Summary:
It was pointed out in [[ https://bugs.llvm.org/show_bug.cgi?id=40528 | Bug 40528 ]] that it is not clear whether insert/deleteEdge can be used to perform multiple updates and [[ https://reviews.llvm.org/D57316#1388344 | a comment in D57316 ]] reveals that the difference between several ways to update the DominatorTree is confusing.
This patch tries to address issues above.
Reviewers: mkazantsev, kuhar, asbirlea, chandlerc, brzycki
Reviewed By: mkazantsev, kuhar, brzycki
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57881
llvm-svn: 354437
Summary:
* NodeToInfo[*] have been allocated so the addresses are stable. We can store them instead of NodePtr to save NumToNode lookups.
* Nodes are traversed twice. Using `Visited` to check the traversal number is expensive and obscure. Just split the two traversals into two loops explicitly.
* The check `VInInfo.DFSNum < LastLinked` is redundant as it is implied by `VInInfo->Parent < LastLinked`
* VLabelInfo PLabelInfo are used to save a NodeToInfo lookup in the second traversal.
Also add some comments explaining eval().
This shows a ~4.5% improvement (9.8444s -> 9.3996s) on
perf stat -r 10 taskset -c 0 opt -passes=$(printf '%.0srequire<domtree>,invalidate<domtree>,' {1..1000})'require<domtree>' -disable-output sqlite-autoconf-3270100/sqlite3.bc
Reviewers: kuhar, sanjoy, asbirlea
Reviewed By: kuhar
Subscribers: brzycki, NutshellySima, kristina, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58327
llvm-svn: 354433
Summary:
After insertion of (From, To), v is affected iff
depth(NCD)+1 < depth(v) && path P from To to v exists where every w on P s.t. depth(v) <= depth(w)
All affected vertices change their idom to NCD.
If a vertex u has changed its depth, it must be a descendant of an
affected vertex v. Its depth must have been updated by UpdateLevel()
called by setIDom() of the first affected ancestor.
So UpdateLevelsAfterInsertion and its bookkeeping variable VisitedNotAffectedQueue are redundant.
Run them only in debug builds as a sanity check.
Reviewers: kuhar
Reviewed By: kuhar
Subscribers: kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58369
llvm-svn: 354429
Summary:
Changes from using a total ordering of known sections to using a
dependency graph approach. This allows our tools to accept and process
binaries that are compliant with the spec and tool conventions that
would have been previously rejected. It also means our own tools can
do less work to enforce an artificially imposed ordering. Using a
general mechanism means fewer special cases and exceptions in the
ordering logic.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58312
llvm-svn: 354426
Summary:
We translate @llvm.used to COFF by generating /include directives
in the .drectve section. However, in LTO links, this happens after
directives have already been processed, so the new directives do
not take effect. This change marks @llvm.used symbols as GCRoots
so that they are preserved as intended.
Fixes PR40733.
Reviewers: rnk, pcc, ruiu
Reviewed By: ruiu
Subscribers: mehdi_amini, steven_wu, dexonsmith, dang, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58255
llvm-svn: 354410
Summary:
Rename MemoryIndex to InitFlags and implement logic for determining
data segment layout in ObjectYAML and MC. Also adds a "passive" flag
for the .section assembler directive although this cannot be assembled
yet because the assembler does not support data sections.
Reviewers: sbc100, aardappel, aheejin, dschuff
Subscribers: jgravelle-google, hiraditya, sunfish, rupprecht, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57938
llvm-svn: 354397
The patch adds support for --hash-filenames to llvm-cov. This option adds md5
hash of the source path to the name of the generated .gcov file. The option is
crucial for cases where you have multiple files with the same name but can't
use --preserve-paths as resulting filenames exceed the limit.
from gcov(1):
```
-x
--hash-filenames
By default, gcov uses the full pathname of the source files to to
create an output filename. This can lead to long filenames that
can overflow filesystem limits. This option creates names of the
form source-file##md5.gcov, where the source-file component is
the final filename part and the md5 component is calculated from
the full mangled name that would have been used otherwise.
```
Patch by Igor Ignatev!
Differential Revision: https://reviews.llvm.org/D58370
llvm-svn: 354379
Summary:
Instruments is a useful tool for finding performance issues in LLVM but it can
be difficult to identify regions of interest on the timeline that we can use
to filter the profiler or allocations instrument. Xcode 10 and the latest
macOS/iOS/etc. added support for the os_signpost() API which allows us to
annotate the timeline with information that's meaningful to LLVM.
