[llvm-exegesis] Save target state before running the benchmark.

Some benchmarked instructions might set target state. Preserve this
state. See PR26418.

Differential Revision: https://reviews.llvm.o

[llvm-exegesis] Save target state before running the benchmark.

Some benchmarked instructions might set target state. Preserve this
state. See PR26418.

Differential Revision: https://reviews.llvm.org/D90592

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Reland rG4fcd1a8e6528:[llvm-exegesis] Add option to check the hardware support for a given feature before benchmarking.

This is mostly for the benefit of the LBR latency mode.
Right now, it perform

Reland rG4fcd1a8e6528:[llvm-exegesis] Add option to check the hardware support for a given feature before benchmarking.

This is mostly for the benefit of the LBR latency mode.
Right now, it performs no checking. If this is run on non-supported hardware, it will produce all zeroes for latency.

Differential Revision: https://reviews.llvm.org/D85254

New change: Updated lit.local.cfg to use pass the right argument to llvm-exegesis to actually request the LBR mode.

Differential Revision: https://reviews.llvm.org/D88670

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Revert "[llvm-exegesis] Add option to check the hardware support for a given feature before benchmarking."

This reverts commit 4fcd1a8e6528ca42fe656f2745e15d2b7f5de495 as
`llvm/test/tools/llvm-exege

Revert "[llvm-exegesis] Add option to check the hardware support for a given feature before benchmarking."

This reverts commit 4fcd1a8e6528ca42fe656f2745e15d2b7f5de495 as
`llvm/test/tools/llvm-exegesis/X86/lbr/mov-add.s` failed on hosts
without LBR supported if the build has LIBPFM enabled. On that host,
`perf_event_open` fails with `EOPNOTSUPP` on LBR config. That change's
basic assumption

> If this is run on a non-supported hardware, it will produce all zeroes for latency.

could not stand as `perf_event_open` system call will fail if the
underlying hardware really don't have LBR supported.

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[llvm-exegesis] Add option to check the hardware support for a given feature before benchmarking.

This is mostly for the benefit of the LBR latency mode.
Right now, it performs no checking. If this

[llvm-exegesis] Add option to check the hardware support for a given feature before benchmarking.

This is mostly for the benefit of the LBR latency mode.
Right now, it performs no checking. If this is run on non-supported hardware, it will produce all zeroes for latency.

Differential Revision: https://reviews.llvm.org/D85254

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[llvm-exegesis] Let Counter returns up to 16 entries

LBR contains (up to) 16 entries for last x branches and the X86LBRCounter (from D77422) should be able to return all those.
Currently, it

[llvm-exegesis] Let Counter returns up to 16 entries

LBR contains (up to) 16 entries for last x branches and the X86LBRCounter (from D77422) should be able to return all those.
Currently, it just returns the latest entry, which could lead to mis-leading measurements.
This patch aslo changes the LatencyBenchmarkRunner to accommodate multi-value readings.

https://reviews.llvm.org/D81050

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[llvm-exegesis] Fix D80610.

Summary:
Using a .data() member on a StringRef was discarding the StringRef
size, breaking llvm-exegesis on machines with counter sums (e.g.
Zen2).

Reviewers: oontvoo

S

[llvm-exegesis] Fix D80610.

Summary:
Using a .data() member on a StringRef was discarding the StringRef
size, breaking llvm-exegesis on machines with counter sums (e.g.
Zen2).

Reviewers: oontvoo

Subscribers: mstojanovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80982

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[llvm-exegesis] Make a few counter methods virtual to allow targets to provide target-specific support.
Misc: Also include errno in failure message.

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

[llvm-exegesis] Make a few counter methods virtual to allow targets to provide target-specific support.
Misc: Also include errno in failure message.

Differential Revision: https://reviews.llvm.org/D80610

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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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Recommit: "[llvm-exegesis] Improve error reporting in Target.cpp"

Summary: Commit 141915963b6ab36ee4e577d1b27673fa4d05b409 was reverted in
abe01e17f648a97666d4fbed41f0861686a17972 because it broke b

Recommit: "[llvm-exegesis] Improve error reporting in Target.cpp"

Summary: Commit 141915963b6ab36ee4e577d1b27673fa4d05b409 was reverted in
abe01e17f648a97666d4fbed41f0861686a17972 because it broke builds testing
without libpfm. A preparatory commit <commit_sha1> was added to enable
this recommit.

Original commit message:

Followup to D74085.
Replace the use of `report_fatal_error()` with returning the error to
`llvm-exegesis.cpp` and handling it there.

Differential Revision: https://reviews.llvm.org/D74113

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Revert "[llvm-exegesis] Improve error reporting" and follow-up.

It broke e.g. all tests under tools/llvm-exegesis/X86/ when libpfm is
not available, see comment on D74085.

This reverts commit b3576

Revert "[llvm-exegesis] Improve error reporting" and follow-up.

It broke e.g. all tests under tools/llvm-exegesis/X86/ when libpfm is
not available, see comment on D74085.

This reverts commit b3576f60ebc8f660afad8120a72473be47517573 and
141915963b6ab36ee4e577d1b27673fa4d05b409.

show more ...

[llvm-exegesis] Improve error reporting in Target.cpp

Followup to D74085.
Replace the use of `report_fatal_error()` with returning the error to
`llvm-exegesis.cpp` and handling it there.

Differenti

[llvm-exegesis] Improve error reporting in Target.cpp

Followup to D74085.
Replace the use of `report_fatal_error()` with returning the error to
`llvm-exegesis.cpp` and handling it there.

Differential Revision: https://reviews.llvm.org/D74113

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[llvm-exegesis] Allow the randomizer to fail nicely...

Summary:
... instead of crashing.
On typical exmaple is when there are no available registers.

