158 Commits

Author SHA1 Message Date
Nikita Popov
067f1c95a4 [LoopVectorizer] Generate test checks (NFC) 2026-02-10 17:01:49 +01:00
Mel Chen
f196b1d66f
[VPlan] Extract reverse operation for reverse accesses (#146525)
This patch introduces VPInstruction::Reverse and extracts the reverse
operations of loaded/stored values from reverse memory accesses. This
extraction facilitates future support for permutation elimination within
VPlan.
2025-12-18 14:57:48 +00:00
Ramkumar Ramachandra
0636225b93
[VPlan] Directly unroll VectorPointerRecipe (#168886)
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.
2025-12-15 10:54:06 +00:00
Ramkumar Ramachandra
2d4a8dadba
[VPlan] Use DL index type consistently for GEPs (#169396)
In preparation to strip VPUnrollPartAccessor and unroll recipes
directly, strip unnecessary complication in getGEPIndexTy, as the unroll
part will no longer be available in follow-ups (see #168886 for
instance). The patch also helps by doing a mass test update up-front.
Narrowing the GEP index type conditionally does not yield any benefit,
and the change is non-functional in terms of emitted assembly. While at
it, avoid hard-coding address-space 0, and use the pointer operand's
address space to get the GEP index type.
2025-11-26 12:25:55 +00:00
Florian Hahn
2016af5652
[VPlan] Create epilogue minimum iteration check in VPlan. (#157545)
Move creation of the minimum iteration check for the epilogue vector
loop to VPlan. This is a first step towards breaking up and moving
skeleton creation for epilogue vectorization to VPlan.

It moves most logic out of EpilogueVectorizerEpilogueLoop: the minimum
iteration check is created directly in VPlan, connecting the check
blocks from the main vector loop is done as post-processing. Next steps
are to move connecting and updating the branches from the check blocks
to VPlan, as well as updating the incoming values for phis.

Test changes are improvements due to folding of live-ins.

PR: https://github.com/llvm/llvm-project/pull/157545
2025-09-25 07:13:38 +00:00
Florian Hahn
50b9ca4dda
[VPlan] Simplify Plan's entry in removeBranchOnConst. (#154510)
After https://github.com/llvm/llvm-project/pull/153643, there may be a
BranchOnCond with constant condition in the entry block.

Simplify those in removeBranchOnConst. This removes a number of
redundant conditional branch from entry blocks.

In some cases, it may also make the original scalar loop unreachable,
because we know it will never execute. In that case, we need to remove
the loop from LoopInfo, because all unreachable blocks may dominate each
other, making LoopInfo invalid. In those cases, we can also completely
remove the loop, for which I'll share a follow-up patch.

Depends on https://github.com/llvm/llvm-project/pull/153643.

PR: https://github.com/llvm/llvm-project/pull/154510
2025-09-18 19:25:05 +01:00
Florian Hahn
4949cb4a5e
[VPlan] Track VPValues instead of VPRecipes in calculateRegisterUsage. (#155301)
Update calculateRegisterUsageForPlan to track live-ness of VPValues
instead of recipes. This gives slightly more accurate results for
recipes that define multiple values (i.e. VPInterleaveRecipe).

When tracking the live-ness of recipes, all VPValues defined by an
VPInterleaveRecipe are considered alive until the last use of any of
them. When tracking the live-ness of individual VPValues, we can
accurately track the individual values until their last use.

Note the changes in large-loop-rdx.ll and pr47437.ll. This patch
restores the original behavior before introducing VPlan-based liveness
tracking.

PR: https://github.com/llvm/llvm-project/pull/155301
2025-09-15 20:55:11 +01:00
Florian Hahn
c3e76b2770
[VPlan] Keep common flags during CSE. (#157664)
During CSE, we don't have to drop all poison-generating flags on
mis-match, we can keep the ones common on both recipes.

PR: https://github.com/llvm/llvm-project/pull/157664
2025-09-10 10:20:48 +00:00
Florian Hahn
9b1b93766d
Reapply "[SCEVExp] Add helper to clean up dead instructions after expansion. (#157308)"
This reverts commit eeb43806eb1b40e690aeeba496ee974172202df9.

