Commit Graph

15 Commits

Author SHA1 Message Date
Michael Maitland 98e342dca2 [RISCV][llvm-mca] Use LMUL Instruments to provide more accurate reports on RISCV
On x86 and AArch, SIMD instructions encode all of the scheduling information in the instruction
itself. For example, VADD.I16 q0, q1, q2 is a neon instruction that operates on 16-bit integer
elements stored in 128-bit Q registers, which leads to eight 16-bit lanes in parallel. This kind
of information impacts how the instruction takes to execute and what dependencies this may cause.

On RISCV however, the data that impacts scheduling is encoded in CSR registers such as vtype or
vl, in addition with the instruction itself. But MCA does not track or use the data in these
registers. This patch fixes this problem by introducing Instruments into MCA.

* Replace `CodeRegions` with `AnalysisRegions`
* Add `Instrument` and `InstrumentManager`
* Add `InstrumentRegions`
* Add RISCV Instrument and `InstrumentManager`
* Parse `Instruments` in driver
* Use instruments to override schedule class
* RISCV use lmul instrument to override schedule class
* Fix unit tests to pass empty instruments
* Add -ignore-im clopt to disable this change

A prior version of this patch was commited in 5e82ee5373. 2323a4ee61 reverted
that change because the unit test files caused build errors. The change with fixes
were committed in b88b8307bf but reverted once again e8e92c8313 due to more
build errors.

This commit adds the prior changes and fixes the build error.

Differential Revision: https://reviews.llvm.org/D137440
2022-11-18 09:55:15 -08:00
Michael Maitland e8e92c8313 Revert "[RISCV][llvm-mca] Use LMUL Instruments to provide more accurate reports on RISCV"
This reverts commit b88b8307bf.
2022-11-15 18:01:46 -08:00
Michael Maitland b88b8307bf [RISCV][llvm-mca] Use LMUL Instruments to provide more accurate reports on RISCV
On x86 and AArch, SIMD instructions encode all of the scheduling information in the instruction
itself. For example, VADD.I16 q0, q1, q2 is a neon instruction that operates on 16-bit integer
elements stored in 128-bit Q registers, which leads to eight 16-bit lanes in parallel. This kind
of information impacts how the instruction takes to execute and what dependencies this may cause.

On RISCV however, the data that impacts scheduling is encoded in CSR registers such as vtype or
vl, in addition with the instruction itself. But MCA does not track or use the data in these
registers. This patch fixes this problem by introducing Instruments into MCA.

* Replace `CodeRegions` with `AnalysisRegions`
* Add `Instrument` and `InstrumentManager`
* Add `InstrumentRegions`
* Add RISCV Instrument and `InstrumentManager`
* Parse `Instruments` in driver
* Use instruments to override schedule class
* RISCV use lmul instrument to override schedule class
* Fix unit tests to pass empty instruments
* Add -ignore-im clopt to disable this change

A prior version of this patch was commited in. It was reverted in
5e82ee5373. 2323a4ee61 reverted
that change because the unit test files caused build errors. This commit adds the original changes
and the fixed test files.

Differential Revision: https://reviews.llvm.org/D137440
2022-11-15 17:42:23 -08:00
Michael Maitland 2323a4ee61 Revert "[RISCV][llvm-mca] Use LMUL Instruments to provide more accurate reports on RISCV"
This reverts commit 5e82ee5373.
2022-11-15 08:04:11 -08:00
Michael Maitland 5e82ee5373 [RISCV][llvm-mca] Use LMUL Instruments to provide more accurate reports on RISCV
On x86 and AArch, SIMD instructions encode all of the scheduling information in the instruction
itself. For example, VADD.I16 q0, q1, q2 is a neon instruction that operates on 16-bit integer
elements stored in 128-bit Q registers, which leads to eight 16-bit lanes in parallel. This kind
of information impacts how the instruction takes to execute and what dependencies this may cause.

On RISCV however, the data that impacts scheduling is encoded in CSR registers such as vtype or
vl, in addition with the instruction itself. But MCA does not track or use the data in these
registers. This patch fixes this problem by introducing Instruments into MCA.