Reviewers: gchatelet

Subscribers: tschuett, ms

[llvm-exegesis] Allow the randomizer to fail nicely...

Summary:
... instead of crashing.
On typical exmaple is when there are no available registers.

Reviewers: gchatelet

Subscribers: tschuett, mstojanovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73196

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[llvm-exegesis] Serial snippet: Restrict the set of back-to-back instructions

Summary:
Right now when picking a back-to-back instruction at random, we might select
instructions that we do not know h

[llvm-exegesis] Serial snippet: Restrict the set of back-to-back instructions

Summary:
Right now when picking a back-to-back instruction at random, we might select
instructions that we do not know how to handle.
Add a ExegesisTarget hook to possibly filter instructions.

Reviewers: gchatelet

Subscribers: tschuett, mstojanovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73161

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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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[llvm-exegesis][NFC] Remove extra `llvm::` qualifications.

Summary: Second patch: in the lib.

Reviewers: gchatelet

Subscribers: nemanjai, tschuett, MaskRay, mgrang, jsji, llvm-commits

Tags: #llvm

[llvm-exegesis][NFC] Remove extra `llvm::` qualifications.

Summary: Second patch: in the lib.

Reviewers: gchatelet

Subscribers: nemanjai, tschuett, MaskRay, mgrang, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68692

llvm-svn: 374158

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[llvm-exegesis] Add options to SnippetGenerator.

Summary:
This adds a `-max-configs-per-opcode` option to limit the number of
configs per opcode.

Reviewers: gchatelet

Subscribers: tschuett, llvm-c

[llvm-exegesis] Add options to SnippetGenerator.

Summary:
This adds a `-max-configs-per-opcode` option to limit the number of
configs per opcode.

Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68642

llvm-svn: 374054

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[llvm-exegesis][NFC] Rename ExegesisTarget::decrementLoopCounterAndLoop()

Summary: To decrementLoopCounterAndJump, and explicitely take the jump target.

Reviewers: gchatelet

Subscribers: tschuett,

[llvm-exegesis][NFC] Rename ExegesisTarget::decrementLoopCounterAndLoop()

Summary: To decrementLoopCounterAndJump, and explicitely take the jump target.

Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68375

llvm-svn: 373571

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[llvm-exegesis] Add loop mode for repeating the snippet.

Summary:
Before this change the Executable function was made by duplicating the
snippet. This change adds a --repetion-mode={loop|duplicate}

[llvm-exegesis] Add loop mode for repeating the snippet.

Summary:
Before this change the Executable function was made by duplicating the
snippet. This change adds a --repetion-mode={loop|duplicate} flag that
allows choosing between this behaviour and wrapping the snippet instructions
in a loop.

The new mode can help measurements when the snippet fits in the DSB by
short-cirtcuiting decoding. The loop adds a dec + jmp to the measurements, but
since these are not part of the critical path, they execute in parallel
with the measured code and do not impact measurements in practice.

Overview of the change:
- New SnippetRepetitor abstraction that handles repeating the snippet.
The assembler delegates repeating the instructions to this class.
- ExegesisTarget learns how to decrement loop counter and jump.
- Some refactoring of the assembler into FunctionFiller/BasicBlockFiller.

Reviewers: gchatelet

Subscribers: mgorny, tschuett, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68125

llvm-svn: 373083

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[llvm-exegesis][X86] Handle CMOVcc/SETcc OPERAND_COND_CODE OperandType

Summary:
D60041 / D60138 refactoring changed how CMOV/SETcc opcodes
are handled. concode is now an immediate, with it's own ope

[llvm-exegesis][X86] Handle CMOVcc/SETcc OPERAND_COND_CODE OperandType

Summary:
D60041 / D60138 refactoring changed how CMOV/SETcc opcodes
are handled. concode is now an immediate, with it's own operand type.

This at least allows to not crash on the opcode.
However, this still won't generate all the snippets
with all the condcode enumerators. D60066 does that.

Reviewers: courbet, gchatelet

Reviewed By: gchatelet

Subscribers: tschuett, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60057

llvm-svn: 357841

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[llvm-exegesis] Allow the target to disable the selection of some registers.

Summary:
This prevents "Cannot encode high byte register in REX-prefixed instruction"
from happening on instructions that

[llvm-exegesis] Allow the target to disable the selection of some registers.

Summary:
This prevents "Cannot encode high byte register in REX-prefixed instruction"
from happening on instructions that require REX encoding when AH & co
get selected.
On the down side, these 4 registers can no longer be selected
automatically, but this avoids having to expose all the X86 encoding
complexity.

Reviewers: gchatelet

Subscribers: tschuett, jdoerfert, llvm-commits, bdb

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59821

llvm-svn: 357003

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[llvm-exegesis] Add throughput mode.

Summary:
This just uses the latency benchmark runner on the parallel uops snippet
generator.

Fixes PR37698.

Reviewers: gchatelet

Subscribers: tschuett, RKSimo

[llvm-exegesis] Add throughput mode.

Summary:
This just uses the latency benchmark runner on the parallel uops snippet
generator.

Fixes PR37698.

Reviewers: gchatelet

Subscribers: tschuett, RKSimon, llvm-commits

Differential Revision: https://reviews.llvm.org/D57000

llvm-svn: 352632

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Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636

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Revert "[llvm-exegesis] Add a snippet generator to generate snippets to compute ROB sizes."

This reverts accidental commit rL346394.

llvm-svn: 346398

[llvm-exegesis] Add a snippet generator to generate snippets to compute ROB sizes.

llvm-svn: 346394

Fix MSVC llvm-exegesis build. NFCI.

MSVC is a bit funny about is_pod.....

llvm-svn: 345252