[LLVM][IR] Use splat syntax when printing Constant[Data]Vector. (#112548)

[InstCombine] Remove some of the complexity-based canonicalization (#91185)

The idea behind this canonicalization is that it allows us to handle less
patterns, because we know that some will be can

[InstCombine] Remove some of the complexity-based canonicalization (#91185)

The idea behind this canonicalization is that it allows us to handle less
patterns, because we know that some will be canonicalized away. This is
indeed very useful to e.g. know that constants are always on the right.

However, this is only useful if the canonicalization is actually
reliable. This is the case for constants, but not for arguments: Moving
these to the right makes it look like the "more complex" expression is
guaranteed to be on the left, but this is not actually the case in
practice. It fails as soon as you replace the argument with another
instruction.

The end result is that it looks like things correctly work in tests,
while they actually don't. We use the "thwart complexity-based
canonicalization" trick to handle this in tests, but it's often a
challenge for new contributors to get this right, and based on the
regressions this PR originally exposed, we clearly don't get this right
in many cases.

For this reason, I think that it's better to remove this complexity
canonicalization. It will make it much easier to write tests for
commuted cases and make sure that they are handled.

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[IR] Remove support for icmp and fcmp constant expressions (#93038)

Remove support for the icmp and fcmp constant expressions.

This is part of:
https://discourse.llvm.org/t/rfc-remove-most-const

[IR] Remove support for icmp and fcmp constant expressions (#93038)

Remove support for the icmp and fcmp constant expressions.

This is part of:
https://discourse.llvm.org/t/rfc-remove-most-constant-expressions/63179

As usual, many of the updated tests will no longer test what they were
originally intended to -- this is hard to preserve when constant
expressions get removed, and in many cases just impossible as the
existence of a specific kind of constant expression was the cause of the
issue in the first place.

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Reapply [IR] Avoid creating icmp/fcmp constant expressions (#92885)

Reapply after https://github.com/llvm/llvm-project/pull/93548,
which should address the lldb failure on macos.

-----

Do not crea

Reapply [IR] Avoid creating icmp/fcmp constant expressions (#92885)

Reapply after https://github.com/llvm/llvm-project/pull/93548,
which should address the lldb failure on macos.

-----

Do not create icmp/fcmp constant expressions in IRBuilder etc anymore,
i.e. treat them as "undesirable". This is in preparation for removing
them entirely.

Part of:
https://discourse.llvm.org/t/rfc-remove-most-constant-expressions/63179

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Revert "[IR] Avoid creating icmp/fcmp constant expressions" (#93087)

Reverts llvm/llvm-project#92885 due to LLDB CI breakages.

[IR] Avoid creating icmp/fcmp constant expressions (#92885)

Do not create icmp/fcmp constant expressions in IRBuilder etc anymore,
i.e. treat them as "undesirable". This is in preparation for remov

[IR] Avoid creating icmp/fcmp constant expressions (#92885)

Do not create icmp/fcmp constant expressions in IRBuilder etc anymore,
i.e. treat them as "undesirable". This is in preparation for removing
them entirely.

Part of:
https://discourse.llvm.org/t/rfc-remove-most-constant-expressions/63179

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[InstCombine] Regenerate all test checks (NFC)

Due to an improvement to name preservation, a lot of InstCombine
tests now show spurious diffs when regenerated.

Rather than regenerating individual f

[InstCombine] Regenerate all test checks (NFC)

Due to an improvement to name preservation, a lot of InstCombine
tests now show spurious diffs when regenerated.

Rather than regenerating individual files when they get touched,
mass-regenerate all UTC-based InstCombine tests. I have then reset
a number of files showing suspicious diffs where the UTC output
has clearly been manually adjusted. I apologize if I missed
anything in the mass of changes.

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[InstCombine] use logical-and matcher to avoid crash

Follow-on to:
ec0b406e16c44f1554

This should prevent crashing for example like issue #58552
by not matching a select-of-vectors-with-scalar-cond

[InstCombine] use logical-and matcher to avoid crash

Follow-on to:
ec0b406e16c44f1554

This should prevent crashing for example like issue #58552
by not matching a select-of-vectors-with-scalar-condition.

The test that shows a regression seems unlikely to occur
in real code.

This also picks up an optimization in the case where a real
(bitwise) logic op is used. We could already convert some
similar select ops to real logic via impliesPoison(), so
we don't see more diffs on commuted tests. Using commutative
matchers (when safe) might also handle one of the TODO tests.

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[InstCombine] add tests for logical-and / logical-or folds; NFC

Similar to 29661fe94bf12ced1 - there are matching
deficiencies and a potential crash lurking in
these patterns.

[InstCombine] use logical-or matcher to avoid crash

This should prevent crashing for the example in issue #58552
by not matching a select-of-vectors-with-scalar-condition.

A similar change is likel

[InstCombine] use logical-or matcher to avoid crash

This should prevent crashing for the example in issue #58552
by not matching a select-of-vectors-with-scalar-condition.

A similar change is likely needed for the related fold to
properly fix that kind of bug.

The test that shows a regression seems unlikely to occur
in real code.

This also picks up an optimization in the case where a real
(bitwise) logic op is used. We could already convert some
similar select ops to real logic via impliesPoison(), so
we don't see more diffs on commuted tests. Using commutative
matchers (when safe) might also handle one of the TODO tests.

