Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.
Patch by: yrouban (Yevgeny Rouban)
Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00
Reviewed By: tejohnson, xbolva00
Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith
Differential Revision: https://reviews.llvm.org/D49412
llvm-svn: 338969
This patch just extract code into a separate function to remove some
duplication between the old and new pass manager pipeline. Due to the
different CGSCC iterators used, not all code duplication was eliminated.
llvm-svn: 338585
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.
Patch by: yrouban (Yevgeny Rouban)
Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00
Reviewed By: tejohnson, xbolva00
Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith
Differential Revision: https://reviews.llvm.org/D49412
llvm-svn: 338494
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.
Patch by: yrouban (Yevgeny Rouban)
Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00
Reviewed By: tejohnson, xbolva00
Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith
Differential Revision: https://reviews.llvm.org/D49412
llvm-svn: 338387
We now, from clang, can turn arrays of
static short g_data[] = {16, 16, 16, 16, 16, 16, 16, 16, 0, 0, 0, 0, 0, 0, 0, 0};
into structs of the form
@g_data = internal global <{ [8 x i16], [8 x i16] }> ...
GlobalOpt will incorrectly SROA it, not realising that the access to the first
element may overflow into the second. This fixes it by checking geps more
thoroughly.
I believe this makes the globalsra-partial.ll test case invalid as the %i value
could be out of bounds. I've re-purposed it as a negative test for this case.
Differential Revision: https://reviews.llvm.org/D49816
llvm-svn: 338192
r337828 resolves a PredicateInfo issue with unnamed types.
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: 337904
Summary:
Without this change, the WholeProgramDevirt pass, which requires the
TargetLibraryInfo, will construct one from the default triple.
Fixes PR38139.
Reviewers: pcc
Subscribers: mehdi_amini, inglorion, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D49278
llvm-svn: 337750
We tested different cap values with a recent commit of Chromium. Our results show that the 32-byte cap yields the smallest binary and all the caps yield similar performance.
Based on the results, we propose to change the cap value to 32-byte.
Patch by Zhaomo Yang!
Differential Revision: https://reviews.llvm.org/D49405
llvm-svn: 337622
Summary:
Enable these passes for CFI and WPD in ThinLTO and LTO with the new pass
manager. Add a couple of tests for both PMs based on the clang tests
tools/clang/test/CodeGen/thinlto-distributed-cfi*.ll, but just test
through llvm-lto2 and not with distributed ThinLTO.
Reviewers: pcc
Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D49429
llvm-svn: 337461
This reverts commit r337081, therefore restoring r337050 (and fix in
r337059), with test fix for bot failure described after the original
description below.
In order to always import the same copy of a linkonce function,
even when encountering it with different thresholds (a higher one then a
lower one), keep track of the summary we decided to import.
This ensures that the backend only gets a single definition to import
for each GUID, so that it doesn't need to choose one.
Move the largest threshold the GUID was considered for import into the
current module out of the ImportMap (which is part of a larger map
maintained across the whole index), and into a new map just maintained
for the current module we are computing imports for. This saves some
memory since we no longer have the thresholds maintained across the
whole index (and throughout the in-process backends when doing a normal
non-distributed ThinLTO build), at the cost of some additional
information being maintained for each invocation of ComputeImportForModule
(the selected summary pointer for each import).
There is an additional map lookup for each callee being considered for
importing, however, this was able to subsume a map lookup in the
Worklist iteration that invokes computeImportForFunction. We also are
able to avoid calling selectCallee if we already failed to import at the
same or higher threshold.
I compared the run time and peak memory for the SPEC2006 471.omnetpp
benchmark (running in-process ThinLTO backends), as well as for a large
internal benchmark with a distributed ThinLTO build (so just looking at
the thin link time/memory). Across a number of runs with and without
this change there was no significant change in the time and memory.
(I tried a few other variations of the change but they also didn't
improve time or peak memory).
The new commit removes a test that no longer makes sense
(Transforms/FunctionImport/hotness_based_import2.ll), as exposed by the
reverse-iteration bot. The test depends on the order of processing the
summary call edges, and actually depended on the old problematic
behavior of selecting more than one summary for a given GUID when
encountered with different thresholds. There was no guarantee even
before that we would eventually pick the linkonce copy with the hottest
call edges, it just happened to work with the test and the old code, and
there was no guarantee that we would end up importing the selected
version of the copy that had the hottest call edges (since the backend
would effectively import only one of the selected copies).
