Commit Graph

37 Commits

Author SHA1 Message Date
Rong Xu a6ff69f6dd [PGO] Context sensitive PGO (part 2)
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
2019-02-28 19:55:07 +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
Wei Mi 66c6c5abea [SampleFDO] handle ProfileSampleAccurate when initializing function entry count
ProfileSampleAccurate is used to indicate the profile has exact match to the
code to be optimized.

Previously ProfileSampleAccurate is handled in ProfileSummaryInfo::isColdCallSite
and ProfileSummaryInfo::isColdBlock. A better solution is to initialize function
entry count to 0 when ProfileSampleAccurate is true, so we don't have to handle
ProfileSampleAccurate in multiple places.

Differential Revision: https://reviews.llvm.org/D55660

llvm-svn: 349088
2018-12-13 21:51:42 +00:00
Wei Mi 7da5a08e1a [SampleFDO] Extend profile-sample-accurate option to cover isFunctionColdInCallGraph
For SampleFDO, when a callsite doesn't appear in the profile, it will not be marked as cold callsite unless the option -profile-sample-accurate is specified.

But profile-sample-accurate doesn't cover function isFunctionColdInCallGraph which is used to decide whether a function should be put into text.unlikely section, so even if the user knows the profile is accurate and specifies profile-sample-accurate, those functions not appearing in the sample profile are still not be put into text.unlikely section right now.

The patch fixes that.

Differential Revision: https://reviews.llvm.org/D55567

llvm-svn: 348940
2018-12-12 17:09:27 +00:00
Vedant Kumar e7b789b529 [ProfileSummary] Standardize methods and fix comment
Every Analysis pass has a get method that returns a reference of the Result of
the Analysis, for example, BlockFrequencyInfo
&BlockFrequencyInfoWrapperPass::getBFI().  I believe that
ProfileSummaryInfo::getPSI() is the only exception to that, as it was returning
a pointer.

Another change is renaming isHotBB and isColdBB to isHotBlock and isColdBlock,
respectively.  Most methods use BB as the argument of variable names while
methods usually refer to Basic Blocks as Blocks, instead of BB.  For example,
Function::getEntryBlock, Loop:getExitBlock, etc.

I also fixed one of the comments.

Patch by Rodrigo Caetano Rocha!

Differential Revision: https://reviews.llvm.org/D54669

llvm-svn: 347182
2018-11-19 05:23:16 +00:00
Easwaran Raman c5e1506ec8 [ProfileSummary] Add options to override hot and cold count thresholds.
Summary:
The hot and cold count thresholds are derived from the summary, but for
debugging purposes it is convenient to provide the actual thresholds.

Reviewers: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D54040

llvm-svn: 346005
2018-11-02 17:39:31 +00:00
Wei Mi b1ef2cc53d [SampleFDO] Fix a bug in getOrCompHotCountThreshold/getOrCompColdCountThreshold
getOrCompHotCountThreshold/getOrCompColdCountThreshold introduced in
https://reviews.llvm.org/D45377 contain a bad mistake and will only return 1 or 0
instead of the true hot/cold cutoff value. The patch fixes the mistake. But the
mistake seems not causing big performance difference according to internal server
benchmarks testing.

Differential Revision: https://reviews.llvm.org/D50370

llvm-svn: 339162
2018-08-07 18:13:10 +00:00
Wei Mi 0c2f6be662 [SampleFDO] Don't treat warm callsite with inline instance in the profile as cold
We found current sampleFDO had a performance issue when triaging a regression.
For a callsite with inline instance in the profile, even if hot callsite inliner
cannot inline it, it may still execute enough times and should not be treated as
cold in regular inliner later. However, currently if such callsite is not inlined
by hot callsite inliner, and the BB where the callsite locates doesn't get
samples from other instructions inside of it, the callsite will have no profile
metadata annotated. In regular inliner cost analysis, if the callsite has no
profile annotated and its caller has profile information, it will be treated as
cold.

The fix changes the isCallsiteHot check and chooses to compare
CallsiteTotalSamples with hot cutoff value computed by ProfileSummaryInfo.

