47 Commits

Author SHA1 Message Date
Teresa Johnson 260d27c8d8 [ThinLTO] Ensure callees get hot threshold when first seen on cold path
This is split out from D27696, since it turned out to be a bug fix and
not part of the NFC efficiency change.

Keep the same adjusted (possibly decayed) threshold in both the worklist
and the ImportList. Otherwise if we encountered it first along a cold
path, the callee would be added to the worklist with a lower decayed
threshold than when it is later encountered along a hot path. But the
logic uses the threshold recorded in the ImportList entry to check if
we should re-add it, and without this patch the threshold recorded there
is the same along both paths so we don't re-add it. Using the
same possibly decayed threshold in the ImportList ensures we re-add it
later with the higher non-decayed hot path threshold.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289843 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-15 18:21:01 +00:00
Mandeep Singh Grang b831a5dabd [llvm] Remove redundant --check-prefix=CHECK from tests
Reviewers: MatzeB, mcrosier, rengolin

Differential Revision: https://reviews.llvm.org/D25894

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285003 91177308-0d34-0410-b5e6-96231b3b80d8
2016-10-24 18:57:55 +00:00
Piotr Padlewski a6db8552b8 [thinlto] Don't decay threshold for hot callsites
Summary:
We don't want to decay hot callsites to import chains of hot
callsites. The same mechanism is used in LIPO.

Reviewers: tejohnson, eraman, mehdi_amini

Subscribers: llvm-commits, mehdi_amini

Differential Revision: https://reviews.llvm.org/D24976

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282833 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-30 03:01:17 +00:00
Piotr Padlewski 584dba4143 [thinlto] Add cold-callsite import heuristic
Summary:
Not tunned up heuristic, but with this small heuristic there is about
+0.10% improvement on SPEC 2006

Reviewers: tejohnson, mehdi_amini, eraman

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D24940

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282733 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-29 17:32:07 +00:00
Piotr Padlewski fdf7354745 [thinlto] Basic thinlto fdo heuristic
Summary:
This patch improves thinlto importer
by importing 3x larger functions that are called from hot block.

I compared performance with the trunk on spec, and there
were about 2% on povray and 3.33% on milc. These results seems
to be consistant and match the results Teresa got with her simple
heuristic. Some benchmarks got slower but I think they are just
noisy (mcf, xalancbmki, omnetpp)- running the benchmarks again with
more iterations to confirm. Geomean of all benchmarks including the noisy ones
were about +0.02%.

I see much better improvement on google branch with Easwaran patch
for pgo callsite inlining (the inliner actually inline those big functions)
Over all I see +0.5% improvement, and I get +8.65% on povray.
So I guess we will see much bigger change when Easwaran patch will land
(it depends on new pass manager), but it is still worth putting this to trunk
before it.

Implementation details changes:
- Removed CallsiteCount.
- ProfileCount got replaced by Hotness
- hot-import-multiplier is set to 3.0 for now,
didn't have time to tune it up, but I see that we get most of the interesting
functions with 3, so there is no much performance difference with higher, and
binary size doesn't grow as much as with 10.0.

Reviewers: eraman, mehdi_amini, tejohnson

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D24638

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282437 91177308-0d34-0410-b5e6-96231b3b80d8
2016-09-26 20:37:32 +00:00
Piotr Padlewski fb2a7f990d Don't import variadic functions
Summary:
This patch adds IsVariadicFunction bit to summary in order
to not import variadic functions. Inliner doesn't inline
variadic functions because it is hard to reason about it.

This one small fix improves Importer by about 16%
(going from 86% to 100% of imported functions that are
inlined anywhere)
on some spec benchmarks like 'int' and others.

Reviewers: eraman, mehdi_amini, tejohnson

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23339

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278432 91177308-0d34-0410-b5e6-96231b3b80d8
2016-08-11 22:13:57 +00:00
Teresa Johnson 385d70633e [PM] Port FunctionImport Pass to new PM
Summary: Port FunctionImport Pass to new PM.

