separate sections.
For ThinLTO, all the function profiles without context has been annotated to
outline functions if possible in prelink phase. In postlink phase, profile
annotation in postlink phase is only meaningful for function profile with
context. If the profile is large, it is better to split the profile into two
parts, one with context and one without, so the profile reading in postlink
phase only has to read the part with context. To have the profile splitting,
we extend the ExtBinary format to support different section arrangement. It
will be flexible to add other section layout in the future without the need
to create new class inheriting from ExtBinary class.
Differential Revision: https://reviews.llvm.org/D94435
in ExtBinary format.
Currently ExtBinary format doesn't support multiple sections with the same type
in the profile. We add the support in this patch. Previously we use the section
type to identify a section uniquely. Now we introduces a LayoutIndex in the
SecHdrTableEntry and use the LayoutIndex to locate the target section. The
allocations of NameTable and FuncOffsetTable are adjusted accordingly.
Currently it works as a NFC because it won't change anything for current layout.
The test for multiple sections support will be included in another patch where a
new type of profile containing multiple sections with the same type is
introduced.
Differential Revision: https://reviews.llvm.org/D93254
This change enables pseudo-probe-based sample counts to be consumed by the sample profile loader under the regular `-fprofile-sample-use` switch with minimal adjustments to the existing sample file formats. After the counts are imported, a probe helper, aka, a `PseudoProbeManager` object, is automatically launched to verify the CFG checksum of every function in the current compilation against the corresponding checksum from the profile. Mismatched checksums will cause a function profile to be slipped. A `SampleProfileProber` pass is scheduled before any of the `SampleProfileLoader` instances so that the CFG checksums as well as probe mappings are available during the profile loading time. The `PseudoProbeManager` object is set up right after the profile reading is done. In the future a CFG-based fuzzy matching could be done in `PseudoProbeManager`.
Samples will be applied only to pseudo probe instructions as well as probed callsites once the checksum verification goes through. Those instructions are processed in the same way that regular instructions would be processed in the line-number-based scenario. In other words, a function is processed in a regular way as if it was reduced to just containing pseudo probes (block probes and callsites).
**Adjustment to profile format **
A CFG checksum field is being added to the existing AutoFDO profile formats. So far only the text format and the extended binary format are supported. For the text format, a new line like
```
!CFGChecksum: 12345
```
is added to the end of the body sample lines. For the extended binary profile format, we introduce a metadata section to store the checksum map from function names to their CFG checksums.
Differential Revision: https://reviews.llvm.org/D92347
MD5 is used.
Currently during sample profile loading, NameTable has to be loaded entirely
up front before any name string is retrieved. That is because NameTable is
stored using ULEB128 encoding and cannot be directly accessed like an array.
However, if MD5 is used to represent name in the NameTable, it has fixed
length. If MD5 names are stored in uint64_t type instead of ULEB128, NameTable
can be accessed like an array then in many cases only part of the NameTable
has to be read. This is helpful for reducing compile time especially when
small source file is compiled. We find that after this change, the elapsed
time to build a large application distributively is reduced by 5% and the
accumulative cpu time used for building is also reduced by 5%. The size of
the profile is slightly reduced with this change by ~0.2%, and that also
indicates encoding MD5 in ULEB128 doesn't save the storage space.
Differential Revision: https://reviews.llvm.org/D92621
This stack of changes introduces `llvm-profgen` utility which generates a profile data file from given perf script data files for sample-based PGO. It’s part of(not only) the CSSPGO work. Specifically to support context-sensitive with/without pseudo probe profile, it implements a series of functionalities including perf trace parsing, instruction symbolization, LBR stack/call frame stack unwinding, pseudo probe decoding, etc. Also high throughput is achieved by multiple levels of sample aggregation and compatible format with one stop is generated at the end. Please refer to: https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s for the CSSPGO RFC.
