[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] Remove the canonicalization of `trunc` to `i1` (#84628)

Remove the canonicalization of `trunc` to `i1` according to the
suggestion of
https://github.com/llvm/llvm-project/pull/83829#

[InstCombine] Remove the canonicalization of `trunc` to `i1` (#84628)

Remove the canonicalization of `trunc` to `i1` according to the
suggestion of
https://github.com/llvm/llvm-project/pull/83829#issuecomment-1986801166

https://github.com/llvm/llvm-project/blob/a84e66a92d7b97f68aa3ae7d2c5839f3fb0d291d/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp#L737-L745

Alive2: https://alive2.llvm.org/ce/z/cacYVA

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[LLVM][tests/Transforms/InstCombine] Convert instances of ConstantExpr based splats to use splat().

This is mostly NFC but some output does change due to consistently
inserting into poison rather th

[LLVM][tests/Transforms/InstCombine] Convert instances of ConstantExpr based splats to use splat().

This is mostly NFC but some output does change due to consistently
inserting into poison rather than undef and using i64 as the index
type for inserts.

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[InstCombine] Infer disjoint flag on Or instructions. (#72912)

The disjoint flag was recently added to IR in #72583

We already set it when we turn an add into an or. This patch sets it on Ors tha

[InstCombine] Infer disjoint flag on Or instructions. (#72912)

The disjoint flag was recently added to IR in #72583

We already set it when we turn an add into an or. This patch sets it on Ors that weren't converted from an Add.

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[InstCombine] Allow simplify demanded transformations on scalable vectors

Differential Revision: https://reviews.llvm.org/D136475

[instcombine] Add basic test coverage for demanded bits of scalable vectors

[InstCombine] fold mul with masked low bit operand to trunc+select

https://alive2.llvm.org/ce/z/o7rQ5q

This shows an extra instruction in some cases, but that is
caused by an existing canonicalizat

[InstCombine] fold mul with masked low bit operand to trunc+select

https://alive2.llvm.org/ce/z/o7rQ5q

This shows an extra instruction in some cases, but that is
caused by an existing canonicalization of trunc -> and+icmp.

Codegen should be better for any target where a multiply is
more costly than the most simple ALU op.

This ends up producing the requested x86 asm from issue #55618,
but it's not the same IR. We are missing a canonicalization
from the negate+mask pattern to the trunc+select created here.

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[InstCombine] Fold a mul with bool value into and

Fixes https://github.com/llvm/llvm-project/issues/55599
X * Y --> X & Y, iff X, Y can be only {0, 1}.
https://alive2.llvm.org/ce/z/_RsTKF

Reviewe

[InstCombine] Fold a mul with bool value into and

Fixes https://github.com/llvm/llvm-project/issues/55599
X * Y --> X & Y, iff X, Y can be only {0, 1}.
https://alive2.llvm.org/ce/z/_RsTKF

Reviewed By: spatel, nikic

Differential Revision: https://reviews.llvm.org/D126040

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[tests] precommit tests for D126040

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D126356

[ValueTracking] Add support for X*X self-multiplication

D108992 added KnownBits handling for 'Quadratic Reciprocity' self-multiplication patterns (bit[1] == 0), which can be used for non-undef value

[ValueTracking] Add support for X*X self-multiplication

D108992 added KnownBits handling for 'Quadratic Reciprocity' self-multiplication patterns (bit[1] == 0), which can be used for non-undef values (poison is OK).

This patch adds noundef selfmultiply handling to value tracking so demanded bits patterns can make use of it.

Differential Revision: https://reviews.llvm.org/D117995

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[InstCombine] generalize 2 LSB of demanded bits for X*X

This is a follow-up suggested in D119060.
Instead of checking each of the bottom 2 bits individually,
we can check them together and handle th

[InstCombine] generalize 2 LSB of demanded bits for X*X

This is a follow-up suggested in D119060.
Instead of checking each of the bottom 2 bits individually,
we can check them together and handle the possibility that
we demand both together.

https://alive2.llvm.org/ce/z/C2ihC2

Differential Revision: https://reviews.llvm.org/D119139

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[InstCombine] add test for demanded 2 low bits of X*X; NFC

[InstCombine] SimplifyDemandedBits - mul(x,x) is odd iff x is odd

https://alive2.llvm.org/ce/z/AXPr3k

[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] Add mul(x,x) tests showing miscompile

As raised by @efriedma on D117995 - the source must not be undef to demand any bits in mul(x,x) other than bit[1]

https://alive2.llvm.org/ce/z/Cx

[InstCombine] Add mul(x,x) tests showing miscompile

As raised by @efriedma on D117995 - the source must not be undef to demand any bits in mul(x,x) other than bit[1]

https://alive2.llvm.org/ce/z/Cxkjen

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[InstCombine] SimplifyDemandedBits - mul(x,x) - if only demand bit[1] then fold to zero

This is a translation of the fold added to codegen with:
2d1390efbe61

Part of solving issue #48027

[InstCombine] try to fold one-demanded-bit-of-multiply

This is a generalization of the icmp fold in D118061 (and that can be abandoned).
We're looking for a disguised form of "odd * odd must be odd"

[InstCombine] try to fold one-demanded-bit-of-multiply

This is a generalization of the icmp fold in D118061 (and that can be abandoned).
We're looking for a disguised form of "odd * odd must be odd".
Some Alive2 proofs to show correctness:
https://alive2.llvm.org/ce/z/60Y8hz
https://alive2.llvm.org/ce/z/HfAP6R

Differential Revision: https://reviews.llvm.org/D118539

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[InstCombine] add tests for potential mul demanded bits fold; NFC

This is discussed as an enhancement in D118539.

[InstCombine] add tests for demanded bit of mul; NFC

[InstCombine] Add test coverage for PR48683

D108992 added self-multiply handling to KnownBits::mul but we don't use it yet..

Revert "Temporarily Revert "Add basic loop fusion pass.""

The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552

[InstCombine] regenerate checks

utils/update_test_checks.py was improved with:
http://reviews.llvm.org/rL265414
to CHECK-NEXT the first line of the IR function. This ensures that nothing bad
has hap

[InstCombine] regenerate checks

utils/update_test_checks.py was improved with:
http://reviews.llvm.org/rL265414
to CHECK-NEXT the first line of the IR function. This ensures that nothing bad
has happened before that.

llvm-svn: 265417

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[InstCombine] use FileCheck for better checking

(testing script for autogeneration of check lines)

llvm-svn: 264434

Change tests from "opt %s" to "opt < %s" so that opt doesn't see the
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally ma

Change tests from "opt %s" to "opt < %s" so that opt doesn't see the
input filename so that opt doesn't print the input filename in the
output so that grep lines in the tests don't unintentionally match
strings in the input filename.

llvm-svn: 81537

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