This reverts commit 0a1123eb43.
Want to revert this because it's causing trouble for PowerPC
I also fixed test fp-model.c which was looking for an incorrect error message
The goal of this patch is to maximize CPU utilization on multi-socket or high core count systems, so that parallel computations such as LLD/ThinLTO can use all hardware threads in the system. Before this patch, on Windows, a maximum of 64 hardware threads could be used at most, in some cases dispatched only on one CPU socket.
== Background ==
Windows doesn't have a flat cpu_set_t like Linux. Instead, it projects hardware CPUs (or NUMA nodes) to applications through a concept of "processor groups". A "processor" is the smallest unit of execution on a CPU, that is, an hyper-thread if SMT is active; a core otherwise. There's a limit of 32-bit processors on older 32-bit versions of Windows, which later was raised to 64-processors with 64-bit versions of Windows. This limit comes from the affinity mask, which historically is represented by the sizeof(void*). Consequently, the concept of "processor groups" was introduced for dealing with systems with more than 64 hyper-threads.
By default, the Windows OS assigns only one "processor group" to each starting application, in a round-robin manner. If the application wants to use more processors, it needs to programmatically enable it, by assigning threads to other "processor groups". This also means that affinity cannot cross "processor group" boundaries; one can only specify a "preferred" group on start-up, but the application is free to allocate more groups if it wants to.
This creates a peculiar situation, where newer CPUs like the AMD EPYC 7702P (64-cores, 128-hyperthreads) are projected by the OS as two (2) "processor groups". This means that by default, an application can only use half of the cores. This situation could only get worse in the years to come, as dies with more cores will appear on the market.
== The problem ==
The heavyweight_hardware_concurrency() API was introduced so that only *one hardware thread per core* was used. Once that API returns, that original intention is lost, only the number of threads is retained. Consider a situation, on Windows, where the system has 2 CPU sockets, 18 cores each, each core having 2 hyper-threads, for a total of 72 hyper-threads. Both heavyweight_hardware_concurrency() and hardware_concurrency() currently return 36, because on Windows they are simply wrappers over std:🧵:hardware_concurrency() -- which can only return processors from the current "processor group".
== The changes in this patch ==
To solve this situation, we capture (and retain) the initial intention until the point of usage, through a new ThreadPoolStrategy class. The number of threads to use is deferred as late as possible, until the moment where the std::threads are created (ThreadPool in the case of ThinLTO).
When using hardware_concurrency(), setting ThreadCount to 0 now means to use all the possible hardware CPU (SMT) threads. Providing a ThreadCount above to the maximum number of threads will have no effect, the maximum will be used instead.
The heavyweight_hardware_concurrency() is similar to hardware_concurrency(), except that only one thread per hardware *core* will be used.
When LLVM_ENABLE_THREADS is OFF, the threading APIs will always return 1, to ensure any caller loops will be exercised at least once.
Differential Revision: https://reviews.llvm.org/D71775
This patch adds DenseMapInfo<> support for BitVector and SmallBitVector.
This is part of https://reviews.llvm.org/D71775, where a BitVector is used as a thread affinity mask.
There are some unnecessary typenames in std/numerics/c.math/abs.pass.cpp;
e.g. they're not in a dependent context.
Patch by Bryce Adelstein Lelbach
Differential Revision: https://reviews.llvm.org/D72106
Having tests that depend on clang inside llvm/ are not a good idea since
it can break incremental `ninja check-llvm`.
Fixes https://llvm.org/PR44798
Reviewed By: lebedev.ri, MaskRay, rsmith
Differential Revision: https://reviews.llvm.org/D74051
Summary:
Reenables importing of constants by default, which was disabled in
D73724 due to excessive thin link times. These inefficiencies were
fixed in D73851.
I re-measured thin link times for a number of binaries that had compile
time explosions with importing of constants previously and confirmed
they no longer have any notable increases with it enabled.
Reviewers: wmi, evgeny777
Subscribers: hiraditya, arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74512
This patch added generation of SIMD bitwise insert BIT/BIF instructions.
In the absence of GCC-like functionality for optimal constraints satisfaction
during register allocation the bitwise insert and select patterns are matched
by pseudo bitwise select BSP instruction with not tied def.