This change supports context-sensitive profile data generation into llvm-profgen. With simultaneous sampling for LBR and call stack, we can identify leaf of LBR sample with calling context from stack sample . During the process of deriving fall through path from LBR entries, we unwind LBR by replaying all the calls and returns (including implicit calls/returns due to inlining) backwards on top of the sampled call stack. Then the state of call stack as we unwind through LBR always represents the calling context of current fall through path.
we have two types of virtual unwinding 1) LBR unwinding and 2) linear range unwinding.
Specifically, for each LBR entry which can be classified into call, return, regular branch, LBR unwinding will replay the operation by pushing, popping or switching leaf frame towards the call stack and since the initial call stack is most recently sampled, the replay should be in anti-execution order, i.e. for the regular case, pop the call stack when LBR is call, push frame on call stack when LBR is return. After each LBR processed, it also needs to align with the next LBR by going through instructions from previous LBR's target to current LBR's source, which we named linear unwinding. As instruction from linear range can come from different function by inlining, linear unwinding will do the range splitting and record counters through the range with same inline context.
With each fall through path from LBR unwinding, we aggregate each sample into counters by the calling context and eventually generate full context sensitive profile (without relying on inlining) to driver compiler's PGO/FDO.
A breakdown of noteworthy changes:
- Added `HybridSample` class as the abstraction perf sample including LBR stack and call stack
* Extended `PerfReader` to implement auto-detect whether input perf script output contains CS profile, then do the parsing. Multiple `HybridSample` are extracted
* Speed up by aggregating `HybridSample` into `AggregatedSamples`
* Added VirtualUnwinder that consumes aggregated `HybridSample` and implements unwinding of calls, returns, and linear path that contains implicit call/return from inlining. Ranges and branches counters are aggregated by the calling context. Here calling context is string type, each context is a pair of function name and callsite location info, the whole context is like `main:1 @ foo:2 @ bar`.
* Added PorfileGenerater that accumulates counters by ranges unfolding or branch target mapping, then generates context-sensitive function profile including function body, inferring callee's head sample, callsite target samples, eventually records into ProfileMap.
* Leveraged LLVM build-in(`SampleProfWriter`) writer to support different serialization format with no stop
- `getCanonicalFnName` for callee name and name from ELF section
- Added regression test for both unwinding and profile generation
Test Plan:
ninja & ninja check-llvm
Reviewed By: hoy, wenlei, wmi
Differential Revision: https://reviews.llvm.org/D89723
This change adds the context-senstive sample PGO infracture described in CSSPGO RFC (https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s). It introduced an abstraction between input profile and profile loader that queries input profile for functions. Specifically, there's now the notion of base profile and context profile, and they are managed by the new SampleContextTracker for adjusting and merging profiles based on inline decisions. It works with top-down profiled guided inliner in profile loader (https://reviews.llvm.org/D70655) for better inlining with specialization and better post-inline profile fidelity. In the future, we can also expose this infrastructure to CGSCC inliner in order for it to take advantage of context-sensitive profile. This change is the consumption part of context-sensitive profile (The generation part is in this stack: https://reviews.llvm.org/D89707). We've seen good results internally in conjunction with Pseudo-probe (https://reviews.llvm.org/D86193). Pacthes for integration with Pseudo-probe coming up soon.
Currently the new infrastructure kick in when input profile contains the new context-sensitive profile; otherwise it's no-op and does not affect existing AutoFDO.
**Interface**
There're two sets of interfaces for query and tracking respectively exposed from SampleContextTracker. For query, now instead of simply getting a profile from input for a function, we can explicitly query base profile or context profile for given call path of a function. For tracking, there're separate APIs for marking context profile as inlined, or promoting and merging not inlined context profile.
- Query base profile (`getBaseSamplesFor`)
Base profile is the merged synthetic profile for function's CFG profile from any outstanding (not inlined) context. We can query base profile by function.
- Query context profile (`getContextSamplesFor`)
Context profile is a function's CFG profile for a given calling context. We can query context profile by context string.
