The basic idea of the pass is to use a circular buffer to log the execution ordering of the functions. We only log the function when it is first executed. We use a 8-byte hash to log the function symbol name.
In this pass, we add three global variables:
(1) an order file buffer: a circular buffer at its own llvm section.
(2) a bitmap for each module: one byte for each function to say if the function is already executed.
(3) a global index to the order file buffer.
At the function prologue, if the function has not been executed (by checking the bitmap), log the function hash, then atomically increase the index.
Differential Revision: https://reviews.llvm.org/D57463
llvm-svn: 355133
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
Current PGO profile counts are not context sensitive. The branch probabilities
for the inlined functions are kept the same for all call-sites, and they might
be very different from the actual branch probabilities. These suboptimal
profiles can greatly affect some downstream optimizations, in particular for
the machine basic block placement optimization.
In this patch, we propose to have a post-inline PGO instrumentation/use pass,
which we called Context Sensitive PGO (CSPGO). For the users who want the best
possible performance, they can perform a second round of PGO instrument/use on
the top of the regular PGO. They will have two sets of profile counts. The
first pass profile will be manly for inline, indirect-call promotion, and
CGSCC simplification pass optimizations. The second pass profile is for
post-inline optimizations and code-gen optimizations.
A typical usage:
// Regular PGO instrumentation and generate pass1 profile.
> clang -O2 -fprofile-generate source.c -o gen
> ./gen
> llvm-profdata merge default.*profraw -o pass1.profdata
// CSPGO instrumentation.
> clang -O2 -fprofile-use=pass1.profdata -fcs-profile-generate -o gen2
> ./gen2
// Merge two sets of profiles
> llvm-profdata merge default.*profraw pass1.profdata -o profile.profdata
// Use the combined profile. Pass manager will invoke two PGO use passes.
> clang -O2 -fprofile-use=profile.profdata -o use
This change touches many components in the compiler. The reviewed patch
(D54175) will committed in phrases.
Differential Revision: https://reviews.llvm.org/D54175
llvm-svn: 354930
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
Summary:
The motivating use case is eliminating duplicate profile data registered
for the same inline function in two object files. Before this change,
users would observe multiple symbol definition errors with VC link, but
links with LLD would succeed.
Users (Mozilla) have reported that PGO works well with clang-cl and LLD,
but when using LLD without this static registration, we would get into a
"relocation against a discarded section" situation. I'm not sure what
happens in that situation, but I suspect that duplicate, unused profile
information was retained. If so, this change will reduce the size of
such binaries with LLD.
Now, Windows uses static registration and is in line with all the other
platforms.
Reviewers: davidxl, wmi, inglorion, void, calixte
Subscribers: mgorny, krytarowski, eraman, fedor.sergeev, hiraditya, #sanitizers, dmajor, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D57929
llvm-svn: 353547
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
We need to keep the underlying profile reader alive as long as the
profile data, because the profile data may contain StringRefs referring
to strings in the reader's name table.
llvm-svn: 349600
Summary:
The goal of this patch is to have the same behaviour than gcc-gcov.
Currently the hit counts for a line is the sum of the counts for each block on that line.
The idea is to detect the cycles in the graph of blocks in using the algorithm by Hawick & James.
The count for a cycle is the min of the counts for each edge in the cycle.
Once we've the count for each cycle, we can sum them and add the transition counts of those cycles.
Fix both https://bugs.llvm.org/show_bug.cgi?id=38065 and https://bugs.llvm.org/show_bug.cgi?id=38066
Reviewers: marco-c, davidxl
Reviewed By: marco-c
Subscribers: vsk, lebedev.ri, sylvestre.ledru, dblaikie, llvm-commits
Differential Revision: https://reviews.llvm.org/D49659
llvm-svn: 342657
The patch saves a function offset table which maps function name index to the
offset of its function profile to the start of the binary profile. By using
the function offset table, for those function profiles which will not be used
when compiling a module, the profile reader does't have to read them. For
profile size around 10~20M, it saves ~10% compile time.
Differential Revision: https://reviews.llvm.org/D51863
llvm-svn: 342283
The patch tries to make sample profile loader independent of profile format
change. It moves compact format related code into FunctionSamples and
SampleProfileReader classes, and sample profile loader only has to interact
with those two classes and will be unaware of profile format changes.
The cleanup also contain some fixes to further remove the difference between
compactbinary format and binary format. After the cleanup using different
formats originated from the same profile will generate the same binaries,
which we verified by compiling two large server benchmarks w/wo thinlto.
Differential Revision: https://reviews.llvm.org/D51643
llvm-svn: 341591
Summary:
The GCOV API can be used to parse gcda/gcno files, but in order to implement custom output formats, users need to reimplement everything.
If the FileInfo members were protected instead of private, they'd be able to reuse the code.
Reviewers: bogner, davide, scott.smith
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D41802
llvm-svn: 338013
Name table occupies a big chunk of size in current binary format sample profile.
In order to reduce its size, the patch changes the sample writer/reader to
save/restore MD5Hash of names in the name table. Sample annotation phase will
also use MD5Hash of name to query samples accordingly.
Experiment shows compact binary format can reduce the size of sample profile by
2/3 compared with binary format generally.
Differential Revision: https://reviews.llvm.org/D47955
llvm-svn: 334447
Summary:
Don't skip functions with the same name but from different files.
