[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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[InstCombine] Fold `select (A &/| B), T, F` if `select B, T, F` is foldable (#76621)

This patch does the following folds:
```
(select A && B, T, F) -> (select A, (select B, T, F), F)
(select A ||

[InstCombine] Fold `select (A &/| B), T, F` if `select B, T, F` is foldable (#76621)

This patch does the following folds:
```
(select A && B, T, F) -> (select A, (select B, T, F), F)
(select A || B, T, F) -> (select A, T, (select B, T, F))
```
if `(select B, T, F)` can be folded into a value or a canonicalized SPF.
Alive2: https://alive2.llvm.org/ce/z/4Bdrbu

The original motivation of this patch is to simplify the following
pattern:
```
%.sroa.speculated.i = tail call i64 @llvm.umax.i64(i64 %sub.ptr.div.i.i, i64 1)
%add.i = add i64 %.sroa.speculated.i, %sub.ptr.div.i.i
%cmp7.i = icmp ult i64 %add.i, %sub.ptr.div.i.i
%cmp9.i = icmp ugt i64 %add.i, 1152921504606846975
%or.cond.i = or i1 %cmp7.i, %cmp9.i
%cond.i = select i1 %or.cond.i, i64 1152921504606846975, i64 %add.i
->
%.sroa.speculated.i = tail call i64 @llvm.umax.i64(i64 %sub.ptr.div.i.i, i64 1)
%add.i = add i64 %.sroa.speculated.i, %sub.ptr.div.i.i
%cmp7.i = icmp ult i64 %add.i, %sub.ptr.div.i.i
%max = call i64 @llvm.umax.i64(i64 %add.i, 1152921504606846975)
%cond.i = select i1 %cmp7.i, i64 1152921504606846975, i64 %max
```
The later form has a better codegen for some backends. It is also more
analysis-friendly than the original one.
Godbolt: https://godbolt.org/z/eK6eb5jf1
Alive2: https://alive2.llvm.org/ce/z/VHlxL2

Compile-time impact:
http://llvm-compile-time-tracker.com/compare.php?from=7c71d3996a72b9b024622f23bf556539b961c88c&to=638ce8666fadaca1ab2639a3c2bc52a4a8508f40&stat=instructions:u

|stage1-O3|stage1-ReleaseThinLTO|stage1-ReleaseLTO-g|stage1-O0-g|stage2-O3|stage2-O0-g|stage2-clang|
|--|--|--|--|--|--|--|
|+0.02%|-0.00%|+0.02%|-0.03%|-0.00%|-0.05%|-0.00%|

It is an alternative to #76203 and #76363 because we can simplify
`select (icmp eq/ne a, b), a, b` into `b` or `a`.
Fixes #75784.
Fixes #76043.

Thank @XChy for providing additional tests.
Co-authored-by: XChy <xxs_chy@outlook.com>

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Reland "[InstCombine] Fold nested selects"

The change was reverted because one of the changes were suspected of
causing a miscompile, but said miscompile was (confirmed to be) fixed
before the rever

Reland "[InstCombine] Fold nested selects"

The change was reverted because one of the changes were suspected of
causing a miscompile, but said miscompile was (confirmed to be) fixed
before the revert happened, by 07ecdd9b1a8af51f07d5f4dfe46845c801482a39.

https://alive2.llvm.org/ce/z/GjCXkB
https://alive2.llvm.org/ce/z/Guz2tt

Fixes https://github.com/llvm/llvm-project/issues/59393

This reverts commit d73383c145ea83d25063246e0c34f5a41fd35293,
and relands commmit 9ddff66d0c9c3e18d56e6b20aa26a2a8cdfb6d2b.

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[InstCombine] Fold logic-and/logic-or by distributive laws part2

Follow up https://reviews.llvm.org/D139408, support `and/or+select` patterns
X && Z || Y && Z --> (X || Y) && Z
https://alive2.llvm.o

[InstCombine] Fold logic-and/logic-or by distributive laws part2

Follow up https://reviews.llvm.org/D139408, support `and/or+select` patterns
X && Z || Y && Z --> (X || Y) && Z
https://alive2.llvm.org/ce/z/EMCkBG
https://alive2.llvm.org/ce/z/Q-YRvr
https://alive2.llvm.org/ce/z/SFkVQc
https://alive2.llvm.org/ce/z/S9MCuJ
https://alive2.llvm.org/ce/z/KZ7zzz

(X || Z) && (Y || Z) --> (X && Y) || Z
https://alive2.llvm.org/ce/z/Ggpa8-
https://alive2.llvm.org/ce/z/nhQRLY
https://alive2.llvm.org/ce/z/zpmEnq
https://alive2.llvm.org/ce/z/7omsrf
https://alive2.llvm.org/ce/z/CWBzBp

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D139630

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[InstCombine] add more tests into select-factorize; NFC

Revert "[InstCombine] Fold nested selects"

One of these two changes is exposing (or causing) some more miscompiles.
A reproducer is in progress, so reverting until resolved.

This reverts commit 9dd

Revert "[InstCombine] Fold nested selects"

One of these two changes is exposing (or causing) some more miscompiles.
A reproducer is in progress, so reverting until resolved.

This reverts commit 9ddff66d0c9c3e18d56e6b20aa26a2a8cdfb6d2b.

show more ...

[InstCombine] Fold logic-and/logic-or by distributive laws

X && Z || Y && Z --> (X || Y) && Z
https://alive2.llvm.org/ce/z/nM6kZb

(X || Z) && (Y || Z) --> (X && Y) || Z
https://alive2.llvm.org/ce/z

[InstCombine] Fold logic-and/logic-or by distributive laws

X && Z || Y && Z --> (X || Y) && Z
https://alive2.llvm.org/ce/z/nM6kZb

(X || Z) && (Y || Z) --> (X && Y) || Z
https://alive2.llvm.org/ce/z/_EWLRR

Fix: https://github.com/llvm/llvm-project/issues/53861

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D139408

show more ...

[InstCombine] Fold nested selects

https://alive2.llvm.org/ce/z/GjCXkB
https://alive2.llvm.org/ce/z/Guz2tt

Fixes https://github.com/llvm/llvm-project/issues/59393

[Instcombine] Add baseline tests for logic-and/logic-or factorization; NFC