Commit Graph

35 Commits

Author SHA1 Message Date
Roman Lebedev 1a0d595f15 [llvm-exegesis] Throughput support in analysis mode
Summary:
D57000 / [[ https://bugs.llvm.org/show_bug.cgi?id=37698 | PR37698 ]] added support for measuring of the inverse throughput.
But the support for the analysis was not added.
This attempts to fix that. (analysis done o bdver2 / piledriver)

First, small-scale experiment:
```
$ ./bin/llvm-exegesis -num-repetitions=10000 -mode=inverse_throughput -opcode-name=BSF64rr
Check generated assembly with: /usr/bin/objdump -d /tmp/snippet-d0acdd.o
---
mode:            inverse_throughput
key:
  instructions:
    - 'BSF64rr RAX RDX'
  config:          ''
  register_initial_values:
    - 'RDX=0x0'
cpu_name:        bdver2
llvm_triple:     x86_64-unknown-linux-gnu
num_repetitions: 10000
measurements:
  - { key: inverse_throughput, value: 3.0278, per_snippet_value: 3.0278 }
error:           ''
info:            instruction has no tied variables picking Uses different from defs
assembled_snippet: 48BA0000000000000000480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2480FBCC2C3
...
```
If we plug `bsfq	%r12, %r10` into llvm-mca:
https://godbolt.org/z/ZtOyhJ
```
Dispatch Width:    4
uOps Per Cycle:    3.00
IPC:               0.50
Block RThroughput: 2.0
```
So RThroughput mismatch exists.

Now, let's upscale and analyse:
{F8207148}
`$ ./bin/llvm-exegesis -mode=analysis -analysis-epsilon=1.0 -benchmarks-file=/tmp/benchmarks-inverse_throughput.yaml -analysis-inconsistencies-output-file=/tmp/clusters.html`:
{F8207172}
{F8207197}
And if we now look at https://www.agner.org/optimize/instruction_tables.pdf,
`Reciprocal throughput` for `BSF r,r` is listed as `3`.
Yay?

Reviewers: courbet, gchatelet

Reviewed By: courbet

Subscribers: tschuett, RKSimon, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57647

llvm-svn: 353023
2019-02-04 09:12:17 +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
Roman Lebedev b311c1d6b8 [llvm-exegesis] Analysis: writeMeasurementValue(): don't alloc string for double each time.
Summary:
Test data: 500kLOC of benchmark.yaml, 23Mb. (that is a subset of the actual uops benchmark i was trying to analyze!)
Old time: (D54382)
```
 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):

       9024.354355      task-clock (msec)         #    1.000 CPUs utilized            ( +-  0.18% )
...
            9.0262 +- 0.0161 seconds time elapsed  ( +-  0.18% )
```
New time:
```
 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):

       8996.541057      task-clock (msec)         #    0.999 CPUs utilized            ( +-  0.19% )
...
            9.0045 +- 0.0172 seconds time elapsed  ( +-  0.19% )
```
-~0.3%, not that much. But this isn't the important part.

Old:
* calls to allocation functions: 2109712
* temporary allocations: 33112
* bytes allocated in total (ignoring deallocations): 4.43 GB

New:
* calls to allocation functions: 2095345 (-0.68%)
* temporary allocations: 18745 (-43.39% !!!)
* bytes allocated in total (ignoring deallocations): 4.31 GB (-2.71%)

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

Reviewed By: courbet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D54383

llvm-svn: 347199
2018-11-19 13:28:17 +00:00
Roman Lebedev f8b28e9bf4 [llvm-exegesis] Analysis::writeSnippet(): be smarter about memory allocations.
Summary:
Test data: 500kLOC of benchmark.yaml, 23Mb. (that is a subset of the actual uops benchmark i was trying to analyze!)
Old time: (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    0m10.487s
user    0m9.745s
sys     0m0.740s
```
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    0m9.599s
user    0m8.824s
sys     0m0.772s

```
Not that much, around -9%. But that is not the good part yet, again.