Reviewers: davidxl
Subscribers: mehdi_amini, inglorion, llvm-commits
Differential Revision: https://reviews.llvm.org/D48670
llvm-svn: 337184
In order to always import the same copy of a linkonce function,
even when encountering it with different thresholds (a higher one then a
lower one), keep track of the summary we decided to import.
This ensures that the backend only gets a single definition to import
for each GUID, so that it doesn't need to choose one.
Move the largest threshold the GUID was considered for import into the
current module out of the ImportMap (which is part of a larger map
maintained across the whole index), and into a new map just maintained
for the current module we are computing imports for. This saves some
memory since we no longer have the thresholds maintained across the
whole index (and throughout the in-process backends when doing a normal
non-distributed ThinLTO build), at the cost of some additional
information being maintained for each invocation of ComputeImportForModule
(the selected summary pointer for each import).
There is an additional map lookup for each callee being considered for
importing, however, this was able to subsume a map lookup in the
Worklist iteration that invokes computeImportForFunction. We also are
able to avoid calling selectCallee if we already failed to import at the
same or higher threshold.
I compared the run time and peak memory for the SPEC2006 471.omnetpp
benchmark (running in-process ThinLTO backends), as well as for a large
internal benchmark with a distributed ThinLTO build (so just looking at
the thin link time/memory). Across a number of runs with and without
this change there was no significant change in the time and memory.
(I tried a few other variations of the change but they also didn't
improve time or peak memory).
Reviewers: davidxl
Subscribers: mehdi_amini, inglorion, llvm-commits
Differential Revision: https://reviews.llvm.org/D48670
llvm-svn: 337050
Summary:
Currently LowerTypeTests emits jumptable entries for all live external
and address-taken functions; however, we could limit the number of
functions that we emit entries for significantly.
For Cross-DSO CFI, we continue to emit jumptable entries for all
exported definitions. In the non-Cross-DSO CFI case, we only need to
emit jumptable entries for live functions that are address-taken in live
functions. This ignores exported functions and functions that are only
address taken in dead functions. This change uses ThinLTO summary data
(now emitted for all modules during ThinLTO builds) to determine
address-taken and liveness info.
The logic for emitting jumptable entries is more conservative in the
regular LTO case because we don't have summary data in the case of
monolithic LTO builds; however, once summaries are emitted for all LTO
builds we can unify the Thin/monolithic LTO logic to only use summaries
to determine the liveness of address taking functions.
This change is a partial fix for PR37474. It reduces the build size for
nacl_helper by ~2-3%, the reduction is due to nacl_helper compiling in
lots of unused code and unused functions that are address taken in dead
functions no longer being being considered live due to emitted jumptable
references. The reduction for chromium is ~0.1-0.2%.
Reviewers: pcc, eugenis, javed.absar
Reviewed By: pcc
Subscribers: aheejin, dexonsmith, dschuff, mehdi_amini, eraman, steven_wu, llvm-commits, kcc
Differential Revision: https://reviews.llvm.org/D47652
llvm-svn: 337038
Summary:
I noticed that the .imports files emitted for distributed ThinLTO
backends do not have consistent ordering. This is because StringMap
iteration order is not guaranteed to be deterministic. Since we already
have a std::map with this information, used when emitting the individual
index files (ModuleToSummariesForIndex), use it for the imports files as
well.
This issue is likely causing some unnecessary rebuilds of the ThinLTO
backends in our distributed build system as the imports files are inputs
to those backends.
Reviewers: pcc, steven_wu, mehdi_amini
Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D48783
llvm-svn: 336721
Summary:
Support for this option is needed for building Linux kernel.
This is a very frequently requested feature by kernel developers.
More details : https://lkml.org/lkml/2018/4/4/601
GCC option description for -fdelete-null-pointer-checks:
This Assume that programs cannot safely dereference null pointers,
and that no code or data element resides at address zero.
-fno-delete-null-pointer-checks is the inverse of this implying that
null pointer dereferencing is not undefined.
This feature is implemented in LLVM IR in this CL as the function attribute
"null-pointer-is-valid"="true" in IR (Under review at D47894).
