30 Commits

Author SHA1 Message Date
Florian Hahn
fca643847d [VPlan] Fix crash caused by not updating all users properly.
Users of VPValues are managed in a vector, so we need to be more
careful when iterating over users while updating them. For now, just
copy them.

Fixes 51798.

(cherry picked from commit 368af7558e55039e4e93c3eed68ce00da86e5e35)
2021-09-13 20:56:27 -07:00
Florian Hahn
ca0aa2b075 Recommit "[VPlan] Add recipe for first-order rec phis, make splicing explicit."
This reverts the revert commit b1777b04dc4b1a9fee0e7effa7e177892ab32ef0.

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the modified memory recipes, but the out-of-date values directly from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 93664503be6b.
2021-07-26 15:50:30 +01:00
Nico Weber
ef8d46554d Revert "[VPlan] Add recipe for first-order rec phis, make splicing explicit."
Makes clang crash: https://reviews.llvm.org/D105008#2903350
This reverts commit d2a73fb44ea0b8c981e4b923f811f18793fc4770.

Also revert a minor formatting follow-up:
This reverts commit 82834a673246f27a541ffcc57e0eb65b008102ef.
2021-07-25 17:39:28 -04:00
Florian Hahn
de477ca54f [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
ac14d3966e [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
d6b40438e4 Recommit "[VPlan] Add VPReductionPHIRecipe (NFC)." and follow-ups.
This reverts commit 706bbfb35bd31051e46ac77aab3e9b2dbc3abe78.

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
4e40134cc8 Revert "[VPlan] Add VPReductionPHIRecipe (NFC)." and follow-ups
This reverts commit 3fed6d443f802c43aade1b5b1b09f5e2f8b3edb1,
bbcbf21ae60c928e07dde6a1c468763b3209d1e6 and
6c3451cd76cbd0cd973d9c2b08b168dcd0bce3c2.

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
29223963b7 [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
e51ded8676 [VPlan] Merge predicated-triangle regions, after sinking.
Sinking scalar operands into predicated-triangle regions may allow
merging regions. This patch adds a VPlan-to-VPlan transform that tries
to merge predicate-triangle regions after sinking.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D100260
2021-06-28 11:10:38 +01:00
Florian Hahn
d6200896bf [VPlan] Do not sink uniform recipes in sinkScalarOperands.
For uniform ReplicateRecipes, only the first lane should be used, so
sinking them would mean we have to compute the value of the first lane
multiple times. Also, at the moment, sinking them causes a crash because
the value of the first lane is re-used by all users.

Reported post-commit for D100258.
2021-05-27 14:07:48 +01:00
Florian Hahn
45eacd3210 [VPlan] Add first VPlan version of sinkScalarOperands.
This patch adds a first VPlan-based implementation of sinking of scalar
operands.

The current version traverse a VPlan once and processes all operands of
a predicated REPLICATE recipe. If one of those operands can be sunk,
it is moved to the block containing the predicated REPLICATE recipe.
Continue with processing the operands of the sunk recipe.

The initial version does not re-process candidates after other recipes
have been sunk. It also cannot partially sink induction increments at
the moment. The VPlan only contains WIDEN-INDUCTION recipes and if the
induction is used for example in a GEP, only the first lane is used and
in the lowered IR the adds for the other lanes can be sunk into the
predicated blocks.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D100258
2021-05-24 15:29:58 +01:00
Florian Hahn
29eeedec33 [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
Mauri Mustonen
3e49aa8f87 [VPlan] Support to widen select intructions in VPlan native path
Add support to widen select instructions in VPlan native path by using a correct recipe when such instructions are encountered. This is already used by inner loop vectorizer.

Previously select instructions get handled by the wrong recipe and resulted in unreachable instruction errors like this one: https://bugs.llvm.org/show_bug.cgi?id=48139.

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D97136
2021-03-10 20:59:53 +00:00
Mauri Mustonen
feef90db23 [VPlan] Support to widen call intructions in VPlan native path
Add support to widen call instructions in VPlan native path by using a correct recipe when such instructions are encountered. This is already used by inner loop vectorizer.

Previously call instructions got handled by wrong recipes and resulted in unreachable instruction errors like this one: https://bugs.llvm.org/show_bug.cgi?id=48139.

Patch by Mauri Mustonen <mauri.mustonen@tuni.fi>

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D97278
2021-03-06 21:59:52 +00:00
Florian Hahn
4aa2677e39 [VPlan] Manage pairs of incoming (VPValue, VPBB) in VPWidenPHIRecipe.
This patch extends VPWidenPHIRecipe to manage pairs of incoming
(VPValue, VPBasicBlock) in the VPlan native path. This is made possible
because we now directly manage defined VPValues for recipes.

By keeping both the incoming value and block in the recipe directly,
code-generation in the VPlan native path becomes independent of the
predecessor ordering when fixing up non-induction phis, which currently
can cause crashes in the VPlan native path.

This fixes PR45958.