Recommit with with a fix for MSan failure (
https://lab.llvm.org/buildbot/#/builders/169/builds/14799), by adding a
set to track deleted values. Using the InsertedInstructions set is not
sufficient, as it use asserting value handles as keys, which may
dereference the value at construction.

Original message:

Add new helper to erase dead instructions inserted during SCEV expansion
but not being used due to InstSimplifyFolder simplifications.

Together with https://github.com/llvm/llvm-project/pull/157307 this also
allows removing some specialized folds, e.g.
https://github.com/llvm/llvm-project/blob/main/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp#L2205

PR: https://github.com/llvm/llvm-project/pull/157308
2025-09-09 09:47:41 +01:00
Florian Hahn
eeb43806eb
Revert "[SCEVExp] Add helper to clean up dead instructions after expansion. (#157308)"
This reverts commit 528b13df571c86a2c5b8305d7974f135d785e30f.

Triggers MSan errors in some configurations, e.g.
https://lab.llvm.org/buildbot/#/builders/169/builds/14799
2025-09-08 14:52:28 +01:00
Florian Hahn
528b13df57
[SCEVExp] Add helper to clean up dead instructions after expansion. (#157308)
Add new helper to erase dead instructions inserted during SCEV expansion
but not being used due to InstSimplifyFolder simplifications.

Together with https://github.com/llvm/llvm-project/pull/157307 this also
allows removing some specialized folds, e.g.
https://github.com/llvm/llvm-project/blob/main/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp#L2205

PR: https://github.com/llvm/llvm-project/pull/157308
2025-09-08 10:53:20 +01:00
Florian Hahn
b50ad945dd
[InstSimplify] Simplify extractvalue (umul_with_overflow(x, 1)). (#157307)
Look through extractvalue to simplify umul_with_overflow where one of
the operands is 1.

This removes some redundant instructions when expanding SCEVs, which in
turn makes the runtime check cost estimate more accurate, reducing the
minimum iterations for which vectorization is profitable.

PR: https://github.com/llvm/llvm-project/pull/157307
2025-09-07 18:32:40 +01:00
Florian Hahn
59d72b57b0
[LV] Modernize and regenerate checks for some tests. 2025-09-06 20:52:29 +01:00
Florian Hahn
f1e91bff42
[LV] Regenerate more checks for missing branch weights. 2025-09-03 22:18:04 +01:00
Ramkumar Ramachandra
d8fd511480
[VPlan] Introduce CSE pass (#151872)
Introduce a simple common-subexpression-elimination pass at the
VPlan-level, running late during the execution of the VPlan. The
long-term vision is to get rid of the legacy non-VPlan-based cse routine
in LV, but this patch doesn't yet fully subsume it.
2025-09-02 12:23:29 +01:00
Nikita Popov
c23b4fbdbb
[IR] Remove size argument from lifetime intrinsics (#150248)
Now that #149310 has restricted lifetime intrinsics to only work on
allocas, we can also drop the explicit size argument. Instead, the size
is implied by the alloca.

This removes the ability to only mark a prefix of an alloca alive/dead.
We never used that capability, so we should remove the need to handle
that possibility everywhere (though many key places, including stack
coloring, did not actually respect this).
2025-08-08 11:09:34 +02:00
Florian Hahn
89ae085859
[VPlan] Remove VPVectorPointer for part 0 after unrolling. (#149735)
VPVectorPointer for part 0 is just the pointer operand. Simplify it
after unrolling. This removes a large number of redundant GEPs with
index 0.

PR: https://github.com/llvm/llvm-project/pull/149735
2025-07-27 13:53:26 +01:00
Florian Hahn
6108d50aed
[VPlan] Add ReductionStartVector VPInstruction. (#142290)
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
2025-06-09 20:59:12 +01:00
Florian Hahn
11713e86b0
[LV] Move VPlan-based calculateRegisterUsage to VPlanAnalysis (NFC). (#135673)
Move VPlan-based calculateRegisterUsage from LoopVectorize
to VPlanAnalysis.cpp. It is a VPlan-based analysis and this helps
to reduce the size of LoopVectorize.

PR: https://github.com/llvm/llvm-project/pull/135673
2025-06-02 17:40:50 +01:00
Florian Hahn
d56deea1e4
[VPlan] Connect Entry to scalar preheader during initial construction. (#140132)
Update initial construction to connect the Plan's entry to the scalar
preheader during initial construction. This moves a small part of the
 skeleton creation out of ILV and will also enable replacing
 VPInstruction::ResumePhi with regular VPPhi recipes.