Reviewers: mehdi_amini, davide

Subscribers: davidxl, llvm-commits

Differential Revision: https://reviews.llvm.org/D22475

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275916 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-18 21:22:24 +00:00
Piotr Padlewski 8969dd96cc Add 'thinlto_src_module' md with asserts or -enable-import-metadata
Summary:
This way the metadata will be only generated when asserts enabled,
or when -enable-import-metadata specified

FIXED missing colon on requires.

Reviewers: tejohnson, eraman, mehdi_amini

Subscribers: mehdi_amini, llvm-commits

Differential Revision: http://reviews.llvm.org/D22167

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274947 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-08 23:01:49 +00:00
Piotr Padlewski a745089940 Revert "Add 'thinlto_src_module' md with asserts or -enable-import-metadata"
Reverting because of 17463
http://lab.llvm.org:8011/builders/clang-x86_64-linux-selfhost-modules/builds/17463

This reverts commit d20cb431bb.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274946 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-08 22:55:48 +00:00
Piotr Padlewski d20cb431bb Add 'thinlto_src_module' md with asserts or -enable-import-metadata
Summary:
This way the metadata will be only generated when asserts enabled,
or when -enable-import-metadata specified

Reviewers: tejohnson, eraman, mehdi_amini

Subscribers: mehdi_amini, llvm-commits

Differential Revision: http://reviews.llvm.org/D22167

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274938 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-08 21:25:39 +00:00
Piotr Padlewski a5ef55b509 Add 'thinlto_src_module' metadata to imported function
Added metadata to be able to make statistics on how many functions
that have been imported have been removed. Also module name might
be helpfull when debugging.

Reviewers: tejohnson, eraman

Subscribers: mehdi_amini, llvm-commits

Differential Revision: http://reviews.llvm.org/D21943

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274668 91177308-0d34-0410-b5e6-96231b3b80d8
2016-07-06 20:26:25 +00:00
Mehdi Amini dd2d6cfee4 ThinLTO: do not import function whose linkage prevents inlining.
There is not point in importing a "weak" or a "linkonce" function
since we won't be able to inline it anyway.
We already had a targeted check for WeakAny, this is using the
same check on GlobalValue as the inline, i.e.
isMayBeOverriddenLinkage()

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268341 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-03 00:27:28 +00:00
Mehdi Amini 2ef976219b Revert "ThinLTO: do not import function whose linkage prevents inlining."
This reverts commit r268315, the tests are not passing.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268317 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-02 22:26:04 +00:00
Mehdi Amini e1cf918848 ThinLTO: do not import function whose linkage prevents inlining.
There is not point in importing a "weak" or a "linkonce" function
since we won't be able to inline it anyway.
We already had a targeted check for WeakAny, this is using the
same check on GlobalValue as the inline, i.e.
isMayBeOverriddenLinkage()

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268315 91177308-0d34-0410-b5e6-96231b3b80d8
2016-05-02 22:11:27 +00:00
Mehdi Amini 0e6037480f ThinLTO/ModuleLinker: add a flag to not always pull-in linkonce when performing importing
Summary:
The function importer already decided what symbols need to be pulled
in. Also these magically added ones will not be in the export list
for the source module, which can confuse the internalizer for
instance.

Reviewers: tejohnson, rafael

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19096

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266948 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-21 01:59:39 +00:00
Teresa Johnson 89c5c63c3c [ThinLTO] Prevent importing of "llvm.used" values
Summary:
This patch prevents importing from (and therefore exporting from) any
module with a "llvm.used" local value. Local values need to be promoted
and renamed when importing, and their presense on the llvm.used variable
indicates that there are opaque uses that won't see the rename. One such
example is a use in inline assembly.

See also the discussion at:
http://lists.llvm.org/pipermail/llvm-dev/2016-April/098047.html

As part of this, move collectUsedGlobalVariables out of Transforms/Utils
and into IR/Module so that it can be used more widely. There are several
other places in LLVM that used copies of this code that can be cleaned
up as a follow on NFC patch.

Reviewers: joker.eph

Subscribers: pcc, llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18986

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266877 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-20 14:39:45 +00:00
Mehdi Amini eb79e6e85d ThinLTO: Make aliases explicit in the summary
To be able to work accurately on the reference graph when taking
decision about internalizing, promoting, renaming, etc. We need
to have the alias information explicit.

