Following the work in PR #107279, this patch applies the annotative
DebugLocs, which indicate that a particular instruction is intentionally
missing a location for a given reason, to existing sites in the compiler
where their conditions apply. This is NFC in ordinary LLVM builds (each
function `DebugLoc::getFoo()` is inlined as `DebugLoc()`), but marks the
instruction in coverage-tracking builds so that it will be ignored by
Debugify, allowing only real errors to be reported. From a developer
standpoint, it also communicates the intentionality and reason for a
missing DebugLoc.
Some notes for reviewers:
- The difference between `I->dropLocation()` and
`I->setDebugLoc(DebugLoc::getDropped())` is that the former _may_ decide
to keep some debug info alive, while the latter will always be empty; in
this patch, I always used the latter (even if the former could
technically be correct), because the former could result in some
(barely) different output, and I'd prefer to keep this patch purely NFC.
- I've generally documented the uses of `DebugLoc::getUnknown()`, with
the exception of the vectorizers - in summary, they are a huge cause of
dropped source locations, and I don't have the time or the domain
knowledge currently to solve that, so I've plastered it all over them as
a form of "fixme".
Update to only build an initial, plain-CFG VPlan once, and then
transform & optimize clones.
This requires changes to ::clone() for VPInstruction and
VPWidenPHIRecipe to allow for proper cloning of the recipes in the
initial VPlan.
PR: https://github.com/llvm/llvm-project/pull/141363
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
Similarly to VPInstructionWithType and VPIRPhi, add VPPhi as a subclass
for VPInstruction. This allows implementing the VPPhiAccessors trait,
making available helpers for generic printing of incoming values /
blocks and accessors for incoming blocks and values.
It will also allow properly verifying def-uses for values used by
VPInstructions with PHI opcodes via
https://github.com/llvm/llvm-project/pull/124838.
PR: https://github.com/llvm/llvm-project/pull/139151
Currently if we try to create a VPInstructionWithType without a FMF via
VPBuilder::createNaryOp we will use the constructor that asserts
`assert(isFPMathOp() && "this op can't take fast-math flags");`.
This fixes it by checking if FMFs have a value, similar to the other
createNaryOp overloads.
This is needed by #129508
This patch adds a WideIVStep opcode that can be used to create a vector
with the steps to increment a wide induction. The opcode has 2 operands
* the vector step
* the scale of the vector step
The opcode is later converted into a sequence of recipes that convert
the scale and step to the target type, if needed, and then multiply
vector step by scale.
This simplifies code that needs to materialize step vectors, e.g.
replacing wide IVs as follow up to
https://github.com/llvm/llvm-project/pull/108378 with an increment of
the wide IV step.
PR: https://github.com/llvm/llvm-project/pull/119284
Now that VPlan is able to fold away redundant branches to the scalar
preheader, we can directly check in VPlan if the scalar tail may
execute. hasScalarTail returns true if the tail may execute.
We know that the scalar tail won't execute if the scalar preheader
doesn't have any predecessors, i.e. is not reachable.
This removes some late uses of the legacy cost model.
PR: https://github.com/llvm/llvm-project/pull/134674
There are some opcodes that currently require specialized recipes, due
to their result type not being implied by their operands, including
casts.
This leads to duplication from defining multiple full recipes.
This patch introduces a new VPInstructionWithType subclass that also
stores the result type. The general idea is to have opcodes needing to
specify a result type to use this general recipe. The current patch
replaces VPScalarCastRecipe with VInstructionWithType, a similar patch
for VPWidenCastRecipe will follow soon.
There are a few proposed opcodes that should also benefit, without the
need of workarounds:
* https://github.com/llvm/llvm-project/pull/129508
* https://github.com/llvm/llvm-project/pull/119284
PR: https://github.com/llvm/llvm-project/pull/129706
Similarly to other recipes, update VPScalarIVStepsRecipe to also take
the runtime VF as argument. This removes some unnecessary runtime VF
computations for scalable vectors. It will also allow dropping the
UF == 1 restriction for narrowing interleave groups required in
577631f0a528.
createInductionAdditionalBypassValues is only used for epilogue
vectorization now. Move it out of ILV, which means we do not have to
thread through ExpandedSCEVs and also don't have to track the bypass
values in ILV. Instead, directly create them if needed after executing
the epilogue plan. This moves more the epilogue specific logic out of
the generic executePlan.
Update initial VPlan-construction in VPlanNativePath in line with the
inner loop path, in that it bails out when encountering constructs it
cannot handle, like non-intrinsic calls.
Fixes https://github.com/llvm/llvm-project/issues/131071.
Nothing in VPlan.h directly depends on VPTransformState, VPCostContext,
VPFRange, VPlanPrinter or VPSlotTracker. Move them out to a separate
header to reduce the size of widely used VPlan.h.
This is a first step towards more cleanly separating declarations in
VPlan.
Besides reducing VPlan.h's size, this also allows including additional
VPlan-related headers in VPlanHelpers.h for use there. An example is
using VPDominatorTree in VPTransformState
(https://github.com/llvm/llvm-project/pull/117138).
