Cleanup includes: Transform/Scalar

Estimated impact on preprocessor output line:
before: 1062981579
after: 1062494547

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cl

Cleanup includes: Transform/Scalar

Estimated impact on preprocessor output line:
before: 1062981579
after: 1062494547

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D120817

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[SimplifyCFG][PhaseOrdering] Defer lowering switch into an integer range comparison and branch until after at least the IPSCCP

That transformation is lossy, as discussed in
https://github.com/llvm/l

[SimplifyCFG][PhaseOrdering] Defer lowering switch into an integer range comparison and branch until after at least the IPSCCP

That transformation is lossy, as discussed in
https://github.com/llvm/llvm-project/issues/53853
and https://github.com/rust-lang/rust/issues/85133#issuecomment-904185574

This is an alternative to D119839,
which would add a limited IPSCCP into SimplifyCFG.

Unlike lowering switch to lookup, we still want this transformation
to happen relatively early, but after giving a chance for the things
like CVP to do their thing. It seems like deferring it just until
the IPSCCP is enough for the tests at hand, but perhaps we need to
be more aggressive and disable it until CVP.

Fixes https://github.com/llvm/llvm-project/issues/53853
Refs. https://github.com/rust-lang/rust/issues/85133

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D119854

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[llvm] Remove redundant member initialization (NFC)

Identified with readability-redundant-member-init.

[NFC][SimplifyCFG] Extract `performBlockTailMerging()` out of `tailMergeBlocksWithSimilarFunctionTerminators()`

[llvm][NFC] Inclusive language: Reword replace uses of sanity in llvm/lib/Transform comments and asserts

Reworded some comments and asserts to avoid usage of `sanity check/test`

Reviewed By: dblaik

[llvm][NFC] Inclusive language: Reword replace uses of sanity in llvm/lib/Transform comments and asserts

Reworded some comments and asserts to avoid usage of `sanity check/test`

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D114372

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[SimplifyCFG] Sanity assert in iterativelySimplifyCFG

We observe a hang within iterativelySimplifyCFG due to infinite
loop execution. Currently, there is no limit to this loop, so
in case of bug it

[SimplifyCFG] Sanity assert in iterativelySimplifyCFG

We observe a hang within iterativelySimplifyCFG due to infinite
loop execution. Currently, there is no limit to this loop, so
in case of bug it just works forever. This patch adds an assert
that will break it after 1000 iterations if it didn't converge.

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[NPM] Added opt option -print-pipeline-passes.

Added opt option -print-pipeline-passes to print a -passes compatible
string describing the built pass pipeline.

As an example:
$ opt -enable-new-pm=1

[NPM] Added opt option -print-pipeline-passes.

Added opt option -print-pipeline-passes to print a -passes compatible
string describing the built pass pipeline.

As an example:
$ opt -enable-new-pm=1 -adce -licm -simplifycfg -o /dev/null /dev/null -print-pipeline-passes
verify,function(adce),function(loop-mssa(licm)),function(simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts>),verify,BitcodeWriterPass

At the moment this is best-effort only and there are some known
limitations:
- Not all passes accepting parameters will print their parameters
(currently only implemented for simplifycfg).
- Some ClassName to pass-name mappings are not unique.
- Some ClassName to pass-name mappings are missing (e.g.
BitcodeWriterPass).

Differential Revision: https://reviews.llvm.org/D108298

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Revert "[NPM] Added opt option -print-pipeline-passes."

This reverts commit c71869ed4c24b3d4d13e2f83ee2c0104013ca129.

[NPM] Added opt option -print-pipeline-passes.

Added opt option -print-pipeline-passes to print a -passes compatible
string describing the built pass pipeline.

As an example:
$ opt -enable-new-pm=1

[NPM] Added opt option -print-pipeline-passes.

Added opt option -print-pipeline-passes to print a -passes compatible
string describing the built pass pipeline.

