Add docs (llvm-lipo.rst) for llvm-lipo.

Test plan:
make -j8 sphinx 
check that ./docs/html/CommandGuide/llvm-lipo.html is built correctly and looks okay.

Differential revision: https://reviews.llvm.org/D62706

llvm-svn: 362848

On the Command Guide page, there are multiple sections with links to the
different documentation pages available for LLVM tools. The "Basic
Tools" section includes tools like llvm-objdump, llvm-nm and so on. The
"Developer Tools" section contains things like FileCheck and lit. This
change moves llvm-readobj into the former block, from the latter.

Reviewed by: MaskRay

Differential Revision: https://reviews.llvm.org/D63011

llvm-svn: 362813

Summary:
This patch is part of a patch series to add support for FileCheck
numeric expressions. This specific patch introduces support for defining
numeric variable in a CHECK directive.

This commit introduces support for defining numeric variable from a
litteral value in the input text. Numeric expressions can then use the
variable provided it is on a later line.

Copyright:
    - Linaro (changes up to diff 183612 of revision D55940)
    - GraphCore (changes in later versions of revision D55940 and
                 in new revision created off D55940)

Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk

Subscribers: hiraditya, llvm-commits, probinson, dblaikie, grimar, arichardson, tra, rnk, kristina, hfinkel, rogfer01, JonChesterfield

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60386

llvm-svn: 362705

Summary:
This updates all places in documentation that refer to "Mac OS X", "OS X", etc.
to instead use the modern name "macOS" when no specific version number is
mentioned.

If a specific version is mentioned, this attempts to use the OS name at the time
of that version:

* Mac OS X for 10.0 - 10.7
* OS X for 10.8 - 10.11
* macOS for 10.12 - present

Reviewers: JDevlieghere

Subscribers: mgorny, christof, arphaman, cfe-commits, lldb-commits, libcxx-commits, llvm-commits

Tags: #clang, #lldb, #libc, #llvm

Differential Revision: https://reviews.llvm.org/D62654

llvm-svn: 362113

Summary:
Terminology introduced by [[#]] blocks is confusing and does not
integrate well with existing terminology.

First, variables referred by [[]] blocks are called "pattern variables"
while the text a CHECK directive needs to match is called a "CHECK
pattern". This is inconsistent with variables in [[#]] blocks since
[[#]] blocks are also found in CHECK pattern yet those variables are
called "numeric variable".

Second, the replacing of both [[]] and [[#]] blocks by the value of the
variable or expression they contain is represented by a
FileCheckPatternSubstitution class. The naming refers to being a
substitution in a CHECK pattern but could be wrongly understood as being
a substitution of a pattern variable.

Third and lastly, comments use "numeric expression" to refer both to the
[[#]] blocks as well as to the numeric expressions these blocks contain
which get evaluated at match time.

This patch solves these confusions by
- calling variables in [[]] and [[#]] blocks as string and numeric
  variables respectively;
- referring to [[]] and [[#]] as substitution *blocks*, with the former
  being a string substitution block and the latter a numeric
  substitution block;
- calling [[]] and [[#]] blocks to be replaced by the value of a
  variable or expression they contain a substitution (as opposed to
  definition when these blocks are used to defined a variable), with the
  former being a string substitution and the latter a numeric
  substitution;
- renaming the FileCheckPatternSubstitution as a FileCheckSubstitution
  class with FileCheckStringSubstitution and
  FileCheckNumericSubstitution subclasses;
- restricting the use of "numeric expression" to refer to the expression
  that is evaluated in a numeric substitution.

While numeric substitution blocks only support numeric substitutions of
numeric expressions at the moment there are plans to augment numeric
substitution blocks to support numeric definitions as well as both a
numeric definition and numeric substitution in the same numeric
substitution block.

Reviewers: jhenderson, jdenny, probinson, arichardson

Subscribers: hiraditya, arichardson, probinson, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62146

llvm-svn: 361445

Summary:
Change example of input text from being llvm block to being gas block
since that text is made-up assembly.

Reviewers: jhenderson, jdenny, probinson, arichardson

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61893

llvm-svn: 360781

This reinstates r360578 (git e47362c1),
reverted in r360653 (git 00439368),
with a fix for the list added in FileCheck.rst to build without error.

Copyright:
    - Linaro (changes up to diff 183612 of revision D55940)
    - GraphCore (changes in later versions of revision D55940 and
                 in new revision created off D55940)

Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar,
arichardson, rnk

Subscribers: hiraditya, llvm-commits, probinson, dblaikie, grimar,
arichardson, tra, rnk, kristina, hfinkel, rogfer01, JonChesterfield

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60385

llvm-svn: 360665

This reverts r360578 (git e47362c1) to
solve the sphinx build failure on
http://lab.llvm.org:8011/builders/llvm-sphinx-docs buildbot.

llvm-svn: 360653

Summary:
This patch is part of a patch series to add support for FileCheck
numeric expressions. This specific patch introduces regular numeric
variables which can be set on the command-line.

