Commit Graph

3276 Commits

Author SHA1 Message Date
Wei Mi e555127435 [SampleFDO] Add an option to turn on/off warning about samples unused.
If a function has sample to use, but cannot use them because of no debug
information, currently a warning will be issued to inform the missing
opportunity.

This warning assumes the binary generating the profile and the binary using
the profile are similar enough. It is not always the case. Sometimes even
if the binaries are not quite similar, we may still get some benefit by
using sampleFDO. In those cases, we may still want to apply sampleFDO but
not want to see a lot of such warnings pop up.

The patch adds an option for the warning.

Differential Revision: https://reviews.llvm.org/D48510

llvm-svn: 335484
2018-06-25 15:40:31 +00:00
Tobias Edler von Koch 7609cb83e6 Re-land "[LTO] Enable module summary emission by default for regular LTO"
Since we are now producing a summary also for regular LTO builds, we
need to run the NameAnonGlobals pass in those cases as well (the
summary cannot handle anonymous globals).

See https://reviews.llvm.org/D34156 for details on the original change.

This reverts commit 6c9ee4a4a438a8059aacc809b2dd57128fccd6b3.

llvm-svn: 335385
2018-06-22 20:23:21 +00:00
Chandler Carruth aa5f4d2e23 Revert r335306 (and r335314) - the Call Graph Profile pass.
This is the first pass in the main pipeline to use the legacy PM's
ability to run function analyses "on demand". Unfortunately, it turns
out there are bugs in that somewhat-hacky approach. At the very least,
it leaks memory and doesn't support -debug-pass=Structure. Unclear if
there are larger issues or not, but this should get the sanitizer bots
back to green by fixing the memory leaks.

llvm-svn: 335320
2018-06-22 05:33:57 +00:00
Michael J. Spencer fc93dd8e18 [Instrumentation] Add Call Graph Profile pass
This patch adds support for generating a call graph profile from Branch Frequency Info.

The CGProfile module pass simply gets the block profile count for each BB and scans for call instructions. For each call instruction it adds an edge from the current function to the called function with the current BB block profile count as the weight.

After scanning all the functions, it generates an appending module flag containing the data. The format looks like:

!llvm.module.flags = !{!0}

!0 = !{i32 5, !"CG Profile", !1}
!1 = !{!2, !3, !4} ; List of edges
!2 = !{void ()* @a, void ()* @b, i64 32} ; Edge from a to b with a weight of 32
!3 = !{void (i1)* @freq, void ()* @a, i64 11}
!4 = !{void (i1)* @freq, void ()* @b, i64 20}

Differential Revision: https://reviews.llvm.org/D48105

llvm-svn: 335306
2018-06-21 23:31:10 +00:00
Francis Visoiu Mistrih ac599b6951 Revert r335206 "Recommit r333268: [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions."
This reverts commit r335206.

As discussed here: https://reviews.llvm.org/rL333740, a fix will come
tomorrow. In the meanwhile, revert this to fix some bots.

llvm-svn: 335272
2018-06-21 19:18:36 +00:00
Florian Hahn d36aa1f763 Recommit r333268: [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.
r335150 should resolve the issues with the clang-with-thin-lto-ubuntu
and clang-with-lto-ubuntu builders.

Original message:
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.

As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.

Reviewers: davide, mssimpso, dberlin, efriedma

Reviewed By: davide, dberlin

llvm-svn: 335206
2018-06-21 07:15:08 +00:00
Florian Hahn a1cc848399 Use SmallPtrSet explicitly for SmallSets with pointer types (NFC).
Currently SmallSet<PointerTy> inherits from SmallPtrSet<PointerTy>. This
patch replaces such types with SmallPtrSet, because IMO it is slightly
clearer and allows us to get rid of unnecessarily including SmallSet.h

Reviewers: dblaikie, craig.topper

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D47836

llvm-svn: 334492
2018-06-12 11:16:56 +00:00
Wei Mi a0c0857e7a [SampleFDO] Add a new compact binary format for sample profile.
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
2018-06-11 22:40:43 +00:00
Teresa Johnson 4ffc3e7834 [ThinLTO] Rename index IsAnalysis flag to HaveGVs (NFC)
With the upcoming patch to add summary parsing support, IsAnalysis would
be true in contexts where we are not performing module summary analysis.
Rename to the more specific and approprate HaveGVs, which is essentially
what this flag is indicating.

llvm-svn: 334140
2018-06-06 22:22:01 +00:00
David Blaikie 31b98d2e99 Move Analysis/Utils/Local.h back to Transforms
Review feedback from r328165. Split out just the one function from the
file that's used by Analysis. (As chandlerc pointed out, the original
change only moved the header and not the implementation anyway - which
was fine for the one function that was used (since it's a
template/inlined in the header) but not in general)

llvm-svn: 333954
2018-06-04 21:23:21 +00:00
Dmitry Mikulin 4539487650 In thin and full LTO + CFI, direct function calls may go through jump table
entries to reach the target. Since these calls don't require type checks,
we can short-circuit them to their real targets, except in cases when they
can be pre-empted.

