Commit Graph

6199 Commits

Author SHA1 Message Date
Jianzhou Zhao
078b488a52 Add raw_fd_stream_test.cpp into CMakeLists.txt
Fixing 0ece51c60c
2020-09-12 07:48:12 +00:00
Jianzhou Zhao
097ba299ca Add raw_fd_stream that supports reading/seeking/writing
This is used by https://reviews.llvm.org/D86905 to support bitcode
writer's incremental flush.
2020-09-12 07:34:19 +00:00
Lang Hames
4ec13fba1c Re-apply "[ORC] Make MaterializationResponsibility immovable..." with fixes.
Re-applies c74900ca672 with fixes for the ThinLtoJIT example.
2020-09-11 14:09:05 -07:00
Florian Hahn
3e455ec545 Revert "[ConstraintSystem] Add helpers to deal with linear constraints."
This reverts commit 3eb141e5078a0ce9d92eadc721bc49d214d23056.

This uses __builtin_mul_overflow which is not available everywhere.
2020-09-11 14:49:04 +01:00
Florian Hahn
7fc90ed94b [ConstraintSystem] Add helpers to deal with linear constraints.
This patch introduces a new ConstraintSystem class, that maintains a set
of linear constraints and uses Fourier–Motzkin elimination to eliminate
constraints to check if there are solutions for the system.

It also adds a convert-constraint-log-to-z3.py script, which can parse
the debug output of the constraint system and convert it to a python
script that feeds the constraints into Z3 and checks if it produces the
same result as the LLVM implementation. This is for verification
purposes.

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D84544
2020-09-11 14:43:22 +01:00
Florian Hahn
336548370d Revert "[ORC] Make MaterializationResponsibility immovable, pass by unique_ptr."
This reverts commit c74900ca67241bf963b7a4cfa1fae8eadf6bb8cd.

This appears to be breaking some builds on macOS and has been causing
build failures on Green Dragon (see below). I am reverting this for now,
to unblock testing on Green Dragon.

http://green.lab.llvm.org/green/job/clang-stage1-cmake-RA-incremental/18144/console

[65/187] /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++  -DBUILD_EXAMPLES -DGTEST_HAS_RTTI=0 -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Iexamples/ThinLtoJIT -I/Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/examples/ThinLtoJIT -Iinclude -I/Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/include -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wstring-conversion -fdiagnostics-color -O3  -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -mmacosx-version-min=10.9    -fno-exceptions -fno-rtti -UNDEBUG -std=c++14 -MD -MT examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o -MF examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o.d -o examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o -c /Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/examples/ThinLtoJIT/ThinLtoDiscoveryThread.cpp
FAILED: examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++  -DBUILD_EXAMPLES -DGTEST_HAS_RTTI=0 -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Iexamples/ThinLtoJIT -I/Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/examples/ThinLtoJIT -Iinclude -I/Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/include -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wstring-conversion -fdiagnostics-color -O3  -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -mmacosx-version-min=10.9    -fno-exceptions -fno-rtti -UNDEBUG -std=c++14 -MD -MT examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o -MF examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o.d -o examples/ThinLtoJIT/CMakeFiles/ThinLtoJIT.dir/ThinLtoDiscoveryThread.cpp.o -c /Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/examples/ThinLtoJIT/ThinLtoDiscoveryThread.cpp
In file included from /Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/examples/ThinLtoJIT/ThinLtoDiscoveryThread.cpp:7:
/Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/examples/ThinLtoJIT/ThinLtoInstrumentationLayer.h:37:68: error: non-virtual member function marked 'override' hides virtual member function
  void emit(MaterializationResponsibility R, ThreadSafeModule TSM) override;
                                                                   ^
/Users/buildslave/jenkins/workspace/clang-stage1-cmake-RA-incremental/llvm-project/llvm/include/llvm/ExecutionEngine/Orc/Layer.h:103:16: note: hidden overloaded virtual function 'llvm::orc::IRLayer::emit' declared here: type mismatch at 1st parameter ('std::unique_ptr<MaterializationResponsibility>' vs 'llvm::orc::MaterializationResponsibility')
  virtual void emit(std::unique_ptr<MaterializationResponsibility> R,
               ^
1 error generated.
2020-09-11 09:35:20 +01:00
Reid Kleckner
e88b0fafb4 Use pragmas to work around MSVC x86_32 debug miscompile bug
Halide users reported this here: https://llvm.org/pr46176
I reported the issue to MSVC here:
https://developercommunity.visualstudio.com/content/problem/1179643/msvc-copies-overaligned-non-trivially-copyable-par.html

