Commit Graph

193 Commits

Author SHA1 Message Date
Nicola Zaghen d34e60ca85 Rename DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240
2018-05-14 12:53:11 +00:00
Benjamin Kramer 1fc0da4849 Make helpers static. NFC.
llvm-svn: 329170
2018-04-04 11:45:11 +00:00
Teresa Johnson 974706ebf7 [ThinLTO] Add an import cutoff for debugging/triaging
Summary:
Adds -import-cutoff=N which will stop importing during the thin link
after N imports. Default is -1 (no  limit).

Reviewers: wmi

Subscribers: inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D45127

llvm-svn: 328934
2018-04-01 15:54:40 +00:00
Vlad Tsyrklevich aab6000684 Reland r327041: [ThinLTO] Keep available_externally symbols live
Summary:
This change fixes PR36483. The bug was originally introduced by a change
that marked non-prevailing symbols dead. This broke LowerTypeTests
handling of available_externally functions, which are non-prevailing.
LowerTypeTests uses liveness information to avoid emitting thunks for
unused functions.

Marking available_externally functions dead is incorrect, the functions
are used though the function definitions are not. This change keeps them
live, and lets the EliminateAvailableExternally/GlobalDCE passes remove
them later instead.

(Reland with a suspected fix for a unit test failure I haven't been able
to reproduce locally)

Reviewers: pcc, tejohnson

Reviewed By: tejohnson

Subscribers: grimar, mehdi_amini, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D43690

llvm-svn: 327360
2018-03-13 05:08:48 +00:00
Eugene Leviant 19e238746b [ThinLTO] Recommit of import global variables
This wasreverted in r326638 due to link problems and fixed
afterwards

llvm-svn: 327254
2018-03-12 10:30:50 +00:00
Eric Christopher 3caa0fd050 Revert "[ThinLTO] Keep available_externally symbols live"
This reverts commit r327041 and the followup attempts at fixing the testcase as they're still failing.

llvm-svn: 327094
2018-03-09 01:25:18 +00:00
Vlad Tsyrklevich 7b66ef1036 [ThinLTO] Keep available_externally symbols live
Summary:
This change fixes PR36483. The bug was originally introduced by a change
that marked non-prevailing symbols dead. This broke LowerTypeTests
handling of available_externally functions, which are non-prevailing.
LowerTypeTests uses liveness information to avoid emitting thunks for
unused functions.

Marking available_externally functions dead is incorrect, the functions
are used though the function definitions are not. This change keeps them
live, and lets the EliminateAvailableExternally/GlobalDCE passes remove
them later instead.

I've also enabled EliminateAvailableExternally for all optimization
levels, I believe it being disabled for O1 was an oversight.

Reviewers: pcc, tejohnson

Reviewed By: tejohnson

Subscribers: grimar, mehdi_amini, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D43690

llvm-svn: 327041
2018-03-08 18:48:03 +00:00
Chandler Carruth a4619d9944 [ThinLTO] Revert r325320: Import global variables
This caused some links to fail with ThinLTO due to missing symbols as
well as causing some binaries to have failures at runtime. We're working
with the author to get a test case, but want to get the tree green
again.

Further, it appears to introduce a data race. While the test usage of
threads was disabled in r325361 & r325362, that isn't an acceptable fix.
I've reverted both of these as well. This code needs to be thread safe.
Test cases for this are already on the original commit thread.

llvm-svn: 326638
2018-03-02 23:40:08 +00:00
Charles Saternos b040fcc693 [ThinLTO] Add GraphTraits for FunctionSummaries
Add GraphTraits definitions to the FunctionSummary and ModuleSummaryIndex classes. These GraphTraits will be used to construct find SCC's in ThinLTO analysis passes.

Third attempt - moved function from lambda to static function due to build failures.

llvm-svn: 325506
2018-02-19 15:14:50 +00:00
Simon Pilgrim 0efed32577 Revert: [llvm] r325448 - [ThinLTO] Add GraphTraits for FunctionSummaries
Add GraphTraits definitions to the FunctionSummary and ModuleSummaryIndex classes. These GraphTraits will be used to construct find SCC's in ThinLTO analysis passes.

Second attempt, since last patch caused stage2 build to fail (now using function_ref rather than std::function).