Differential Revision: https://reviews.llvm.org/D46326

llvm-svn: 333937
2018-06-04 18:18:12 +00:00
Vlad Tsyrklevich 6867ab7c90 [ThinLTOBitcodeWriter] Emit summaries for regular LTO modules
Summary:
Emit summaries for bitcode modules that are only destined for the
regular LTO portion of the build so they can participate in
summary-based dead stripping.

This change reduces the size of a nacl_helper build with cfi-icall
enabled by 7%, removing the majority of the overhead due to enabling
cfi-icall. The cfi-icall size increase was caused by compiling in lots
of unused code and cfi-icall generating jumptable references to unused
symbols that could no longer be removed by -Wl,-gc-sections. Increasing
the visibility of summary-based dead stripping prevented jumptable
entries being created for unused symbols from the regular LTO portion
of the build.

Reviewers: pcc

Reviewed By: pcc

Subscribers: dschuff, mehdi_amini, inglorion, eraman, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D47594

llvm-svn: 333768
2018-06-01 15:20:47 +00:00
Florian Hahn 8a17f1f43e Revert r333740: IPSCCP] Use PredicateInfo to propagate facts from cmp.
This is breaking the clang-with-thin-lto-ubuntu bot.

llvm-svn: 333745
2018-06-01 12:58:43 +00:00
Florian Hahn f4df554f32 Recommit r333268: [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.

As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.

Reviewers: davide, mssimpso, dberlin, efriedma

Reviewed By: davide, dberlin

Differential Revision: https://reviews.llvm.org/D45330

llvm-svn: 333740
2018-06-01 10:48:54 +00:00
Benjamin Kramer 0deb9a9a1f Extend the GlobalObject metadata interface
- Make eraseMetadata return whether it changed something
- Wire getMetadata for a single MDNode efficiently into the attachment
map
- Add hasMetadata, which is less weird than checking getMetadata ==
nullptr on a multimap.

Use it to simplify code.

llvm-svn: 333649
2018-05-31 13:29:58 +00:00
Vlad Tsyrklevich 178fdb1a3b [LowerTypeTests] Discard extern_weak linkage for definitions
Summary:
Fix PR37625. It's possible for an extern_weak declaration to be emitted
to the merged module when a definition exists in the ThinLTO portion of
the build; discard the linkage on the declaration in that case.
(otherwise we copy the linkage to the alias to the jumptable and fail)

Reviewers: pcc

Reviewed By: pcc

Subscribers: mehdi_amini, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D47494

llvm-svn: 333604
2018-05-30 22:39:52 +00:00
Benjamin Kramer c8bd5449e0 [CalledValuePropagation] Just use a sorted vector instead of a set.
The set properties are never used, so a vector is enough. No
functionality change intended.

While there add some std::moves to SparseSolver.

llvm-svn: 333582
2018-05-30 19:31:11 +00:00
Chandler Carruth 71fd27043e [PM/LoopUnswitch] When using the new SimpleLoopUnswitch pass, schedule
loop-cleanup passes at the beginning of the loop pass pipeline, and
re-enqueue loops after even trivial unswitching.

This will allow us to much more consistently avoid simplifying code
while doing trivial unswitching. I've also added a test case that
specifically shows effective iteration using this technique.

I've unconditionally updated the new PM as that is always using the
SimpleLoopUnswitch pass, and I've made the pipeline changes for the old
PM conditional on using this new unswitch pass. I added a bunch of
comments to the loop pass pipeline in the old PM to make it more clear
what is going on when reviewing.

Hopefully this will unblock doing *partial* unswitching instead of just
full unswitching.

Differential Revision: https://reviews.llvm.org/D47408

llvm-svn: 333493
2018-05-30 02:46:45 +00:00
David Green aee7ad0cde Revert 333358 as it's failing on some builders.
I'm guessing the tests reply on the ARM backend being built.

llvm-svn: 333359
2018-05-27 12:54:33 +00:00
David Green 3034281b43 [UnrollAndJam] Add a new Unroll and Jam pass
This is a simple implementation of the unroll-and-jam classical loop
optimisation.