This commit introduces regular numeric variable that can be set on the
command-line with the -D option to a numeric value. They can then be
used in CHECK patterns in numeric expression with the same shape as
@LINE numeric expression, ie. VAR, VAR+offset or VAR-offset where offset
is an integer literal.

The commit also enable strict whitespace in the verbose.txt testcase to
check that the position or the location diagnostics. It fixes one of the
existing CHECK in the process which was not accurately testing a
location diagnostic (ie. the diagnostic was correct, not the CHECK).

Copyright:
    - Linaro (changes up to diff 183612 of revision D55940)
    - GraphCore (changes in later versions of revision D55940 and
                 in new revision created off D55940)

Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk

Subscribers: hiraditya, llvm-commits, probinson, dblaikie, grimar, arichardson, tra, rnk, kristina, hfinkel, rogfer01, JonChesterfield

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60385

llvm-svn: 360578

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

Summary:
This patch is part of a patch series to add support for FileCheck
numeric expressions. This specific patch introduces the @LINE numeric
expressions.

This commit introduces a new syntax to express a relation a numeric
value in the input text must have with the line number of a given CHECK
pattern: [[#<@LINE numeric expression>]]. Further commits build on that
to express relations between several numeric values in the input text.
To help with naming, regular variables are renamed into pattern
variables and old @LINE expression syntax is referred to as legacy
numeric expression.

Compared to existing @LINE expressions, this new syntax allow arbitrary
spacing between the component of the expression. It offers otherwise the
same functionality but the commit serves to introduce some of the data
structure needed to support more general numeric expressions.

Copyright:
    - Linaro (changes up to diff 183612 of revision D55940)
    - GraphCore (changes in later versions of revision D55940 and
                 in new revision created off D55940)

Reviewers: jhenderson, chandlerc, jdenny, probinson, grimar, arichardson, rnk

Subscribers: hiraditya, llvm-commits, probinson, dblaikie, grimar, arichardson, tra, rnk, kristina, hfinkel, rogfer01, JonChesterfield

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60384

llvm-svn: 359741

llvm-svn: 359625

llvm-svn: 359619

Add overlap functionality to llvm-profdata tool to compute the similarity
between two profile files.

Differential Revision: https://reviews.llvm.org/D60977

llvm-svn: 359612

This adds an alias for llvm-symbolizer with different defaults so that
it can be used as a drop-in replacement for GNU's addr2line.

If a substring "addr2line" is found in the tool's name:
  * it defaults "-i", "-f" and "-C" to OFF;
  * it uses "--output-style=GNU" by default.

Differential Revision: https://reviews.llvm.org/D60067

llvm-svn: 358749

With the latest changes, the option gets useful for users of
llvm-symbolizer, not only for the upcoming llvm-addr2line.

Differential Revision: https://reviews.llvm.org/D60816

llvm-svn: 358748

llvm-svn: 358643

It makes more sense to print out the number of micro opcodes that are issued
every cycle rather than the number of instructions issued per cycle.
This behavior is also consistent with the dispatch-stats: numbers from the two
views can now be easily compared.

llvm-svn: 357919

Reviewers: courbet

Subscribers: llvm-commits, bdb

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60317

llvm-svn: 357769

Summary:
This is an alternative to D59539.

Let's suppose we have measured 4 different opcodes, and got: `0.5`, `1.0`, `1.5`, `2.0`.
Let's suppose we are using `-analysis-clustering-epsilon=0.5`.
By default now we will start processing the `0.5` point, find that `1.0` is it's neighbor, add them to a new cluster.
Then we will notice that `1.5` is a neighbor of `1.0` and add it to that same cluster.
Then we will notice that `2.0` is a neighbor of `1.5` and add it to that same cluster.
So all these points ended up in the same cluster.
This may or may not be a correct implementation of dbscan clustering algorithm.

But this is rather horribly broken for the reasons of comparing the clusters with the LLVM sched data.
Let's suppose all those opcodes are currently in the same sched cluster.
If i specify `-analysis-inconsistency-epsilon=0.5`, then no matter
the LLVM values this cluster will **never** match the LLVM values,
and thus this cluster will **always** be displayed as inconsistent.