Resume phis need 2 incoming values to start with, the second being the
bypass value from the scalar ph (and used to replicate the incoming
value for other bypass blocks). Adding the extra edge ensures we
incoming values for resume phis match the incoming blocks.

PR: https://github.com/llvm/llvm-project/pull/140132
2025-05-27 16:07:56 +01:00
Maryam Moghadas
a750893fea
[VPlan][LV] Fix invalid truncation in VPScalarIVStepsRecipe (#137832)
Replace CreateTrunc with CreateSExtOrTrunc in VPScalarIVStepsRecipe to
safely handle type conversion. This prevents assertion failures from
invalid truncation when StartIdx0 has a smaller integer type than
IntStepTy. The assertion was introduced by commit 783a846.
Fixes https://github.com/llvm/llvm-project/issues/137185
2025-05-06 12:48:21 -04:00
Florian Hahn
6f92339d9e
[LV] Compute register usage for interleaving on VPlan. (#126437)
Add a version of calculateRegisterUsage that works estimates register
usage for a VPlan. This mostly just ports the existing code, with some
updates to figure out what recipes will generate vectors vs scalars.

There are number of changes in the computed register usages, but they
should be more accurate w.r.t. to the generated vector code.

There are the following changes:

 * Scalar usage increases in most cases by 1, as we always create a
   scalar canonical IV, which is alive across the loop and is not
   considered by the legacy implementation

 * Output is ordered by insertion, now scalar registers are added first
   due the canonical IV phi.

 * Using the VPlan, we now also more precisely know if an induction will
   be vectorized or scalarized.

Depends on https://github.com/llvm/llvm-project/pull/126415

PR: https://github.com/llvm/llvm-project/pull/126437
2025-04-08 20:52:50 +01:00
Florian Hahn
783a846507
[VPlan] Add VF as operand to VPScalarIVStepsRecipe.
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.
2025-03-28 21:48:59 +00:00
Florian Hahn
2c7d40b2f0
[VPlan] Generalize SCALAR-STEPS removal to any unroll factor.
Follow-up to dfca6c0d3bf9d1a056 to extend isUnrolled handle any unrolled
VPlan, which means there's a single UF, but it will be > 1 if unrolling
took place.
2025-03-26 21:03:50 +00:00
Florian Hahn
dfca6c0d3b
[VPlan] Remove no-op SCALAR-STEPS after unrolling. (#123655)
After unrolling, there may be additional simplifications that can be
applied. One example is removing SCALAR-STEPS for the first part where
only the first lane is demanded.

This removes redundant adds of 0 from a large number of tests (~200),
many which I am still working on updating.

In preparation for removing redundant WideIV steps added in
https://github.com/llvm/llvm-project/pull/119284.

PR: https://github.com/llvm/llvm-project/pull/123655
2025-03-25 12:57:24 +00:00
Florian Hahn
11b8699572
[LV] Don't skip instrs with side-effects in reg pressure computation. (#126415)
calculateRegisterUsage adds end points for each user of an instruction
to Ends and ignores instructions not added to it, i.e. instructions with
no users.

This means things like stores aren't included, which in turn means
values that are only used in stores are also not included for
consideration. This means we underestimate the register usage in cases
where the only users are things like stores.

Update the code to don't skip instructions without users (i.e. not in
Ends) if they have side-effects.

PR: https://github.com/llvm/llvm-project/pull/126415
2025-03-19 15:13:43 +00:00
Ramkumar Ramachandra
3b9f9645e0
[LV] Regen a couple of tests with UTC (#127785) 2025-02-20 15:27:51 +00:00
Florian Hahn
32c4493d5f
[VPlan] Add incoming values for all predecessor to ResumePHI (NFCI).
Follow-up as discussed when using VPInstruction::ResumePhi for all resume
values (#112147). This patch explicitly adds incoming values for each
predecessor in VPlan. This simplifies codegen and allows transformations
adjusting the predecessors of blocks with

NFC modulo incoming block order in phis.
2025-02-09 11:20:20 +00:00
Florian Hahn
7f3428d3ed
[VPlan] Compute induction end values in VPlan. (#112145)
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
2024-12-29 19:05:08 +00:00
Florian Hahn
4ad0fdd163
[VPlan] Remove reverse() of predecessors from VPInstruction::generate.
This was originally done to reduce the diff for the change. Remove it
and update the remaining tests. NFC modulo reordering of incoming
values.