It is expanded later after register allocation with def tied
to BSL/BIT/BIF depending on operands registers.
This allows to get rid of redundant moves.
Reviewers: t.p.northover, samparker, dmgreen
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D74147
Summary:
The CheckAtomic module performs two tests to determine if passing
'-latomic' to the linker is required: one for 64-bit atomics, and
another for non-64-bit atomics. clangd only uses the result from
HAVE_CXX_ATOMICS64_WITHOUT_LIB. This is incomplete because there are
uses of non-64-bit atomics in the code, such as the ReplyOnce::Replied
of type std::atomic<bool> defined in clangd/ClangdLSPServer.cpp.
Fix by also checking for the result of HAVE_CXX_ATOMICS_WITHOUT_LIB.
See also: https://reviews.llvm.org/D68964
Reviewers: ilya-biryukov, nridge, kadircet, beanz, compnerd, luismarques
Reviewed By: luismarques
Tags: #clang
Differential Revision: https://reviews.llvm.org/D69869
Summary: Adds the RedHat Linux triple to the list of 64-bit RISC-V triples.
Without this the gcc libraries wouldn't be found by clang on a redhat/fedora
system, as the search list included `/usr/lib/gcc/riscv64-redhat-linux-gnu`
but the correct path didn't include the `-gnu` suffix.
Reviewers: lenary, asb, dlj
Reviewed By: lenary
Tags: #clang
Differential Revision: https://reviews.llvm.org/D74399
The static asserts in span<T, N>::front() and span<T, N>::back() are
incorrect as they may be triggered from valid code due to evaluation
of a never taken branch:
span<int, 0> foo;
if (!foo.empty()) {
auto x = foo.front();
}
The problem is that the branch is always evaluated by the compiler,
creating invalid compile errors for span<T, 0>.
Thanks to Michael Schellenberger Costa for the patch.
Differential Revision: https://reviews.llvm.org/D71995
Summary:
Currently template parameters has symbolkind `Unknown`. This patch
introduces a new kind `TemplateParm` for templatetemplate, templatetype and
nontypetemplate parameters.
Also adds tests in clangd hover feature.
Reviewers: sammccall
Subscribers: kristof.beyls, ilya-biryukov, jkorous, arphaman, usaxena95, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73696
Without PSHUFB we are better using ROTL (expanding to OR(SHL,SRL)) than using the generic v16i8 shuffle lowering - but if we can widen to v8i16 or more then the existing shuffles are still the better option.
REAPPLIED: Original commit rG11c16e71598d was reverted at rGde1d90299b16 as it wasn't accounting for later lowering. This version emits ROTLI or the OR(VSHLI/VSRLI) directly to avoid the issue.
Summary: LLVM configuration fails with 'unable to guess system type' on riscv64.
Add support for detecting riscv32 and riscv64 systems.
Patch by Gokturk Yuksek (gokturk)
Reviewers: erichkeane, rengolin, mgorny, aaron.ballman, beanz, luismarques
Reviewed By: luismarques
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68899
Replace use of widenPath in comparePaths with UTF8ToUTF16. widenPath
does a lot more than just conversion from UTF-8 to UTF-16. This is not
necessary for CompareStringOrdinal and could possibly even cause
problems.
Differential Revision: https://reviews.llvm.org/D74477
Prior to this patch, if a DW_LNE_set_address opcode was parsed with an
address size (i.e. with a length after the opcode) of anything other 1,
2, 4, or 8, an llvm_unreachable would be hit, as the data extractor does
not support other values. This patch introduces a new error check that
verifies the address size is one of the supported sizes, in common with
other places within the DWARF parsing.
This patch also fixes calculation of a generated line table's size in
unit tests. One of the tests in this patch highlighted a bug introduced
in 1271cde474, when non-byte operands were used as arguments for
extended or standard opcodes.