Reverted due to buildbot failures

llvm-svn: 325454
2018-02-18 00:01:36 +00:00
Charles Saternos 35878ee7a4 [ThinLTO] Add GraphTraits for FunctionSummaries
Add GraphTraits definitions to the FunctionSummary and ModuleSummaryIndex classes. These GraphTraits will be used to construct find SCC's in ThinLTO analysis passes.

Second attempt, since last patch caused stage2 build to fail (now using function_ref rather than std::function).

llvm-svn: 325448
2018-02-17 21:39:24 +00:00
Eugene Leviant 7331a0bf1c [ThinLTO] Import global variables
Differential revision: https://reviews.llvm.org/D43077

llvm-svn: 325320
2018-02-16 08:11:04 +00:00
Volodymyr Sapsai 2ad768bb13 Revert "[ThinLTO] Add GraphTraits for FunctionSummaries"
It caused assertion failure
Assertion failed: (!DD.IsLambda && !MergeDD.IsLambda && "faked up lambda definition?"), function MergeDefinitionData, file /Users/buildslave/jenkins/workspace/clang-stage1-configure-RA/llvm/tools/clang/lib/Serialization/ASTReaderDecl.cpp, line 1675.

on the second stage build bots.

llvm-svn: 324932
2018-02-12 20:43:31 +00:00
Charles Saternos d3e7d19f59 [ThinLTO] Add GraphTraits for FunctionSummaries
Add GraphTraits definitions to the FunctionSummary and ModuleSummaryIndex classes. These GraphTraits will be used to construct find SCC's in ThinLTO analysis passes.

llvm-svn: 324854
2018-02-11 22:06:20 +00:00
Steven Wu 33ba93c2b5 [ThinLTO] Teach ThinLTO about auto hide symbols
Summary:
For symbols that has linkonce_odr linkage and unnamed_addr, it can be
auto hide by linker to avoid weak external symbols. Teach ThinLTO to
perform auto hide so it can safely promote linkonce_odr to weak symbols
without breaking this nice property.

Reviewers: tejohnson, mehdi_amini

Reviewed By: tejohnson

Subscribers: inglorion, eraman, rnk, pcc, llvm-commits

Differential Revision: https://reviews.llvm.org/D43130

llvm-svn: 324757
2018-02-09 18:34:08 +00:00
Teresa Johnson 5a95c47730 [ThinLTO] Convert dead alias to declarations
Summary:
This complements the fixes in r323633 and r324075 which drop the
definitions of dead functions and variables, respectively.

Fixes PR36208.

Reviewers: grimar, rafael

Subscribers: mehdi_amini, llvm-commits, inglorion

Differential Revision: https://reviews.llvm.org/D42856

llvm-svn: 324242
2018-02-05 15:44:27 +00:00
George Rimar 0410afd1a3 [ThinLTO] - Add comment. NFC.
Was requested during review of D42798.

llvm-svn: 324095
2018-02-02 15:06:09 +00:00
Peter Collingbourne 7873669be5 LTO: Drop comdats when converting definitions to declarations.
Differential Revision: https://reviews.llvm.org/D42715

llvm-svn: 323844
2018-01-31 02:51:03 +00:00
George Rimar eaf5172ca6 [ThinLTO] - Stop internalizing and drop non-prevailing symbols.
Implementation marks non-prevailing symbols as not live in the summary.
Then them are dropped in backends.

Fixes https://bugs.llvm.org/show_bug.cgi?id=35938

Differential revision: https://reviews.llvm.org/D42107

llvm-svn: 323633
2018-01-29 08:03:30 +00:00
Easwaran Raman c73cec84c9 Re-land "[ThinLTO] Add call edges' relative block frequency to per-module summary."
It was reverted after buildbot regressions.