The CL updates several passes that assumed null pointer dereferencing is
undefined to not optimize when the "null-pointer-is-valid"="true"
attribute is present.
Reviewers: t.p.northover, efriedma, jyknight, chandlerc, rnk, srhines, void, george.burgess.iv
Reviewed By: efriedma, george.burgess.iv
Subscribers: eraman, haicheng, george.burgess.iv, drinkcat, theraven, reames, sanjoy, xbolva00, llvm-commits
Differential Revision: https://reviews.llvm.org/D47895
llvm-svn: 336613
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 Loop
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: 336062
and diretory.
Also cleans up all the associated naming to be consistent and removes
the public access to the pass ID which was unused in LLVM.
Also runs clang-format over parts that changed, which generally cleans
up a bunch of formatting.
This is in preparation for doing some internal cleanups to the pass.
Differential Revision: https://reviews.llvm.org/D47352
llvm-svn: 336028
Summary:
The InlinerFunctionImportStats will collect and dump stats regarding how
many function inlined into the module were imported by ThinLTO.
Reviewers: wmi, dexonsmith
Subscribers: mehdi_amini, inglorion, llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D48729
llvm-svn: 335914
Summary:
Rather than just print the GUID, when it is available in the index,
print the global name as well in the function import thin link debug
messages. Names will be available when the combined index is being
built by the same process, e.g. a linker or "llvm-lto2 run".
Reviewers: davidxl
Subscribers: mehdi_amini, inglorion, eraman, steven_wu, llvm-commits
Differential Revision: https://reviews.llvm.org/D48612
llvm-svn: 335760
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
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
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
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
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
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
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
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
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
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
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
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
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
- 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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
This was exposed by enabling expensive checks, which causes llvm::sort
to sort randomly.
Differential Revision: https://reviews.llvm.org/D45901
llvm-svn: 331573
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
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
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
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
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
(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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
- 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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
Summary:
The intent of this is to allow the code to be used with ThinLTO. In
Thinlink phase, a traditional Callgraph can not be computed even though
all the necessary information (nodes and edges of a call graph) is
available. This is due to the fact that CallGraph class is closely tied
to the IR. This patch first extends GraphTraits to add a CallGraphTraits
graph. This is then used to implement a version of counts propagation
on a generic callgraph.
Reviewers: davidxl
Subscribers: mehdi_amini, tejohnson, llvm-commits
Differential Revision: https://reviews.llvm.org/D42311
llvm-svn: 323475
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
Summary:
When creating the debug fragments for a SRA'd struct, use the fields'
offsets, taken from the struct layout, as the offsets for the resulting
fragments. This fixes an issue where GlobalOpt would emit fragments with
incorrect offsets for padded fields.
This should solve PR36016.
Patch by David Stenberg.
Reviewers: aprantl
Reviewed By: aprantl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42489
llvm-svn: 323411
Combine expression patterns to form expressions with fewer, simple instructions.
This pass does not modify the CFG.
For example, this pass reduce width of expressions post-dominated by TruncInst
into smaller width when applicable.
It differs from instcombine pass in that it contains pattern optimization that
requires higher complexity than the O(1), thus, it should run fewer times than
instcombine pass.
Differential Revision: https://reviews.llvm.org/D38313
llvm-svn: 323321
Summary:
Currently, there is no way to extract a basic block from a function easily. This patch
extends llvm-extract to extract the specified basic block(s).
Reviewers: loladiro, rafael, bogner
Reviewed By: bogner
Subscribers: hintonda, mgorny, qcolombet, llvm-commits
Differential Revision: https://reviews.llvm.org/D41638
llvm-svn: 323266
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
candidates with coldcc attribute.
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: 322721
While updating clang tests for having clang set dso_local I noticed
that:
- There are *a lot* of tests to update.
- Many of the updates are redundant.
They are redundant because a GV is "obviously dso_local". This patch
starts formalizing that a bit by requiring that internal and private
GVs be dso_local too. Since they all are, we don't have to print
dso_local to the textual representation, making it a bit more compact
and easier to read.
llvm-svn: 322317
Summary:
LowerTypeTests moves some function definitions from individual object
files to the merged module, leaving a stub to be called in the merged
module's jump table. If an alias was pointing to such a function
definition LowerTypeTests would fail because the alias would be left
without a definition to point to.