- Track inlined context profile (`markContextSamplesInlined`)
When a function is inlined for given calling context, we need to mark the context profile for that context as inlined. This is to make sure we don't include inlined context profile when synthesizing base profile for that inlined function.
- Track not-inlined context profile (`promoteMergeContextSamplesTree`)
When a function is not inlined for given calling context, we need to promote the context profile tree so the not inlined context becomes top-level context. This preserve the sub-context under that function so later inline decision for that not inlined function will still have context profile for its call tree. Note that profile will be merged if needed when promoting a context profile tree if any of the node already exists at its promoted destination.
**Implementation**
Implementation-wise, `SampleContext` is created as abstraction for context. Currently it's a string for call path, and we can later optimize it to something more efficient, e.g. context id. Each `SampleContext` also has a `ContextState` indicating whether it's raw context profile from input, whether it's inlined or merged, whether it's synthetic profile created by compiler. Each `FunctionSamples` now has a `SampleContext` that tells whether it's base profile or context profile, and for context profile what is the context and state.
On top of the above context representation, a custom trie tree is implemented to track and manager context profiles. Specifically, `SampleContextTracker` is implemented that encapsulates a trie tree with `ContextTireNode` as node. Each node of the trie tree represents a frame in calling context, thus the path from root to a node represents a valid calling context. We also track `FunctionSamples` for each node, so this trie tree can serve efficient query for context profile. Accordingly, context profile tree promotion now becomes moving a subtree to be under the root of entire tree, and merge nodes for subtree if this move encounters existing nodes.
**Integration**
`SampleContextTracker` is now also integrated with AutoFDO, `SampleProfileReader` and `SampleProfileLoader`. When we detected input profile contains context-sensitive profile, `SampleContextTracker` will be used to track profiles, and all profile query will go to `SampleContextTracker` instead of `SampleProfileReader` automatically. Tracking APIs are called automatically for each inline decision from `SampleProfileLoader`.
Differential Revision: https://reviews.llvm.org/D90125
and indirect call promotion candidate.
Profile remapping is a feature to match a function in the module with its
profile in sample profile if the function name and the name in profile look
different but are equivalent using given remapping rules. This is a useful
feature to keep the performance stable by specifying some remapping rules
when sampleFDO targets are going through some large scale function signature
change.
However, currently profile remapping support is only valid for outline
function profile in SampleFDO. It cannot match a callee with an inline
instance profile if they have different but equivalent names. We found
that without the support for inline instance profile, remapping is less
effective for some large scale change.
To add that support, before any remapping lookup happens, all the names
in the profile will be inserted into remapper and the Key to the name
mapping will be recorded in a map called NameMap in the remapper. During
name lookup, a Key will be returned for the given name and it will be used
to extract an equivalent name in the profile from NameMap. So with the help
of the NameMap, we can translate any given name to an equivalent name in
the profile if it exists. Whenever we try to match a name in the module to
a name in the profile, we will try the match with the original name first,
and if it doesn't match, we will use the equivalent name got from remapper
to try the match for another time. In this way, the patch can enhance the
profile remapping support for searching inline instance and searching
indirect call promotion candidate.
In a planned large scale change of int64 type (long long) to int64_t (long),
we found the performance of a google internal benchmark degraded by 2% if
nothing was done. If existing profile remapping was enabled, the performance
degradation dropped to 1.2%. If the profile remapping with the current patch
was enabled, the performance degradation further dropped to 0.14% (Note the
experiment was done before searching indirect call promotion candidate was
added. We hope with the remapping support of searching indirect call promotion
candidate, the degradation can drop to 0% in the end. It will be evaluated
post commit).
Differential Revision: https://reviews.llvm.org/D86332
is enabled.
When -sample-profile-merge-inlinee is enabled, new FunctionSamples may be
created during profile merge without GUIDToFuncNameMap being initialized.
That will occasionally cause compiler crash. The patch fixes it.