Original commit message:

This allows relative block frequency of call edges to be passed
to the thinlink stage where it will be used to compute synthetic
entry counts of functions.

llvm-svn: 323460
2018-01-25 19:27:17 +00:00
Eugene Leviant 28d8a49f42 [ThinLTO] Re-commit of dot dumper after test fix
llvm-svn: 323116
2018-01-22 13:35:40 +00:00
Eugene Leviant 72b9bdb71a Temporarily revert r323062 to investigate buildbot failures
llvm-svn: 323065
2018-01-21 10:22:19 +00:00
Eugene Leviant 453c976a63 [ThinLTO] Implement summary visualizer
Differential revision: https://reviews.llvm.org/D41297

llvm-svn: 323062
2018-01-21 07:27:32 +00:00
Eugene Leviant c95b49603e [ThinLTO] Remove unused code
This is a re-commit of r320464, after patch for gold plugin
was landed.

llvm-svn: 320968
2017-12-18 10:53:45 +00:00
Teresa Johnson 69b2de8466 Fix NDEBUG build problem in r320895
Fix incorrect placement of #endif causing NDEBUG build failures.

llvm-svn: 320897
2017-12-16 00:29:31 +00:00
Teresa Johnson 81bbf74265 [ThinLTO] Enable importing of aliases as copy of aliasee
Summary:
This implements a missing feature to allow importing of aliases, which
was previously disabled because alias cannot be available_externally.
We instead import an alias as a copy of its aliasee.

Some additional work was required in the IndexBitcodeWriter for the
distributed build case, to ensure that the aliasee has a value id
in the distributed index file (i.e. even when it is not being
imported directly).

This is a performance win in codes that have many aliases, e.g. C++
applications that have many constructor and destructor aliases.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D40747

llvm-svn: 320895
2017-12-16 00:18:12 +00:00
Eugene Leviant d53f3da772 Revert r320464 as it breaks gold plugin tests
llvm-svn: 320467
2017-12-12 10:12:46 +00:00
Eugene Leviant 3695183395 [ThinLTO] Remove unused code from thinLTOInternalizeModule
Differential revision: https://reviews.llvm.org/D40970

llvm-svn: 320464
2017-12-12 09:12:32 +00:00
Eugene Zelenko e9ea08a097 [Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 315383
2017-10-10 22:49:55 +00:00
Dehao Chen ea523ddb1b Revert the change that accidentally went in r314806.
llvm-svn: 314807
2017-10-03 15:50:42 +00:00
Dehao Chen f464627f28 Update getMergedLocation to check the instruction type and merge properly.
Summary: If the merged instruction is call instruction, we need to set the scope to the closes common scope between 2 locations, otherwise it will cause trouble when the call is getting inlined.

Reviewers: dblaikie, aprantl

Reviewed By: dblaikie, aprantl

Subscribers: llvm-commits, sanjoy

Differential Revision: https://reviews.llvm.org/D37877

llvm-svn: 314694
2017-10-02 18:13:14 +00:00
Teresa Johnson f625118ec7 [ThinLTO] Fix dead stripping analysis for SamplePGO
Summary:
The fix for dead stripping analysis in the case of SamplePGO indirect
calls to local functions (r313151) introduced the possibility of an
infinite loop.

Make sure we check for the value being already live after we update it
for SamplePGO indirect call handling.

Reviewers: danielcdh

Subscribers: mehdi_amini, inglorion, llvm-commits, eraman

Differential Revision: https://reviews.llvm.org/D38086

llvm-svn: 313766
2017-09-20 17:09:47 +00:00
Peter Collingbourne cfbd089237 Reland r313157, "ThinLTO: Correctly follow aliasee references when dead stripping." which was reverted in r313222.
This reland includes a fix for the LowerTypeTests pass so that it
looks past aliases when determining which type identifiers are live.

Differential Revision: https://reviews.llvm.org/D37842

llvm-svn: 313229
2017-09-14 05:02:59 +00:00
Hans Wennborg ae050afeb9 Revert r313157 "ThinLTO: Correctly follow aliasee references when dead stripping."
This broke Chromium's CFI build; see crbug.com/765004.

> We were previously handling aliases during dead stripping by adding
> the aliased global's "original name" GUID to the worklist. This will
> lead to incorrect behaviour if the global has local linkage because
> the original name GUID will not correspond to the global's GUID in
> the summary.
>
> Because an alias is just another name for the global that it
> references, there is no need to mark the referenced global as used,
> or to follow references from any other copies of the global. So all
> we need to do is to follow references from the aliasee's summary
> instead of the alias.
>
> Differential Revision: https://reviews.llvm.org/D37789

llvm-svn: 313222
2017-09-14 00:40:14 +00:00
Peter Collingbourne d067c8ed59 ThinLTO: Correctly follow aliasee references when dead stripping.
We were previously handling aliases during dead stripping by adding
the aliased global's "original name" GUID to the worklist. This will
lead to incorrect behaviour if the global has local linkage because
the original name GUID will not correspond to the global's GUID in
the summary.