Reviewed by: dblaikie
Differential Revision: https://reviews.llvm.org/D73962
This is the second dwp preparatory patch. When a SymbolFileDWARFDwo will
hold more than one split unit, it will not be able to be uniquely owned
by a single DWARFUnit. I achieve this by changing the
unique_ptr<SymbolFileDWARFDwo> member of DWARFUnit to
shared_ptr<DWARFUnit>. The shared_ptr points to a DWARFUnit, but it is
in fact holding the entire SymbolFileDWARFDwo alive. This is the same
method used by llvm DWARFUnit (except that is uses the DWARFContext
class).
Differential Revision: https://reviews.llvm.org/D73782
The code generation is exactly the same as it was.
But not that the special handling of untied tasks is still handled by
emitUntiedSwitch in clang.
Differential Revision: https://reviews.llvm.org/D69828
Experimental targets are meant to be maintained by the community behind
the target. They are not monitored by the primary build bots. This
change clarifies that it is this communities responsibility for things
like test fixes related to the target caused by changes unrelated to
that target.
See http://lists.llvm.org/pipermail/llvm-dev/2020-February/139115.html
for a full discussion.
Reviewed by: rupprecht, lattner, MaskRay
Differential Revision: https://reviews.llvm.org/D74538
This pass would currently build, but fail to run when this backend isn't
linked in. On the other hand, we'd like it to initialize only the NVPTX
backend, which isn't possible if we continue to build it without the
backend available. Instead of building a broken configuration, let's
skip building the pass entirely.
Differential Revision: https://reviews.llvm.org/D74592
Summary:
This was added in 2018 (r339929), when we were still using the
hand-rolled test runner.
It does not seem to be relevant anymore. In fact as far as I can tell,
it's a big no-op now as the exclusive_test_subdir variable is never set.
Reviewers: vsk, JDevlieghere
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D74551
The commit switching the calling convention for memrefs (5a1778057)
inadvertently introduced a bug in the function argument attribute conversion:
due to incorrect indexing of function arguments it was not assigning the
attributes to the arguments beyond those generated from the first original
argument. This was not caught in the commit since the test suite does have a
test for converting multi-argument functions with argument attributes. Fix the
bug and add relevant tests.
Summary: Support for PIC with tests for global variables and function calls.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D74536
That's where nowadays those tests reside, those outliers were created
before the migration but committed after,
so they just awkwardly reside in the old place.
This reverts b3a0c4d7dc for
TestBreakpointHitCount.py because it's now timing out on the Windows
bot. I'm not sure this is the cause, but the substitution doesn't look
correct anyway...
After the recent change that grouped some of the ABI plugins together,
those plugins ended up with multiple initializers per plugin. This is
incompatible with my proposed approach of generating the initializers
dynamically, which is why I've grouped them together in a new entry
point.
Differential revision: https://reviews.llvm.org/D74451
Summary:
This is second attempt to fix the problem with incorrect dependencies reported in presence of invariant load. Initial fix (https://reviews.llvm.org/D64405) was reverted due to a regression reported in https://reviews.llvm.org/D70516.
The original fix changed caching behavior for invariant loads. Namely such loads are not put into the second level cache (NonLocalDepInfo). The problem with that fix is the first level cache (CachedNonLocalPointerInfo) still works as if invariant loads were in the second level cache. The solution is in addition to not putting dependence results into the second level cache avoid putting info about invariant loads into the first level cache as well.
Reviewers: jdoerfert, reames, hfinkel, efriedma
Reviewed By: jdoerfert
Subscribers: DaniilSuchkov, hiraditya, bmahjour, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73027
When the DW_AT_call_return_pc matches a relocation, the call return pc
would get relocated twice, once because of the relocation in the object
file and once because of dsymutil. The same problem exists for the low
and high PC and the fix is the same. We remember the low, high and
return pc of the original DIE and relocate that, rather than the
potentially already relocated value.
Reviewed offline by Fred Riss.
Summary: This revision adds support to the declarative parser for formatting enum attributes in the symbolized form. It uses this new functionality to port several of the SPIRV parsers over to the declarative form.
Differential Revision: https://reviews.llvm.org/D74525
Summary:
Also make return calls terminator instructions so epilogues are
inserted before them rather than after them. Together, these changes
make WebAssembly's tail call optimization more stack-safe.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73943
Evgeniy Brevnov