The solution is obviously to split off some of these opcodes into different sched cluster.
But how do i do that? Out of 4 opcodes displayed in the inconsistency report,
which ones are the "bad ones"? Which ones are the most different from the checked-in data?
I'd need to go in to the `.yaml` and look it up manually.

The trivial solution is to, when creating clusters, don't use the full dbscan algorithm,
but instead "pick some unclustered point, pick all unclustered points that are it's neighbor,
put them all into a new cluster, repeat". And just so as it happens, we can arrive
at that algorithm by not performing the "add neighbors of a neighbor to the cluster" step.

But that won't work well once we teach analyze mode to operate in on-1D mode
(i.e. on more than a single measurement type at a time), because the clustering would
depend on the order of the measurements.

Instead, let's just create a single cluster per opcode, and put all the points of that opcode into said cluster.
And simultaneously check that every point in that cluster is a neighbor of every other point in the cluster,
and if they are not, the cluster (==opcode) is unstable.

This is //yet another// step to bring me closer to being able to continue cleanup of bdver2 sched model..

Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=40880 | PR40880 ]].

Reviewers: courbet, gchatelet

Reviewed By: courbet

Subscribers: tschuett, jdoerfert, RKSimon, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59820

llvm-svn: 357152

A section containing metadata on remark diagnostics will be emitted if
the flag (-mllvm) -remarks-section is present.

For now, the metadata is:

* a magic number for remarks: "REMARKS\0"
* the version number: a little-endian uint64_t
* the absolute file path to the serialized remark diagnostics: a
  null-terminated string.

Differential Revision: https://reviews.llvm.org/D59571

llvm-svn: 357043

Summary:
CoverageExporterJson::renderFiles accounts for most of the execution time given a large profdata file with multiple binaries.

Proposed solution is to generate JSON for each file in parallel and sort at the end to preserve deterministic output. Also added flags to skip generating parts of the output to trim the output size.

Patch by Sajjad Mirza (@sajjadm).

Reviewers: Dor1s, vsk

Reviewed By: Dor1s, vsk

Subscribers: liaoyuke, mgrang, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59277

llvm-svn: 356178

This patch adds a new flag named -bottleneck-analysis to print out information
about throughput bottlenecks.

MCA knows how to identify and classify dynamic dispatch stalls. However, it
doesn't know how to analyze and highlight kernel bottlenecks.  The goal of this
patch is to teach MCA how to correlate increases in backend pressure to backend
stalls (and therefore, the loss of throughput).

From a Scheduler point of view, backend pressure is a function of the scheduler
buffer usage (i.e. how the number of uOps in the scheduler buffers changes over
time). Backend pressure increases (or decreases) when there is a mismatch
between the number of opcodes dispatched, and the number of opcodes issued in
the same cycle.  Since buffer resources are limited, continuous increases in
backend pressure would eventually leads to dispatch stalls. So, there is a
strong correlation between dispatch stalls, and how backpressure changed over
time.

This patch teaches how to identify situations where backend pressure increases
due to:
 - unavailable pipeline resources.
 - data dependencies.

Data dependencies may delay execution of instructions and therefore increase the
time that uOps have to spend in the scheduler buffers. That often translates to
an increase in backend pressure which may eventually lead to a bottleneck.
Contention on pipeline resources may also delay execution of instructions, and
lead to a temporary increase in backend pressure.

Internally, the Scheduler classifies instructions based on whether register /
memory operands are available or not.

An instruction is marked as "ready to execute" only if data dependencies are
fully resolved.
Every cycle, the Scheduler attempts to execute all instructions that are ready
to execute. If an instruction cannot execute because of unavailable pipeline
resources, then the Scheduler internally updates a BusyResourceUnits mask with
the ID of each unavailable resource.

ExecuteStage is responsible for tracking changes in backend pressure. If backend
pressure increases during a cycle because of contention on pipeline resources,
then ExecuteStage sends a "backend pressure" event to the listeners.
That event would contain information about instructions delayed by resource
pressure, as well as the BusyResourceUnits mask.

Note that ExecuteStage also knows how to identify situations where backpressure
increased because of delays introduced by data dependencies.

The SummaryView observes "backend pressure" events and prints out a "bottleneck
report".

Example of bottleneck report:

```
Cycles with backend pressure increase [ 99.89% ]
Throughput Bottlenecks:
  Resource Pressure       [ 0.00% ]
  Data Dependencies:      [ 99.89% ]
   - Register Dependencies [ 0.00% ]
   - Memory Dependencies   [ 99.89% ]
```

A bottleneck report is printed out only if increases in backend pressure
eventually caused backend stalls.

About the time complexity:

Time complexity is linear in the number of instructions in the
Scheduler::PendingSet.