This patch causes timer start and end events to emit signposts. When used with
-time-passes, this causes the passes to be annotated on the Instruments timeline.
In addition to visually showing the duration of passes on the timeline, it also
allows us to filter the profile and allocations instrument down to an individual
pass allowing us to find the issues within that pass without being drowned out
by the noise from other parts of the compiler.
Using this in conjunction with the Time Profiler (in high frequency mode) and
the Allocations instrument is how I found the SparseBitVector that should have
been a BitVector and the DenseMap that could be replaced by a sorted vector a
couple months ago. I added NamedRegionTimers to TableGen and used the resulting
annotations to identify the slow portions of the Register Info Emitter. Some of
these were placed according to educated guesses while others were placed
according to hot functions from a previous profile. From there I filtered the
profile to a slow portion and the aforementioned issues stood out in the
profile.
To use this feature enable LLVM_SUPPORT_XCODE_SIGNPOSTS in CMake and run the
compiler under Instruments with -time-passes like so:
instruments -t 'Time Profiler' bin/llc -time-passes -o - input.ll'
Then open the resulting trace in Instruments.
There was a talk at WWDC 2018 that explained the feature which can be found at
https://developer.apple.com/videos/play/wwdc2018/405/ if you'd like to know
more about it.
Reviewers: bogner
Reviewed By: bogner
Subscribers: jdoerfert, mgorny, kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D52954
llvm-svn: 354365
Fix:
Replace
assert(!IO.getContext() && "The IO context is initialized already");
with
assert(IO.getContext() && "The IO context is not initialized");
(this was introduced in r354329, where I tried to quickfix the darwin BB
and seems copypasted the assert from the wrong place).
Original commit message:
The section is described here:
https://refspecs.linuxfoundation.org/LSB_1.3.0/gLSB/gLSB/symverrqmts.html
Patch just teaches obj2yaml/yaml2obj to dump and parse such sections.
We did the finalization of string tables very late,
and I had to move the logic to make it a bit earlier.
That was needed in this patch since .gnu.version_r adds strings to .dynstr.
This might also be useful for implementing other special sections.
Everything else changed in this patch seems to be straightforward.
Differential revision: https://reviews.llvm.org/D58119
llvm-svn: 354335
The section is described here:
https://refspecs.linuxfoundation.org/LSB_1.3.0/gLSB/gLSB/symverrqmts.html
Patch just teaches obj2yaml/yaml2obj to dump and parse such sections.
We did the finalization of string tables very late,
and I had to move the logic to make it a bit earlier.
That was needed in this patch since .gnu.version_r adds strings to .dynstr.
This might also be useful for implementing other special sections.
Everything else changed in this patch seems to be straightforward.
Differential revision: https://reviews.llvm.org/D58119
llvm-svn: 354328
Summary:
After (x,y) is inserted, depth-based search finds all affected v that satisfies:
depth(nca(x,y))+1 < depth(v) && there exists a path P from y to v where every w on P satisfies depth(v) <= depth(w)
This reduces to a widest path problem (maximizing the depth of the
minimum vertex in the path) which can be solved by a modified version of
Dijkstra with a bucket queue (named depth-based search in the paper).
The algorithm visits vertices in decreasing order of bucket number.
However, the current code misused priority_queue to extract them in
increasing order. I cannot think of a failing scenario but it surely may
process vertices more than once due to the local usage of Processed.
This patch fixes this bug and simplifies/optimizes the code a bit. Also
add more comments.
Reviewers: kuhar
Reviewed By: kuhar
Subscribers: kristina, jdoerfert, llvm-commits, NutshellySima, brzycki
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58349
llvm-svn: 354306
The motivating x86 cases for forming the intrinsic are shown in PR31754 and PR40487:
https://bugs.llvm.org/show_bug.cgi?id=31754https://bugs.llvm.org/show_bug.cgi?id=40487
..and those are shown in the IR test file and x86 codegen file.
Matching the usubo pattern is harder than uaddo because we have 2 independent values rather than a def-use.
This adds a TLI hook that should preserve the existing behavior for uaddo formation, but disables usubo
formation by default. Only x86 overrides that setting for now although other targets will likely benefit
by forming usbuo too.
Differential Revision: https://reviews.llvm.org/D57789
llvm-svn: 354298
This is a follow-up to r354246 and a reimplementation of https://reviews.llvm.org/D57097?id=186600
that should not trigger any UB thanks to the use of an union.