As an example:
$ opt -enable-new-pm=1 -adce -licm -simplifycfg -o /dev/null /dev/null -print-pipeline-passes
verify,function(adce),function(loop-mssa(licm)),function(simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-sink-common-insts>),verify,BitcodeWriterPass

At the moment this is best-effort only and there are some known
limitations:
- Not all passes accepting parameters will print their parameters
(currently only implemented for simplifycfg).
- Some ClassName to pass-name mappings are not unique.
- Some ClassName to pass-name mappings are missing (e.g.
BitcodeWriterPass).

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[SimplifyCFG] Tail-merging all blocks with `resume` terminator

Similar to what we already do for `ret` terminators.
As noted by @rnk, clang seems to already generate a single `ret`/`resume`,
so this

[SimplifyCFG] Tail-merging all blocks with `resume` terminator

Similar to what we already do for `ret` terminators.
As noted by @rnk, clang seems to already generate a single `ret`/`resume`,
so this isn't likely to cause widespread changes.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D104849

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[SimplifyCFG] Tail-merging all blocks with `ret` terminator

Based ontop of D104598, which is a NFCI-ish refactoring.
Here, a restriction, that only empty blocks can be merged, is lifted.

Reviewed B

[SimplifyCFG] Tail-merging all blocks with `ret` terminator

Based ontop of D104598, which is a NFCI-ish refactoring.
Here, a restriction, that only empty blocks can be merged, is lifted.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D104597

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[NFCI-ish][SimplifyCFGPass] Rework and generalize `ret` block tail-merging

This changes the approach taken to tail-merge the blocks
to always create a new block instead of trying to reuse some block

[NFCI-ish][SimplifyCFGPass] Rework and generalize `ret` block tail-merging

This changes the approach taken to tail-merge the blocks
to always create a new block instead of trying to reuse some block,
and generalizes it to support dealing not with just the `ret` in the future.

This effectively lifts the CallBr restriction, although this isn't really intentional.
That is the only non-NFC change here, i'm not sure if it's reasonable/feasible to temporarily retain it.

Other restrictions of the transform remain.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D104598

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[NFCI] SimplifyCFGPass: mergeEmptyReturnBlocks(): use DeleteDeadBlocks()

In this case, it does the same thing as the original pattern does.

SimplifyCFG has a few lurking miscompilations about delet

[NFCI] SimplifyCFGPass: mergeEmptyReturnBlocks(): use DeleteDeadBlocks()

In this case, it does the same thing as the original pattern does.

SimplifyCFG has a few lurking miscompilations about deleting blocks that
have their address taken, and consistently using DeleteDeadBlocks() instead
of a hand-rolled pattern will allow to weed those cases out easierly.

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[NewPM] Don't mark AA analyses as preserved

Currently all AA analyses marked as preserved are stateless, not taking
into account their dependent analyses. So there's no need to mark them
as preserve

[NewPM] Don't mark AA analyses as preserved

Currently all AA analyses marked as preserved are stateless, not taking
into account their dependent analyses. So there's no need to mark them
as preserved, they won't be invalidated unless their analyses are.

SCEVAAResults was the one exception to this, it was treated like a
typical analysis result. Make it like the others and don't invalidate
unless SCEV is invalidated.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D102032

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[NFCI][SimplifyCFG] mergeEmptyReturnBlocks(): improve Dominator Tree updating

Same as with previous patches.

[SimplifyCFG] Change 'LoopHeaders' to be ArrayRef<WeakVH>, not a naked set, thus avoiding dangling pointers

If i change it to AssertingVH instead, a number of existing tests fail,
which means we don

[SimplifyCFG] Change 'LoopHeaders' to be ArrayRef<WeakVH>, not a naked set, thus avoiding dangling pointers

If i change it to AssertingVH instead, a number of existing tests fail,
which means we don't consistently remove from the set when deleting blocks,
which means newly-created blocks may happen to appear in that set
if they happen to occupy the same memory chunk as did some block
that was in the set originally.

There are many places where we delete blocks,
and while we could probably consistently delete from LoopHeaders
when deleting a block in transforms located in SimplifyCFG.cpp itself,
transforms located elsewhere (Local.cpp/BasicBlockUtils.cpp) also may
delete blocks, and it doesn't seem good to teach them to deal with it.