The average slowdown tends to be in the range of ~5-6%.
For memory intensive kernels, the slowdown can be significant if flag
-noalias=false is specified. In the worst case scenario I have observed a
slowdown of ~30% when flag -noalias=false was specified.

We can definitely recover part of that slowdown if we optimize class LSUnit (by
doing extra bookkeeping to speedup queries). For now, this new analysis is
disabled by default, and it can be enabled via flag -bottleneck-analysis. Users
of MCA as a library can enable the generation of pressure events through the
constructor of ExecuteStage.

This patch partially addresses https://bugs.llvm.org/show_bug.cgi?id=37494

Differential Revision: https://reviews.llvm.org/D58728

llvm-svn: 355308

Part 2 of CSPGO changes (mostly related to ProfileSummary).
Note that I use a default parameter in setProfileSummary() and getSummary().
This is to break the dependency in clang. I will make the parameter explicit
after changing clang in a separated patch.

Differential Revision: https://reviews.llvm.org/D54175

llvm-svn: 355131

Summary:
This eps param is used for two distinct things:
* initial point clusterization
* checking clusters against the llvm values

What if one wants to only look at highly different clusters, without changing
the clustering itself? In particular, this helps to weed out noisy measurements
(since the clusterization epsilon is still small, so there is a better chance
that noisy measurements from the same opcode will go into different clusters)

By splitting it into two params it is now possible.

This is nearly-free performance-wise:
Old:
```
$ perf stat -r 25 ./bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency-1.yaml -analysis-inconsistencies-output-file=/tmp/clusters-old.html
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 10099 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-old.html'
...
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency-1.yaml -analysis-inconsistencies-output-file=/tmp/clusters-old.html' (25 runs):

            390.01 msec task-clock                #    0.998 CPUs utilized            ( +-  0.25% )
                12      context-switches          #   31.735 M/sec                    ( +- 27.38% )
                 0      cpu-migrations            #    0.000 K/sec
              4745      page-faults               # 12183.732 M/sec                   ( +-  0.54% )
        1562711900      cycles                    # 4012303.327 GHz                   ( +-  0.24% )  (82.90%)
         185567822      stalled-cycles-frontend   #   11.87% frontend cycles idle     ( +-  0.52% )  (83.30%)
         392106234      stalled-cycles-backend    #   25.09% backend cycles idle      ( +-  1.31% )  (33.79%)
        1839236666      instructions              #    1.18  insn per cycle
                                                  #    0.21  stalled cycles per insn  ( +-  0.15% )  (50.37%)
         407035764      branches                  # 1045074878.710 M/sec              ( +-  0.12% )  (66.80%)
          10896459      branch-misses             #    2.68% of all branches          ( +-  0.17% )  (83.20%)

          0.390629 +- 0.000972 seconds time elapsed  ( +-  0.25% )
```
```
$ perf stat -r 9 ./bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency.yml -analysis-inconsistencies-output-file=/tmp/clusters-old.html
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 50572 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-old.html'
...
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency.yml -analysis-inconsistencies-output-file=/tmp/clusters-old.html' (9 runs):

           6803.36 msec task-clock                #    0.999 CPUs utilized            ( +-  0.96% )
               262      context-switches          #   38.546 M/sec                    ( +- 23.06% )
                 0      cpu-migrations            #    0.065 M/sec                    ( +- 76.03% )
             13287      page-faults               # 1953.206 M/sec                    ( +-  0.32% )
       27252537904      cycles                    # 4006024.257 GHz                   ( +-  0.95% )  (83.31%)
        1496314935      stalled-cycles-frontend   #    5.49% frontend cycles idle     ( +-  0.97% )  (83.32%)
       16128404524      stalled-cycles-backend    #   59.18% backend cycles idle      ( +-  0.30% )  (33.37%)
       17611143370      instructions              #    0.65  insn per cycle
                                                  #    0.92  stalled cycles per insn  ( +-  0.05% )  (50.04%)
        3894906599      branches                  # 572537147.437 M/sec               ( +-  0.03% )  (66.69%)
         116314514      branch-misses             #    2.99% of all branches          ( +-  0.20% )  (83.35%)

            6.8118 +- 0.0689 seconds time elapsed  ( +-  1.01%)
```
New:
```
$ perf stat -r 25 ./bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency-1.yaml -analysis-inconsistencies-output-file=/tmp/clusters-new.html
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 10099 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-new.html'
...
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency-1.yaml -analysis-inconsistencies-output-file=/tmp/clusters-new.html' (25 runs):

            400.14 msec task-clock                #    0.998 CPUs utilized            ( +-  0.66% )
                12      context-switches          #   29.429 M/sec                    ( +- 25.95% )
                 0      cpu-migrations            #    0.100 M/sec                    ( +-100.00% )
              4714      page-faults               # 11796.496 M/sec                   ( +-  0.55% )
        1603131306      cycles                    # 4011840.105 GHz                   ( +-  0.66% )  (82.85%)
         199538509      stalled-cycles-frontend   #   12.45% frontend cycles idle     ( +-  2.40% )  (83.10%)
         402249109      stalled-cycles-backend    #   25.09% backend cycles idle      ( +-  1.19% )  (34.05%)
        1847783963      instructions              #    1.15  insn per cycle
                                                  #    0.22  stalled cycles per insn  ( +-  0.18% )  (50.64%)
         407162722      branches                  # 1018925730.631 M/sec              ( +-  0.12% )  (67.02%)
          10932779      branch-misses             #    2.69% of all branches          ( +-  0.51% )  (83.28%)

           0.40077 +- 0.00267 seconds time elapsed  ( +-  0.67% )

lebedevri@pini-pini:/build/llvm-build-Clang-release$ perf stat -r 9 ./bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency.yml -analysis-inconsistencies-output-file=/tmp/clusters-new.html
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 50572 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-new.html'
...
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency.yml -analysis-inconsistencies-output-file=/tmp/clusters-new.html' (9 runs):

           6947.79 msec task-clock                #    1.000 CPUs utilized            ( +-  0.90% )
               217      context-switches          #   31.236 M/sec                    ( +- 36.16% )
                 1      cpu-migrations            #    0.096 M/sec                    ( +- 50.00% )
             13258      page-faults               # 1908.389 M/sec                    ( +-  0.34% )
       27830796523      cycles                    # 4006032.286 GHz                   ( +-  0.89% )  (83.30%)
        1504554006      stalled-cycles-frontend   #    5.41% frontend cycles idle     ( +-  2.10% )  (83.32%)
       16716574843      stalled-cycles-backend    #   60.07% backend cycles idle      ( +-  0.65% )  (33.38%)
       17755545931      instructions              #    0.64  insn per cycle
                                                  #    0.94  stalled cycles per insn  ( +-  0.09% )  (50.04%)
        3897255686      branches                  # 560980426.597 M/sec               ( +-  0.06% )  (66.70%)
         117045395      branch-misses             #    3.00% of all branches          ( +-  0.47% )  (83.34%)

            6.9507 +- 0.0627 seconds time elapsed  ( +-  0.90% )
```