Differential Revision: https://reviews.llvm.org/D45377

llvm-svn: 332058
2018-05-10 23:02:27 +00:00
George Burgess IV ceecd45b4d Fix a typo in a comment; NFC
llvm-svn: 329935
2018-04-12 18:36:01 +00:00
Easwaran Raman e5b8de2f1f Add a ProfileCount class to represent entry counts.
Summary:
The class wraps a uint64_t and an enum to represent the type of profile
count (real and synthetic) with some helper methods.

Reviewers: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41883

llvm-svn: 322771
2018-01-17 22:24:23 +00:00
Easwaran Raman a17f220590 Add hasProfileData() to check if a function has profile data. NFC.
Summary:
This replaces calls to getEntryCount().hasValue() with hasProfileData
that does the same thing. This refactoring is useful to do before adding
synthetic function entry counts but also a useful cleanup IMO even
otherwise. I have used hasProfileData instead of hasRealProfileData as
David had earlier suggested since I think profile implies "real" and I
use the phrase "synthetic entry count" and not "synthetic profile count"
but I am fine calling it hasRealProfileData if you prefer.

Reviewers: davidxl, silvas

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41461

llvm-svn: 321331
2017-12-22 01:33:52 +00:00
Teresa Johnson a4ce3bfdda [PGO] Function section hotness prefix should look at all blocks
Summary:
The function section prefix for PGO based layout (e.g. hot/unlikely)
should look at the hotness of all blocks not just the entry BB.
A function with a cold entry but a very hot loop should be placed in the
hot section, for example, so that it is located close to other hot
functions it may call. For SamplePGO it was already looking at the
branch weights on calls, and I made that code conditional on whether
this is SamplePGO since it was essentially a noop for instrumentation
PGO anyway.

Reviewers: davidxl

Subscribers: eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D41395

llvm-svn: 321197
2017-12-20 17:53:10 +00:00
Dehao Chen f0e27e63e7 Move accurate-sample-profile into the function attribute.
Summary: We need to have accurate-sample-profile in function attribute so that it works with LTO.

Reviewers: davidxl, rsmith

Reviewed By: davidxl

Subscribers: sanjoy, mehdi_amini, javed.absar, llvm-commits, eraman

Differential Revision: https://reviews.llvm.org/D37113

llvm-svn: 311706
2017-08-24 21:37:04 +00:00
Dehao Chen 63799512b2 Adjust the hotness threshold from 99.9% to 99%.
Summary: We originally set the hotness threshold as 99.9% to be consistent with gcc FDO. But because the inline heuristic is different between 2 compilers: llvm uses bottom-up algorithm while gcc uses priority based. The LLVM algorithm tends to inline too much early that prevents hot callsites from further inlined into its caller. Due to this restriction, we think it is reasonable to lower the hotness threshold to give priority to those that are really hot. Our experiments show that this change would improve performance on large applications. Note that the inline heuristic has great room for further tuning. Once the inline heuristics are refined, we could adjust this threshold to allow inlining for less hot callsites.

Reviewers: davidxl, tejohnson, eraman

Reviewed By: tejohnson

Subscribers: sanjoy, llvm-commits

Differential Revision: https://reviews.llvm.org/D36317

llvm-svn: 310065
2017-08-04 16:20:54 +00:00
Teresa Johnson 8482e56920 Use profile summary to disable peeling for huge working sets
Summary:
Detect when the working set size of a profiled application is huge,
by comparing the number of counts required to reach the hot percentile
in the profile summary to a large threshold*.

When the working set size is determined to be huge, disable peeling
to avoid bloating the working set further.

*Note that the selected threshold (15K) is significantly larger than the
largest working set value in SPEC cpu2006 (which is gcc at around 11K).

Reviewers: davidxl

Subscribers: mehdi_amini, mzolotukhin, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D36288

llvm-svn: 310005
2017-08-03 23:42:58 +00:00
Dehao Chen f58df39529 Do not want to use BFI to get profile count for sample pgo
Summary: For SamplePGO, we already record the callsite count in the call instruction itself. So we do not want to use BFI to get profile count as it is less accurate.