Differential Revision: https://reviews.llvm.org/D84994
Summary:
Add the --hot-func-list feature to llvm-profdata show for sample profiles. This feature prints a list of hot functions whose max sample count are above the 99% threshold, with their numbers of total samples, total samples percentage, max samples, entry samples, and their function names.
Test Plan:
Reviewers: wenlei, hoyFB
Reviewed By: wenlei, hoyFB
Subscribers: hoyFB, wenlei, weihe, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D82355
Summary: Add the --hot-func-list feature to llvm-profdata show for sample profiles. This feature prints a list of hot functions whose max sample count are above the 99% threshold, with their numbers of total samples, total samples percentage, max samples, entry samples, and their function names.
Reviewers: wmi, hoyFB, wenlei
Reviewed By: wmi
Subscribers: hoyFB, wenlei, llvm-commits, weihe
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D81800
This patch addresses two issues related to adding inline functions to the import list while recursively going through the profiling data.
1. For callsite samples, only add an inlined function to the import list if it's from outside of the module (i.e. only has a declaration inside the module).
2. For body samples, add each target function to the import list if it's from outside of the module (i.e. only has a declaration inside the module). Previously we were using getSubProgram() to check whether it has dbg info, which is inaccurate. This fix properly add imports and could improve the quality of the pass.
Added a few changes to the test to catch these cases.
Differential Revision: https://reviews.llvm.org/D79379
Summary:
In D65848 the function getFuncNameInModule was refactored to no longer use module.
This diff removes the parameter and rename the function name to avoid confusion.
Reviewers: wenlei, wmi, davidxl
Reviewed By: wenlei
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79310
Fix the error of show-prof-info.test on some platforms without zlib.
The common profile usage is to collect profile from a target and then use the profile to guide the optimized build for the same target. There are some cases that no profile can be collected for a target. In those cases, although no full profile is available, it is possible to have some partial profile collected from other targets to optimize common libraries and utilities. A flag is needed to tell the partial profile from the full profile apart, so compiler can use different strategy for them.
Differential Revision: https://reviews.llvm.org/D77426
The common profile usage is to collect profile from a target and then use the profile to guide the optimized build for the same target. There are some cases that no profile can be collected for a target. In those cases, although no full profile is available, it is possible to have some partial profile collected from other targets to optimize common libraries and utilities. A flag is needed to tell the partial profile from the full profile apart, so compiler can use different strategy for them.
Differential Revision: https://reviews.llvm.org/D77426
Compbinary format uses MD5 to represent strings in name table. That gives smaller profile without the need of compression/decompression when writing/reading the profile. The patch adds the support in extbinary format. It is off by default but user can choose to enable it.
Note the feature of using MD5 in name table can bring very small chance of name conflict leading to profile mismatch. Besides, profile using the feature won't have the profile remapping support.
Differential Revision: https://reviews.llvm.org/D76255
StringMap.h is very popular (4K uses), and it doesn't need to see
BumpPtrAllocator, which is relatively expensive according to
ClangBuildAnalyzer. StringMap only needs MallocAllocator, so split that
into AllocatorBase.h and use it instead.
Here is the change in header uses:
$ diff -u thedeps-before.txt thedeps-after.txt | \
grep '^[-+] ' | sort | uniq -c | sort -nr
3993 + ../llvm/include/llvm/Support/AllocatorBase.h
758 - ../llvm/include/llvm/Support/Allocator.h
270 - ../llvm/include/llvm/Support/Alignment.h
13 - ../llvm/include/llvm/Support/Host.h
6 - ../llvm/include/llvm/ADT/StringMap.h
4 - ../llvm/include/llvm/Support/SwapByteOrder.h
4 - ../llvm/include/llvm/Support/MathExtras.h
4 - ../llvm/include/llvm/Support/AlignOf.h
4 - ../llvm/include/llvm/ADT/SmallVector.h
1 - ../llvm/include/llvm/Support/PointerLikeTypeTraits.h
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D73392
Suppose an inline instance has hot total sample count but 0 entry count, and
it is an indirect call target. If the indirect call has no other call target
and inline instance associated with it and it is promoted, currently the
conditional branch generated by indirect call promotion will have invalid
branch profile which is !{!"branch_weights", i32 0, i32 0} -- because the
entry count of the promoted target is 0 and the total entry count of all
targets is also 0. This caused a SEGV in Control Height Reduction and may
cause problem in other passes.