The basic idea is that we take an outer loop of the form:

for i..
  ForeBlocks(i)
  for j..
    SubLoopBlocks(i, j)
  AftBlocks(i)

Instead of doing normal inner or outer unrolling, we unroll as follows:

for i... i+=2
  ForeBlocks(i)
  ForeBlocks(i+1)
  for j..
    SubLoopBlocks(i, j)
    SubLoopBlocks(i+1, j)
  AftBlocks(i)
  AftBlocks(i+1)
Remainder

So we have unrolled the outer loop, then jammed the two inner loops into
one. This can lead to a simpler inner loop if memory accesses can be shared
between the now-jammed loops.

To do this we have to prove that this is all safe, both for the memory
accesses (using dependence analysis) and that ForeBlocks(i+1) can move before
AftBlocks(i) and SubLoopBlocks(i, j).

Differential Revision: https://reviews.llvm.org/D41953

llvm-svn: 333358
2018-05-27 12:11:21 +00:00
Florian Hahn 718af2f817 Revert r333268: [IPSCCP] Use PredicateInfo to propagate facts from...
Reverting this to see if this is causing the failures of the
clang-with-thin-lto-ubuntu bot.

[IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.

This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.

As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.

Reviewers: davide, mssimpso, dberlin, efriedma

Reviewed By: davide, dberlin

Differential Revision: https://reviews.llvm.org/D45330

llvm-svn: 333323
2018-05-25 23:32:02 +00:00
Florian Hahn b4a70b9f47 [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.
This patch updates IPSCCP to use PredicateInfo to propagate
facts to true branches predicated by EQ and to false branches
predicated by NE.

As a follow up, we should be able to extend it to also propagate additional
facts about nonnull.

Reviewers: davide, mssimpso, dberlin, efriedma

Reviewed By: davide, dberlin

Differential Revision: https://reviews.llvm.org/D45330

llvm-svn: 333268
2018-05-25 11:12:33 +00:00
Jakub Kuderski ef33edd9b5 [Dominators] Add PDT constructor from Function
Summary: This patch adds a PDT constructor from Function and lets codes previously using a local class to do this use PostDominatorTree class directly.

Reviewers: davide, kuhar, grosser, dberlin

Reviewed By: kuhar

Author: NutshellySima

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D46709

llvm-svn: 333102
2018-05-23 17:29:21 +00:00
Nicola Zaghen 03d0b91f43 Remove DEBUG macro.
Now that the LLVM_DEBUG() macro landed on the various sub-projects
the DEBUG macro can be removed.
Also change the new uses of DEBUG to LLVM_DEBUG.

Differential Revision: https://reviews.llvm.org/D46952

llvm-svn: 333091
2018-05-23 15:09:29 +00:00
Nico Weber e4a12cfa2f revert r332610, it breaks cfi, see D46326
llvm-svn: 332838
2018-05-21 11:44:39 +00:00
Dmitry Mikulin 3c6b4e35bd In thin and full LTO + CFI, direct function calls may go through jump table
entries to reach the target. Since these calls don't require type checks,
we can short-circuit them to their real targets.

Differential Revision: https://reviews.llvm.org/D46326

llvm-svn: 332610
2018-05-17 14:29:07 +00:00
whitequark 8f0ab258bd [MergeFunctions] Fix merging of small weak functions
When two interposable functions are merged, we cannot replace
uses and have to emit calls to a common internal function. However,
writeThunk() will not actually emit a thunk if the function is too
small. This leaves us in a broken state where mergeTwoFunctions
already rewired the functions, but writeThunk doesn't do anything.

This patch changes the implementation so that:

 * writeThunk() does just that.
 * The direct replacement of calls is moved into mergeTwoFunctions()
   into the non-interposable case only.
 * isThunkProfitable() is extracted and will be called for
   the non-iterposable case always, and in the interposable case
   only if uses are still left after replacement.

This issue has been introduced in https://reviews.llvm.org/D34806,
where the code for checking thunk profitability has been moved.

Differential Revision: https://reviews.llvm.org/D46804

Reviewed By: whitequark

llvm-svn: 332342
2018-05-15 11:31:07 +00:00
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
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
Vedant Kumar e0b5f86b30 [STLExtras] Add distance() for ranges, pred_size(), and succ_size()
This commit adds a wrapper for std::distance() which works with ranges.
As it would be a common case to write `distance(predecessors(BB))`, this
also introduces `pred_size()` and `succ_size()` helpers to make that
easier to write.

Differential Revision: https://reviews.llvm.org/D46668

llvm-svn: 332057
2018-05-10 23:01:54 +00:00
Teresa Johnson 59da890c96 [NewPM] Emit inliner NoDefinition missed optimization remark
Summary: Makes this consistent with the old PM.

Reviewers: eraman

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D46526

llvm-svn: 331709
2018-05-08 01:45:46 +00:00
Dmitry Mikulin 738bac77c1 Remove explicit setting of the CFI jumptable section name, it does not appear
to be needed: jump table sections are created with .cfi.jumptable suffix. With
this change each jump table is placed in a separate section, which allows the
linker to re-order them.