PR: https://github.com/llvm/llvm-project/pull/124104
- Consider MainLoopVF * IC when determining whether Epilogue
Vectorization is profitable
- Allow the same VF for the Epilogue as for the main loop
- Use an upper bound for the trip count of the Epilogue when choosing
the Epilogue VF
PR: https://github.com/llvm/llvm-project/pull/108190
---------
Co-authored-by: Florian Hahn <flo@fhahn.com>
Update VPlan to include the scalar loop header. This allows retiring
VPLiveOut, as the remaining live-outs can now be handled by adding
operands to the wrapped phis in the scalar loop header.
Note that the current version only includes the scalar loop header, no
other loop blocks and also does not wrap it in a region block.
PR: https://github.com/llvm/llvm-project/pull/109975
Update VPInterleaveRecipe to always use the pointer to member 0 as
pointer argument. This in many cases helps to remove unneeded index
adjustments and simplifies VPInterleaveRecipe::execute.
In some rare cases, the address of member 0 does not dominate the insert
position of the interleave group. In those cases a PtrAdd VPInstruction
is emitted to compute the address of member 0 based on the address of
the insert position. Alternatively we could hoist the recipe computing
the address of member 0.
Use the reduction resume values from the phis in the scalar header,
instead of collecting them in a map. This removes some complexity from
the general executePlan code paths and pushes it to only the epilogue
vectorization part.
This patch implements explicit unrolling by UF as VPlan transform. In
follow up patches this will allow simplifying VPTransform state (no need
to store unrolled parts) as well as recipe execution (no need to
generate code for multiple parts in an each recipe). It also allows for
more general optimziations (e.g. avoid generating code for recipes that
are uniform-across parts).
It also unifies the logic dealing with unrolled parts in a single place,
rather than spreading it out across multiple places (e.g. VPlan post
processing for header-phi recipes previously.)
In the initial implementation, a number of recipes still take the
unrolled part as additional, optional argument, if their execution
depends on the unrolled part.
The computation for start/step values for scalable inductions changed
slightly. Previously the step would be computed as scalar and then
splatted, now vscale gets splatted and multiplied by the step in a
vector mul.
This has been split off https://github.com/llvm/llvm-project/pull/94339
which also includes changes to simplify VPTransfomState and recipes'
::execute.
The current version mostly leaves existing ::execute untouched and
instead sets VPTransfomState::UF to 1.
A follow-up patch will clean up all references to VPTransformState::UF.
Another follow-up patch will simplify VPTransformState to only store a
single vector value per VPValue.
PR: https://github.com/llvm/llvm-project/pull/95842
Extend VPBuilder to allow creating VPDerivedIVRecipe, VPScalarCastRecipe
and VPScalarIVStepsRecipe.
Use them to simplify the code to create scalar IV steps slightly.
Use getBestVF to select VF up-front and only use
selectVectorizationFactor to get the VF legacy VF to check the
vectorization decision matches the VPlan-based cost model.
PR: https://github.com/llvm/llvm-project/pull/103033
As suggested in https://github.com/llvm/llvm-project/pull/103033, more
accurately rename to getPlanFor , as it simplify returns the VPlan for
VF, relying on the fact that there is a single VPlan for each VF at the
moment.
This patch moves the logic to create remarks for instructions with
invalid costs to work on recipes and decoupling it from
selectVectorizationFactor. This is needed to replace the remaining uses
of selectVectorizationFactor with getBestPlan using the VPlan-based cost
model.
The current implementation iterates over all VPlans and their recipes
again, to find recipes with invalid costs, which is more work but will
only be done when remarks for LV are enabled. Once the remaining uses of
selectVectorizationFactor are retired, we can collect VPlans with
invalid costs as part of getBestPlan if we want to optimize the remarks
case a bit, at the cost of adding additional complexity.
PR: https://github.com/llvm/llvm-project/pull/99322
Replace getBestPlan by getBestVF which simply finds the best
VF out of the VFs for the available VPlans.
Then use getBestPlan to retrieve the corresponding VPlan.
This allows using getBestVF & getBestPlan for epilogue vectorization
as well. As the same plan may be used to vectorize both the main
and epilogue loop, restricting the VF of the best plan would cause
issues.
PR: https://github.com/llvm/llvm-project/pull/98821
This reverts commit 6f538f6a2d3224efda985e9eb09012fa4275ea92.
A number of crashes have been fixed by separate fixes, including
ttps://github.com/llvm/llvm-project/pull/96622. This version of the
PR also pre-computes the costs for branches (except the latch) instead
of computing their costs as part of costing of replicate regions, as
there may not be a direct correspondence between original branches and
number of replicate regions.
Original message:
This adds a new interface to compute the cost of recipes, VPBasicBlocks,
VPRegionBlocks and VPlan, initially falling back to the legacy cost model
for all recipes. Follow-up patches will gradually migrate recipes to
compute their own costs step-by-step.