Function entry count of an inline instance is computed by a heuristic --
using either the sample of the starting line or starting inner inline
instance. The patch changes the heuristic a little bit so that when total
sample count is larger than 0, the computed entry count will be at least 1.
Then the new branch profile will be !{!"branch_weights", i32 1, i32 0}.
Differential Revision: https://reviews.llvm.org/D72790
Summary:
When sample profile loader decides not to inline a previously inlined call-site, we adjust the profile of outlined function simply by scaling up its profile counts by call-site count. This means the context-sensitive profile of that inlined instance will be thrown away. This commit try to keep context-sensitive profile for such cases:
- Instead of scaling outlined function's profile, we now properly merge the FunctionSamples of inlined instance into outlined function, including all recursively inlined profile.
- Instead of adjusting the profile for negative inline decision at the end of the sample profile loader pass, we do the profile merge right after processing each function. This change paired with top-down ordering of annotation/inline-replay (a separate diff) will make sure we recursively merge profile back before the profile is used for annotation and inline replay.
A new switch -sample-profile-merge-inlinee is added to enable the new profile merge for tuning. It should be the default behavior eventually.
Reviewers: wmi, davidxl
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70653
in ExtBinary format
Currently for Text, Binary and ExtBinary format profiles, when we compile a
module with samplefdo, even if there is no function showing up in the profile,
we have to load all the function profiles from the profile input. That is a
waste of compile time.
CompactBinary format profile has already had the support of loading function
profiles on demand. In this patch, we add the support to load profile on
demand for ExtBinary format. It will work no matter the sections in ExtBinary
format profile are compressed or not. Experiment shows it reduces the time to
compile a server benchmark by 30%.
When profile remapping and loading function profiles on demand are both used,
extra work needs to be done so that the loading on demand process will take
the name remapping into consideration. It will be addressed in a follow-up
patch.
Differential Revision: https://reviews.llvm.org/D68601
llvm-svn: 374233
Previously ExtBinary profile format only supports compression using zlib for
profile symbol list. In this patch, we extend the compression support to any
section. User can select some or all of the sections to compress. In an
experiment, for a 45M profile in ExtBinary format, compressing name table
reduced its size to 24M, and compressing all the sections reduced its size
to 11M.
Differential Revision: https://reviews.llvm.org/D68253
llvm-svn: 373914
or the size of the profile for profile in ExtBinary format.
Fix a test failure on Mac.
[SampleFDO] Expose an interface to return the size of a section or the
size of the profile for profile in ExtBinary format.
Sometimes we want to limit the size of the profile by stripping some functions
with low sample count or by stripping some function names with small text size
from profile symbol list. That requires the profile reader to have the
interfaces returning the size of a section or the size of total profile. The
patch add those interfaces.
At the same time, add some dump facility to show the size of each section.
Differential revision: https://reviews.llvm.org/D67726
llvm-svn: 372478
of the profile for profile in ExtBinary format.
Sometimes we want to limit the size of the profile by stripping some functions
with low sample count or by stripping some function names with small text size
from profile symbol list. That requires the profile reader to have the
interfaces returning the size of a section or the size of total profile. The
patch add those interfaces.
At the same time, add some dump facility to show the size of each section.
llvm-svn: 372439
1. zlib::compress accept &size_t but the param is an uint64_t.
2. Some systems don't have zlib installed. Don't use compression by default.
llvm-svn: 370564
cold versus function being newly added.
This is the second half of https://reviews.llvm.org/D66374.
Profile symbol list is the collection of function symbols showing up in
the binary which generates the current profile. It is used to discriminate
function being cold versus function being newly added. Profile symbol list
is only added for profile with ExtBinary format.
