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

[InstCombine] Fold `(icmp pred (trunc nuw/nsw X), C)` -> `(icmp pred X, (zext/sext C))`

This is valid as long as the sign of the wrap flag doesn't differ from
the sign of the `pred`.

Proofs: https:

[InstCombine] Fold `(icmp pred (trunc nuw/nsw X), C)` -> `(icmp pred X, (zext/sext C))`

This is valid as long as the sign of the wrap flag doesn't differ from
the sign of the `pred`.

Proofs: https://alive2.llvm.org/ce/z/35NsrR

NB: The online Alive2 hasn't been updated with `trunc nuw/nsw`
support, so the proofs must be reproduced locally.

Closes #87935

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[InstCombine] Add tests for folding `(icmp pred (trunc nuw/nsw X), C)`; NFC

[InstCombine] add nuw to any (1<<x)

https://alive2.llvm.org/ce/z/9EjDKE

This was mentioned as a missing fold in D139598.

It can unlock follow-on folds in some cases.
This verifies one of the chang

[InstCombine] add nuw to any (1<<x)

https://alive2.llvm.org/ce/z/9EjDKE

This was mentioned as a missing fold in D139598.

It can unlock follow-on folds in some cases.
This verifies one of the changed tests:
https://alive2.llvm.org/ce/z/B_btDM

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[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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[InstCombine] Add one more test for shl_trunc_icmp. nfc

[InstCombine] Precommit tests for shl_trunc_icmp. nfc

[InstCombine] fold icmp of truncated left shift, part 2

(trunc (1 << Y) to iN) == 2**C --> Y == C
(trunc (1 << Y) to iN) != 2**C --> Y != C
https://alive2.llvm.org/ce/z/xnFPo5

Follow-up to d9e1f9d7

[InstCombine] fold icmp of truncated left shift, part 2

(trunc (1 << Y) to iN) == 2**C --> Y == C
(trunc (1 << Y) to iN) != 2**C --> Y != C
https://alive2.llvm.org/ce/z/xnFPo5

Follow-up to d9e1f9d7591b0d3e4d. This was a suggested
enhancement mentioned in issue #51889.

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[InstCombine] Fold icmp of truncated left shift

(trunc (1 << Y) to iN) == 0 --> Y u>= N
(trunc (1 << Y) to iN) != 0 --> Y u< N

These can be generalized in several ways as noted by the TODO
items,

[InstCombine] Fold icmp of truncated left shift

(trunc (1 << Y) to iN) == 0 --> Y u>= N
(trunc (1 << Y) to iN) != 0 --> Y u< N

These can be generalized in several ways as noted by the TODO
items, but this handles the pattern in the motivating bug report.

Fixes #51889

Differential Revision: https://reviews.llvm.org/D115480

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[InstCombine] add tests for icmp-of-trunc; NFC

[InstCombine] canonicalize 'icmp (trunc X), C' to 'icmp (X & Mask), C'

I looked at canonicalizing in the other direction, but that causes
many potential regressions and infinite loops because we alr

[InstCombine] canonicalize 'icmp (trunc X), C' to 'icmp (X & Mask), C'

I looked at canonicalizing in the other direction, but that causes
many potential regressions and infinite loops because we already
(possibly wrongly) canonicalize "trunc X to i1" into an and+icmp.

This has a data layout restriction to avoid creating illegal
mask instructions, but we could remove that if we can show
that the backend can undo this when needed.

The motivating example from issue #56119 is modeled by the
PhaseOrdering test.

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[InstCombine] add tests for icmp (trunc X), C; NFC

[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] use decomposeBitTestICmp to make icmp (trunc X), C more consistent

This is a follow-on suggested in D112634.
Two folds that were added with that patch are subsumed in the call to
decom

[InstCombine] use decomposeBitTestICmp to make icmp (trunc X), C more consistent

This is a follow-on suggested in D112634.
Two folds that were added with that patch are subsumed in the call to
decomposeBitTestICmp, and two other folds are potentially inverted.

The deleted folds were very specialized by instcombine standards
because they were restricted to legal integer types based on the data
layout. This generalizes the canonical form independent of target/types.

This change has a reasonable chance of exposing regressions either in
IR or codegen, but I don't have any evidence for either of those yet.
A spot check of asm across several in-tree targets shows variations
that I expect are mostly neutral.

We have one improvement in an existing IR test that I noted with a
comment. Using mask ops might also make more code match with D114272.

Differential Revision: https://reviews.llvm.org/D114386

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[InstCombine] canonicalize icmp with trunc op into mask and cmp, part 2

If C is a high-bit mask:
(trunc X) u< C --> (X & C) != C (are any masked-high-bits clear?)

If C is low-bit mask:
(trunc X) u>

[InstCombine] canonicalize icmp with trunc op into mask and cmp, part 2

If C is a high-bit mask:
(trunc X) u< C --> (X & C) != C (are any masked-high-bits clear?)

If C is low-bit mask:
(trunc X) u> C --> (X & ~C) != 0 (are any masked-high-bits set?)

If C is not-of-power-of-2 (one clear bit):
(trunc X) u> C --> (X & (C+1)) == C+1 (are all masked-high-bits set?)

This extends the fold added with:
acabad9ff6bf (https://alive2.llvm.org/ce/z/aFr7qV)

Using decomposeBitTestICmp() to generalize this is a planned follow-up, but that requires removing an inverse fold.

Here are Alive2 generalizations for these folds:
https://alive2.llvm.org/ce/z/u-ZpC_ (ult, the previous patch)
https://alive2.llvm.org/ce/z/YsuAu2 (ult, this patch)
https://alive2.llvm.org/ce/z/ekktQP (ugt, low bitmask)
https://alive2.llvm.org/ce/z/pJY9wR (ugt, one clear bit)

Differential Revision: https://reviews.llvm.org/D112634

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[InstCombine] add signbit tests for icmp with trunc; NFC

[InstCombine] adjust test for icmp fold; NFC

I missed that the bitwidth changed from the previous test in the sequence.

[InstCombine] add tests for icmp with trunc op; NFC

[InstCombine] add tests for icmp with trunc operand; NFC

[InstCombine] try to canonicalize icmp with trunc op into mask and cmp

The motivating test is based on:
https://llvm.org/PR52260

We have better analysis for X == 0, so try harder to form that.

[InstCombine] add tests for icmp with trunc op; NFC