[InstCombine] Generalize and consolidate phi translation check (#106051)

The foldOpIntoPhi() transforms requires all operands to be
phi-translatable. This can be the case either because they are ph

[InstCombine] Generalize and consolidate phi translation check (#106051)

The foldOpIntoPhi() transforms requires all operands to be
phi-translatable. This can be the case either because they are phi nodes
in the same block, or because the operand dominates the block.

Currently, most callers of foldOpIntoPhi() satisfy this pre-condition by
requiring a constant operand, which trivially dominates everything. Only
selects had handling for variable operands.

Move this logic into foldOpIntoPhi(), so things are handled correctly if
other callers are generalized. Also make the implementation a bit more
general by querying the dominator tree.

show more ...

[InstCombine] Add additional tests for select of phi transform (NFC)

Test coverage for the canSelectOperandBeMappingIntoPredBlock()
logic.

[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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[InstCombine] If inst in unreachable refers to an inst change it to poison (#78444)

Instructions in unreachable basic blocks are removed, but terminators
are not. In this case, even instructions th

[InstCombine] If inst in unreachable refers to an inst change it to poison (#78444)

Instructions in unreachable basic blocks are removed, but terminators
are not. In this case, even instructions that are only referenced by
a terminator, such as a return instruction, cannot be processed
properly.

This patch changes the operand of a return instruction in an
unreachable basic block to poison if it refers to the instruction,
allowing the instruction to be properly processed.

Fixes #65107.

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[ConstExpr] Avoid creation of select constant expressions

These expressions will now only be created if explicitly requested
in IR/bitcode (and by LowerTypeTests, which has a tricky to remove
use).

[ConstExpr] Avoid creation of select constant expressions

These expressions will now only be created if explicitly requested
in IR/bitcode (and by LowerTypeTests, which has a tricky to remove
use).

This is in preparation for removing these expressions entirely,
but also fixes #60983 in the meantime.

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Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify

Relative to the previous attempt, this is rebased over the
InstSimplify fix in ac74e7a7806480a000c9a3502405c3dedd8810de,
which addres

Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify

Relative to the previous attempt, this is rebased over the
InstSimplify fix in ac74e7a7806480a000c9a3502405c3dedd8810de,
which addresses the miscompile reported in PR58401.

-----

foldOpIntoPhi() currently only folds operations into the phi if all
but one operands constant-fold. The two exceptions to this are freeze
and select, where we allow more general simplification.

This patch makes foldOpIntoPhi() generally simplification based and
removes all the instruction-specific logic. We just try to simplify
the instruction for each operand, and for the (potentially) one
non-simplified operand, we move it into the new block with adjusted
operands.

This fixes https://github.com/llvm/llvm-project/issues/57448, which
was my original motivation for the change.

Differential Revision: https://reviews.llvm.org/D134954

show more ...

Revert "Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify"

This reverts commit 333246b48ea4a70842e78c977cc92d365720465f.

It looks like this patch causes a mis-compile:
https://github

Revert "Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify"

This reverts commit 333246b48ea4a70842e78c977cc92d365720465f.

It looks like this patch causes a mis-compile:
https://github.com/llvm/llvm-project/issues/58401

Fixes #58401.

show more ...

Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify

Relative to the previous attempt, this adjusts simplification to
use the correct context instruction: We need to use the terminator
o

Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify

Relative to the previous attempt, this adjusts simplification to
use the correct context instruction: We need to use the terminator
of the incoming block, not the original instruction.

-----

foldOpIntoPhi() currently only folds operations into the phi if all
but one operands constant-fold. The two exceptions to this are freeze
and select, where we allow more general simplification.

This patch makes foldOpIntoPhi() generally simplification based and
removes all the instruction-specific logic. We just try to simplify
the instruction for each operand, and for the (potentially) one
non-simplified operand, we move it into the new block with adjusted
operands.

This fixes https://github.com/llvm/llvm-project/issues/57448, which
was my original motivation for the change.

Differential Revision: https://reviews.llvm.org/D134954

show more ...

Revert "Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify"

This reverts commit e94619b955104841cc2a4a6febe4025ee140194e.

Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify

The infinite loop seen on buildbots should be fixed by
11897708c0229c92802e747564e7c34b722f045f (assuming there are not
multiple infi

Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify

The infinite loop seen on buildbots should be fixed by
11897708c0229c92802e747564e7c34b722f045f (assuming there are not
multiple infinite combine loops...)

-----

foldOpIntoPhi() currently only folds operations into the phi if all
but one operands constant-fold. The two exceptions to this are freeze
and select, where we allow more general simplification.

This patch makes foldOpIntoPhi() generally simplification based and
removes all the instruction-specific logic. We just try to simplify
the instruction for each operand, and for the (potentially) one
non-simplified operand, we move it into the new block with adjusted
operands.

This fixes https://github.com/llvm/llvm-project/issues/57448, which
was my original motivation for the change.

Differential Revision: https://reviews.llvm.org/D134954

show more ...

