[LV] Do not LoopSimplify/LCSSA after generating main vector loop.

At the moment LV runs LoopSimplify and reconstructs LCSSA form after
generating the main vector loop and before generating the epilo

[LV] Do not LoopSimplify/LCSSA after generating main vector loop.

At the moment LV runs LoopSimplify and reconstructs LCSSA form after
generating the main vector loop and before generating the epilogue
vector loop.

In practice, this adds a new exit block for the scalar loop because the
middle block now also branches to the original exit block of the scalar
loop. It also requires adding a new LCSSA phi in the newly created exit
block.

This complicates things when modeling exit values in VPlan, because we
would need to update the VPlan for the epilogue loop to update the newly
created LCSSA phi node.

But none of that should be necessary, as all analysis requiring
loop-simplify form is already done at this point and LCSSA form of the
original loop is not broken.

Reviewed By: bmahjour

Differential Revision: https://reviews.llvm.org/D125810

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[LV] Regenerate check lines for some tests.

Make sure the auto-generated check lines are up-to-date for some files,
to reduce the test diff in upcoming changes

Revert "[NFCI] Regenerate SROA/LoopVectorize test checks"

This reverts commit 14e3450fb57305aa9ff3e9e60687b458e43835c9.

[NFCI] Regenerate LoopVectorize test checks

Recommit "[VPlan] Introduce recipe to build scalar steps."

This reverts the revert commit ff93260bf6bddfbad1fa65c4d5184988885b900f.

The underlying issue causing the PPC bot failures has been fixed

Recommit "[VPlan] Introduce recipe to build scalar steps."

This reverts the revert commit ff93260bf6bddfbad1fa65c4d5184988885b900f.

The underlying issue causing the PPC bot failures has been fixed in
cbaac1473403 and a corresponding test case has been added in
ad2cad1c521c.

Original message:

This patch adds a new VPScalarIVStepsRecipe to handle building scalar
steps.

In the first patch, it only handles the case where there is no vector
induction variable needed.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D115953

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Revert "[VPlan] Introduce recipe to build scalar steps."

This reverts commit 49b23f451cf713036c99573a35daed308d2ac894.

This appears to break some PPC build bots. Revert while I investigate.

[VPlan] Introduce recipe to build scalar steps.

This patch adds a new VPScalarIVStepsRecipe to handle building scalar
steps.

In the first patch, it only handles the case where there is no vector
in

[VPlan] Introduce recipe to build scalar steps.

This patch adds a new VPScalarIVStepsRecipe to handle building scalar
steps.

In the first patch, it only handles the case where there is no vector
induction variable needed.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D115953

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[LV] Restore metadata to disable runtime unrolling for epilogue loop.

After d4a8fc3a87a1 LV stopped adding metadata to disable runtime
unrolling to the vectorized epilogue loop. This was missed beca

[LV] Restore metadata to disable runtime unrolling for epilogue loop.

After d4a8fc3a87a1 LV stopped adding metadata to disable runtime
unrolling to the vectorized epilogue loop. This was missed because
278aa65cc495 removed the relevant test coverage.

This patch fixes that by adding the relevant metadata after
vector loop generation.

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[SCEVExpander] Only check overflow if it is needed.

9345ab3a4550 updated generateOverflowCheck to skip creating checks that
always evaluate to false. This in turn means that we only need to check
fo

[SCEVExpander] Only check overflow if it is needed.

9345ab3a4550 updated generateOverflowCheck to skip creating checks that
always evaluate to false. This in turn means that we only need to check
for overflows if the result of the multiplication is actually used.

Sink the Or for the overflow check into ComputeEndCheck, so it is only
created when there's an actual check.

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[SCEVExpand] Only create required predicate checks.

Currently generateOverflowCheck always creates code for Step being
negative and positive, followed by a select at the end depending on
Step's sign

[SCEVExpand] Only create required predicate checks.

Currently generateOverflowCheck always creates code for Step being
negative and positive, followed by a select at the end depending on
Step's sign.

This patch updates the code to only create either the checks for step
being positive or negative, if the sign is known.

Follow-up to D116696.

Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D116747

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[SCEVExpand] Do not create redundant 'or false' for pred expansion.

This patch updates SCEVExpander::expandUnionPredicate to not create
redundant 'or false, x' instructions. While those are triviall

[SCEVExpand] Do not create redundant 'or false' for pred expansion.

This patch updates SCEVExpander::expandUnionPredicate to not create
redundant 'or false, x' instructions. While those are trivially
foldable, they can be easily avoided and hinder code that checks the
size/cost of the generated checks before further folds.

I am planning on look into a few other similar improvements to code
generated by SCEVExpander.

I remember a while ago @lebedev.ri working on doing some trivial folds
like that in IRBuilder itself, but there where concerns that such
changes may subtly break existing code.

Reviewed By: reames, lebedev.ri

Differential Revision: https://reviews.llvm.org/D116696

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Revert rest of `IRBuilderBase`'s short-circuiting folds

Upon further investigation and discussion,
this is actually the opposite direction from what we should be taking,
and this direction wouldn't

Revert rest of `IRBuilderBase`'s short-circuiting folds

Upon further investigation and discussion,
this is actually the opposite direction from what we should be taking,
and this direction wouldn't solve the motivational problem anyway.

Additionally, some more (polly) tests have escaped being updated.
So, let's just take a step back here.

This reverts commit f3190dedeef9da2109ea57e4cb372f295ff53b88.
This reverts commit 749581d21f2b3f53e4fca4eb8728c942d646893b.
This reverts commit f3df87d57e096143670e0fd396e81d43393a2dd2.
This reverts commit ab1dbcecd6f0969976fafd62af34730436ad5944.