* Replace `CodeRegions` with `AnalysisRegions`
* Add `Instrument` and `InstrumentManager`
* Add `InstrumentRegions`
* Add RISCV Instrument and `InstrumentManager`
* Parse `Instruments` in driver
* Use instruments to override schedule class
* RISCV use lmul instrument to override schedule class
* Fix unit tests to pass empty instruments
* Add -ignore-im clopt to disable this change

Differential Revision: https://reviews.llvm.org/D137440
2022-11-15 07:54:06 -08:00
Kazu Hirata 7dc3575ef2 [llvm] Remove redundant return and continue statements (NFC)
Identified with readability-redundant-control-flow.
2021-01-14 20:30:34 -08:00
Jonas Devlieghere 0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
Andrea Di Biagio 4e62554bfa [MCA] Add support for nested and overlapping region markers
This patch fixes PR41523
https://bugs.llvm.org/show_bug.cgi?id=41523

Regions can now nest/overlap provided that they have different names.
Anonymous regions cannot overlap.

Region end markers must specify the region name. The only exception is for when
there is only one user-defined region; in that particular case, the region end
marker doesn't need to specify a name.

Incorrect region end markers are no longer ignored. Instead, the tool reports an
error and we exit with an error code.

Added test cases to verify the new diagnostic error messages.

Updated the llvm-mca docs to reflect this feature change.

Differential Revision: https://reviews.llvm.org/D61676

llvm-svn: 360351
2019-05-09 15:18:09 +00:00
Andrea Di Biagio d52a542e4c [MCA] Don't add a name to the default code region.
This is done in preparation for a patch that fixes PR41523.

llvm-svn: 360243
2019-05-08 11:00:43 +00:00
Andrea Di Biagio 86654dd8a0 [MCA] Slightly refactor CodeRegion.h. NFCI
Also, use a SmallVector instead of a std::vector for the code region.

llvm-svn: 360240
2019-05-08 10:44:05 +00:00
Chandler Carruth 2946cd7010 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
2019-01-19 08:50:56 +00:00
Fangrui Song 5a8fd65700 [llvm-mca] Move namespace mca inside llvm::
Summary: This allows to remove `using namespace llvm;` in those *.cpp files

When we want to revisit the decision (everything resides in llvm::mca::*) in the future, we can move things to a nested namespace of llvm::mca::, to conceptually make them separate from the rest of llvm::mca::*

Reviewers: andreadb, mattd

Reviewed By: andreadb

Subscribers: javed.absar, tschuett, gbedwell, llvm-commits

Differential Revision: https://reviews.llvm.org/D53407

llvm-svn: 345612
2018-10-30 15:56:08 +00:00
Andrea Di Biagio db158be646 [llvm-mca] Remove a couple of using directives and a bunch of redundant namespace llvm prefixes. NFC
llvm-svn: 344916
2018-10-22 16:28:07 +00:00
Andrea Di Biagio 01b9fd6868 [llvm-mca] Use llvm::ArrayRef in class SourceMgr. NFCI
Class SourceMgr now uses type ArrayRef<MCInst> to reference the
sequence of code from a "CodeRegion".

llvm-svn: 344911
2018-10-22 15:36:15 +00:00
Andrea Di Biagio c65901282b [llvm-mca] Add the ability to mark regions of code for analysis (PR36875)
This patch teaches llvm-mca how to parse code comments in search for special
"markers" used to select regions of code.

Example:

# LLVM-MCA-BEGIN My Code Region
  ....
# LLVM-MCA-END

The MCAsmLexer now delegates to an object of class MCACommentParser (i.e. an
AsmCommentConsumer) the parsing of code comments to search for begin/end code
region markers.

A comment starting with substring "LLVM-MCA-BEGIN" marks the beginning of a new
region of code.  A comment starting with substring "LLVM-MCA-END" marks the end
of the last region.

This implementation doesn't allow regions to overlap. Each region can have a
optional description; internally, each region is identified by a range of source
code locations (SMLoc).

MCInst objects are added to a region R only if the source location for the
MCInst is in the range of locations specified by R.

By default, the tool allocates an implicit "Default" code region which contains
every source location.  See new tests llvm-mca-marker-*.s for a few examples.

A new Backend object is created for every region. So, the analysis is conducted
on every parsed code region.  The final report is the union of the reports
generated for every code region.  Note that empty regions are skipped.

Special "[#] Code Region - ..." strings are used in the report to mark the
portion which is specific to a code region only. For example, see
llvm-mca-markers-5.s.

Differential Revision: https://reviews.llvm.org/D45433

llvm-svn: 329590
2018-04-09 16:39:52 +00:00