Differential Revision: http://reviews.llvm.org/D18836

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266517 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-16 06:56:44 +00:00
Adrian Prantl 4eeaa0da04 [PR27284] Reverse the ownership between DICompileUnit and DISubprogram.
Currently each Function points to a DISubprogram and DISubprogram has a
scope field. For member functions the scope is a DICompositeType. DIScopes
point to the DICompileUnit to facilitate type uniquing.

Distinct DISubprograms (with isDefinition: true) are not part of the type
hierarchy and cannot be uniqued. This change removes the subprograms
list from DICompileUnit and instead adds a pointer to the owning compile
unit to distinct DISubprograms. This would make it easy for ThinLTO to
strip unneeded DISubprograms and their transitively referenced debug info.

Motivation
----------

Materializing DISubprograms is currently the most expensive operation when
doing a ThinLTO build of clang.

We want the DISubprogram to be stored in a separate Bitcode block (or the
same block as the function body) so we can avoid having to expensively
deserialize all DISubprograms together with the global metadata. If a
function has been inlined into another subprogram we need to store a
reference the block containing the inlined subprogram.

Attached to https://llvm.org/bugs/show_bug.cgi?id=27284 is a python script
that updates LLVM IR testcases to the new format.

http://reviews.llvm.org/D19034
<rdar://problem/25256815>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266446 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-15 15:57:41 +00:00
Mehdi Amini 387bdb41b0 Revert "Make aliases explicit in the summary"
Inadvertently commited...

This reverts commit e618ec9378.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266215 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-13 17:20:07 +00:00
Mehdi Amini e618ec9378 Make aliases explicit in the summary
Summary:
To be able to work accurately on the reference graph when taking decision
about internalizing, promoting, renaming, etc. We need to have the alias
information explicit.

Reviewers: tejohnson

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D18836

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266214 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-13 17:18:42 +00:00
Mehdi Amini e58bfc97e6 Move summary creation out of llvm-as into opt
Summary:
Let keep llvm-as "dumb": it converts textual IR to bitcode. This
commit removes the dependency from llvm-as to libLLVMAnalysis.
We'll add back summary in llvm-as if we get to a textual
representation for it at some point. In the meantime, opt seems
like a better place for that.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19032

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266131 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-12 21:35:18 +00:00
Mehdi Amini 18a65be70f ThinLTO renaming: use module hash instead of position in the summary
This is more robust to changes in the link ordering.

Differential Revision: http://reviews.llvm.org/D18946

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266018 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-11 23:26:46 +00:00
Teresa Johnson 7ca333b425 [ThinLTO] Move summary computation from BitcodeWriter to new pass
Summary:
This is the first step in also serializing the index out to LLVM
assembly.

The per-module summary written to bitcode is moved out of the bitcode
writer and to a new analysis pass (ModuleSummaryIndexWrapperPass).
The pass itself uses a new builder class to compute index, and the
builder class is used directly in places where we don't have a pass
manager (e.g. llvm-as).

Because we are computing summaries outside of the bitcode writer, we no
longer can use value ids created by the bitcode writer's
ValueEnumerator. This required changing the reference graph edge type
to use a new ValueInfo class holding a union between a GUID (combined
index) and Value* (permodule index). The Value* are converted to the
appropriate value ID during bitcode writing.

Also, this enables removal of the BitWriter library's dependence on the
Analysis library that was previously required for the summary computation.

Reviewers: joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18763

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265941 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-11 13:58:45 +00:00
Teresa Johnson 7e69f9988e Fix bot errors from r265327, exact GUID which depends on path
E.g. http://bb.pgr.jp/builders/ninja-x64-msvc-RA-centos6/builds/21919

The source file path name will affect exact GUID, don't try to match
exact value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265334 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-04 19:11:00 +00:00
Teresa Johnson 0a41a31987 [ThinLTO] Add option to dump value name to GUID mapping
Summary:
Useful for debugging since we lose this correlation after the permodule
summary/VST is read and until we later materialize source modules in the
function importer.

Reviewers: joker.eph

Subscribers: llvm-commits, joker.eph

Differential Revision: http://reviews.llvm.org/D18555

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265327 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-04 18:52:58 +00:00