Differential Revision: https://reviews.llvm.org/D46537

llvm-svn: 331680
2018-05-07 21:30:15 +00:00
Peter Collingbourne e04ecc88de LowerTypeTests: Fix non-determinism in code that handles icall branch funnels.
This was exposed by enabling expensive checks, which causes llvm::sort
to sort randomly.

Differential Revision: https://reviews.llvm.org/D45901

llvm-svn: 331573
2018-05-05 00:51:55 +00:00
Adrian Prantl 4dfcc4a788 Remove @brief commands from doxygen comments, too.
This is a follow-up to r331272.

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

https://reviews.llvm.org/D46290

llvm-svn: 331275
2018-05-01 16:10:38 +00:00
Adrian Prantl 5f8f34e459 Remove \brief commands from doxygen comments.
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
2018-05-01 15:54:18 +00:00
Adrian Prantl 210a29de7b Fix a bug in GlobalOpt's handling of DIExpressions.
This patch adds support for fragment expressions
TryToShrinkGlobalToBoolean() which were previously just dropped.

Thanks to Reid Kleckner for providing me a reproducer!

llvm-svn: 331086
2018-04-27 21:41:36 +00:00
Eli Friedman e06539456c [LowerTypeTests] Mark .cfi.jumptable nounwind.
It doesn't unwind, and the wrong marking leads to the creation of an
.eh_frame section when it isn't necessary.

Differential Revision: https://reviews.llvm.org/D46082

llvm-svn: 331008
2018-04-27 00:32:24 +00:00
Vlad Tsyrklevich b768d235a9 Revert "Enable EliminateAvailableExternally pass for -O1"
This reverts commit r330961 because it breaks a handful of clang tests.

llvm-svn: 330964
2018-04-26 17:54:53 +00:00
Vlad Tsyrklevich 42c5a9c29a Enable EliminateAvailableExternally pass for -O1
Summary:
Follow-up to D43690, the EliminateAvailableExternally pass currently
runs under -O0 and -O2 and up. Under -O1 we would still want to drop
available_externally symbols to reduce space without inlining having
run.

Reviewers: tejohnson

Reviewed By: tejohnson

Subscribers: mehdi_amini, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D46093

llvm-svn: 330961
2018-04-26 17:33:24 +00:00
David Blaikie ba47dd16c5 Fix some layering in AggressiveInstCombine (avoiding inclusion of Scalar.h)
llvm-svn: 330726
2018-04-24 15:40:07 +00:00
David Blaikie a27771b62f InstCombine: Fix layering by not including Scalar.h in InstCombine
(notionally Scalar.h is part of libLLVMScalarOpts, so it shouldn't be
included by InstCombine which doesn't/shouldn't need to depend on
ScalarOpts)

llvm-svn: 330669
2018-04-24 00:48:59 +00:00
Sean Fertile 18f17333dd [PartialInlining] Fix Crash from holding a reference to a destructed ORE.
The callback used to create an ORE for the legacy PI pass caches the allocated
object in a unique_ptr in the runOnModule function, and returns a reference to
that object. Under certian circumstances we can end up holding onto that
reference after the OREs destruction. Rather then allowing the new and legacy
passes to create ORE object in diffrent ways, create the ORE at the point of
use.

Differential Revision: https://reviews.llvm.org/D43219

llvm-svn: 330473
2018-04-20 19:56:26 +00:00
Vlad Tsyrklevich 230b256783 LowerTypeTests: Propagate symver directives
Summary:
This change fixes https://crbug.com/834474, a build failure caused by
LowerTypeTests not preserving .symver symbol versioning directives for
exported functions. Emit symver information to ThinLTO summary data and
then propagate symver directives for exported functions to the merged
module.

Emitting symver information to the summaries increases the size of
intermediate build artifacts for a Chromium build by less than 0.2%.

Reviewers: pcc

Reviewed By: pcc

Subscribers: tejohnson, mehdi_amini, eraman, llvm-commits, eugenis, kcc

Differential Revision: https://reviews.llvm.org/D45798

llvm-svn: 330387
2018-04-20 01:36:48 +00:00
Mandeep Singh Grang 636d94db3b [Transforms] Change std::sort to llvm::sort in response to r327219
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: kcc, pcc, danielcdh, jmolloy, sanjoy, dberlin, ruiu

Reviewed By: ruiu

Subscribers: ruiu, llvm-commits

Differential Revision: https://reviews.llvm.org/D45142

llvm-svn: 330059
2018-04-13 19:47:57 +00:00
Eli Friedman e1938cbc87 Don't call skipModule for CFI lowering passes.
opt-bisect shouldn't skip these passes; they lower intrinsics which
no other pass can handle.

llvm-svn: 329961
2018-04-12 22:04:11 +00:00
George Burgess IV 48ee59b6f0 [DeadArgElim] Remove allocsize attributes on callsites
We're already removing allocsize attributes from Functions that we
remove args from, since removing arguments from a function may make the
allocsize attribute incorrect. It appears we forgot to also remove them
from callsites.