This change 1) emits information about aliases to the ThinLTO summary,
2) replaces aliases pointing to function definitions that are moved to
the merged module with function declarations, and 3) re-emits those
aliases in the merged module pointing to the correct function
definitions.
The patch does not correctly fix all possible mis-uses of aliases in
LowerTypeTests. For example, it does not handle aliases with a different
type from the pointed to function.
The addition of alias data increases the size of Chrome build artifacts
by less than 1%.
Reviewers: pcc
Reviewed By: pcc
Subscribers: mehdi_amini, eraman, mgrang, llvm-commits, eugenis, kcc
Differential Revision: https://reviews.llvm.org/D41741
llvm-svn: 322139
Summary:
This pass synthesizes function entry counts by traversing the callgraph
and using the relative block frequencies of the callsites. The intended
use of these counts is in inlining to determine hot/cold callsites in
the absence of profile information.
The pass is split into two files with the code that propagates the
counts in a callgraph in a Utils file. I plan to add support for
propagation in the thinlto link phase and the propagation code will be
shared and hence this split. I did not add support to the old PM since
hot callsite determination in inlining is not possible in old PM
(although we could use hot callee heuristic with synthetic counts in the
old PM it is not worth the effort tuning it)
Reviewers: davidxl, silvas
Subscribers: mgorny, mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D41604
llvm-svn: 322110
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
Summary:
In r277849, getEntryCount was changed to return None when the entry
count was 0, specifically for SamplePGO where it means no samples were
recorded. However, for instrumentation PGO a 0 entry count should be
returned directly, since it does mean that the function was completely
cold. Otherwise we end up treating these functions conservatively
in isFunctionEntryCold() and isColdBB().
Instead, for SamplePGO use -1 when there are no samples, and change
getEntryCount to return None when the value is -1.
Reviewers: danielcdh, davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D41307
llvm-svn: 321018
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
This should solve:
https://bugs.llvm.org/show_bug.cgi?id=34603
...by preventing SimplifyCFG from altering redundant instructions before early-cse has a chance to run.
It changes the default (canonical-forming) behavior of SimplifyCFG, so we're only doing the
sinking transform later in the optimization pipeline.
Differential Revision: https://reviews.llvm.org/D38566
llvm-svn: 320749
Summary:
This is LLVM instrumentation for the new HWASan tool. It is basically
a stripped down copy of ASan at this point, w/o stack or global
support. Instrumenation adds a global constructor + runtime callbacks
for every load and store.
HWASan comes with its own IR attribute.
A brief design document can be found in
clang/docs/HardwareAssistedAddressSanitizerDesign.rst (submitted earlier).
Reviewers: kcc, pcc, alekseyshl
Subscribers: srhines, mehdi_amini, mgorny, javed.absar, eraman, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D40932
llvm-svn: 320217
Summary:
Make enum ModRefInfo an enum class. Changes to ModRefInfo values should
be done using inline wrappers.
This should prevent future bit-wise opearations from being added, which can be more error-prone.
Reviewers: sanjoy, dberlin, hfinkel, george.burgess.iv
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40933
llvm-svn: 320107
This patch factors out the main code transformation utilities in the pgo-driven
indirect call promotion pass and places them in Transforms/Utils. The change is
intended to be a non-functional change, letting non-pgo-driven passes share a
common implementation with the existing pgo-driven pass.
The common utilities are used to conditionally promote indirect call sites to
direct call sites. They perform the underlying transformation, and do not
consider profile information. The pgo-specific details (e.g., the computation
of branch weight metadata) have been left in the indirect call promotion pass.
Differential Revision: https://reviews.llvm.org/D40658
llvm-svn: 319963
Summary:
The aim is to make ModRefInfo checks and changes more intuitive
and less error prone using inline methods that abstract the bit operations.
Ideally ModRefInfo would become an enum class, but that change will require
a wider set of changes into FunctionModRefBehavior.
Reviewers: sanjoy, george.burgess.iv, dberlin, hfinkel
Subscribers: nlopes, llvm-commits
Differential Revision: https://reviews.llvm.org/D40749
llvm-svn: 319821
If the thin module has no references to an internal global in the
merged module, we need to make sure to preserve that property if the
global is a member of a comdat group, as otherwise promotion can end
up adding global symbols to the comdat, which is not allowed.