Clean up after https://github.com/llvm/llvm-project/pull/114292.
2024-12-17 20:44:32 +00:00
Nikita Popov
1157187496
[VPlan] Propagate all GEP flags (#119899)
Store GEPNoWrapFlags instead of only InBounds and propagate them.
2024-12-17 13:48:50 +01:00
Florian Hahn
43045051d4
[VPlan] Modernize VPWidenIntOrFpInductionRecipe printing (NFC).
Modernize VPWidenIntOrFpInductionRecipe printing by including the result
VPValue and all operand VPValues, similar to VPScalarIVStepsRecipe and
VPDerivedIVRecipe.
2024-12-15 20:46:52 +00:00
Florian Hahn
6c8f41d336
[VPlan] Hook IR blocks into VPlan during skeleton creation (NFC) (#114292)
As a first step to move towards modeling the full skeleton in VPlan,
start by wrapping IR blocks created during legacy skeleton creation in
VPIRBasicBlocks and hook them into the VPlan. This means the skeleton
CFG is represented in VPlan, just before execute. This allows moving
parts of skeleton creation into recipes in the VPBBs gradually.

Note that this allows retiring some manual DT updates, as this will be
handled automatically during VPlan execution.

PR: https://github.com/llvm/llvm-project/pull/114292
2024-12-12 15:58:16 +00:00
Florian Hahn
7f7f540a48
Reapply "[VPlan] Update scalar induction resume values in VPlan. (#110577)"
This reverts commit f09b16e2671cbcdf7cb7dc7ed705db092a9deda1.

The crash when building llvm-test-suite with stage2 should have been
fixed by 1091fad31a83d5ab87eb6fa11fe3bdb3f0d152ea.
2024-12-06 19:41:51 +00:00
Nikita Popov
f09b16e267 Revert "[VPlan] Update scalar induction resume values in VPlan. (#110577)"
This reverts commit 0678e2058364ec10b94560d27ec7138dfa003287.
This reverts commit 1091fad31a83d5ab87eb6fa11fe3bdb3f0d152ea.

Causes crashes in llvm-test-suite when using stage 2 clang.
2024-12-06 18:01:42 +01:00
Florian Hahn
0678e20583
[VPlan] Update scalar induction resume values in VPlan. (#110577)
Updated ILV.createInductionResumeValues (now createInductionResumeVPValue)
to directly update the VPIRInstructions wrapping the original phis with the 
created resume values.

This is the first step towards modeling them completely in VPlan.
Subsequent patches will move creation of the resume values completely
into VPlan.

Depends on https://github.com/llvm/llvm-project/pull/109975.

PR: https://github.com/llvm/llvm-project/pull/110577
2024-12-06 12:26:19 +00:00
Julian Nagele
a8538b9138
[LV] Vectorize Epilogues for loops with small VF but high IC (#108190)
- 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>
2024-11-17 19:35:32 +00:00
Tex Riddell
818d715989
[Analysis] atan2: isTriviallyVectorizable; add to massv and accelerate veclibs (#113637)
This change is part of this proposal:
https://discourse.llvm.org/t/rfc-all-the-math-intrinsics/78294

- Return true for atan2 from isTriviallyVectorizable
- Add atan2 to VecFuncs.def for massv and accelerate libraries.
- Add atan2 to hasOptimizedCodeGen
- Add atan2 support in llvm/lib/Analysis/ValueTracking.cpp
llvm::getIntrinsicForCallSite and update vectorization tests
- Add atan2 name check to isLoweredToCall in
llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
- Note: there's no test coverage for these names in isLoweredToCall, except that Transforms/TailCallElim/inf-recursion.ll is impacted by the "fabs" case

Thanks to @jroelofs for the atan2 accelerate veclib and associated test
additions, plus the hasOptimizedCodeGen addition.