I.e. it's +2.6% slowdown for one whole sweep, or +2% for 5 whole sweeps.
Within noise i'd say.

Should help with [[ https://bugs.llvm.org/show_bug.cgi?id=40787 | PR40787 ]].

Reviewers: courbet, gchatelet

Reviewed By: courbet

Subscribers: tschuett, RKSimon, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58476

llvm-svn: 354767

Summary:
Given an instruction `Opcode`, we can make benchmarks (measurements) of the
instruction characteristics/performance. Then, to facilitate further analysis
we group the benchmarks with *similar* characteristics into clusters.
Now, this is all not entirely deterministic. Some instructions have variable
characteristics, depending on their arguments. And thus, if we do several
benchmarks of the same instruction `Opcode`, we may end up with *different*
performance characteristics measurements. And when we then do clustering,
these several benchmarks of the same instruction `Opcode` may end up being
clustered into *different* clusters. This is not great for further analysis.

We shall find every `Opcode` with benchmarks not in just one cluster, and move
*all* the benchmarks of said `Opcode` into one new unstable cluster per `Opcode`.

I have solved this by making `ClusterId` a bit field, adding a `IsUnstable` bit,
and introducing `-analysis-display-unstable-clusters` switch to toggle between
displaying stable-only clusters and unstable-only clusters.

The reclusterization is deterministically stable, produces identical reports
between runs. (Or at least that is what i'm seeing, maybe it isn't)