Revert "Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify"

This reverts commit e1dd2cd063785ea3a6004c8d173f13113b1b8265 because
the original commit b20e34b39f72f2be035dfb7367b6880fd2c

Revert "Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify"

This reverts commit e1dd2cd063785ea3a6004c8d173f13113b1b8265 because
the original commit b20e34b39f72f2be035dfb7367b6880fd2cf213a had
a dramatic increase in the build time of RTfuzzer, which caused Fuchsia
Clang toolchain builders to timeout:
https://luci-milo.appspot.com/ui/p/fuchsia/builders/toolchain.ci/clang-linux-x64/b8801248587754572961/overview

show more ...

Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify

Reapply with a fix for the case where an operand simplified back
to the original phi: We need to map this case to the new phi node.

Reapply [InstCombine] Switch foldOpIntoPhi() to use InstSimplify

Reapply with a fix for the case where an operand simplified back
to the original phi: We need to map this case to the new phi node.

-----

foldOpIntoPhi() currently only folds operations into the phi if all
but one operands constant-fold. The two exceptions to this are freeze
and select, where we allow more general simplification.

This patch makes foldOpIntoPhi() generally simplification based and
removes all the instruction-specific logic. We just try to simplify
the instruction for each operand, and for the (potentially) one
non-simplified operand, we move it into the new block with adjusted
operands.

This fixes https://github.com/llvm/llvm-project/issues/57448, which
was my original motivation for the change.

show more ...

Revert "[InstCombine] Switch foldOpIntoPhi() to use InstSimplify"

This reverts commit b20e34b39f72f2be035dfb7367b6880fd2cf213a.

This causes RAUW type mismatch assertions on some buildbots,
revertin

Revert "[InstCombine] Switch foldOpIntoPhi() to use InstSimplify"

This reverts commit b20e34b39f72f2be035dfb7367b6880fd2cf213a.

This causes RAUW type mismatch assertions on some buildbots,
reverting for now.

show more ...

[InstCombine] Switch foldOpIntoPhi() to use InstSimplify

foldOpIntoPhi() currently only folds operations into the phi if all
but one operands constant-fold. The two exceptions to this are freeze
and

[InstCombine] Switch foldOpIntoPhi() to use InstSimplify

foldOpIntoPhi() currently only folds operations into the phi if all
but one operands constant-fold. The two exceptions to this are freeze
and select, where we allow more general simplification.

This patch makes foldOpIntoPhi() generally simplification based and
removes all the instruction-specific logic. We just try to simplify
the instruction for each operand, and for the (potentially) one
non-simplified operand, we move it into the new block with adjusted
operands.

This fixes https://github.com/llvm/llvm-project/issues/57448, which
was my original motivation for the change.

show more ...

[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

show more ...

[InstCombine] Add test for phi translation during select of phi fold (NFC)

The phi translation performed during this fold is important for
correctness, but was apparently untested.

[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

show more ...

[InstCombine] avoid crash sinking to unreachable block

The test is reduced from the example in D82005.

Similar to 94f6d365e, the test here would assert in
the DomTree when we tried to convert a sel

[InstCombine] avoid crash sinking to unreachable block

The test is reduced from the example in D82005.

Similar to 94f6d365e, the test here would assert in
the DomTree when we tried to convert a select to a
phi with an unreachable block operand.

We may want to add some kind of guard code in DomTree
itself to avoid this sort of problem.

show more ...

[InstCombine] avoid crash on phi with unreachable incoming block (PR48369)

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] canonicalize select shuffles by commuting

In PR41304:
https://bugs.llvm.org/show_bug.cgi?id=41304
...we have a case where we want to fold a binop of select-shuffle (blended) values.

R

[InstCombine] canonicalize select shuffles by commuting

In PR41304:
https://bugs.llvm.org/show_bug.cgi?id=41304
...we have a case where we want to fold a binop of select-shuffle (blended) values.

Rather than try to match commuted variants of the pattern, we can canonicalize the
shuffles and check for mask equality with commuted operands.

We don't produce arbitrary shuffle masks in instcombine, but select-shuffles are a
special case that the backend is required to handle because we already canonicalize
vector select to this shuffle form.

So there should be no codegen difference from this change. It's possible that this
improves CSE in IR though.

Differential Revision: https://reviews.llvm.org/D60016

llvm-svn: 357366

show more ...

[InstCombine] autogenerate complete checks; NFC

llvm-svn: 357291

Fix some misc. -enable-var-scope violations

llvm-svn: 318006

[InstCombine] Set correct insertion point for selects generated while folding phis

Summary:
When we fold vector constants that are operands of phi's that feed into select,
we need to set the correct

[InstCombine] Set correct insertion point for selects generated while folding phis

Summary:
When we fold vector constants that are operands of phi's that feed into select,
we need to set the correct insertion point for the *new* selects that get generated.
The correct insertion point is the incoming block for the phi.
Such cases can occur with patch r298845, which fixed folding of
vector constants, but the new selects could be inserted incorrectly (as the added
test case shows).

Reviewers: majnemer, spatel, sanjoy

Reviewed by: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D34162

llvm-svn: 305591

show more ...

rename instcombine test file. NFC

llvm-svn: 298904