Without this, I get verifier errors on `@Test2`.

It probably wouldn't be too hard to make DAE properly update allocsize
attributes instead of dropping them, but I can't think of a scenario
where that'd be useful in practice.

llvm-svn: 329868
2018-04-12 02:06:01 +00:00
Vitaly Buka 9cb59b92cc Fix warning by cl::opt<int> -> cl::opt<unsigned>
llvm-svn: 329461
2018-04-06 21:41:17 +00:00
Vitaly Buka 66f53d71f7 Runtime flag to control branch funnel threshold
Reviewers: pcc

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D45193

llvm-svn: 329459
2018-04-06 21:32:36 +00:00
Benjamin Kramer 1fc0da4849 Make helpers static. NFC.
llvm-svn: 329170
2018-04-04 11:45:11 +00:00
Vlad Tsyrklevich 07cf78cdad Fix bad copy-and-paste in r329108
llvm-svn: 329118
2018-04-03 21:40:27 +00:00
Vlad Tsyrklevich d17f61ea3b Add the ShadowCallStack attribute
Summary:
Introduce the ShadowCallStack function attribute. It's added to
functions compiled with -fsanitize=shadow-call-stack in order to mark
functions to be instrumented by a ShadowCallStack pass to be submitted
in a separate change.

Reviewers: pcc, kcc, kubamracek

Reviewed By: pcc, kcc

Subscribers: cryptoad, mehdi_amini, javed.absar, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D44800

llvm-svn: 329108
2018-04-03 20:10:40 +00:00
Rong Xu 5a8d4c3357 [DeadArgumentElim] Clone function level metadatas
Some Function level metadatas, such as function entry count, are not cloned in
DeadArgumentElim. This happens a lot in lto/thinlto because of DeadArgumentElim
after internalization.

This patch clones the metadatas in the original function to the new function.

Differential Revision: https://reviews.llvm.org/D44127

llvm-svn: 328991
2018-04-02 17:27:38 +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
David Blaikie a373d18eb7 Transforms: Introduce Transforms/Utils.h rather than spreading the declarations amongst Scalar.h and IPO.h
Fixes layering - Transforms/Utils shouldn't depend on including a Scalar
or IPO header, because Scalar and IPO depend on Utils.

llvm-svn: 328717
2018-03-28 17:44:36 +00:00
Benjamin Kramer 8840f644b4 [DeadArgElim] Strip allocsize attributes when deleting an argument.
Since allocsize refers to the argument number it gets invalidated when
an argument is removed and the numbers shift.

llvm-svn: 328481
2018-03-26 09:44:24 +00:00
Fedor Sergeev 6660fd0f95 [PM][FunctionAttrs] add NoUnwind attribute inference to PostOrderFunctionAttrs pass
Summary:
This was motivated by absence of PrunEH functionality in new PM.
It was decided that a proper way to do PruneEH is to add NoUnwind inference
into PostOrderFunctionAttrs and then perform normal SimplifyCFG on top.

This change generalizes attribute handling implemented for (a removal of)
Convergent attribute, by introducing a generic builder-like class
   AttributeInferer

It registers all the attribute inference requests, storing per-attribute
predicates into a vector, and then goes through an SCC Node, scanning all
the instructions for not breaking attribute assumptions.

The main idea is that as soon all the instructions from all the functions
of SCC Node conform to attribute assumptions then we are free to infer
the attribute as set for all the functions of SCC Node.

It handles two distinct cases of attributes:
   - those that might break due to derefinement of the function code

     for these attributes we are allowed to apply inference only if all the
     functions are "exact definitions". Example - NoUnwind.

   - those that do not care about derefinement

     for these attributes we are allowed to apply inference as soon as we see
     any function definition. Example - removal of Convergent attribute.

Also in this commit:
* Converted all the FunctionAttrs tests to use FileCheck and added new-PM
  invocations to them

* FunctionAttrs/convergent.ll test demonstrates a difference in behavior between
   new and old PM implementations. Marked with FIXME.