Reviewers: tejohnson, davidxl, eraman

Reviewed By: eraman

Subscribers: sanjoy, llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D36025

llvm-svn: 309964
2017-08-03 17:11:41 +00:00
Easwaran Raman dadc0f11ad Add hasProfileSummary and has{Sample|Instrumentation}Profile methods
ProfileSummaryInfo already checks whether the module has sample profile
in determining profile counts. This will also be useful in inliner to
clean up threshold updates.

llvm-svn: 303204
2017-05-16 20:14:39 +00:00
Teresa Johnson 2a6b7991d4 Restrict call metadata based hotness detection to Sample PGO mode
Summary:
Don't use the metadata on call instructions for determining hotness
unless we are in sample PGO mode, where it is needed because profile
counts are not accurate. In instrumentation mode this is not necessary
and does more harm than good when calls have VP metadata that hasn't
been properly scaled after transformations or dropped after constant
prop based devirtualization (both should be fixed, but we don't need
to do this in the first place for instrumentation PGO).

This required adjusting a number of tests to distinguish between sample
and instrumentation PGO handling, and to add in profile summary metadata
so that getProfileCount can get the summary.

Reviewers: davidxl, danielcdh

Subscribers: aemerson, rengolin, mehdi_amini, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D32877

llvm-svn: 302844
2017-05-11 23:18:05 +00:00
Dehao Chen 775341a14c Use isFunctionHotInCallGraph to set the function section prefix.
Summary: The current prefix based function layout algorithm only looks at function's entry count, which is not sufficient. A function should be grouped together if its entry count or any call edge count is hot.

Reviewers: davidxl, eraman

Reviewed By: eraman

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31225

llvm-svn: 298656
2017-03-23 23:14:11 +00:00
Davide Italiano 574e59786e [ProfileSummaryInfo] Remove unneeded braces. NFCI.
llvm-svn: 297506
2017-03-10 20:50:51 +00:00
Dehao Chen c2048155a0 Refactor the PSI to extract getCallSiteCount and remove checks for profile type.
Summary: There is no need to check profile count as only CallInst will have metadata attached.

Reviewers: eraman

Reviewed By: eraman

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30799

llvm-svn: 297500
2017-03-10 19:45:16 +00:00
Dehao Chen 22645eea7a Do not use branch metadata to check if a basic block is hot.
Summary: We should not use that to check basic block hotness as optimization may mess it up.

Reviewers: eraman

Reviewed By: eraman

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30800

llvm-svn: 297437
2017-03-10 01:44:37 +00:00
Easwaran Raman a7bdb8a513 Compute summary before calling extractProfTotalWeight
extractProfTotalWeight checks if the profile type is sample profile, but
before that we have to ensure that summary is available. Also expanded
the unittest to test the case where there is no summar

Differential Revision: https://reviews.llvm.org/D28708

llvm-svn: 291982
2017-01-14 00:32:37 +00:00
Easwaran Raman b035f914e4 ProfileSummaryInfo improvements.
* Add is{Hot|Cold}CallSite methods
* Fix a bug in isHotBB where it was looking for MD_prof on a return instruction
* Use MD_prof data only if sample profiling was used to collect profiles.
* Add an unit test to ProfileSummaryInfo

Differential Revision: https://reviews.llvm.org/D28584

llvm-svn: 291878
2017-01-13 01:34:00 +00:00
Chandler Carruth dab4eae274 [PM] Change the static object whose address is used to uniquely identify
analyses to have a common type which is enforced rather than using
a char object and a `void *` type when used as an identifier.

This has a number of advantages. First, it at least helps some of the
confusion raised in Justin Lebar's code review of why `void *` was being
used everywhere by having a stronger type that connects to documentation
about this.

However, perhaps more importantly, it addresses a serious issue where
the alignment of these pointer-like identifiers was unknown. This made
it hard to use them in pointer-like data structures. We were already
dodging this in dangerous ways to create the "all analyses" entry. In
a subsequent patch I attempted to use these with TinyPtrVector and
things fell apart in a very bad way.

And it isn't just a compile time or type system issue. Worse than that,
the actual alignment of these pointer-like opaque identifiers wasn't
guaranteed to be a useful alignment as they were just characters.

This change introduces a type to use as the "key" object whose address
forms the opaque identifier. This both forces the objects to have proper
alignment, and provides type checking that we get it right everywhere.
It also makes the types somewhat less mysterious than `void *`.

We could go one step further and introduce a truly opaque pointer-like
type to return from the `ID()` static function rather than returning
`AnalysisKey *`, but that didn't seem to be a clear win so this is just
the initial change to get to a reliably typed and aligned object serving
is a key for all the analyses.

