Avoid shuffle self-assignment in EXPENSIVE_CHECKS builds

Some versions of libstdc++ perform self-assignment in std::shuffle. This
breaks the EXPENSIVE_CHECKS builds of TableGen due to an incorrect a

Avoid shuffle self-assignment in EXPENSIVE_CHECKS builds

Some versions of libstdc++ perform self-assignment in std::shuffle. This
breaks the EXPENSIVE_CHECKS builds of TableGen due to an incorrect assertion
in libstdc++.

See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85828.

Fixes https://llvm.org/PR37652

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D98167

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[llvm-exegesis] Ignore instructions using custom inserter

Some instructions defined in table-gen files sets usesCustomInserter
bit, which means it has to be lowered by target code and isn't actually

[llvm-exegesis] Ignore instructions using custom inserter

Some instructions defined in table-gen files sets usesCustomInserter
bit, which means it has to be lowered by target code and isn't actually
valid instruction at MC level. So we should treat them like pseudo
instructions.

Reviewed By: gchatelet

Differential Revision: https://reviews.llvm.org/D94898

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[llvm-exegesis] Do not try to assign random registers twice.

Doing a random assignment assigns both tested (forward) and back-to-back
(backward) instructions.

When none of the tested instruction an

[llvm-exegesis] Do not try to assign random registers twice.

Doing a random assignment assigns both tested (forward) and back-to-back
(backward) instructions.

When none of the tested instruction and back-to-back instruction have
implicit aliasing, we're currently trying to do a random register
asignment twice.

Fix this (see PR26418).

Differential Revision: https://reviews.llvm.org/D90380

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[llvm-exegesis] Exploring X86::OperandType::OPERAND_COND_CODE

Summary:
Currently, we only have nice exploration for LEA instruction,
while for the rest, we rely on `randomizeUnsetVariables()`
to som

[llvm-exegesis] Exploring X86::OperandType::OPERAND_COND_CODE

Summary:
Currently, we only have nice exploration for LEA instruction,
while for the rest, we rely on `randomizeUnsetVariables()`
to sometimes generate something interesting.
While that works, it isn't very reliable in coverage :)

Here, i'm making an assumption that while we may want to explore
multi-instruction configs, we are most interested in the
characteristics of the main instruction we were asked about.

Which we can do, by taking the existing `randomizeMCOperand()`,
and turning it on it's head - instead of relying on it to randomly fill
one of the interesting values, let's pregenerate all the possible interesting
values for the variable, and then generate as much `InstructionTemplate`
combinations of these possible values for variables as needed/possible.

Of course, that requires invasive changes to no longer pass just the
naked `Instruction`, but sometimes partially filled `InstructionTemplate`.

As it can be seen from the test, this allows us to explore
`X86::OperandType::OPERAND_COND_CODE` for instructions
that take such an operand.
I'm hoping this will greatly simplify exploration.

Reviewers: courbet, gchatelet

Reviewed By: gchatelet

Subscribers: orodley, mgorny, sdardis, tschuett, jrtc27, atanasyan, mstojanovic, andreadb, RKSimon, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74156

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Revert "Remove redundant "std::move"s in return statements"

The build failed with

error: call to deleted constructor of 'llvm::Error'

errors.

This reverts commit 1c2241a7936bf85aa68aef94bd40c3b

Revert "Remove redundant "std::move"s in return statements"

The build failed with

error: call to deleted constructor of 'llvm::Error'

errors.

This reverts commit 1c2241a7936bf85aa68aef94bd40c3ba77d8ddf2.

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Remove redundant "std::move"s in return statements

Make llvm::StringRef to std::string conversions explicit.

This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly m

Make llvm::StringRef to std::string conversions explicit.

This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.

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[llvm-exegesis] Don't use unsupported aliasing instructions

Since some instruction types aren't allowed as the main instruction also
don't allow them for aliasing instructions.

Differential Revisio

[llvm-exegesis] Don't use unsupported aliasing instructions

Since some instruction types aren't allowed as the main instruction also
don't allow them for aliasing instructions.

Differential Revision: https://reviews.llvm.org/D73220

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[llvm-exegesis] Restrict to allowed back-to-back instructions in SerialSnippetGenerator.

Summary: Followup to D73161.

Reviewers: gchatelet, mstojanovic

Subscribers: tschuett, llvm-commits

Tags: #

[llvm-exegesis] Restrict to allowed back-to-back instructions in SerialSnippetGenerator.

Summary: Followup to D73161.

Reviewers: gchatelet, mstojanovic

Subscribers: tschuett, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73256

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[llvm-exegesis][NFC] Disassociate snippet generators from benchmark runners

The addition of `inverse_throughput` mode highlighted the disjointedness
of snippet generators and benchmark runners becau

[llvm-exegesis][NFC] Disassociate snippet generators from benchmark runners

The addition of `inverse_throughput` mode highlighted the disjointedness
of snippet generators and benchmark runners because it used the
`UopsSnippetGenerator` with the `LatencyBenchmarkRunner`.
To keep the code consistent tie the snippet generators to
parallelization/serialization rather than their benchmark runners.

Renaming `LatencySnippetGenerator` -> `SerialSnippetGenerator`.
Renaming `UopsSnippetGenerator` -> `ParallelSnippetGenerator`.

Differential Revision: https://reviews.llvm.org/D72928

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