Commit Graph

6206 Commits

Author SHA1 Message Date
Igor Kudrin a845ebd633 [DebugInfo] Make offsets of dwarf units 64-bit (19/19).
In the case of LTO, several DWARF units can be emitted in one section.
For an extremely large application, they may exceed the limit of 4GiB
for 32-bit offsets. As it is now possible to emit 64-bit debugging info,
the patch enables storing the larger offsets.

Differential Revision: https://reviews.llvm.org/D87026
2020-09-15 12:23:32 +07:00
Igor Kudrin cae7c1eb78 [DebugInfo] Use a common method to determine a suitable form for section offsts (6/19).
This is mostly an NFC patch because the involved methods are used when
emitting DWO files, which is incompatible with DWARFv3, or for platforms
where DWARF64 is not supported yet.

Differential Revision: https://reviews.llvm.org/D87015
2020-09-15 11:30:38 +07:00
Igor Kudrin 5dd1c59188 [DebugInfo] Fix emitting DWARF64 compilation units (5/19).
The patch also adds a method to choose an appropriate DWARF form
to represent section offsets according to the version and the format
of producing debug info.

Differential Revision: https://reviews.llvm.org/D87014
2020-09-15 11:30:30 +07:00
Igor Kudrin c3c501f5d7 [DebugInfo] Add new emitting methods for values which depend on the DWARF format (3/19).
These methods are going to be used in subsequent patches.

Differential Revision: https://reviews.llvm.org/D87010
2020-09-15 11:30:10 +07:00
Igor Kudrin a8058c6f8d [DebugInfo] Fix DIE value emitters to be compatible with DWARF64 (2/19).
DW_FORM_sec_offset and DW_FORM_strp imply values of different sizes with
DWARF32 and DWARF64. The patch fixes DIE value classes to use correct
sizes when emitting their values. For DIELocList it ensures that the
requested DWARF form matches the current DWARF format because that class
uses a method that selects the size automatically.

Differential Revision: https://reviews.llvm.org/D87009
2020-09-15 11:30:02 +07:00
Igor Kudrin 380e746bcc [DebugInfo] Fix methods of AsmPrinter to emit values corresponding to the DWARF format (1/19).
These methods are used to emit values which are 32-bit in DWARF32 and
64-bit in DWARF64. The patch fixes them so that they choose the length
automatically, depending on the DWARF format set in the Context.

Differential Revision: https://reviews.llvm.org/D87008
2020-09-15 11:29:48 +07:00
Tyker 78de7297ab Reland [AssumeBundles] Use operand bundles to encode alignment assumptions
NOTE: There is a mailing list discussion on this: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

Complemantary to the assumption outliner prototype in D71692, this patch
shows how we could simplify the code emitted for an alignemnt
assumption. The generated code is smaller, less fragile, and it makes it
easier to recognize the additional use as a "assumption use".

As mentioned in D71692 and on the mailing list, we could adopt this
scheme, and similar schemes for other patterns, without adopting the
assumption outlining.
2020-09-12 15:36:06 +02:00
Jianzhou Zhao 19531a81f1 Add raw_fd_stream_test.cpp into CMakeLists.txt
Fixing 0ece51c60c
2020-09-12 07:48:12 +00:00
Jianzhou Zhao 0ece51c60c 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 7dcd0042e8 Re-apply "[ORC] Make MaterializationResponsibility immovable..." with fixes.
Re-applies c74900ca67 with fixes for the ThinLtoJIT example.
2020-09-11 14:09:05 -07:00
Florian Hahn 8da6ae4ce1 Revert "[ConstraintSystem] Add helpers to deal with linear constraints."
This reverts commit 3eb141e507.

This uses __builtin_mul_overflow which is not available everywhere.
2020-09-11 14:49:04 +01:00
Florian Hahn 3eb141e507 [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 c0825fa5fc Revert "[ORC] Make MaterializationResponsibility immovable, pass by unique_ptr."
This reverts commit c74900ca67.

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 4e3edef4b8 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 c74900ca67 [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 54fcea86b1 Revert "[Support] Use unique_function rather than std::function for ThreadPool TaskTy."
This reverts commit d9c8b0256c.

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 d9c8b0256c [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 1919b65052 [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 a6183d0f02 [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 25ce1e0497 [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 e7b40c5492 [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 5350e1b509 [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 69f2c79f2a [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 1673a08044 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 b21ddded8f [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 94948f3c92 [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 224d8153b5 [llvm] [unittests] Fix failing test 'FileCollectorTest.addDirectory'
This fixes a regression in the test suite introduced by
fad75598d2
2020-09-02 00:54:37 +03:00
Sergej Jaskiewicz fad75598d2 [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 0d966ae4b2 [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 3e753ce1ab [ORC] Add unit test for HasMaterializationSideEffectsOnly failure behavior. 2020-09-01 12:34:34 -07:00
Matt Arsenault 35c94d3f7e GlobalISel: Port smarter known bits for umin/umax from DAG 2020-09-01 12:50:15 -04:00
Matt Arsenault 759482ddaa GlobalISel: Implement computeKnownBits for G_BSWAP and G_BITREVERSE 2020-09-01 12:49:57 -04:00
Matt Arsenault 92090e8bd8 GlobalISel: Implement computeKnownBits for G_UNMERGE_VALUES 2020-09-01 11:19:27 -04:00
Raphael Isemann 5ffd940ac0 Reland [FileCheck] Move FileCheck implementation out of LLVMSupport into its own library
This relands e9a3d1a401 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 b16ac94419 [ORC] Remove a stray semicolon, silencing warnings. NFC. 2020-08-31 22:25:25 +03:00
Raphael Isemann ed89eb3571 Revert "[FileCheck] Move FileCheck implementation out of LLVMSupport into its own library"
This reverts commit e9a3d1a401. Seems the new
FileCheck library doesn't link on some bots. Reverting for now.
2020-08-31 11:38:40 +02:00
Raphael Isemann e9a3d1a401 [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 1d01fc100b [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 998709b7d5 [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 e1d5f7d003 [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 12e832cbcb [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 b9b954b8bb Fix Windows x86 compilation after a6a37a2fcd 2020-08-28 10:53:20 -04:00
David Sherwood f4257c5832 [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 c78d2766fd [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 5feca7c9c3 GlobalISel: Implement computeNumSignBits for G_SEXT_INREG 2020-08-27 19:44:37 -04:00
Vitaly Buka 23524fdece [ValueTracking] Replace recursion with Worklist
Now findAllocaForValue can handle nontrivial phi cycles.
2020-08-27 14:44:49 -07:00
Vitaly Buka a6927c8621 [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 531f7063ba GlobalISel: Implement known bits for G_MERGE_VALUES 2020-08-27 14:07:18 -04:00
Alexandre Ganea a6a37a2fcd [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 6ccacb4680 [NFC][ValueTracking] Cleanup a test 2020-08-27 03:25:10 -07:00