This codepath is apparently not covered by LLVM's unit tests, so I added
coverage in a unit test.

If we want to support this configuration going forward, it means that is
in general not safe to pass a SmallVector<T, N> by value if alignof(T)
is greater than 4. This doesn't appear to come up often because passing
a SmallVector by value is inefficient and not idiomatic: it copies the
inline storage. In this case, the SmallVector<LLT,4> is captured by
value by a lambda, and the lambda is passed by value into std::function,
and that's how we hit the bug.

Differential Revision: https://reviews.llvm.org/D87475
2020-09-10 14:50:01 -07:00
Lang Hames
9d3b846676 [ORC] Make MaterializationResponsibility immovable, pass by unique_ptr.
Making MaterializationResponsibility instances immovable allows their
associated VModuleKeys to be updated by the ExecutionSession while the
responsibility is still in-flight. This will be used in the upcoming
removable code feature to enable safe merging of resource keys even if
there are active compiles using the keys being merged.
2020-09-10 13:21:46 -07:00
Lang Hames
4b2ec2e0f8 Revert "[Support] Use unique_function rather than std::function for ThreadPool TaskTy."
This reverts commit d9c8b0256cfc673c2413b13993c9440be598818f.

Some MSVC std::packaged_task implementations are not compatible with move-only types.
This caused failures on some of the Windows builders (e.g.
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/69412).

Reverting until I can come up with a workaround.
2020-09-10 11:53:09 -07:00
Lang Hames
12a4a51f26 [Support] Use unique_function rather than std::function for ThreadPool TaskTy.
This will allow non-copyable function objects (e.g. lambdas that capture
unique_ptrs) to be used with ThreadPool.

Differential Revision: https://reviews.llvm.org/D87467
2020-09-10 10:46:46 -07:00
Sam Parker
65c15bce07 [ARM] Tail predicate VQDMULH and VQRDMULH
Mark the family of instructions as valid for tail predication.

Differential Revision: https://reviews.llvm.org/D87348
2020-09-10 08:20:07 +01:00
Juneyoung Lee
55591e689c [ValueTracking] isKnownNonZero, computeKnownBits for freeze
This implements support for isKnownNonZero, computeKnownBits when freeze is involved.

```
  br (x != 0), BB1, BB2
BB1:
  y = freeze x
```

In the above program, we can say that y is non-zero. The reason is as follows:

(1) If x was poison, `br (x != 0)` raised UB
(2) If x was fully undef, the branch again raised UB
(3) If x was non-zero partially undef, say `undef | 1`, `freeze x` will return a nondeterministic value which is also non-zero.
(4) If x was just a concrete value, it is trivial

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D75808
2020-09-10 08:07:38 +09:00
Juneyoung Lee
bd9d25252a [ValueTracking] Add UndefOrPoison/Poison-only version of relevant functions
This patch adds isGuaranteedNotToBePoison and programUndefinedIfUndefOrPoison.

isGuaranteedNotToBePoison will be used at D75808. The latter function is used at isGuaranteedNotToBePoison.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D84242
2020-09-09 20:00:26 +09:00
Sergej Jaskiewicz
16b7e4e602 [llvm] [unittest] Allow getting a C string from the TempDir helper class
The TempDir.path() member function returns a StringRef. We've been
calling the data() method on that StringRef, which does not guarantee
to return a null-terminated string (required by chdir and other POSIX
functions).