* PruneEH tests were converted to new-PM as well, using function-attrs+simplify-cfg
  combo as intended

* some of "other" tests were updated since function-attrs now infers 'nounwind'
  even for old PM pipeline

* -disable-nounwind-inference hidden option added as a possible workaround for a supposedly
  rare case when nounwind being inferred by default presents a problem

Reviewers: chandlerc, jlebar

Reviewed By: jlebar

Subscribers: eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D44415

llvm-svn: 328377
2018-03-23 21:46:16 +00:00
David Blaikie 301627f875 Move SampleProfile.h into IPO along with the rest of the IPO pass headers
llvm-svn: 328262
2018-03-22 22:42:44 +00:00
David Blaikie 376294c23a Finish moving the IPSCCP pass from Scalar to IPO - moving the registration
llvm-svn: 328259
2018-03-22 22:07:53 +00:00
David Blaikie 3bbf5af0ac Fix layering between SCCP and IPO SCCP
Transforms/Scalar/SCCP.cpp implemented both the Scalar and IPO SCCP, but
this meant Transforms/Scalar including Transfroms/IPO headers, creating
a circular dependency. (IPO depends on Scalar already) - so move the IPO
SCCP shims out into IPO and the basic library implementation accessible
from Scalar/SCCP.h to be used from the IPO/SCCP.cpp implementation.

llvm-svn: 328250
2018-03-22 21:41:29 +00:00
David Blaikie 2965a01e98 Move the initialization of the Meta Renamer pass over to IPO along with the rest of it that was moved in r328209
llvm-svn: 328234
2018-03-22 19:36:54 +00:00
Matt Morehouse 236cdaf84c [SimplifyCFG] Create attribute for fuzzing-specific optimizations.
Summary:
When building with libFuzzer, converting control flow to selects or
obscuring the original operands of CMPs reduces the effectiveness of
libFuzzer's heuristics.

This patch provides an attribute to disable or modify certain optimizations
for optimal fuzzing signal.

Provides a less aggressive alternative to https://reviews.llvm.org/D44057.

Reviewers: vitalybuka, davide, arsenm, hfinkel

Reviewed By: vitalybuka

Subscribers: junbuml, mehdi_amini, wdng, javed.absar, hiraditya, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D44232

llvm-svn: 328214
2018-03-22 17:07:51 +00:00
David Blaikie 0368417595 Move MetaRenamer from Transforms/UTils to Transforms/IPO since it implements part of IPO.h
llvm-svn: 328209
2018-03-22 15:57:47 +00:00
David Blaikie 2be3922807 Fix a couple of layering violations in Transforms
Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering.

Transforms depends on Transforms/Utils, not the other way around. So
remove the header and the "createStripGCRelocatesPass" function
declaration (& definition) that is unused and motivated this dependency.

Move Transforms/Utils/Local.h into Analysis because it's used by
Analysis/MemoryBuiltins.cpp.

llvm-svn: 328165
2018-03-21 22:34:23 +00:00
Oren Ben Simhon fdd72fd522 [X86] Added support for nocf_check attribute for indirect Branch Tracking
X86 Supports Indirect Branch Tracking (IBT) as part of Control-Flow Enforcement Technology (CET).
IBT instruments ENDBR instructions used to specify valid targets of indirect call / jmp.
The `nocf_check` attribute has two roles in the context of X86 IBT technology:
	1. Appertains to a function - do not add ENDBR instruction at the beginning of the function.
	2. Appertains to a function pointer - do not track the target function of this pointer by adding nocf_check prefix to the indirect-call instruction.

This patch implements `nocf_check` context for Indirect Branch Tracking.
It also auto generates `nocf_check` prefixes before indirect branchs to jump tables that are guarded by range checks.

Differential Revision: https://reviews.llvm.org/D41879

llvm-svn: 327767
2018-03-17 13:29:46 +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
Volkan Keles 4ecdb44a64 BlockExtractor: Don’t delete functions directly
Blocks may have function calls, so don’t erase functions
directly to avoid erasing a function that has a user.

llvm-svn: 327340
2018-03-12 22:28:18 +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
Florian Hahn a7dcfa746e [PartialInlining] Use isInlineViable to detect constructs preventing inlining.
Use isInlineViable to prevent inlining of functions with non-inlinable
constructs, in case cost analysis is skipped.

Reviewers: efriedma, sfertile, davide, davidxl

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D42846

llvm-svn: 327207
2018-03-10 14:53:44 +00:00
Peter Collingbourne 2974856ad4 Use branch funnels for virtual calls when retpoline mitigation is enabled.
The retpoline mitigation for variant 2 of CVE-2017-5715 inhibits the
branch predictor, and as a result it can lead to a measurable loss of
performance. We can reduce the performance impact of retpolined virtual
calls by replacing them with a special construct known as a branch
funnel, which is an instruction sequence that implements virtual calls
to a set of known targets using a binary tree of direct branches. This
allows the processor to speculately execute valid implementations of the
virtual function without allowing for speculative execution of of calls
to arbitrary addresses.