Part of: Implement the atan2 HLSL Function #70096.
2024-11-08 16:07:38 -08:00
Paul Walker
38fffa630e
[LLVM][IR] Use splat syntax when printing Constant[Data]Vector. (#112548) 2024-11-06 11:53:33 +00:00
zhijian lin
a51712751c
[PowerPC][LLC] Utilize PPC::getNormalizedPPCTargetCPU() to set CPU (#113943)
Utilize common API in PPCTargetParser
(https://github.com/llvm/llvm-project/pull/97541) to set default CPU
with same interfaces for LLC.
This will update AIX default CPU to pwr7 and LoP powerppc64 default CPU
to ppc64.
2024-11-04 09:40:54 -05:00
Florian Hahn
53266f73f0
[VPlan] Run DCE after unrolling.
This cleans up a number of dead recipes after unrolling if only their
first or last parts are used. This simplifies a number of tests.

Fixes https://github.com/llvm/llvm-project/issues/109581.
2024-09-22 22:08:46 +01:00
Florian Hahn
a794ee4559
[VPlan] Add VPValue for VF, use it for VPWidenIntOrFpInductionRecipe. (#95305)
Similar to VFxUF, also add a VF VPValue to VPlan and use it to get the
runtime VF in VPWidenIntOrFpInductionRecipe. Code for VF is only
generated if there are users of VF, to avoid unnecessary test changes.

PR: https://github.com/llvm/llvm-project/pull/95305
2024-09-10 10:41:35 +01:00
Philip Reames
2c7786e94a
Prefer use of 0.0 over -0.0 for fadd reductions w/nsz (in IR) (#106770)
This is a follow up to 924907bc6, and is mostly motivated by consistency
but does include one additional optimization. In general, we prefer 0.0
over -0.0 as the identity value for an fadd. We use that value in
several places, but don't in others. So, let's be consistent and use the
same identity (when nsz allows) everywhere.

This creates a bunch of test churn, but due to 924907bc6, most of that
churn doesn't actually indicate a change in codegen. The exception is
that this change enables the use of 0.0 for nsz, but *not* reasoc, fadd
reductions. Or said differently, it allows the neutral value of an
ordered fadd reduction to be 0.0.
2024-09-03 09:16:37 -07:00
Philip Reames
4b553f4916 Regen a bunch of vectorizer tests to avoid naming churn in upcoming review 2024-08-30 10:13:02 -07:00
Florian Hahn
5a42a677aa
[VPlan] Mark VPVectorPointer as only using the first part of the ptr.
VPVectorPointerRecipe only uses the first part of the pointer operand,
so mark it accordingly.

Follow-up suggested as part of
https://github.com/llvm/llvm-project/pull/99808.
2024-08-12 08:46:55 +01:00
Florian Hahn
710dab6e18
[VPlan] Remove VPPredInstPHIRecipes without users after region merging.
After merging replicate regions, VPPredInstPHIRecipes may become unused.
Remove them directly instead of moving them to the merged region.
2024-07-20 13:21:32 +01:00
Florian Hahn
55483379e2
[VPlan] Update test to use CHECK variables.
Update test to avoid using hard-coded VPValue IDs.
2024-07-16 13:04:10 +01:00
Florian Hahn
99d6c6d936
[VPlan] Model branch cond to enter scalar epilogue in VPlan. (#92651)
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
2024-07-05 10:08:42 +01:00
Florian Hahn
3808ba78de
[VPlan] Model middle block via VPIRBasicBlock. (#95816)
Use VPIRBasicBlock to wrap the middle block and implement patching up
branches in predecessors in VPIRBasicBlock::execute. The IR middle block
is only created after skeleton creation. Initially a regular
VPBasicBlock is created, which will later be replaced by a
VPIRBasicBlock once the middle IR basic block has been created.

Note that this slightly changes the order of instructions created in the
middle block; code generated by recipe execution in the middle block
will now be inserted before the terminator (and in between the compare
to used by the terminator). The original order will be restored in
https://github.com/llvm/llvm-project/pull/92651.


PR: https://github.com/llvm/llvm-project/pull/95816
2024-06-20 13:42:20 +01:00
Florian Hahn
7c0c9d640d
[LV] Add tests with multiple conditions feedin exit branches.
Test cases for the recent buildbot failures:
        https://lab.llvm.org/buildbot/#/builders/17/builds/47
        https://lab.llvm.org/buildbot/#/builders/168/builds/37
2024-06-15 21:31:37 +01:00