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[InstCombine] add tests for logical-and / logical-or folds; NFC

[InstCombine] allow more commutative matches for logical-and to select fold

This is a sibling transform to the fold just above it. That was changed
to allow the corresponding commuted patterns with:

[InstCombine] allow more commutative matches for logical-and to select fold

This is a sibling transform to the fold just above it. That was changed
to allow the corresponding commuted patterns with:
307307456277
e1bd759ea567
8628e6df7000

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[InstCombine] use freeze to enable poison-safe logic->select fold

Without a freeze, this transform can leak poison to the output:
https://alive2.llvm.org/ce/z/GJuF9i

This makes the transform as uni

[InstCombine] use freeze to enable poison-safe logic->select fold

Without a freeze, this transform can leak poison to the output:
https://alive2.llvm.org/ce/z/GJuF9i

This makes the transform as uniform as possible, and it can help
reduce patterns like issue #58313 (although that particular
example probably still needs another transform).

Differential Revision: https://reviews.llvm.org/D136527

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[InstCombine] add test for logical-ands to select; NFC

[InstCombine] allow more matches for logical-ands --> select

This allows patterns with real 'and' instructions because
those are safe to transform:
https://alive2.llvm.org/ce/z/7-U_Ak

[InstCombine] allow more commutative matches for logical-and to select fold

When the common value is part of either select condition,
this is safe to reduce. Otherwise, it is not poison-safe
(with t

[InstCombine] allow more commutative matches for logical-and to select fold

When the common value is part of either select condition,
this is safe to reduce. Otherwise, it is not poison-safe
(with the select form of the pattern):
https://alive2.llvm.org/ce/z/FxQTzB

This is another patch motivated by issue #58313.

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[InstCombine] allow some commutative matches for logical-and to select fold

This is obviously correct for real logic instructions,
and it also works for the poison-safe variants that use
selects:
ht

[InstCombine] allow some commutative matches for logical-and to select fold

This is obviously correct for real logic instructions,
and it also works for the poison-safe variants that use
selects:
https://alive2.llvm.org/ce/z/wyHiwX

This is motivated by the lack of 'xor' folding seen in issue #58313.
This more general fold should help reduce some of those patterns,
but I'm not sure if this specific case does anything for that
particular example.

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[InstCombine] match logical and/or more generally in fold to select

This allows the regular bitwise logic opcodes in addition to the
poison-safe select variants:
https://alive2.llvm.org/ce/z/8xB9gy

[InstCombine] match logical and/or more generally in fold to select

This allows the regular bitwise logic opcodes in addition to the
poison-safe select variants:
https://alive2.llvm.org/ce/z/8xB9gy

Handling commuted variants safely is likely trickier, so that's
left to another patch.

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[InstCombine] add tests for logical selects; NFC

[test][InstCombine] Update some test cases to use opaque pointers

These tests cases were converted using the script at
https://gist.github.com/nikic/98357b71fd67756b0f064c9517b62a34

Differential Re

[test][InstCombine] Update some test cases to use opaque pointers

These tests cases were converted using the script at
https://gist.github.com/nikic/98357b71fd67756b0f064c9517b62a34

Differential Revision: https://reviews.llvm.org/D135094

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[test] Use -passes=instcombine instead of -instcombine in lots of tests. NFC

Another step moving away from the deprecated syntax of specifying
pass pipeline in opt.

Differential Revision: https://r

[test] Use -passes=instcombine instead of -instcombine in lots of tests. NFC

Another step moving away from the deprecated syntax of specifying
pass pipeline in opt.

Differential Revision: https://reviews.llvm.org/D119081

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[InstCombine] Fully disable select to and/or i1 folding

This is a patch that disables the poison-unsafe select -> and/or i1 folding.

It has been blocking D72396 and also has been the source of a fe

[InstCombine] Fully disable select to and/or i1 folding

This is a patch that disables the poison-unsafe select -> and/or i1 folding.

It has been blocking D72396 and also has been the source of a few miscompilations
described in llvm.org/pr49688 .
D99674 conditionally blocked this folding and successfully fixed the latter one.
The former one was still blocked, and this patch addresses it.

Note that a few test functions that has `_logical` suffix are now deoptimized.
These are created by @nikic to check the impact of disabling this optimization
by copying existing original functions and replacing and/or with select.

I can see that most of these are poison-unsafe; they can be revived by introducing
freeze instruction. I left comments at fcmp + select optimizations (or-fcmp.ll, and-fcmp.ll)
because I think they are good targets for freeze fix.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D101191

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[InstCombine] Fold more select of selects using isImpliedCondition

This is a simple folding that does these:

```
select x_inv, true, (select y, x, false)
=>
select x_inv, true, y
```
https://alive2

[InstCombine] Fold more select of selects using isImpliedCondition

This is a simple folding that does these:

```
select x_inv, true, (select y, x, false)
=>
select x_inv, true, y
```
https://alive2.llvm.org/ce/z/-STJ2d

```
select (select y, x, false), true, x_inv
=>
select y, true, x_inv
```
https://alive2.llvm.org/ce/z/6ruYt6

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D101807

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[InstCombine] Precommit tests for D101807 (NFC)

[InstCombine] Add a few more patterns for folding select of select

This is a patch that folds select of select to salvage some optimizations after select -> and/or folding is disabled.

```
select (

[InstCombine] Add a few more patterns for folding select of select

This is a patch that folds select of select to salvage some optimizations after select -> and/or folding is disabled.

```
select (select a, true, b), c, false -> select a, c, false
select c, (select a, true, b), false -> select c, a, false
if c implies that b is false (isImpliedCondition).
```
https://alive2.llvm.org/ce/z/ANatjt, https://alive2.llvm.org/ce/z/rv8zTB

```
sel (sel c, a, false), true, (sel !c, b, false) -> sel c, a, b
sel (sel !c, a, false), true, (sel c, b, false) -> sel c, b, a
```
https://alive2.llvm.org/ce/z/U2kp-t, https://alive2.llvm.org/ce/z/bc88EE

See D101191

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D101375

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