Timings/comparisons:
old (current trunk/head) {F8303582}
```
$ perf stat -r 25 ./bin/llvm-exegesis -mode=analysis -analysis-epsilon=0.5 -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-inverse_throughput.yaml -analysis-inconsistencies-output-file=/tmp/clusters-old.html
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 43970 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-old.html'
...
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 43970 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-old.html'

 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=0.5 -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-inverse_throughput.yaml -analysis-inconsistencies-output-file=/tmp/clusters-old.html' (25 runs):

           6624.73 msec task-clock                #    0.999 CPUs utilized            ( +-  0.53% )
               172      context-switches          #   25.965 M/sec                    ( +- 29.89% )
                 0      cpu-migrations            #    0.042 M/sec                    ( +- 56.54% )
             31073      page-faults               # 4690.754 M/sec                    ( +-  0.08% )
       26538711696      cycles                    # 4006230.292 GHz                   ( +-  0.53% )  (83.31%)
        2017496807      stalled-cycles-frontend   #    7.60% frontend cycles idle     ( +-  0.93% )  (83.32%)
       13403650062      stalled-cycles-backend    #   50.51% backend cycles idle      ( +-  0.33% )  (33.37%)
       19770706799      instructions              #    0.74  insn per cycle
                                                  #    0.68  stalled cycles per insn  ( +-  0.04% )  (50.04%)
        4419821812      branches                  # 667207369.714 M/sec               ( +-  0.03% )  (66.69%)
         121741669      branch-misses             #    2.75% of all branches          ( +-  0.28% )  (83.34%)

            6.6283 +- 0.0358 seconds time elapsed  ( +-  0.54% )
```

patch, with reclustering but without filtering (i.e. outputting all the stable *and* unstable clusters) {F8303586}
```
$ perf stat -r 25 ./bin/llvm-exegesis -mode=analysis -analysis-epsilon=0.5 -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-inverse_throughput.yaml -analysis-inconsistencies-output-file=/tmp/clusters-new-all.html
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 43970 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-new-all.html'
...
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 43970 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-new-all.html'

 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=0.5 -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-inverse_throughput.yaml -analysis-inconsistencies-output-file=/tmp/clusters-new-all.html' (25 runs):

           6475.29 msec task-clock                #    0.999 CPUs utilized            ( +-  0.31% )
               213      context-switches          #   32.952 M/sec                    ( +- 23.81% )
                 1      cpu-migrations            #    0.130 M/sec                    ( +- 43.84% )
             31287      page-faults               # 4832.057 M/sec                    ( +-  0.08% )
       25939086577      cycles                    # 4006160.279 GHz                   ( +-  0.31% )  (83.31%)
        1958812858      stalled-cycles-frontend   #    7.55% frontend cycles idle     ( +-  0.68% )  (83.32%)
       13218961512      stalled-cycles-backend    #   50.96% backend cycles idle      ( +-  0.29% )  (33.37%)
       19752995402      instructions              #    0.76  insn per cycle
                                                  #    0.67  stalled cycles per insn  ( +-  0.04% )  (50.04%)
        4417079244      branches                  # 682195472.305 M/sec               ( +-  0.03% )  (66.70%)
         121510065      branch-misses             #    2.75% of all branches          ( +-  0.19% )  (83.34%)

            6.4832 +- 0.0229 seconds time elapsed  ( +-  0.35% )
```
Funnily, *this* measurement shows that said reclustering actually improved performance.

patch, with reclustering, only the stable clusters {F8303594}
```
$ perf stat -r 25 ./bin/llvm-exegesis -mode=analysis -analysis-epsilon=0.5 -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-inverse_throughput.yaml -analysis-inconsistencies-output-file=/tmp/clusters-new-stable.html
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 43970 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-new-stable.html'
...
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 43970 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-new-stable.html'

 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=0.5 -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-inverse_throughput.yaml -analysis-inconsistencies-output-file=/tmp/clusters-new-stable.html' (25 runs):

           6387.71 msec task-clock                #    0.999 CPUs utilized            ( +-  0.13% )
               133      context-switches          #   20.792 M/sec                    ( +- 23.39% )
                 0      cpu-migrations            #    0.063 M/sec                    ( +- 61.24% )
             31318      page-faults               # 4903.256 M/sec                    ( +-  0.08% )
       25591984967      cycles                    # 4006786.266 GHz                   ( +-  0.13% )  (83.31%)
        1881234904      stalled-cycles-frontend   #    7.35% frontend cycles idle     ( +-  0.25% )  (83.33%)
       13209749965      stalled-cycles-backend    #   51.62% backend cycles idle      ( +-  0.16% )  (33.36%)
       19767554347      instructions              #    0.77  insn per cycle
                                                  #    0.67  stalled cycles per insn  ( +-  0.04% )  (50.03%)
        4417480305      branches                  # 691618858.046 M/sec               ( +-  0.03% )  (66.68%)
         118676358      branch-misses             #    2.69% of all branches          ( +-  0.07% )  (83.33%)

            6.3954 +- 0.0118 seconds time elapsed  ( +-  0.18% )
```
Performance improved even further?! Makes sense i guess, less clusters to print.