Introduce the c_str() method in the TempDir class, which returns the
proper string without the need to create a copy of the path at use site.
2020-09-09 01:53:15 +03:00
Jay Foad
3381408aad [KnownBits] Implement accurate unsigned and signed max and min
Use the new implementation in ValueTracking, SelectionDAG and
GlobalISel.

Differential Revision: https://reviews.llvm.org/D87034
2020-09-07 09:09:01 +01:00
Zi Xuan Wu
a51dedaf25 [ELF] Add a new e_machine value EM_CSKY and add some CSKY relocation types
This is the split part of D86269, which add a new ELF machine flag called EM_CSKY and related relocations.
Some target-specific flags and tests for csky can be added in follow-up patches later.

Differential Revision: https://reviews.llvm.org/D86610
2020-09-07 10:42:28 +08:00
Simon Pilgrim
6f6a13c34a SelectionDAG.h - remove unnecessary FunctionLoweringInfo.h include. NFCI.
Use forward declarations and move the include down to dependent files that actually use it.

This also exposes a number of implicit dependencies on KnownBits.h
2020-09-03 18:33:25 +01:00
Zi Xuan Wu
ed26c15759 [RFC][Target] Add a new triple called Triple::csky
Before upstream a new target called CSKY, make a new triple of that called Triple::csky.
For now, it's a 32-bit little endian target and the detail can be referred at D86269.

This is the split part of D86269, which add a new target called CSKY.

Differential Revision: https://reviews.llvm.org/D86505
2020-09-02 12:46:09 +08:00
Varun Gandhi
99d53ed697 [ADT] Make Optional a literal type.
This allows returning Optional values from constexpr contexts.

Reviewed By: fhahn, dblaikie, rjmccall

Differential Revision: https://reviews.llvm.org/D86354
2020-09-01 16:13:40 -07:00
Sergej Jaskiewicz
1842e5f0f3 [llvm] [unittests] Fix failing test 'FileCollectorTest.addDirectory'
This fixes a regression in the test suite introduced by
fad75598d272b9a5591fb7d9b591cf00cdf5022c
2020-09-02 00:54:37 +03:00
Sergej Jaskiewicz
0975a7654a [llvm] [unittests] Remove temporary files after they're not needed
Some LLVM unit tests forget to clean up temporary files and
directories. Introduce RAII classes for cleaning them up.

Refactor the tests to use those classes.

Differential Revision: https://reviews.llvm.org/D83228
2020-09-02 00:34:44 +03:00
Florian Hahn
2248875209 [Loads] Add canReplacePointersIfEqual helper.
This patch adds an initial, incomeplete and unsound implementation of
canReplacePointersIfEqual to check if a pointer value A can be replaced
by another pointer value B, that are deemed to be equivalent through
some means (e.g. information from conditions).

Note that is in general not sound to blindly replace pointers based on
equality, for example if they are based on different underlying objects.

LLVM's memory model is not completely settled as of now; see
https://bugs.llvm.org/show_bug.cgi?id=34548 for a more detailed
discussion.

The initial version of canReplacePointersIfEqual only rejects a very
specific case: replacing a pointer with a constant expression that is
not dereferenceable. Such a replacement is problematic and can be
restricted relatively easily without impacting most code. Using it to
limit replacements in GVN/SCCP/CVP only results in small differences in
7 programs out of MultiSource/SPEC2000/SPEC2006 on X86 with -O3 -flto.

This patch is supposed to be an initial step to improve the current
situation and the helper should be made stricter in the future. But this
will require careful analysis of the impact on performance.