This patch extends the whole-program devirtualization pass to replace
certain virtual calls with calls to branch funnels, which are
represented using a new llvm.icall.jumptable intrinsic. It also extends
the LowerTypeTests pass to recognize the new intrinsic, generate code
for the branch funnels (x86_64 only for now) and lay out virtual tables
as required for each branch funnel.

The implementation supports full LTO as well as ThinLTO, and extends the
ThinLTO summary format used for whole-program devirtualization to
support branch funnels.

For more details see RFC:
http://lists.llvm.org/pipermail/llvm-dev/2018-January/120672.html

Differential Revision: https://reviews.llvm.org/D42453

llvm-svn: 327163
2018-03-09 19:11:44 +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
Fedor Indutny 1571b1271e [ArgumentPromotion] don't break musttail invariant PR36543
Summary:
Do not break musttail invariant by promoting arguments of musttail
callee or caller.

Reviewers: sanjoy, dberlin, hfinkel, george.burgess.iv, fhahn, rnk

Reviewed By: rnk

Subscribers: rnk, llvm-commits

Differential Revision: https://reviews.llvm.org/D43926

llvm-svn: 326521
2018-03-02 00:59:27 +00:00
Reid Kleckner cb9611ca67 [DAE] don't remove args of musttail target/caller
`musttail` requires identical signatures of caller and callee. Removing
arguments breaks `musttail` semantics.

PR36441

Patch by Fedor Indutny

Differential Revision: https://reviews.llvm.org/D43708

llvm-svn: 326394
2018-03-01 00:09:35 +00:00
Jonas Devlieghere 9ca064552a [GlobalOpt] don't change CC of musttail calle(e|r)
When the function has musttail call - its cc is fixed to be equal to the
cc of the musttail callee. In such case (and in the case of the musttail
callee), GlobalOpt should not change the cc to fastcc as it will break
the invariant.

This fixes PR36546

Patch by: Fedor Indutny (indutny)

Differential revision: https://reviews.llvm.org/D43859

llvm-svn: 326376
2018-02-28 22:28:44 +00:00
Eric Christopher 675dcf02a8 Update comment for whether or not we can optimize an alias - we're
checking the alias and not the aliasee. If the alias can be interposed
then we shouldn't do anything.

llvm-svn: 325837
2018-02-22 23:12:11 +00:00
Luke Cheeseman 6c1e6bbe0c [FunctionAttrs][ArgumentPromotion][GlobalOpt] Disable some optimisations passes for naked functions
- Fix for bug 36078.
- Prevent the functionattrs, function-attrs, globalopt and argpromotion passes
  from changing naked functions.
- These passes can perform some alterations to the functions that should not be
  applied. An example is removing parameters that are seemingly not used because
  they are only referenced in the inline assembly. Another example is marking
  the function as fastcc.

llvm-svn: 325788
2018-02-22 14:42:08 +00:00
Mircea Trofin 56950974d4 [SampleProf] NFC. Expose reusable functionality in SampleProfile.
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
2018-02-22 06:42:57 +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
Rafael Espindola 7186753218 Pass a module reference to CloneModule.
It can never be null and most callers were already using references or
std::unique_ptr.

llvm-svn: 325160
2018-02-14 19:50:40 +00:00
Rafael Espindola 6a86e25d90 Pass a reference to a module to the bitcode writer.
This simplifies most callers as they are already using references or
std::unique_ptr.

llvm-svn: 325155
2018-02-14 19:11:32 +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
Dmitry Mikulin 5cf73cea9c [ThinLTO] Skip BlockAddresses while replacing uses in function import.
Differential Revision: https://reviews.llvm.org/D43027

llvm-svn: 324658
2018-02-08 22:14:56 +00:00
George Rimar d3704f67ad Recommit r324455 "[ThinLTO] - Simplify code in ThinLTOBitcodeWriter."
With fix: reimplemented.

Original commit message:
Recently introduced convertToDeclaration is very similar
to code used in filterModule function.
Patch reuses it to reduce duplication.

Differential revision: https://reviews.llvm.org/D42971

llvm-svn: 324574
2018-02-08 07:23:24 +00:00
George Rimar 545652491d Revert r324455 "[ThinLTO] - Simplify code in ThinLTOBitcodeWriter."
It broke BB:
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/23721

llvm-svn: 324458
2018-02-07 08:46:36 +00:00
George Rimar 5f133dc99b [ThinLTO] - Simplify code in ThinLTOBitcodeWriter.
Recently introduced convertToDeclaration is very similar
to code used in filterModule function.
Patch reuses it to reduce duplication.