Thanks to Richard Smith and Justin Lebar for helping pick plausible
names and avoid making this refactoring many times. =] And thanks to
Sean for the super fast review!

While here, I've tried to move away from the "PassID" nomenclature
entirely as it wasn't really helping and is overloaded with old pass
manager constructs. Now we have IDs for analyses, and key objects whose
address can be used as IDs. Where possible and clear I've shortened this
to just "ID". In a few places I kept "AnalysisID" to make it clear what
was being identified.

Differential Revision: https://reviews.llvm.org/D27031

llvm-svn: 287783
2016-11-23 17:53:26 +00:00
Dehao Chen 38a666d6e5 Add isHotBB helper function to ProfileSummaryInfo
Summary: This will unify all BB hotness checks.

Reviewers: eraman, davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26353

llvm-svn: 286415
2016-11-09 23:36:02 +00:00
Dehao Chen c87bc79d90 Tune isHotFunction/isColdFunction
Summary: This patch sets function as hot if function's entry count is hot/cold.

Reviewers: eraman, davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25048

llvm-svn: 283852
2016-10-11 05:19:00 +00:00
Dehao Chen 84287abf43 Rename isHotFunction/isColdFunction to isFunctionEntryHot/isFunctionEntryCold. (NFC)
This is in preparation for https://reviews.llvm.org/D25048

llvm-svn: 283805
2016-10-10 21:47:28 +00:00
Piotr Padlewski f3d122cd02 NFC fix doxygen comments
llvm-svn: 282950
2016-09-30 21:05:49 +00:00
Dehao Chen 5461d8bdb5 Refactor the ProfileSummaryInfo to use doInitialization and doFinalization to handle Module update.
Summary: This refactors the change in r282616

Reviewers: davidxl, eraman, mehdi_amini

Subscribers: mehdi_amini, davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D25041

llvm-svn: 282630
2016-09-28 21:00:58 +00:00
Dehao Chen 80c8ebb4d8 Fix the bug when -compile-twice is specified, the PSI will be invalidated.
Summary:
When using llc with -compile-twice, module is generated twice, but getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI will still get the old PSI with the original (invalidated) Module. This patch checks if the module has changed when calling getPSI, if yes, update the module and invalidate the Summary.
The bug does not show up in the current llc because PSI is not used in CodeGen yet. But with https://reviews.llvm.org/D24989, the bug will be exposed by test/CodeGen/PowerPC/pr26378.ll

Reviewers: eraman, davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24993

llvm-svn: 282616
2016-09-28 18:41:14 +00:00
Sean Silva fd03ac6a0c Consistently use ModuleAnalysisManager
Besides a general consistently benefit, the extra layer of indirection
allows the mechanical part of https://reviews.llvm.org/D23256 that
requires touching every transformation and analysis to be factored out
cleanly.

Thanks to David for the suggestion.

llvm-svn: 278078
2016-08-09 00:28:38 +00:00
Chandler Carruth 164a2aa6f4 [PM] Remove support for omitting the AnalysisManager argument to new
pass manager passes' `run` methods.

This removes a bunch of SFINAE goop from the pass manager and just
requires pass authors to accept `AnalysisManager<IRUnitT> &` as a dead
argument. This is a small price to pay for the simplicity of the system
as a whole, despite the noise that changing it causes at this stage.

This will also helpfull allow us to make the signature of the run
methods much more flexible for different kinds af passes to support
things like intelligently updating the pass's progression over IR units.

While this touches many, many, files, the changes are really boring.
Mostly made with the help of my trusty perl one liners.

Thanks to Sean and Hal for bouncing ideas for this with me in IRC.

llvm-svn: 272978
2016-06-17 00:11:01 +00:00
Richard Trieu fae70b6f2b Add null checks before using a pointer.
llvm-svn: 272359
2016-06-10 01:42:05 +00:00
Easwaran Raman 019e0bf592 Reapply r271728 after adding move cobstructor for ProfileSummaryInfo
llvm-svn: 271745
2016-06-03 22:54:26 +00:00
Easwaran Raman 94edaaaefb Revert r271728 as it breaks Windows build
llvm-svn: 271738
2016-06-03 21:14:26 +00:00
Easwaran Raman d142050f3a Analysis pass to access profile summary info
Differential Revision: http://reviews.llvm.org/D20648

llvm-svn: 271728
2016-06-03 20:37:19 +00:00