Old:
* calls to allocation functions: 3347676
* temporary allocations: 277818
* bytes allocated in total (ignoring deallocations): 10.52 GB

New:
* calls to allocation functions: 2109712 (-36%)
* temporary allocations: 33112 (-88%)
* bytes allocated in total (ignoring deallocations): 4.43 GB (-58% *sic*)

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

Reviewed By: courbet, MaskRay

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D54382

llvm-svn: 347198
2018-11-19 13:28:14 +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
Fangrui Song 2e83b2e9ee Use llvm::{all,any,none}_of instead std::{all,any,none}_of. NFC
llvm-svn: 344774
2018-10-19 06:12:02 +00:00
Clement Courbet 5a768ddd44 [llvm-exegesis][NFC] Revert rL343682 "Fix unused variable warning".
That was not the proper fix: the variable is used in debug mode.

llvm-svn: 343685
2018-10-03 12:48:50 +00:00
Clement Courbet 8a5a6be47a [llvm-exegesis] Fix rL343680 in release mode.
llvm-svn: 343684
2018-10-03 12:35:35 +00:00
Clement Courbet af50a5b85f [llvm-exegesis][NFC] Fix unused variable warning.
llvm-svn: 343682
2018-10-03 12:27:43 +00:00
Clement Courbet d5a39553ff [llvm-exegesis] Resolve variant classes in analysis.
Summary: See PR38884.

Reviewers: gchatelet

Subscribers: tschuett, RKSimon, llvm-commits

Differential Revision: https://reviews.llvm.org/D52825

llvm-svn: 343680
2018-10-03 11:50:25 +00:00
Clement Courbet 30183093ab [llvm-exegesis] Fix PR39096.
Summary: The key is now the resource name, not the resource id.

Reviewers: gchatelet

Subscribers: tschuett, RKSimon, llvm-commits

Differential Revision: https://reviews.llvm.org/D52607

llvm-svn: 343208
2018-09-27 13:26:37 +00:00
Fangrui Song 0cac726a00 llvm::sort(C.begin(), C.end(), ...) -> llvm::sort(C, ...)
Summary: The convenience wrapper in STLExtras is available since rL342102.

Reviewers: dblaikie, javed.absar, JDevlieghere, andreadb

Subscribers: MatzeB, sanjoy, arsenm, dschuff, mehdi_amini, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, eraman, aheejin, kbarton, JDevlieghere, javed.absar, gbedwell, jrtc27, mgrang, atanasyan, steven_wu, george.burgess.iv, dexonsmith, kristina, jsji, llvm-commits

Differential Revision: https://reviews.llvm.org/D52573

llvm-svn: 343163
2018-09-27 02:13:45 +00:00
Clement Courbet 28d4f85824 [llvm-exegesis] Get rid of debug_string.
Summary:
THis is a backwards-compatible change (existing files will work as
expected).

See PR39082.

Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D52546

llvm-svn: 343108
2018-09-26 13:35:10 +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 4273e1e828 [llvm-exegesis] Print the whole snippet in analysis.
Summary:
On hover, the whole asm snippet is displayed, including operands.

This requires the actual assembly output instead of just the MCInsts:
This is because some pseudo-instructions get lowered to actual target
instructions during codegen (e.g. ABS_Fp32 -> SSE or X87).

Reviewers: gchatelet

Subscribers: mgorny, tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D48164

llvm-svn: 334805
2018-06-15 07:30:45 +00:00
Clement Courbet 49fad1cbf2 [llvm-exegesis] Use BenchmarkResult::Instructions instead of OpcodeName
Summary:
Get rid of OpcodeName.

To remove the opcode name from an old file:
```
cat old_file | sed '/opcode_name.*/d'
```

Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D48121

llvm-svn: 334691
2018-06-14 06:57:52 +00:00
Clement Courbet 62b34fa89a [llvm-exegesis] move Mode from Key to BenchmarResult.
Moves the Mode field out of the Key. The existing yaml benchmark results can be fixed with the following script:

```
readonly FILE=$1
readonly MODE=latency # Change to uops to fix a uops benchmark.
cat $FILE | \
  sed "/^\ \+mode:\ \+$MODE$/d" | \
  sed "/^cpu_name.*$/i mode:            $MODE"
```

Differential Revision: https://reviews.llvm.org/D47813

Authored by: Guillaume Chatelet

llvm-svn: 334079
2018-06-06 09:42:36 +00:00
Clement Courbet 2cb97b95a2 [llvm-exegesis][NFC] Use an enum instead of a string for benchmark mode.
Summary: YAML encoding is backwards-compatible.

Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D47705

llvm-svn: 333886
2018-06-04 11:43:40 +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 df79e79e22 [llvm-exegesis] Analysis: Display idealized sched class port pressure.
Summary: Screenshot in phabricator diff.

Reviewers: gchatelet

Subscribers: mgorny, tschuett, mgrang, llvm-commits

Differential Revision: https://reviews.llvm.org/D47329

llvm-svn: 333753
2018-06-01 14:18:02 +00:00
Clement Courbet ae8ae5dc78 [llvm-exegesis] Analysis: Show value extents.
Summary: Screenshot attached in phabricator.

Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D47318

llvm-svn: 333181
2018-05-24 12:41:02 +00:00
Clement Courbet b1f1b50da9 [llvm-exegesis] Analysis: show debug string instead of raw key if provided.
Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D47315

llvm-svn: 333175
2018-05-24 11:26:00 +00:00
Clement Courbet 2637e5f828 [llvm-exegesis] Show sched class details in analysis.
Summary: And update docs.

Reviewers: gchatelet

Subscribers: tschuett, craig.topper, RKSimon, llvm-commits

Differential Revision: https://reviews.llvm.org/D47254

llvm-svn: 333169
2018-05-24 10:47:05 +00:00
Clement Courbet 17d3c257b9 [llvm-exegesis] Analysis output uses HTML.
Summary: This makes the report much more readable.

Reviewers: gchatelet

Subscribers: tschuett, mgrang, craig.topper, RKSimon, llvm-commits

Differential Revision: https://reviews.llvm.org/D47189

llvm-svn: 332979
2018-05-22 13:31:29 +00:00
Clement Courbet a1bee62308 [llvm-exegesis] Remove redudant explicit template instantiations.
llvm-svn: 332611
2018-05-17 14:37:31 +00:00
Clement Courbet cf21074603 [llvm-exegesis] Write out inconsistencies to a file.
Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D47013

llvm-svn: 332608
2018-05-17 13:41:28 +00:00
Clement Courbet 448550d947 [llvm-exegesis] Analysis: detect clustering inconsistencies.
Summary:
Warn on instructions that should have the same performance
characteristics according to the sched model but actually
differ in their benchmarks.

Next step: Make the display nicer to browse, I was thinking maybe html.

Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D46945

llvm-svn: 332601
2018-05-17 12:25:18 +00:00
Clement Courbet c922e07796 [llvm-exegesis] Fix unused variable warning in release mode.
llvm-svn: 332455
2018-05-16 11:49:15 +00:00
Clement Courbet 4022b6c42f Fix unused variable warning in r332437.
llvm-svn: 332441
2018-05-16 09:10:04 +00:00
Clement Courbet 6d6c1a99d7 [llvm-exegesis] Analysis: Display sched class for instructions.
Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D46883

llvm-svn: 332437
2018-05-16 08:47:21 +00:00
Clement Courbet a66bfaa4c0 [llvm-exegesis] Split AsmTemplate.Name into components.
Summary:
AsmTemplate becomes IntructionBenchmarkKey, which has three components.
This allows retreiving the opcode for analysis.

Reviewers: gchatelet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D46873

llvm-svn: 332348
2018-05-15 13:07:05 +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 4623da8991 [llvm-exegesis] Fix a warning in r332221
comparison of integers of different signs: 'const unsigned long' and 'const int' [-Werror,-Wsign-compare]

unittests/tools/llvm-exegesis/BenchmarkResultTest.cpp:60:5: note: in instantiation of function template specialization 'testing::internal::EqHelper<false>::Compare<unsigned long, int>' requested here
    ASSERT_EQ(FromDiskVector.size(), 1);

llvm-svn: 332230
2018-05-14 11:31:02 +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