Because an alias is just another name for the global that it
references, there is no need to mark the referenced global as used,
or to follow references from any other copies of the global. So all
we need to do is to follow references from the aliasee's summary
instead of the alias.

Differential Revision: https://reviews.llvm.org/D37789

llvm-svn: 313157
2017-09-13 17:09:20 +00:00
Teresa Johnson 1958083d35 [ThinLTO] For SamplePGO, need to handle ICP targets consistently in thin link
Summary:
SamplePGO indirect call profiles record the target as the original GUID
for statics. The importer had special handling to map to the normal GUID
in that case. The dead global analysis needs the same treatment or
inconsistencies arise, resulting in linker unsats due to some dead
symbols being exported and kept, leaving in references to other dead
symbols that are removed.

This can happen when a SamplePGO profile collected by one binary is used
for a different binary, so the indirect call profiles may not accurately
reflect live targets.

Reviewers: danielcdh

Subscribers: mehdi_amini, inglorion, llvm-commits, eraman

Differential Revision: https://reviews.llvm.org/D37783

llvm-svn: 313151
2017-09-13 15:16:38 +00:00
Benjamin Kramer 154411e0e7 [FunctionImport] Avoid unused variable warnings in Release builds
Just skip the entire block in NDEBUG. No functionality change intended.

llvm-svn: 312031
2017-08-29 20:24:39 +00:00
Teresa Johnson 2df7fc7991 [ThinLTO] Clean up stale alias import handling
Summary:
Remove some code that was no longer needed. The first FIXME is
stale since we long ago started using the index to drive importing,
rather than doing force importing based on linkage type. And
now with r309278, we no longer import any aliases.

Reviewers: dblaikie

Subscribers: inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D37266

llvm-svn: 312019
2017-08-29 18:15:34 +00:00
Teresa Johnson 73305f82e9 [ThinLTO] Fix ThinLTO crash
Summary:
Follow up to fix in r311023, which fixed the case where the combined
index is written to disk. The same samplePGO logic exists for the
in-memory index when computing imports, so we need to filter out
GlobalVariable summaries there too.

Reviewers: davidxl

Subscribers: inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D36919

llvm-svn: 311254
2017-08-19 18:04:25 +00:00
Xinliang David Li 24524f314c Fix typo /NFC
llvm-svn: 310737
2017-08-11 17:49:20 +00:00
Dehao Chen 8260d66556 Increase the ImportHotMultiplier to 10.0
Summary: The original 3.0 hot mupltiplier is too small, and would prevent hot callsites from being inline. This patch increases the hot multilier to 10.0

Reviewers: davidxl, tejohnson

Reviewed By: tejohnson

Subscribers: llvm-commits, sanjoy

Differential Revision: https://reviews.llvm.org/D35969

llvm-svn: 309344
2017-07-28 01:02:34 +00:00
Davide Italiano 82c7d3768d [FunctionImport] Prefer isa<> to dyn_cast<> as the value is not used.
This change makes GCC7 happy again.

llvm-svn: 309305
2017-07-27 18:38:09 +00:00
David Blaikie 2f0cc477ab ThinLTO: Don't import aliases of any kind (even linkonce_odr)
Summary:
Until a more advanced version of importing can be implemented for
aliases (one that imports an alias as an available_externally definition
of the aliasee), skip the narrow subset of cases that was possible but
came at a cost: aliases of linkonce_odr functions could be imported
because the linkonce_odr function could be safely duplicated from the
source module. This came/comes at the cost of not being able to 'home'
imported linkonce functions (they had to be emitted linkonce_odr in all
the destination modules (even if they weren't used by an alias) rather
than as available_externally - causing extra object size).

Tangentially, this also was the only reason ThinLTO would emit multiple
CUs in to the resulting DWARF - which happens to be a problem for
Fission (there's a fix for this in GDB but not released yet, etc).
(actually it's not the only reason - but I'm sending a patch to fix the
other reason shortly)

There's no reason to believe this particularly narrow alias importing
was especially/meaningfully important, only that it was /possible/ to
implement in this way. When a more general solution is done, it should
still satisfy the DWARF concerns above, since the import will still be
available_externally, and thus not create extra CUs.

