Commit Graph

21 Commits

Author SHA1 Message Date
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
Clement Courbet 176388c973 Revert rL350035 "[llvm-exegesis] Clustering: don't enqueue a point multiple times"
Let's discuss this on the review thread before submitting.

llvm-svn: 350207
2019-01-02 09:21:00 +00:00
Fangrui Song cd93d7ef43 [llvm-exegesis] Clustering: don't enqueue a point multiple times
Summary:
SetVector uses both DenseSet and vector, which is time/memory inefficient. The points are represented as natural numbers so we can replace the DenseSet part by indexing into a vector<char> instead.

Don't cargo cult the pseudocode on the wikipedia DBSCAN page. This is a standard BFS style algorithm (the similar loops have been used several times in other LLVM components): every point is processed at most once, thus the queue has at most NumPoints elements. We represent it with a vector and allocate it outside of the loop to avoid allocation in the loop body.

We check `Processed[P]` to avoid enqueueing a point more than once, which also nicely saves us a `ClusterIdForPoint_[Q].isUndef()` check.

Many people hate the oneshot abstraction but some favor it, therefore we make a compromise, use a lambda to abstract away the neighbor adding process.

Delete the comment `assert(Neighbors.capacity() == (Points_.size() - 1));` as it is wrong.

llvm-svn: 350035
2018-12-23 20:48:52 +00:00
Simon Pilgrim 96408bb04a Revert rL349136: [llvm-exegesis] Optimize ToProcess in dbScan
Summary:
Use `vector<char> Added + vector<size_t> ToProcess` to replace `SetVector ToProcess`

We also check `Added[P]` to enqueueing a point more than once, which
also saves us a `ClusterIdForPoint_[Q].isUndef()` check.

Reviewers: courbet, RKSimon, gchatelet, john.brawn, lebedev.ri

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D54442
........
Patch wasn't approved and breaks buildbots

llvm-svn: 349139
2018-12-14 09:25:08 +00:00
Fangrui Song 92537ccc7e [llvm-exegesis] Optimize ToProcess in dbScan
Summary:
Use `vector<char> Added + vector<size_t> ToProcess` to replace `SetVector ToProcess`

We also check `Added[P]` to enqueueing a point more than once, which
also saves us a `ClusterIdForPoint_[Q].isUndef()` check.

Reviewers: courbet, RKSimon, gchatelet, john.brawn, lebedev.ri

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D54442

llvm-svn: 349136
2018-12-14 08:27:35 +00:00
Roman Lebedev 71fdb57640 [llvm-exegesis] (+final perf overview) InstructionBenchmarkClustering::rangeQuery(): reserve for the upper bound of Neighbors
Summary:
As it was pointed out in D54388+D54390, the maximal size of `Neighbors` is known,
it will contain at most Points_.size() minus one (the center of the cluster)

While that is the upper bound, meaning in the most cases, the actual count
will be much smaller, since D54390 made the allocation persistent,
we no longer have to worry about overly-optimistically `reserve()`ing.

Old: (D54393)
```
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html' (16 runs):

       6553.167456      task-clock (msec)         #    1.000 CPUs utilized            ( +-  0.21% )
...
            6.5547 +- 0.0134 seconds time elapsed  ( +-  0.20% )
```
New:
```
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html' (16 runs):

       6315.057872      task-clock (msec)         #    0.999 CPUs utilized            ( +-  0.24% )
...
            6.3187 +- 0.0160 seconds time elapsed  ( +-  0.25% )
```
And that is another -~4%.


Since this is the last (as of this moment) patch in this patch series,
it is a good time to summarize:
Old: (svn trunk, as stated in D54381)
```
$ time ./bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html &> /dev/null

real    0m24.884s
user    0m24.099s
sys     0m0.785s
```
So these patches, on a given benchmark,
has decreased llvm-exegesis analysis time by 74.62%.

There surely is more room for further improvements.
D54514 may improve thins by -11.5% more (relative to this patch).
Parallelization may improve things further significantly, too.