This may still be subject to the problem solved by std::launder, but I'm unsure how it interacts whith union.
/me plans to revert if this triggers any relevant bot failure. At least this validates in Release mode with
clang 6.0.1 and gcc 4.8.5.
llvm-svn: 354264
Second attempt, trying to navigate out of the UB zone using
union for storage instead of raw bytes.
I'm prepared to revert that commit as soon as validation breaks,
which is likely to happen.
llvm-svn: 354246
Summary:
A store to an object whose lifetime is about to end can be removed.
See PR40550 for motivation.
Reviewers: niravd
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D57541
llvm-svn: 354244
This class is used for two difference tablegen generated tables. For one of the tables the Value FeatureBitset only has one bit set. For the other usage the Implies field was unused.
This patch changes the Value field to just be an unsigned. For the usage that put a real vector in bitset, we now use the previously unused Implies field and leave the Value field unused instead.
This is good for a 16K reduction in the size of llc on my local build with all targets enabled.
llvm-svn: 354243
Second attempt, trying to navigate out of the UB zone using
union for storage instead of raw bytes.
I'm prepared to revert that commit as soon as validation breaks,
which is likely to happen.
llvm-svn: 354238
Summary: The C API don't have the bindings to create enumerators, needed to create an enumeration.
Reviewers: whitequark, CodaFi, harlanhaskins, deadalnix
Reviewed By: whitequark, CodaFi, harlanhaskins
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58323
llvm-svn: 354237
In preparation for supporting vector expansion.
Add an isPostTypeLegalization flag to makeLibCall(), because this
expansion relies on the legalized form using MERGE_VALUES. Drop
the corresponding variant of ExpandLibCall, which is no longer used.
Differential Revision: https://reviews.llvm.org/D58006
llvm-svn: 354226
With or without PGO data applied, splitting early in the pipeline
(either before the inliner or shortly after it) regresses performance
across SPEC variants. The cause appears to be that splitting hides
context for subsequent optimizations.
Schedule splitting late again, in effect reversing r352080, which
scheduled the splitting pass early for code size benefits (documented in
https://reviews.llvm.org/D57082).
Differential Revision: https://reviews.llvm.org/D58258
llvm-svn: 354158
This is another attempt at implementating optional storage
for trivially copyable type, using an union instead of a
raw buffer to hold the actual storage. This make it possible
to get rid of the reinterpret_cast, and hopefully to fix the UB
of the previous attempts.
This validates fine on my laptop for gcc 8.2 and gcc 4.8, I'll
revert if it breaks the validation.
llvm-svn: 354137
and
r354055 "Optional specialization for trivially copyable types, part2"
These are suspected to cause Clang to get miscompiled on Ubuntu 14.04
(Trusty) which uses GCC 4.8.4. Reverting for an hour to see if this
helps. See llvm-commits thread.
> Recommit Optional specialization for trivially copyable types
>
> Unfortunately the original code gets misscompiled by GCC (at least 8.1),
> this is a tentative workaround using std::memcpy instead of inplace new
> for trivially copyable types. I'll revert if it breaks.
>
> Original revision: https://reviews.llvm.org/D57097
llvm-svn: 354126
https://reviews.llvm.org/D58073
Speed up insertion during the initial populating phase into the
GISelWorkList by deferring repeatedly resizing the DenseMap.
This results in ~10% improvement in the combiner passes, and
~3% speedup in the Legalizer.
reviewed by: aemerson.
llvm-svn: 354093
as long as their uses does not contain calls to functions that capture
the argument (potentially allowing the blockaddress to "escape" the
lifetime of the caller).
TODO:
- add more tests
- fix crash in llvm::updateCGAndAnalysisManagerForFunctionPass when
invoking Transforms/Inline/blockaddress.ll
llvm-svn: 354079
Summary:
The changes to disable LTO unit splitting by default (r350949) and
detect inconsistently split LTO units (r350948) are causing some crashes
when the inconsistency is detected in multiple threads simultaneously.
Fix that by having the code always look for the inconsistently split
LTO units during the thin link, by checking for the presence of type
tests recorded in the summaries.
Modify test added in r350948 to remove single threading required to fix
a bot failure due to this issue (and some debugging options added in the
process of diagnosing it).
Reviewers: pcc
Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57561
llvm-svn: 354062
Chen Zheng