It also adds getBestPlan function to LVP which computes the cost of all
VPlans and picks the most profitable one together with the most
profitable VF.
The VPlan selected by the VPlan cost model is executed and there is an
assert to catch cases where the VPlan cost model and the legacy cost
model disagree. Even though I checked a number of different build
configurations on AArch64 and X86, there may be some differences
that have been missed.
Additional discussions and context can be found in @arcbbb's
https://github.com/llvm/llvm-project/pull/67647 and
https://github.com/llvm/llvm-project/pull/67934 which is an earlier
version of the current PR.
PR: https://github.com/llvm/llvm-project/pull/92555
The HeaderVPBB is retrieved in a similar fashion already.
This is in preparation for splitting up the very large
tryToBuildVPlanWithVPRecipes into several distinct functions, as
suggested multiple times, including in
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
This reverts commit 242cc200ccb24e22eaf54aed7b0b0c84cfc54c0b and
eea150c84053035163f307b46549a2997a343ce9, as it is causing a build bot
failure and there have been a number of crashes reported at
https://github.com/llvm/llvm-project/pull/92555
This reverts commit 6f538f6a2d3224efda985e9eb09012fa4275ea92.
Extra tests for crashes discovered when building Chromium have been
added in fb86cb7ec157689e, 3be7312f81ad2.
Original message:
This adds a new interface to compute the cost of recipes, VPBasicBlocks,
VPRegionBlocks and VPlan, initially falling back to the legacy cost model
for all recipes. Follow-up patches will gradually migrate recipes to
compute their own costs step-by-step.
It also adds getBestPlan function to LVP which computes the cost of all
VPlans and picks the most profitable one together with the most
profitable VF.
The VPlan selected by the VPlan cost model is executed and there is an
assert to catch cases where the VPlan cost model and the legacy cost
model disagree. Even though I checked a number of different build
configurations on AArch64 and X86, there may be some differences
that have been missed.
Additional discussions and context can be found in @arcbbb's
https://github.com/llvm/llvm-project/pull/67647 and
https://github.com/llvm/llvm-project/pull/67934 which is an earlier
version of the current PR.
PR: https://github.com/llvm/llvm-project/pull/92555
This reverts commit 90fd99c0795711e1cf762a02b29b0a702f86a264.
This reverts commit 43e6f46936e177e47de6627a74b047ba27561b44.
Causes crashes, see comments on https://github.com/llvm/llvm-project/pull/92555.
This reverts commit 46080abe9b136821eda2a1a27d8a13ceac349f8c.
Extra tests have been added in 52d29eb287.
Original message:
This adds a new interface to compute the cost of recipes, VPBasicBlocks,
VPRegionBlocks and VPlan, initially falling back to the legacy cost model
for all recipes. Follow-up patches will gradually migrate recipes to
compute their own costs step-by-step.
It also adds getBestPlan function to LVP which computes the cost of all
VPlans and picks the most profitable one together with the most
profitable VF.
The VPlan selected by the VPlan cost model is executed and there is an
assert to catch cases where the VPlan cost model and the legacy cost
model disagree. Even though I checked a number of different build
configurations on AArch64 and X86, there may be some differences
that have been missed.
Additional discussions and context can be found in @arcbbb's
https://github.com/llvm/llvm-project/pull/67647 and
https://github.com/llvm/llvm-project/pull/67934 which is an earlier
version of the current PR.
PR: https://github.com/llvm/llvm-project/pull/92555
This adds a new interface to compute the cost of recipes, VPBasicBlocks,
VPRegionBlocks and VPlan, initially falling back to the legacy cost model
for all recipes. Follow-up patches will gradually migrate recipes to
compute their own costs step-by-step.
It also adds getBestPlan function to LVP which computes the cost of all
VPlans and picks the most profitable one together with the most
profitable VF.
The VPlan selected by the VPlan cost model is executed and there is an
assert to catch cases where the VPlan cost model and the legacy cost
model disagree. Even though I checked a number of different build
configurations on AArch64 and X86, there may be some differences
that have been missed.
Additional discussions and context can be found in @arcbbb's
https://github.com/llvm/llvm-project/pull/67647 and
https://github.com/llvm/llvm-project/pull/67934 which is an earlier
version of the current PR.
PR: https://github.com/llvm/llvm-project/pull/92555
This reverts the revert commit c6e01627acf859.
This patch includes a fix for any-of reductions and epilogue
vectorization. Extra test coverage for the issue that caused the revert
has been added in bce3bfced5fe0b019 and an assertion has been added in
c7209cbb8be7a3c65813.
--------------------------------
Original commit message:
Update AnyOf reduction code generation to only keep track of the AnyOf
property in a boolean vector in the loop, only selecting either the new
or start value in the middle block.
The patch incorporates feedback from https://reviews.llvm.org/D153697.
This fixes the #62565, as now there aren't multiple uses of the
start/new values.
Fixes https://github.com/llvm/llvm-project/issues/62565
PR: https://github.com/llvm/llvm-project/pull/78304