Reviewers: courbet, MaskRay, RKSimon, gchatelet, john.brawn

Reviewed By: courbet, MaskRay

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D54415

llvm-svn: 347204
2018-11-19 13:28:41 +00:00
Roman Lebedev 8e315b66c2 [llvm-exegesis] Move InstructionBenchmarkClustering::isNeighbour() into header
Summary:
Old: (D54390)
```
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html' (10 runs):

       7432.421721      task-clock (msec)         #    1.000 CPUs utilized            ( +-  0.15% )
...
            7.4336 +- 0.0115 seconds time elapsed  ( +-  0.15% )
```
New:
```
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html' (10 runs):

       6569.936144      task-clock (msec)         #    1.000 CPUs utilized            ( +-  0.22% )
...
            6.5711 +- 0.0143 seconds time elapsed  ( +-  0.22% )
```
And another -12%. You'd think it would be `inline`d anyway, but no! :)

Reviewers: courbet, MaskRay, RKSimon, gchatelet, john.brawn

Reviewed By: courbet, MaskRay

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D54393

llvm-svn: 347203
2018-11-19 13:28:36 +00:00
Roman Lebedev 666d855fbb [llvm-exegesis] InstructionBenchmarkClustering::rangeQuery(): write into llvm::SmallVectorImpl& output parameter
Summary:
I do believe this is the correct fix.
We call `rangeQuery()` *very* often. And many times it's output vector is large (tens of thousands entries), so small-size-opt won't help.

Old: (D54389)
```
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html' (10 runs):

       7934.528363      task-clock (msec)         #    1.000 CPUs utilized            ( +-  0.19% )
...
            7.9354 +- 0.0148 seconds time elapsed  ( +-  0.19% )
```
New:
```
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html' (10 runs):

       7383.793440      task-clock (msec)         #    1.000 CPUs utilized            ( +-  0.47% )
...
            7.3868 +- 0.0340 seconds time elapsed  ( +-  0.46% )
```
And another -7%. And that isn't even the good bit yet.

Old:
* calls to allocation functions: 2081419
* temporary allocations: 219658 (10.55%)
* bytes allocated in total (ignoring deallocations): 4.31 GB

New:
* calls to allocation functions: 1880295 (-10%)
* temporary allocations: 18758 (1%) (-91% *sic*)
* bytes allocated in total (ignoring deallocations): 545.15 MB (-88% *sic*)

Reviewers: courbet, MaskRay, RKSimon, gchatelet, john.brawn

Reviewed By: courbet, MaskRay

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D54390

llvm-svn: 347202
2018-11-19 13:28:31 +00:00
Roman Lebedev 5c5b1ea725 [llvm-exegesis] InstructionBenchmarkClustering::dbScan(): replace std::vector<> with std::deque<> in llvm::SetVector<>
Summary:
Old: (D54388)
```
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html' (10 runs):

       8606.323981      task-clock (msec)         #    1.000 CPUs utilized            ( +-  0.11% )
...
           8.60773 +- 0.00978 seconds time elapsed  ( +-  0.11% )
```
New:
```
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html' (10 runs):

       7971.403653      task-clock (msec)         #    1.000 CPUs utilized            ( +-  0.14% )
...
            7.9728 +- 0.0113 seconds time elapsed  ( +-  0.14% )
```
Another -~7%.

Reviewers: courbet, MaskRay, RKSimon, gchatelet, john.brawn

Reviewed By: courbet, RKSimon

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D54389

llvm-svn: 347201
2018-11-19 13:28:26 +00:00
Roman Lebedev 8aecb0c489 [llvm-exegesis] InstructionBenchmarkClustering::rangeQuery(): use llvm::SmallVector<size_t, 0> for storage.
Summary:
Old: (D54383)
```
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html' (10 runs):

       9098.781978      task-clock (msec)         #    1.000 CPUs utilized            ( +-  0.16% )
...
            9.1015 +- 0.0148 seconds time elapsed  ( +-  0.16% )
```
New:
```
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html' (10 runs):

       8553.352480      task-clock (msec)         #    1.000 CPUs utilized            ( +-  0.12% )
...
            8.5539 +- 0.0105 seconds time elapsed  ( +-  0.12% )
```
So another -6%.
That is because the `SmallVector` **doubles** it size when reallocating, which is great here,
since we can't `reserve()` since we can't know how many `Neighbors` we will have.

Reviewers: courbet, MaskRay, RKSimon, gchatelet, john.brawn

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D54388

llvm-svn: 347200
2018-11-19 13:28:22 +00:00
Roman Lebedev 0b4b512826 [llvm-exegesis] InstructionBenchmarkClustering::dbScan(): use llvm::SetVector<> instead of ILLEGAL std::unordered_set<>
Summary:
Test data: 500kLOC of benchmark.yaml, 23Mb. (that is a subset of the actual uops benchmark i was trying to analyze!)
Old time:
```
$ time ./bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html &> /dev/null

real    0m24.884s
user    0m24.099s
sys     0m0.785s
```
New time:
```
$ time ./bin/llvm-exegesis -mode=analysis -analysis-epsilon=100000 -benchmarks-file=/tmp/benchmarks.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html &> /dev/null

real    0m10.469s
user    0m9.797s
sys     0m0.672s
```
So -60%. And that isn't the good bit yet.