Reviewed By: aqjune

Differential Revision: https://reviews.llvm.org/D85524
2020-09-01 20:57:41 +01:00
Lang Hames
4dfbee4abb [ORC] Add unit test for HasMaterializationSideEffectsOnly failure behavior. 2020-09-01 12:34:34 -07:00
Matt Arsenault
731e73be24 GlobalISel: Port smarter known bits for umin/umax from DAG 2020-09-01 12:50:15 -04:00
Matt Arsenault
942cf2892e GlobalISel: Implement computeKnownBits for G_BSWAP and G_BITREVERSE 2020-09-01 12:49:57 -04:00
Matt Arsenault
fbbea16c6b GlobalISel: Implement computeKnownBits for G_UNMERGE_VALUES 2020-09-01 11:19:27 -04:00
Raphael Isemann
c3c7a59967 Reland [FileCheck] Move FileCheck implementation out of LLVMSupport into its own library
This relands e9a3d1a401b07cbf7b11695637f1b549782a26cd which was originally
missing linking LLVMSupport into LLMVFileCheck which broke the SHARED_LIBS build.

Original summary:

The actual FileCheck logic seems to be implemented in LLVMSupport. I don't see a
good reason for having FileCheck implemented there as it has a very specific use
while LLVMSupport is a dependency of pretty much every LLVM tool there is. In
fact, the only use of FileCheck I could find (outside the FileCheck tool and the
FileCheck unit test) is a single call in GISelMITest.h.

This moves the FileCheck logic to its own LLVMFileCheck library. This way only
FileCheck and the GlobalISelTests now have a dependency on this code.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D86344
2020-09-01 14:59:28 +02:00
Martin Storsjö
ecdd8dabe2 [ORC] Remove a stray semicolon, silencing warnings. NFC. 2020-08-31 22:25:25 +03:00
Raphael Isemann
20366c891d Revert "[FileCheck] Move FileCheck implementation out of LLVMSupport into its own library"
This reverts commit e9a3d1a401b07cbf7b11695637f1b549782a26cd. Seems the new
FileCheck library doesn't link on some bots. Reverting for now.
2020-08-31 11:38:40 +02:00
Raphael Isemann
aecb52031b [FileCheck] Move FileCheck implementation out of LLVMSupport into its own library
The actual FileCheck logic seems to be implemented in LLVMSupport. I don't see a
good reason for having FileCheck implemented there as it has a very specific use
while LLVMSupport is a dependency of pretty much every LLVM tool there is. In
fact, the only use of FileCheck I could find (outside the FileCheck tool and the
FileCheck unit test) is a single call in GISelMITest.h.

This moves the FileCheck logic to its own LLVMFileCheck library. This way only
FileCheck and the GlobalISelTests now have a dependency on this code.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D86344
2020-08-31 11:24:41 +02:00
Xing GUO
e15bcf56b0 [Test] Simplify DWARF test cases. NFC.
The Length, AbbrOffset and Values fields of the debug_info section are
optional. This patch helps remove them and simplify test cases.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D86857
2020-08-31 14:03:48 +08:00
Thomas Preud'homme
14ecb9c6d9 [FileCheck] Add precision to format specifier
Add printf-style precision specifier to pad numbers to a given number of
digits when matching them if the value is smaller than the given
precision. This works on both empty numeric expression (e.g. variable
definition from input) and when matching a numeric expression. The
syntax is as follows:

[[#%.<precision><format specifier>, ...]

where <format specifier> is optional and ... can be a variable
definition or not with an empty expression or not. In the absence of a
precision specifier, a variable definition will accept leading zeros.

Reviewed By: jhenderson, grimar

Differential Revision: https://reviews.llvm.org/D81667
2020-08-30 19:40:57 +01:00
Lang Hames
aa6cb2b9d1 [ORC] Add getDFSLinkOrder / getReverseDFSLinkOrder methods to JITDylib.
DFS and Reverse-DFS linkage orders are used to order execution of
deinitializers and initializers respectively.