Differential revision: https://reviews.llvm.org/D42971

llvm-svn: 324455
2018-02-07 08:32:35 +00:00
Petar Jovanovic 714f241304 [DeadArgumentElim] Set pointer to DISubprogram before calling RAUW. NFC
It is better to update pointer of the DISuprogram before we call RAUW for
still live arguments of the function, because with the change reviewed in
D42541 in RAUW we compare DISubprograms rather than functions itself.

Patch by Djordje Todorovic.

Differential Revision: https://reviews.llvm.org/D42794

llvm-svn: 324335
2018-02-06 11:11:28 +00:00
Peter Collingbourne 29c6f4833c ThinLTOBitcodeWriter: Do not include module-level inline asm in the merged module.
If the inline asm provides the definition of a symbol, this can result
in duplicate symbol errors.

Differential Revision: https://reviews.llvm.org/D42944

llvm-svn: 324313
2018-02-06 03:29:18 +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
Mikael Holmen b69e5b7393 [GlobalOpt] Include padding in debug fragments
Summary:
When creating the debug fragments for a SRA'd variable, use the types'
allocation sizes. This fixes issues where the pass would emit too small
fragments, placed at the wrong offset, for padded types.

An example of this is long double on x86. The type is represented using
x86_fp80, which is 10 bytes, but the value is aligned to 12/16 bytes.
The padding is included in the type's DW_AT_byte_size attribute;
therefore, the fragments should also include that. Newer GCC releases
(I tested 7.2.0) emit 12/16-byte pieces for long double. Earlier
releases, e.g. GCC 5.5.0, behaved as LLVM did, i.e. by emitting a
10-byte piece, followed by an empty 2/6-byte piece for the padding.

Failing to cover all `DW_AT_byte_size' bytes of a value with non-empty
pieces results in the value being printed as <optimized out> by GDB.

Patch by: David Stenberg

Reviewers: aprantl, JDevlieghere

Reviewed By: aprantl, JDevlieghere

Subscribers: llvm-commits

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D42807

llvm-svn: 324066
2018-02-02 10:34:13 +00:00
Amara Emerson 93b0ff20c9 [GlobalOpt] Improve common case efficiency of static global initializer evaluation
For very, very large global initializers which can be statically evaluated, the
code would create vectors of temporary Constants, modifying them in place,
before committing the resulting Constant aggregate to the global's initializer
value. This had effectively O(n^2) complexity in the size of the global
initializer and would cause memory and non-termination issues compiling some
workloads.

This change performs the static initializer evaluation and creation in batches,
once for each global in the evaluated IR memory. The existing code is maintained
as a last resort when the initializers are more complex than simple values in a
large aggregate. This should theoretically by NFC, no test as the example case
is massive. The existing test cases pass with this, as well as the llvm test
suite.

To give an example, consider the following C++ code adapted from the clang
regression tests:
struct S {
 int n = 10;
 int m = 2 * n;
 S(int a) : n(a) {}
};

template<typename T>
struct U {
 T *r = &q;
 T q = 42;
 U *p = this;
};

U<S> e;

The global static constructor for 'e' will need to initialize 'r' and 'p' of
the outer struct, while also initializing the inner 'q' structs 'n' and 'm'
members. This batch algorithm will simply use general CommitValueTo() method
to handle the complex nested S struct initialization of 'q', before
processing the outermost members in a single batch. Using CommitValueTo() to
handle member in the outer struct is inefficient when the struct/array is
very large as we end up creating and destroy constant arrays for each
initialization.
For the above case, we expect the following IR to be generated:

%struct.U = type { %struct.S*, %struct.S, %struct.U* }
%struct.S = type { i32, i32 }
@e = global %struct.U { %struct.S* gep inbounds (%struct.U, %struct.U* @e,
                                                 i64 0, i32 1),
                        %struct.S { i32 42, i32 84 }, %struct.U* @e }
The %struct.S { i32 42, i32 84 } inner initializer is treated as a complex
constant expression, while the other two elements of @e are "simple".

Differential Revision: https://reviews.llvm.org/D42612

llvm-svn: 323933
2018-01-31 23:56:07 +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
Zaara Syeda 1f59ae311b Re-commit : [PowerPC] Add handling for ColdCC calling convention and a pass to mark
candidates with coldcc attribute.

This recommits r322721 reverted due to sanitizer memory leak build bot failures.

Original commit message:
This patch adds support for the coldcc calling convention for Power.
This changes the set of non-volatile registers. It includes a pass to stress
test the implementation by marking all static directly called functions with
the coldcc attribute through the option -enable-coldcc-stress-test. It also
includes an option, -ppc-enable-coldcc, to add the coldcc attribute to
functions which are cold at all call sites based on BlockFrequencyInfo when
the containing function does not call any non cold functions.

Differential Revision: https://reviews.llvm.org/D38413

llvm-svn: 323778
2018-01-30 16:17:22 +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