Old:
* calls to allocation functions: 106560180  (yes, 107 *million* allocations.)
* bytes allocated in total (ignoring deallocations): 12.17 GB

New:
* calls to allocation functions: 3347676  (-96.86%)  (just 3 mil)
* bytes allocated in total (ignoring deallocations): 10.52 GB (~2GB less)

---

Two points i want to raise:
* `std::unordered_set<>` should not have been used there in the first place.
  It is banned by the https://llvm.org/docs/ProgrammersManual.html#other-set-like-container-options
* There is no tests, so i'm not fully sure this is correct.
  Since it was unordered set, i guess there are zero restrictions on the order, and anything will be ok?
* I tried other containers suggested in https://llvm.org/docs/ProgrammersManual.html#set-like-containers-std-set-smallset-setvector-etc,
  this `llvm::SetVector<>` seems to be best here.

Reviewers: courbet, MaskRay, RKSimon, gchatelet, john.brawn

Reviewed By: courbet

Subscribers: kristina, bobsayshilol, tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D54381

llvm-svn: 347197
2018-11-19 13:28:09 +00:00
Fangrui Song 32401afd8c [llvm-exegesis] Move namespace exegesis inside llvm::
Summary:
This allows simplifying references of llvm::foo with foo when the needs
come in the future.

Reviewers: courbet, gchatelet

Reviewed By: gchatelet

Subscribers: javed.absar, tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D53455

llvm-svn: 344922
2018-10-22 17:10:47 +00:00
Clement Courbet 684a5f6753 [llvm-exegesis] Output the unscaled value as well as the scaled one.
Summary: See PR38936 for context.

Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D52500

llvm-svn: 343081
2018-09-26 08:37:21 +00:00
Clement Courbet 7228721b30 [llvm-exegesis] Analysis: Show inconsistencies between checked-in and measured data.
Summary:
We now highlight any sched classes whose measurements do not match the
LLVM SchedModel. "bad" clusters are marked in red.

Screenshot in phabricator diff.

Reviewers: gchatelet

Subscribers: tschuett, mgrang, RKSimon, llvm-commits

Differential Revision: https://reviews.llvm.org/D47639

llvm-svn: 333884
2018-06-04 11:11:55 +00:00
Clement Courbet cdb0eb88e3 Fix compilation under pre-c++14 gccs.
llvm-svn: 332346
2018-05-15 12:38:06 +00:00
Clement Courbet 37f0ca0328 [llvm-exegesis] Add an analysis mode.
Summary:
The analysis mode gives the user a clustered view of the measurement results.
Next steps are (requires the split ok AsmTemplate.Name into {mnemonic, mode}):
 - Show the sched class.
 - Highlight any inconsistencies with the checked-in data.

Reviewers: gchatelet

Subscribers: mgorny, llvm-commits, tschuett

Differential Revision: https://reviews.llvm.org/D46865

llvm-svn: 332344
2018-05-15 12:08:00 +00:00
Clement Courbet dffc4ca4f2 [llvm-exegesis] Revert accidentally commited code.
llvm-svn: 332231
2018-05-14 11:35:37 +00:00
Clement Courbet 3d479fe81c [llvm-exegesis] Add an analysis mode.
The analysis mode gives the user a clustered view of the measurement results and
highlights any inconsistencies with the checked-in data.

llvm-svn: 332229
2018-05-14 11:30:56 +00:00
Clement Courbet 967154148d Re-land r331622 "[llvm-exegesis] Add a library to cluster benchmark results."
Add missing move.

llvm-svn: 331624
2018-05-07 09:09:48 +00:00
Clement Courbet e9174bc2c8 Revert r331622 "[llvm-exegesis] Add a library to cluster benchmark results."
Breaks build over llvm::Error copy construction.

llvm-svn: 331623
2018-05-07 08:30:18 +00:00
Clement Courbet a7fb139e9d [llvm-exegesis] Add a library to cluster benchmark results.
Reviewers: gchatelet

Subscribers: mgorny, tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D46432

llvm-svn: 331622
2018-05-07 08:20:00 +00:00