This patch replaces uses of special purpose DFS order functions in
MachOPlatform and LLJIT with uses of the new methods.
2020-08-29 15:17:06 -07:00
Xing GUO
1d4cd95b57 [DWARFYAML] Make the debug_abbrev_offset field optional.
This patch helps make the debug_abbrev_offset field optional. We don't
need to calculate the value of this field in the future.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D86614
2020-08-29 14:54:52 +08:00
Alexandre Ganea
38b940febb Fix Windows x86 compilation after a6a37a2fcd2a8048a75bd0d8280497ed89d73224 2020-08-28 10:53:20 -04:00
David Sherwood
56b8c35591 [SVE] Make ElementCount members private
This patch changes ElementCount so that the Min and Scalable
members are now private and can only be accessed via the get
functions getKnownMinValue() and isScalable(). In addition I've
added some other member functions for more commonly used operations.
Hopefully this makes the class more useful and will reduce the
need for calling getKnownMinValue().

Differential Revision: https://reviews.llvm.org/D86065
2020-08-28 14:43:53 +01:00
Georgii Rymar
d85c803e57 [unittests/Object] - Add testing for missing ELF formats.
This adds all missing format values that are defined in
ELFObjectFile<ELFT>::getFileFormatName().

Differential revision: https://reviews.llvm.org/D86625
2020-08-28 11:22:53 +03:00
Matt Arsenault
f54c1fe9ec GlobalISel: Implement computeNumSignBits for G_SEXT_INREG 2020-08-27 19:44:37 -04:00
Vitaly Buka
2df7657efb [ValueTracking] Replace recursion with Worklist
Now findAllocaForValue can handle nontrivial phi cycles.
2020-08-27 14:44:49 -07:00
Vitaly Buka
4f88f9a474 [NFC][ValueTracking] Add OffsetZero into findAllocaForValue
For StackLifetime after finding alloca we need to check that
values ponting to the begining of alloca.

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D86692
2020-08-27 13:46:22 -07:00
Matt Arsenault
b3488037c4 GlobalISel: Implement known bits for G_MERGE_VALUES 2020-08-27 14:07:18 -04:00
Alexandre Ganea
1c64f56c35 [Support] On Windows, add optional support for {rpmalloc|snmalloc|mimalloc}
This patch optionally replaces the CRT allocator (i.e., malloc and free) with rpmalloc (mixed public domain licence/MIT licence) or snmalloc (MIT licence) or mimalloc (MIT licence). Please note that the source code for these allocators must be available outside of LLVM's tree.

To enable, use `cmake ... -DLLVM_INTEGRATED_CRT_ALLOC=D:/git/rpmalloc -DLLVM_USE_CRT_RELEASE=MT` where `D:/git/rpmalloc` has already been git clone'd from `https://github.com/mjansson/rpmalloc`. The same applies to snmalloc and mimalloc.

When enabled, the allocator will be embeded (statically linked) into the LLVM tools & libraries. This currently only works with the static CRT (/MT), although using the dynamic CRT (/MD) could potentially work as well in the future.

When enabled, this changes the memory stack from:
  new/delete -> MS VC++ CRT malloc/free -> HeapAlloc -> VirtualAlloc
to:
  new/delete -> {rpmalloc|snmalloc|mimalloc} -> VirtualAlloc

The goal of this patch is to bypass the application's global heap - which is thread-safe thus inducing locking - and instead take advantage of a modern lock-free, thread cache, allocator. On a 6-core Xeon Skylake we observe a 2.5x decrease in execution time when linking a large scale application with LLD and ThinLTO (12 min 20 sec -> 5 min 34 sec), when all hardware threads are being used (using LLD's flag /opt:lldltojobs=all). On a dual 36-core Xeon Skylake with all hardware threads used, we observe a 24x decrease in execution time (1 h 2 min -> 2 min 38 sec) when linking a large application with LLD and ThinLTO. Clang build times also see a decrease in the range 5-10% depending on the configuration.