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[IR] `IRBuilderBase::CreateOr()`: fix short-circuiting for constant on LHS

There is no guarantee that the constant is on RHS here,
we have to handle both cases.

Refs. https://reviews.llvm.org/D1093

[IR] `IRBuilderBase::CreateOr()`: fix short-circuiting for constant on LHS

There is no guarantee that the constant is on RHS here,
we have to handle both cases.

Refs. https://reviews.llvm.org/D109368#3089809

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[IR] `IRBuilderBase::CreateSelect()`: if cond is a constant i1, short-circuit

While we could emit such a tautological `select`,
it will stick around until the next instsimplify invocation,
which may

[IR] `IRBuilderBase::CreateSelect()`: if cond is a constant i1, short-circuit

While we could emit such a tautological `select`,
it will stick around until the next instsimplify invocation,
which may happen after we count the cost of this redundant `select`.
Which is precisely what happens with loop vectorization legality checks,
and that artificially increases the cost of said checks,
which is bad.

There is prior art for this in `IRBuilderBase::CreateAnd()`/`IRBuilderBase::CreateOr()`.

Refs. https://reviews.llvm.org/D109368#3089809

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[LV] Update more target-specific tests after 23c2f2e6b24d.

Revert "[NFC] remove explicit default value for strboolattr attribute in tests"

This reverts commit bda6e5bee04c75b1f1332b4fd1ac4e8ef6c3c247.

See https://lab.llvm.org/buildbot/#/builders/109/builds

Revert "[NFC] remove explicit default value for strboolattr attribute in tests"

This reverts commit bda6e5bee04c75b1f1332b4fd1ac4e8ef6c3c247.

See https://lab.llvm.org/buildbot/#/builders/109/builds/15424 for instance

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[NFC] remove explicit default value for strboolattr attribute in tests

Since d6de1e1a71406c75a4ea4d5a2fe84289f07ea3a1, no attributes is quivalent to
setting attribute to false.

This is a preliminar

[NFC] remove explicit default value for strboolattr attribute in tests

Since d6de1e1a71406c75a4ea4d5a2fe84289f07ea3a1, no attributes is quivalent to
setting attribute to false.

This is a preliminary commit for https://reviews.llvm.org/D99080

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[NewPM][opt] Run the "default" AA pipeline by default

We tend to assume that the AA pipeline is by default the default AA
pipeline and it's confusing when it's empty instead.

PR48779

Initially rev

[NewPM][opt] Run the "default" AA pipeline by default

We tend to assume that the AA pipeline is by default the default AA
pipeline and it's confusing when it's empty instead.

PR48779

Initially reverted due to BasicAA running analyses in an unspecified
order (multiple function calls as parameters), fixed by fetching
analyses before the call to construct BasicAA.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D95117

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Revert "[NewPM][opt] Run the "default" AA pipeline by default"

This reverts commit be611431cd1f5c826a55b531db92a63e84323866.

Other/new-pm-lto-defaults.ll failing

[NewPM][opt] Run the "default" AA pipeline by default

We tend to assume that the AA pipeline is by default the default AA
pipeline and it's confusing when it's empty instead.

PR48779

Reviewed By:

[NewPM][opt] Run the "default" AA pipeline by default

We tend to assume that the AA pipeline is by default the default AA
pipeline and it's confusing when it's empty instead.

PR48779

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D95117

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[IR] Let IRBuilder's CreateVectorSplat/CreateShuffleVector use poison as placeholder

This patch updates IRBuilder to create insertelement/shufflevector using poison as a placeholder.

Reviewed By: n

[IR] Let IRBuilder's CreateVectorSplat/CreateShuffleVector use poison as placeholder

This patch updates IRBuilder to create insertelement/shufflevector using poison as a placeholder.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D93793

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[LV] Epilogue Vectorization with Optimal Control Flow (Recommit)

This is yet another attempt at providing support for epilogue
vectorization following discussions raised in RFC http://llvm.1065342.n

[LV] Epilogue Vectorization with Optimal Control Flow (Recommit)

This is yet another attempt at providing support for epilogue
vectorization following discussions raised in RFC http://llvm.1065342.n5.nabble.com/llvm-dev-Proposal-RFC-Epilog-loop-vectorization-tt106322.html#none
and reviews D30247 and D88819.

Similar to D88819, this patch achieve epilogue vectorization by
executing a single vplan twice: once on the main loop and a second
time on the epilogue loop (using a different VF). However it's able
to handle more loops, and generates more optimal control flow for
cases where the trip count is too small to execute any code in vector
form.

Reviewed By: SjoerdMeijer

Differential Revision: https://reviews.llvm.org/D89566

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[LV] Epilogue Vectorization with Optimal Control Flow

This is yet another attempt at providing support for epilogue
vectorization following discussions raised in RFC http://llvm.1065342.n5.nabble.co

[LV] Epilogue Vectorization with Optimal Control Flow

This is yet another attempt at providing support for epilogue
vectorization following discussions raised in RFC http://llvm.1065342.n5.nabble.com/llvm-dev-Proposal-RFC-Epilog-loop-vectorization-tt106322.html#none
and reviews D30247 and D88819.

Similar to D88819, this patch achieve epilogue vectorization by
executing a single vplan twice: once on the main loop and a second
time on the epilogue loop (using a different VF). However it's able
to handle more loops, and generates more optimal control flow for
cases where the trip count is too small to execute any code in vector
form.

Reviewed By: SjoerdMeijer

Differential Revision: https://reviews.llvm.org/D89566

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