During profile use compilation, when profile-sample-accurate is enabled,
a function without profile will be regarded as cold only when it is
contained in that list.
Differential Revision: https://reviews.llvm.org/D66766
llvm-svn: 370563
This is a patch split from https://reviews.llvm.org/D66374. It tries to add
a new format of profile called ExtBinary. The format adds a section header
table to the profile and organize the profile in sections, so the future
extension like adding a new section or extending an existing section will be
easier while keeping backward compatiblity feasible.
Differential Revision: https://reviews.llvm.org/D66513
llvm-svn: 369798
We currently get this warning when compiling with libc++:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/set:454:26: warning: the specified comparator type does not provide a const call operator [-Wuser-defined-warnings]
static_assert(sizeof(__diagnose_non_const_comparator<_Key, _Compare>()), "");
^
llvm-project/llvm/include/llvm/ProfileData/SampleProf.h:193:29: note: in instantiation of template class 'std::__1::set<std::__1::pair<llvm::StringRef, unsigned long long>, llvm::sampleprof::SampleRecord::CallTargetComparator, std::__1::allocator<std::__1::pair<llvm::StringRef, unsigned long long> > >' requested here
const SortedCallTargetSet getSortedCallTargets() const {
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__tree:967:5: note: from 'diagnose_if' attribute on '__diagnose_non_const_comparator<std::__1::pair<llvm::StringRef, unsigned long long>, llvm::sampleprof::SampleRecord::CallTargetComparator>':
_LIBCPP_DIAGNOSE_WARNING(!std::__invokable<_Compare const&, _Tp const&, _Tp const&>::value,
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/__config:1320:21: note: expanded from macro '_LIBCPP_DIAGNOSE_WARNING'
__attribute__((diagnose_if(__VA_ARGS__, "warning")))
^ ~~~~~~~~~~~
1 warning generated.
llvm-svn: 369500
Summary:
StringMap is used for storing call target to frequency map for AutoFDO. However the iterating order of StringMap is non-deterministic, which leads to non-determinism in AutoFDO profile output. Now new API getSortedCallTargets and SortCallTargets are added for deterministic ordering and output.
Roundtrip test for text profile and binary profile is added.
Reviewers: wmi, davidxl, danielcdh
Subscribers: hiraditya, mgrang, llvm-commits, twoh
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66191
llvm-svn: 369440
Summary:
This commit fixed a race condition from multi-threaded thinLTO backends that causes non-deterministic memory corruption for a data structure used only by AutoFDO with compact binary profile.
GUIDToFuncNameMap, a static data member of type DenseMap in FunctionSamples is used as a per-module mapping from function name MD5 to name string when input AutoFDO profile is in compact binary format. However with ThinLTO, we can have parallel backends modifying and accessing the class static map concurrently. The fix is to make GUIDToFuncNameMap a member of SampleProfileLoader instead of a file static data.
Reviewers: wmi, davidxl, danielcdh
Subscribers: mehdi_amini, inglorion, hiraditya, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65848
llvm-svn: 368596
Summary:
Add hooks for determining the policy used to decide whether/how
to chop off symbol 'suffixes' when locating a given function
in a sample profile.
Prior to this change, any function symbols of the form "X.Y" were
elided/truncated into just "X" when looking up things in a sample
profile data file.
With this change, the policy on suffixes can be changed by adding a
new attribute "sample-profile-suffix-elision-policy" to the function:
this attribute can have the value "all" (the default), "selected", or
"none". A value of "all" preserves the previous behavior (chop off
everything after the first "." character, then treat that as the
symbol name). A value of "selected" chops off only the rightmost
".llvm.XXXX" suffix (where "XXX" is any string not containing a "."
char). A value of "none" indicates that names should be left as is.
Subscribers: jdoerfert, wmi, mtrofin, danielcdh, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58832
llvm-svn: 356146
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
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
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
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:
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