That change makes it possible to generate code coverage reports from
different binaries compiled from different sources even if there are functions
with non-unique names. Without that change, code coverage for such functions is
missing except of the first function processed.
Reviewers: vsk, morehouse
Reviewed By: vsk
Subscribers: llvm-commits, kcc
Differential Revision: https://reviews.llvm.org/D46478
llvm-svn: 331801
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Differential Revision: https://reviews.llvm.org/D46290
llvm-svn: 331272
Summary:
r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-determinism caused due to undefined sorting
order of objects having the same key.
To make use of that infrastructure we need to invoke llvm::sort instead of std::sort.
Note: This patch is one of a series of patches to replace *all* std::sort to llvm::sort.
Refer the comments section in D44363 for a list of all the required patches.
Reviewers: echristo, zturner, mzolotukhin, lhames
Reviewed By: echristo
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45135
llvm-svn: 328940
Summary:
This reverts commit 364eb09576a7667bc6d3ff80c52a83014ccac976 and separates out
the portion that was fixing binary reader error propagation - turns out, there
are production cases where that causes a regression.
Will re-introduce the error propagation fix separately.
The fix to the text reader error propagation is still "in".
Reviewers: bkramer
Reviewed By: bkramer
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44807
llvm-svn: 328244
Summary:
This fixes a unittest failure introduced by D44717
D44717 introduced lazy sorting of the internal data structures of the
symbol table. The AddrToMD5Map getter was potentially exposing
inconsistent (unsorted) state. We could sort in the accessor, however,
a client may store the pointer and thus bypass the internal state
management of the symbol table. The alternative in this CL blocks
direct access to the state, thus ensuring consistent
externally-observable state.
Reviewers: davidxl, xur, eraman
Reviewed By: xur
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44757
llvm-svn: 328163
Summary:
External functions appearing as indirect call targets could not be
found in the SymTab, and the value:counter record was represented,
in the text format, using an empty string for the name. This would
then cause a silent parsing error when reading.
This CL:
- adds explicit support for such functions
- fixes the places where we would not propagate errors when reading
- addresses a performance issue due to eager resorting of the SymTab.
Reviewers: xur, eraman, davidxl
Reviewed By: davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44717
llvm-svn: 328132
Summary:
Exposing getOffset and findFunctionSamples as members of
SampleProfile. They are intimately tied to design choices of the
sample profile format - using offsets instead of line numbers, and
traversing inlined functions stack, respectively.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43605
llvm-svn: 325747
This change swaps FunctionSamples to a std::map. This saves us around
17% of the memory required to parse sample profiles. To put hard numbers
on this, clang now eats around 1.3GB of RAM instead of 1.6GB while
parsing a 50MB profile.
The CPU time taken by a large profile merge (3.1GB of data across 226
files) is also reduced by ~11% by this patch (1:09.08 vs 1:01.11).
This was split out at the request of reviewers in D41152.
llvm-svn: 320764
This class was split between libIR and libSupport, which breaks under
modular code generation. Move it into the one library that uses it,
ProfileData, to resolve this issue.
llvm-svn: 317366
Summary: In the compile phase of SamplePGO+ThinLTO, ICP is not invoked. Instead, indirect call targets will be included as function metadata for ThinIndex to buidl the call graph. This should not only include functions defined in other modules, but also functions defined in the same module, otherwise ThinIndex may find the callee dead and eliminate it, while ICP in backend will revive the symbol, which leads to undefined symbol.
Reviewers: tejohnson
Reviewed By: tejohnson
Subscribers: sanjoy, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D39480
llvm-svn: 317118
LineCoverageIterator makes it easy for clients of coverage data to
determine line execution counts for a file or function. The coverage
iteration logic is tricky enough that it really pays not to have
multiple copies of it. Hopefully having just one implementation in LLVM
will make the iteration logic easier to test, reuse, and update.
This commit is NFC but I've added a unit test to go along with it just
because it's easy to do now.
llvm-svn: 316141
Summary: In the current implementation, we only have accurate profile count for standalone symbols. For inlined functions, we do not have entry count data because it's not available in LBR. In this patch, we use the first instruction's frequency to estimiate the function's entry count, especially for inlined functions. This may be inaccurate due to debug info in optimized code. However, this is a better estimate than the static 80/20 estimation we have in the current implementation.
Reviewers: tejohnson, davidxl
Reviewed By: tejohnson
Subscribers: sanjoy, llvm-commits, aprantl
Differential Revision: https://reviews.llvm.org/D38478
llvm-svn: 315369
There is data racing to the static variable RecordIndex in index profile reader
when merging in multiple threads. Make it a member variable in
IndexedInstrProfReader to fix this.
Differential Revision: https://reviews.llvm.org/D38431
llvm-svn: 314990
Summary: In SamplePGO ThinLTO compile phase, we will not invoke ICP as it may introduce confusion to the 2nd annotation. This patch extracted that logic and makes it clearer before profile annotation. In the mean time, we need to make function importing process both inlined callsites as well as not promoted indirect callsites.
Reviewers: tejohnson
Reviewed By: tejohnson
Subscribers: sanjoy, mehdi_amini, llvm-commits, inglorion
Differential Revision: https://reviews.llvm.org/D38094
llvm-svn: 314619
Passing "-dump" to llvm-cov will now print more detailed information
about function hash and counter mismatches. This should make it easier
to debug *.profdata files which contain incorrect records, and to debug
other scenarios where coverage goes missing due to mismatch issues.
llvm-svn: 313853