Since we at most only ever delete from LoopHeaders,
let's just delegate to WeakVH to do that automatically.

But to be honest, personally, i'm not sure that the idea
behind LoopHeaders is sound.

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[SimplifyCFGPass] iterativelySimplifyCFG(): support lazy DomTreeUpdater

This boils down to how we deal with early-increment iterator
over function's basic blocks: not only we need to early-increment

[SimplifyCFGPass] iterativelySimplifyCFG(): support lazy DomTreeUpdater

This boils down to how we deal with early-increment iterator
over function's basic blocks: not only we need to early-increment,
after that we also need to skip all the blocks
that are scheduled for removal, as per DomTreeUpdater.

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[SimplifyCFGPass] mergeEmptyReturnBlocks(): skip blocks scheduled for removal as per DomTreeUpdater

Thus supporting lazy DomTreeUpdater mode,
where the domtree updates (and thus block removals)
aren

[SimplifyCFGPass] mergeEmptyReturnBlocks(): skip blocks scheduled for removal as per DomTreeUpdater

Thus supporting lazy DomTreeUpdater mode,
where the domtree updates (and thus block removals)
aren't applied immediately, but are delayed
until last possible moment.

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[NFCI][SimplifyCFG] Prefer to add Insert edges before Delete edges into DomTreeUpdater, if reasonable

This has a measurable impact on the number of DomTree recalculations.
While this doesn't handle

[NFCI][SimplifyCFG] Prefer to add Insert edges before Delete edges into DomTreeUpdater, if reasonable

This has a measurable impact on the number of DomTree recalculations.
While this doesn't handle all the cases,
it deals with the most obvious ones.

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[SimplifyCFGPass] mergeEmptyReturnBlocks(): switch to non-permissive DomTree updates

... which requires not inserting an edge that already exists.

[NFCI] SimplifyCFG: switch to non-permissive DomTree updates, where possible

Notably, this doesn't switch *every* case, remaining cases
don't actually pass sanity checks in non-permissve mode,
and t

[NFCI] SimplifyCFG: switch to non-permissive DomTree updates, where possible

Notably, this doesn't switch *every* case, remaining cases
don't actually pass sanity checks in non-permissve mode,
and therefore require further analysis.

Note that SimplifyCFG still defaults to not preserving DomTree by default,
so this is effectively a NFC change.

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[SimplifyCFGPass] Ensure that DominatorTreeWrapperPass is init'd before SimplifyCFG

It's probably better than hoping that it will happen to be
already initialized.

[SimplifyCFG] Teach mergeEmptyReturnBlocks() to preserve DomTree

A first real transformation that didn't already knew how to do that,
but it's pretty tame - either change successor of all the predec

[SimplifyCFG] Teach mergeEmptyReturnBlocks() to preserve DomTree

A first real transformation that didn't already knew how to do that,
but it's pretty tame - either change successor of all the predecessors
of a block and carefully delay deletion of the block until afterwards
the DomTree updates are appled, or add a successor to the block.

There wasn't a great test coverage for this, so i added extra, to be sure.

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[SimplifyCFG] MergeBlockIntoPredecessor() already knows how to preserve DomTree

... so just ensure that we pass DomTreeUpdater it into it.

Fixes DomTree preservation for a large number of tests,
al

[SimplifyCFG] MergeBlockIntoPredecessor() already knows how to preserve DomTree

... so just ensure that we pass DomTreeUpdater it into it.

Fixes DomTree preservation for a large number of tests,
all of which are marked as such so that they do not regress.

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[SimplifyCFG] removeUnreachableBlocks() already knows how to preserve DomTree

... so just ensure that we pass DomTreeUpdater it into it.

Apparently, there were no dedicated tests just for that func

[SimplifyCFG] removeUnreachableBlocks() already knows how to preserve DomTree

... so just ensure that we pass DomTreeUpdater it into it.

Apparently, there were no dedicated tests just for that functionality,
so i'm adding one here.

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