patch, with reclustering, only the unstable clusters {F8303601}
```
$ perf stat -r 25 ./bin/llvm-exegesis -mode=analysis -analysis-epsilon=0.5 -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-inverse_throughput.yaml -analysis-inconsistencies-output-file=/tmp/clusters-new-unstable.html -analysis-display-unstable-clusters
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 43970 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-new-unstable.html'
...
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 43970 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-new-unstable.html'

 Performance counter stats for './bin/llvm-exegesis -mode=analysis -analysis-epsilon=0.5 -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-inverse_throughput.yaml -analysis-inconsistencies-output-file=/tmp/clusters-new-unstable.html -analysis-display-unstable-clusters' (25 runs):

           6124.96 msec task-clock                #    1.000 CPUs utilized            ( +-  0.20% )
               194      context-switches          #   31.709 M/sec                    ( +- 20.46% )
                 0      cpu-migrations            #    0.039 M/sec                    ( +- 49.77% )
             31413      page-faults               # 5129.261 M/sec                    ( +-  0.06% )
       24536794267      cycles                    # 4006425.858 GHz                   ( +-  0.19% )  (83.31%)
        1676085087      stalled-cycles-frontend   #    6.83% frontend cycles idle     ( +-  0.46% )  (83.32%)
       13035595603      stalled-cycles-backend    #   53.13% backend cycles idle      ( +-  0.16% )  (33.36%)
       18260877653      instructions              #    0.74  insn per cycle
                                                  #    0.71  stalled cycles per insn  ( +-  0.05% )  (50.03%)
        4112411983      branches                  # 671484364.603 M/sec               ( +-  0.03% )  (66.68%)
         114066929      branch-misses             #    2.77% of all branches          ( +-  0.11% )  (83.32%)

            6.1278 +- 0.0121 seconds time elapsed  ( +-  0.20% )
```
This tells us that the actual `-analysis-inconsistencies-output-file=` outputting only takes ~0.4 sec for 43970 benchmark points (3 whole sweeps)
(Also, wow this is fast, it used to take several minutes originally)

Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=40715 | PR40715 ]].

Reviewers: courbet, gchatelet

Reviewed By: courbet

Subscribers: tschuett, jdoerfert, llvm-commits, RKSimon

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58355

llvm-svn: 354441

The patch adds support for --hash-filenames to llvm-cov. This option adds md5
hash of the source path to the name of the generated .gcov file. The option is
crucial for cases where you have multiple files with the same name but can't
use --preserve-paths as resulting filenames exceed the limit.

from gcov(1):

```
-x
--hash-filenames
    By default, gcov uses the full pathname of the source files to to
    create an output filename.  This can lead to long filenames that
    can overflow filesystem limits.  This option creates names of the
    form source-file##md5.gcov, where the source-file component is
    the final filename part and the md5 component is calculated from
    the full mangled name that would have been used otherwise.
```

Patch by Igor Ignatev!

Differential Revision: https://reviews.llvm.org/D58370

llvm-svn: 354379

Reviewers: courbet, gchatelet

Reviewed By: courbet, gchatelet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D54895

llvm-svn: 354250

Summary:
Up until the point i have looked in the source, i didn't even understood that
i can disable 'cluster' output. I have always silenced it via ` &> /dev/null`.
(And hoped it wasn't contributing much of the run time.)

While i expect that it has it's use-cases i never once needed it so far.
If i forget to silence it, console is completely flooded with that output.

How about not expecting users to opt-out of analyses,
but to explicitly specify the analyses that should be performed?

Reviewers: courbet, gchatelet

Reviewed By: courbet

Subscribers: tschuett, RKSimon, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D57648

llvm-svn: 353021

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

The address isn't dynamically relocated. The object is.

llvm-svn: 352477

If a stack trace or similar has a list of addresses from an executable
or DSO loaded at a variable address (e.g. due to ASLR), the addresses
will not directly correspond to the addresses stored in the object file.
If a user wishes to use llvm-symbolizer, they have to subtract the load
address from every address. This is somewhat inconvenient, especially as
the output of --print-address will result in the adjusted address being
listed, rather than the address coming from the stack trace, making it
harder to map results between the two.

This change adds a new switch to llvm-symbolizer --adjust-vma which
takes an offset, which is then used to automatically do this
calculation. The printed address remains the input address (allowing for
easy mapping), whilst the specified offset is applied to the addresses
when performing the lookup.

The switch is conceptually similar to llvm-objdump's new switch of the
same name (see D57051), which in turn mirrors a GNU switch. There is no
equivalent switch in addr2line.

Reviewed by: grimar

Differential Revision: https://reviews.llvm.org/D57151

llvm-svn: 352195

This change adds two options, -i and -inlines as aliases for the -inlining option to llvm-symbolizer to improve compatibility with the GNU addr2line utility which accepts these options.

It also modifies existing tests that use -inlining to exercise these new aliases as well.