This situation can arise if the external global in the thin module
has dead constant users, which would cause use_empty() to return
false and would cause us to try to promote it. To prevent this from
happening, discard the dead constant users before asking whether a
global is empty.
Differential Revision: https://reviews.llvm.org/D40593
llvm-svn: 319494
Support for outlining multiple regions of each function is added, as well as some basic heuristics to determine which regions are good to outline. Outline candidates limited to regions that are single-entry & single-exit. We also avoid outlining regions that produce live-exit variables, which may inhibit some forms of code motion (like commoning).
Fallback to the regular partial inlining scheme is retained when either i) no regions are identified for outlining in the function, or ii) the outlined function could not be inlined in any of its callers.
Differential Revision: https://reviews.llvm.org/D38190
llvm-svn: 319398
Clang implements the -finstrument-functions flag inherited from GCC, which
inserts calls to __cyg_profile_func_{enter,exit} on function entry and exit.
This is useful for getting a trace of how the functions in a program are
executed. Normally, the calls remain even if a function is inlined into another
function, but it is useful to be able to turn this off for users who are
interested in a lower-level trace, i.e. one that reflects what functions are
called post-inlining. (We use this to generate link order files for Chromium.)
LLVM already has a pass for inserting similar instrumentation calls to
mcount(), which it does after inlining. This patch renames and extends that
pass to handle calls both to mcount and the cygprofile functions, before and/or
after inlining as controlled by function attributes.
Differential Revision: https://reviews.llvm.org/D39287
llvm-svn: 318195
Summary:
This patch extends the partial inliner to support inlining parts of
vararg functions, if the vararg handling is done in the outlined part.
It adds a `ForwardVarArgsTo` argument to InlineFunction. If it is
non-null, all varargs passed to the inlined function will be added to
all calls to `ForwardVarArgsTo`.
The partial inliner takes care to only pass `ForwardVarArgsTo` if the
varargs handing is done in the outlined function. It checks that vastart
is not part of the function to be inlined.
`test/Transforms/CodeExtractor/PartialInlineNoInline.ll` (already part
of the repo) checks we do not do partial inlining if vastart is used in
a basic block that will be inlined.
Reviewers: davide, davidxl, grosser
Reviewed By: davide, davidxl, grosser
Subscribers: gyiu, grosser, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D39607
llvm-svn: 318028
Summary:
In ThinLTO compilation, we exit populateModulePassManager early and
were not adding PM extension passes meant to run at the end of the
pipeline. This includes sanitizer passes. Add these passes before
the early exit.
A test will be added to projects/compiler-rt.
Reviewers: pcc
Subscribers: mehdi_amini, inglorion, llvm-commits
Differential Revision: https://reviews.llvm.org/D39565
llvm-svn: 317714
Blockaddresses refer to the function itself, therefore replacing them
would cause an assertion in doRAUW.
Fixes https://bugs.llvm.org/show_bug.cgi?id=35201
This was found when trying CFI on a proprietary kernel by Dmitry Mikulin.
Differential Revision: https://reviews.llvm.org/D39695
llvm-svn: 317527
Summary: When computing the SUM for indirect call promotion, if the callsite is already promoted in the profile, it will be promoted before ICP. In the current implementation, ICP only sees remaining counts in SUM. This may cause extra indirect call targets being promoted. This patch updates the SUM to include the counts already promoted earlier. This way we do not end up promoting too many indirect call targets.
Reviewers: tejohnson
Reviewed By: tejohnson
Subscribers: llvm-commits, sanjoy
Differential Revision: https://reviews.llvm.org/D38763
llvm-svn: 317502
This recommit r317351 after fixing a buildbot failure.
Original commit message:
Summary:
This change add a pass which tries to split a call-site to pass
more constrained arguments if its argument is predicated in the control flow
so that we can expose better context to the later passes (e.g, inliner, jump
threading, or IPA-CP based function cloning, etc.).
As of now we support two cases :
1) If a call site is dominated by an OR condition and if any of its arguments
are predicated on this OR condition, try to split the condition with more
constrained arguments. For example, in the code below, we try to split the
call site since we can predicate the argument (ptr) based on the OR condition.
