748b4d32cbddf58a1ff83f3ff178ec1ad49edc.
This is causing some failures when building Spec2017 with scalable
vectors. Reverting to investigate.
|
|
Changes VPReplicateRecipe to extract the last lane from an unconditional,
uniform store instruction. collectLoopUniforms will also add stores to
the list of uniform instructions where Legal->isUniformMemOp is true.
setCostBasedWideningDecision now sets the widening decision for
all uniform memory ops to Scalarize, where previously GatherScatter
may have been chosen for scalable stores.
This fixes an assert ("Cannot yet scalarize uniform stores") in
setCostBasedWideningDecision when we have a loop containing a
uniform i1 store and a scalable VF, which we cannot create a scatter for.
Reviewed By: sdesmalen, david-arm, fhahn
Differential Revision: https://reviews.llvm.org/D112725
|
|
This patch makes SLP and LV emit operations with initial vectors set to poison constant instead of undef.
This is a part of efforts for using poison vector instead of undef to represent "doesn't care" vector.
The goal is to make nice shufflevector optimizations valid that is currently incorrect due to the tricky interaction between undef and poison (see https://bugs.llvm.org/show_bug.cgi?id=44185 ).
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D94061
|
|
Previously the branch from the middle block to the scalar preheader & exit
was being set-up at the end of skeleton creation in completeLoopSkeleton.
Inserting SCEV or runtime checks may result in LCSSA phis being created,
if they are required. Adjusting branches afterwards may break those
PHIs.
To avoid this, we can instead create the branch from the middle block
to the exit after we created the middle block, so we have the final CFG
before potentially adjusting/creating PHIs.
This fixes a crash for the included test case. For the non-crashing
case, this is almost a NFC with respect to the generated code. The
only change is the order of the predecessors of the involved branch
targets.
Note an assertion was moved from LoopVersioning() to
LoopVersioning::versionLoop. Adjusting the branches means loop-simplify
form may be broken before constructing LoopVersioning. But LV only uses
LoopVersioning to annotate the loop instructions with !noalias metadata,
which does not require loop-simplify form.
This is a fix for an existing issue uncovered by D93317.
|
|
LV fails with assertion checking that UF > 0. We already set UF to 1 if it is 0 except the case when IC > MaxInterleaveCount. The fix is to set UF to 1 for that case as well.
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D87679
|