This fixes PR40073.

Reviewed by: jhenderson, Quolyk, ruiu

Differential Revision: https://reviews.llvm.org/D57083

llvm-svn: 351999

This fixes https://bugs.llvm.org/show_bug.cgi?id=40072.

GNU addr2line's --functions switch is off by default, has a short alias
of -f, and does not take an argument. This patch changes llvm-symbolizer
to allow the second and third point (changing the default behaviour may
have negative impacts on users). If the option is missing a value, it
now treats it as "linkage".

This change does cause one previously valid command-line to behave
differently. Before --functions <value> was accepted, but now only
--functions=<value> is allowed (as well as --functions). The old
behaviour will result in the value being treated as a positional
argument.

The previous testing for --functions=short has been pulled out into a
new test that also tests the other accepted values and option formats.

Reviewed by: ruiu

Differential Revision: https://reviews.llvm.org/D57049

llvm-svn: 351968

The old diagnostic form of the trace produced by -v and -vv looks
like:

```
check1:1:8: remark: CHECK: expected string found in input
CHECK: abc
       ^
<stdin>:1:3: note: found here
; abc def
  ^~~
```

When dumping annotated input is requested (via -dump-input), I find
that this old trace is not useful and is sometimes harmful:

1. The old trace is mostly redundant because the same basic
   information also appears in the input dump's annotations.

2. The old trace buries any error diagnostic between it and the input
   dump, but I find it useful to see any error diagnostic up front.

3. FILECHECK_OPTS=-dump-input=fail requests annotated input dumps only
   for failed FileCheck calls.  However, I have to also add -v or -vv
   to get a full set of annotations, and that can produce massive
   output from all FileCheck calls in all tests.  That's a real
   problem when I run this in the IDE I use, which grinds to a halt as
   it tries to capture all that output.

When -dump-input=fail|always, this patch suppresses the old trace from
-v or -vv.  Error diagnostics still print as usual.  If you want the
old trace, perhaps to see variable expansions, you can set
-dump-input=none (the default).

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D55825

llvm-svn: 351881

This fixes https://bugs.llvm.org/show_bug.cgi?id=40068.

--basenames is a GNU addr2line switch which strips the directory names
from the file path in the output.

Reviewed by: ruiu

Differential Revision: https://reviews.llvm.org/D56919

llvm-svn: 351795

Summary: Provides -no-demangle as alias for -demangle=false. Motivation: https://bugs.llvm.org/show_bug.cgi?id=40075

Reviewers: jhenderson, ruiu

Reviewed By: jhenderson

Subscribers: erik.pilkington, rupprecht, llvm-commits

Differential Revision: https://reviews.llvm.org/D56773

llvm-svn: 351735

This change adds demangling support to the ELF side of llvm-readobj,
under the switch --demangle/-C.

The following places are demangled: symbol table dumps (static and
dynamic), relocation dumps (static and dynamic), addrsig dumps, call
graph profile dumps, and group section signature symbols.

Although GNU readelf doesn't support demangling, it is still a useful
feature to have, and brings it on a par with llvm-objdump's
capabilities.

This fixes https://bugs.llvm.org/show_bug.cgi?id=40054.

Reviewed by: grimar, rupprecht

Differential Revision: https://reviews.llvm.org/D56791

llvm-svn: 351450

Summary: Provides -C as alias to -demangle. Motivation: https://bugs.llvm.org/show_bug.cgi?id=40069.

Reviewers: jhenderson, ruiu, rnk, fjricci

Reviewed By: jhenderson, ruiu

Subscribers: rupprecht, erik.pilkington, llvm-commits

Differential Revision: https://reviews.llvm.org/D56591

llvm-svn: 351300

Summary:
When running llvm-objdump with the -macho option objdump will by default
disassemble only the __TEXT,__text section (or __TEXT_EXEC,__text when
disassembling MH_KEXT_BUNDLE files). The -disassemble-all option is
treated no diferently than -disassemble.

This change upates llvm-objdump's MachO parsing code to disassemble all
__text sections found in a file when -disassemble-all is specified. This
is useful for disassembling files with more than one __text section, or
when disassembling files whose __text section is not present in __TEXT.

I added a lit test case that verifies "llvm-objdump -m -d" and 
"llvm-objdump -m -D" produce the expected results on a reference binary. 
I also updated the CommandGuide documentation for llvm-objdump.rst and
verified it renders correctly as man and html.

rdar://42899338

Reviewers: ab, pete, lhames

Reviewed By: lhames

Subscribers: rupprecht, llvm-commits

Differential Revision: https://reviews.llvm.org/D56649

llvm-svn: 351238