Reviewed By: sguggill

Differential Revision: https://reviews.llvm.org/D96773
2021-02-22 09:44:25 +00:00
Florian Hahn
90a5f6130c [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
dac217d015 [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
52a13d4927 [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
Florian Hahn
1010e3b222 [VPlan] Replace uses with new value in VPInstructionsToVPRecipe (NFC).
Now that VPRecipeBase inherits from VPDef, we can always use the new
VPValue for replacement, if the recipe defines one. Given the recipes
that are supported at the moment, all new recipes must have either 0 or
1 defined values.
2021-01-25 19:38:08 +00:00
Florian Hahn
22dcffd655 [VPlan] Keep start value in VPWidenIntOrFpInductionRecipe (NFC).
This patch updates VPWidenIntOrFpInductionRecipe to hold the start value
for the induction variable. This makes the start value explicit and
allows for adjusting the start value for a VPlan.

The flexibility will be used in further patches.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D92129
2021-01-06 11:47:33 +00:00
Florian Hahn
000449765c [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
558e62b1e8 [VPlan] Add & use VPValue for VPWidenGEPRecipe operands (NFC).
This patch adds VPValue version of the GEP's operands to
VPWidenGEPRecipe and uses them during code-generation.

Reviewers: Ayal, gilr, rengolin

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D80220
2020-06-26 20:59:17 +01:00
Florian Hahn
b4d044fb18 Recommit "[VPlan] Add & use VPValue operands for VPWidenRecipe (NFC)."
The crash that caused the original revert has been fixed in
a3c964a278b4. I also added a reduced version of the crash reproducer.

This reverts the revert commit 2107af9ccfdfe67a90ea9ed4f3bfd7c72c4e29ac.
2020-04-29 11:40:39 +01:00
Mehdi Amini
42af8719d5 Revert "[VPlan] Add & use VPValue operands for VPWidenRecipe (NFC)."
This reverts commit 9245c7ac13480ed48ae339ad0e68cbe680cd0642.

This is triggering a segfault in XLA downstream, we'll follow-up with
a reproducer, it is likely influenced by TTI/TLI settings or other
options as a simple `opt -loop-vectorize` invocation on the IR
before the crash does not reproduce immediately.
2020-04-24 05:07:32 +00:00
Florian Hahn
1d82c3d44a [VPlan] Add & use VPValue operands for VPWidenRecipe (NFC).
This patch adds VPValue version of the instruction operands to
VPWidenRecipe and uses them during code-generation.

Similar to D76373 this reduces ingredient def-use usage by ILV as
a step towards full VPlan-based def-use relations.

Reviewers: rengolin, Ayal, gilr

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D76992
2020-04-23 12:16:46 +01:00
Florian Hahn
e03568e786 [VPlan] Use one VPWidenRecipe per original IR instruction. (NFC).
This patch changes VPWidenRecipe to only store a single original IR
instruction. This is the first required step towards modeling it's
operands as VPValues and also towards breaking it up into a
VPInstruction.

Discussed as part of D74695.

Reviewers: Ayal, gilr, rengolin

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D76988
2020-03-29 13:47:28 +01:00
Gil Rapaport
41cef53616 [LV] Replace stored value with a VPValue (NFCI)
InnerLoopVectorizer's code called during VPlan execution still relies on
original IR's def-use relations to decide which vector code to generate,
limiting VPlan transformations ability to modify def-use relations and still
have ILV generate the vector code.
This commit introduces a VPValue for VPWidenMemoryInstructionRecipe to use as
the stored value. The recipe is generated with a VPValue wrapping the stored
value of the scalar store. This reduces ingredient def-use usage by ILV as a
step towards full VPlan-based def-use relations.

Differential Revision: https://reviews.llvm.org/D76373
2020-03-25 19:36:55 +02:00
David Green
6e60c4c134 [LoopVectorizer] Change types of lists from pointers to references. NFC
getReductionVars, getInductionVars and getFirstOrderRecurrences were all
being returned from LoopVectorizationLegality as pointers to lists. This
just changes them to be references, cleaning up the interface slightly.

Differential Revision: https://reviews.llvm.org/D75448
2020-03-02 15:04:41 +00:00
Gil Rapaport
1da8cca5cd [LV] VPValues for memory operation pointers (NFCI)
Memory instruction widening recipes use the pointer operand of their load/store
ingredient for generating the needed GEPs, making it difficult to feed these
recipes with pointers based on other ingredients or none at all.
This patch modifies these recipes to use a VPValue for the pointer instead, in
order to reduce ingredient def-use usage by ILV as a step towards full
VPlan-based def-use relations. The recipes are constructed with VPValues bound
to these ingredients, maintaining current behavior.

Differential revision: https://reviews.llvm.org/D70865
2020-01-10 09:24:59 +02:00
Florian Hahn
c0a866cb87 [VPlan] Rename VPlanHCFGTransforms to VPlanTransforms (NFC).
The file is intended to gather various VPlan transformations, not only
CFG related transforms. Actually, the only transformation there is not
CFG related.

Reviewers: Ayal, gilr, hsaito, rengolin

Reviewed By: gilr

Differential Revision: https://reviews.llvm.org/D70732
2019-12-07 08:56:35 +00:00