Split from :
if (!ptr || c)
callee(ptr);
to :
if (!ptr)
callee(null ptr) // set the known constant value
else if (c)
callee(nonnull ptr) // set non-null attribute in the argument
2) We can also split a call-site based on constant incoming values of a PHI
For example,
from :
BB0:
%c = icmp eq i32 %i1, %i2
br i1 %c, label %BB2, label %BB1
BB1:
br label %BB2
BB2:
%p = phi i32 [ 0, %BB0 ], [ 1, %BB1 ]
call void @bar(i32 %p)
to
BB0:
%c = icmp eq i32 %i1, %i2
br i1 %c, label %BB2-split0, label %BB1
BB1:
br label %BB2-split1
BB2-split0:
call void @bar(i32 0)
br label %BB2
BB2-split1:
call void @bar(i32 1)
br label %BB2
BB2:
%p = phi i32 [ 0, %BB2-split0 ], [ 1, %BB2-split1 ]
llvm-svn: 317362
Summary:
This change add a pass which tries to split a call-site to pass
more constrained arguments if its argument is predicated in the control flow
so that we can expose better context to the later passes (e.g, inliner, jump
threading, or IPA-CP based function cloning, etc.).
As of now we support two cases :
1) If a call site is dominated by an OR condition and if any of its arguments
are predicated on this OR condition, try to split the condition with more
constrained arguments. For example, in the code below, we try to split the
call site since we can predicate the argument (ptr) based on the OR condition.
Split from :
if (!ptr || c)
callee(ptr);
to :
if (!ptr)
callee(null ptr) // set the known constant value
else if (c)
callee(nonnull ptr) // set non-null attribute in the argument
2) We can also split a call-site based on constant incoming values of a PHI
For example,
from :
BB0:
%c = icmp eq i32 %i1, %i2
br i1 %c, label %BB2, label %BB1
BB1:
br label %BB2
BB2:
%p = phi i32 [ 0, %BB0 ], [ 1, %BB1 ]
call void @bar(i32 %p)
to
BB0:
%c = icmp eq i32 %i1, %i2
br i1 %c, label %BB2-split0, label %BB1
BB1:
br label %BB2-split1
BB2-split0:
call void @bar(i32 0)
br label %BB2
BB2-split1:
call void @bar(i32 1)
br label %BB2
BB2:
%p = phi i32 [ 0, %BB2-split0 ], [ 1, %BB2-split1 ]
Reviewers: davidxl, huntergr, chandlerc, mcrosier, eraman, davide
Reviewed By: davidxl
Subscribers: sdesmalen, ashutosh.nema, fhahn, mssimpso, aemerson, mgorny, mehdi_amini, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D39137
llvm-svn: 317351
Summary:
InlineFunction can fail, for example when trying to inline vararg
fuctions. In those cases, we do not want to bump partial inlining
counters or set AnyInlined to true, because this could leave an unused
function hanging around.
Reviewers: davidxl, davide, gyiu
Reviewed By: davide
Subscribers: llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D39581
llvm-svn: 317314
Summary: In the compile phase of SamplePGO+ThinLTO, ICP is not invoked. Instead, indirect call targets will be included as function metadata for ThinIndex to buidl the call graph. This should not only include functions defined in other modules, but also functions defined in the same module, otherwise ThinIndex may find the callee dead and eliminate it, while ICP in backend will revive the symbol, which leads to undefined symbol.
Reviewers: tejohnson
Reviewed By: tejohnson
Subscribers: sanjoy, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D39480
llvm-svn: 317118
This is necessary because DCE is applied to full LTO modules. Without
this change, a reference from a dead ThinLTO global to a dead full
LTO global will result in an undefined reference at link time.
This problem is only observable when --gc-sections is disabled, or
when targeting COFF, as the COFF port of lld requires all symbols to
have a definition even if all references are dead (this is consistent
with link.exe).
This change also adds an EliminateAvailableExternally pass at -O0. This
is necessary to handle the situation on Windows where a non-prevailing
copy of a linkonce_odr function has an SEH filter function; any
such filters must be DCE'd because they will contain a call to the
llvm.localrecover intrinsic, passing as an argument the address of the
function that the filter belongs to, and llvm.localrecover requires
this function to be defined locally.