Differential Revision: https://reviews.llvm.org/D71786
2020-08-27 11:09:46 -04:00
Vitaly Buka
c66ff34562 [NFC][ValueTracking] Cleanup a test 2020-08-27 03:25:10 -07:00
Vitaly Buka
368c7592ca [NFC][ValueTracking] Fix typo in test 2020-08-27 03:01:30 -07:00
Vitaly Buka
afd0abc1f8 [ValueTracking] Support select in findAllocaForValue 2020-08-27 02:13:52 -07:00
Georgii Rymar
0c993fd620 [unittests/Object] - Simplify the code in ELFObjectFileTest.cpp, NFCI.
This refactors/rewrites the code to remove duplication.

Differential revision: https://reviews.llvm.org/D86623
2020-08-27 12:06:04 +03:00
Vitaly Buka
f918804878 [NFC] Add unittests for findAllocaForValue 2020-08-27 01:54:19 -07:00
Arthur Eubanks
d74ec65308 [ConstProp] Remove ConstantPropagation
As discussed in
http://lists.llvm.org/pipermail/llvm-dev/2020-July/143801.html.

Currently no users outside of unit tests.

Replace all instances in tests of -constprop with -instsimplify.
Notable changes in tests:
* vscale.ll - @llvm.sadd.sat.nxv16i8 is evaluated by instsimplify, use a fake intrinsic instead
* InsertElement.ll - insertelement undef is removed by instsimplify in @insertelement_undef
llvm/test/Transforms/ConstProp moved to llvm/test/Transforms/InstSimplify/ConstProp

Reviewed By: lattner, nikic

Differential Revision: https://reviews.llvm.org/D85159
2020-08-26 15:51:30 -07:00
Wei Mi
d9e172d0fb [SampleFDO] Enhance profile remapping support for searching inline instance
and indirect call promotion candidate.

Profile remapping is a feature to match a function in the module with its
profile in sample profile if the function name and the name in profile look
different but are equivalent using given remapping rules. This is a useful
feature to keep the performance stable by specifying some remapping rules
when sampleFDO targets are going through some large scale function signature
change.

However, currently profile remapping support is only valid for outline
function profile in SampleFDO. It cannot match a callee with an inline
instance profile if they have different but equivalent names. We found
that without the support for inline instance profile, remapping is less
effective for some large scale change.

To add that support, before any remapping lookup happens, all the names
in the profile will be inserted into remapper and the Key to the name
mapping will be recorded in a map called NameMap in the remapper. During
name lookup, a Key will be returned for the given name and it will be used
to extract an equivalent name in the profile from NameMap. So with the help
of the NameMap, we can translate any given name to an equivalent name in
the profile if it exists. Whenever we try to match a name in the module to
a name in the profile, we will try the match with the original name first,
and if it doesn't match, we will use the equivalent name got from remapper
to try the match for another time. In this way, the patch can enhance the
profile remapping support for searching inline instance and searching
indirect call promotion candidate.

In a planned large scale change of int64 type (long long) to int64_t (long),
we found the performance of a google internal benchmark degraded by 2% if
nothing was done. If existing profile remapping was enabled, the performance
degradation dropped to 1.2%. If the profile remapping with the current patch
was enabled, the performance degradation further dropped to 0.14% (Note the
experiment was done before searching indirect call promotion candidate was
added. We hope with the remapping support of searching indirect call promotion
candidate, the degradation can drop to 0% in the end. It will be evaluated
post commit).

Differential Revision: https://reviews.llvm.org/D86332
2020-08-26 11:07:35 -07:00
Dibya Ranjan Mishra
ef1ac54803 [Support] Allow printing the stack trace only for a given depth
Differential Revision: https://reviews.llvm.org/D85458
2020-08-26 09:27:42 -04:00