Since now all aliases are treated the same, I removed/simplified some
test cases since they were testing corner cases where there are no
longer any corners.

Reviewers: tejohnson, mehdi_amini

Differential Revision: https://reviews.llvm.org/D35875

llvm-svn: 309278
2017-07-27 15:09:06 +00:00
Teresa Johnson f9dc3deaa6 Revert "Restore with fix "[ThinLTO] Ensure we always select the same function copy to import""
This reverts commit r308114 (and follow on fixes to test).

There is a linking failure in a ThinLTO bot:
http://green.lab.llvm.org/green/job/clang-stage2-configure-Rthinlto_build/3663/

(and undefined reference). It seems like it must be a second order
effect of the heuristic change I made, and may take some time to try
to reproduce locally and track down. Therefore, reverting for now.

llvm-svn: 308206
2017-07-17 19:25:38 +00:00
Teresa Johnson a7660b0127 Restore with fix "[ThinLTO] Ensure we always select the same function copy to import"
This restores r308078/r308079 with a fix for bot non-determinisim (make
sure we run llvm-lto in single threaded mode so the debug output doesn't get
interleaved).

llvm-svn: 308114
2017-07-15 22:58:06 +00:00
Chandler Carruth d78a38ed2e Revert r308078 (and subsequent tweak in r308079) which introduces a test
that appears to exhibit non-determinism and is flaking on the bots
pretty consistently.

r308078: [ThinLTO] Ensure we always select the same function copy to import
r308079: Require asserts in new test that uses debug flag
llvm-svn: 308095
2017-07-15 13:50:26 +00:00
Teresa Johnson 82b4fb1afe [ThinLTO] Ensure we always select the same function copy to import
Summary:
Check if the first eligible callee is under the instruction threshold.
Checking this on the first eligible callee ensures that we don't end
up selecting different callees to import when we invoke this routine
with different thresholds due to reaching the callee via paths that
are shallower or hotter (when there are multiple copies, i.e. with
weak or linkonce linkage). We don't want to leave the decision of which
copy to import up to the backend.

Reviewers: mehdi_amini

Subscribers: inglorion, fhahn, llvm-commits

Differential Revision: https://reviews.llvm.org/D35436

llvm-svn: 308078
2017-07-15 04:53:05 +00:00
Dehao Chen 64c46574b0 Increase the import-threshold for crtical functions.
Summary: For interative sample-pgo, if a hot call site is inlined in the profiling binary, we should inline it in before profile annotation in the backend. Before that, the compile phase first collects all GUIDs that needs to be imported and creates virtual "hot" call edge in the summary. However, "hot" is not good enough to guarantee the callsites get inlined. This patch introduces "critical" call edge, and assign much higher importing threshold for those edges.

Reviewers: tejohnson

Reviewed By: tejohnson

Subscribers: sanjoy, mehdi_amini, llvm-commits, eraman

Differential Revision: https://reviews.llvm.org/D35096

llvm-svn: 307439
2017-07-07 21:01:00 +00:00
Davide Italiano f4891d29f8 [lib/LTO] Add a comment to explain where we set the linkage in the summary.
Pointed out by Teresa!

llvm-svn: 307305
2017-07-06 20:04:20 +00:00
Davide Italiano 6a5fbe52fa [LTO] Fix the interaction between linker redefined symbols and ThinLTO
This is the same as r304719 but for ThinLTO.
The substantial difference is that in this case we don't have
whole visibility, just the summary.
In the LTO case, when we got the resolution for the input file we
could just see if the linker told us whether a symbol was linker
redefined (using --wrap or --defsym) and switch the linkage directly
for the GV.

Here, we have the summary. So, we record that the linkage changed
from <whatever it was> to $weakany to prevent IPOs across this symbol
boundaries and actually just switch the linkage at FunctionImport time.

This patch should also fixes the lld bits (as all the scaffolding for
communicating if a symbol is linker redefined should be there & should
be the same), but I'll make sure to add some tests there as well.

Fixes PR33192.

Differential Revision:  https://reviews.llvm.org/D35064

llvm-svn: 307303
2017-07-06 19:58:26 +00:00