Fixes PR35142.
Differential Revision: https://reviews.llvm.org/D39484
llvm-svn: 317108
This is no-functional-change-intended.
This is repackaging the functionality of D30333 (defer switch-to-lookup-tables) and
D35411 (defer folding unconditional branches) with pass parameters rather than a named
"latesimplifycfg" pass. Now that we have individual options to control the functionality,
we could decouple when these fire (but that's an independent patch if desired).
The next planned step would be to add another option bit to disable the sinking transform
mentioned in D38566. This should also make it clear that the new pass manager needs to
be updated to limit simplifycfg in the same way as the old pass manager.
Differential Revision: https://reviews.llvm.org/D38631
llvm-svn: 316835
This patch adds a new pass for attaching !callees metadata to indirect call
sites. The pass propagates values to call sites by performing an IPSCCP-like
analysis using the generic sparse propagation solver. For indirect call sites
having a small set of possible callees, the attached metadata indicates what
those callees are. The metadata can be used to facilitate optimizations like
intersecting the function attributes of the possible callees, refining the call
graph, performing indirect call promotion, etc.
Differential Revision: https://reviews.llvm.org/D37355
llvm-svn: 316576
MergeFunctions uses (through FunctionComparator) a map of GlobalValues
to identifiers because it needs to compare functions and globals
do not have an inherent total order. Thus, FunctionComparator
(through GlobalNumberState) has a ValueMap<GlobalValue *>.
r315852 added a RAUW on globals that may have been previously
encountered by the FunctionComparator, which would replace
a GlobalValue * key with a ConstantExpr *, which is illegal.
This commit adjusts that code path to remove the function being
replaced from the ValueMap as well.
llvm-svn: 316145
Summary:
std::unordered_multimap happens to be very slow when the number of elements
grows large. On one of our internal applications we observed a 17x compile time
improvement from changing it to DenseMap.
Reviewers: mehdi_amini, serge-sans-paille, davide
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38916
llvm-svn: 316045
This can result in significant code size savings in some cases,
e.g. an interrupt table all filled with the same assembly stub
in a certain Cortex-M BSP results in code blowup by a factor of 2.5.
Differential Revision: https://reviews.llvm.org/D34806
llvm-svn: 315853
This reduces code size for constructs like vtables or interrupt
tables that refer to functions in global initializers.
Differential Revision: https://reviews.llvm.org/D34805
llvm-svn: 315852
It is possible for both a base and a derived class to be satisfied
with a unique vtable. If a program contains casts of the same pointer
to both of those types, the CFI checks will be lowered to this
(with ThinLTO):
if (p != &__typeid_base_global_addr)
trap();
if (p != &__typeid_derived_global_addr)
trap();
The optimizer may then use the first condition combined
with the assumption that __typeid_base_global_addr and
__typeid_derived_global_addr may not alias to optimize away the second
comparison, resulting in an unconditional trap.
This patch fixes the bug by giving imported globals the type [0 x i8]*,
which prevents the optimizer from assuming that they do not alias.
Differential Revision: https://reviews.llvm.org/D38873
llvm-svn: 315753
parameterized emit() calls
Summary: This is not functional change to adopt new emit() API added in r313691.
Reviewed By: anemet
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38285
llvm-svn: 315476
Summary: In the current implementation, we only have accurate profile count for standalone symbols. For inlined functions, we do not have entry count data because it's not available in LBR. In this patch, we use the first instruction's frequency to estimiate the function's entry count, especially for inlined functions. This may be inaccurate due to debug info in optimized code. However, this is a better estimate than the static 80/20 estimation we have in the current implementation.
Reviewers: tejohnson, davidxl
Reviewed By: tejohnson
Subscribers: sanjoy, llvm-commits, aprantl
Differential Revision: https://reviews.llvm.org/D38478
llvm-svn: 315369
Summary: stripPointerCast is not reliably returning the value that's being type-casted. Instead it may look further at function attributes to further propagate the value. Instead of relying on stripPOintercast, the more reliable solution is to directly use the pointer to the promoted direct call.
Reviewers: tejohnson, davidxl
Reviewed By: tejohnson
Subscribers: llvm-commits, sanjoy
Differential Revision: https://reviews.llvm.org/D38603
llvm-svn: 315077
David Bolvansky