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
As far as I can tell, malloc.h is only being used here to provide
a definition of mallinfo (malloc itself is declared in stdlib.h via
cstdlib). We already have a macro for whether mallinfo is available,
so switch to using that instead.
Differential Revision: https://reviews.llvm.org/D57807
llvm-svn: 353329
llvm::is_trivially_copyable portability is verified at compile time using
std::is_trivially_copyable as the reference implementation.
Unfortunately, the latter is not available on all platforms, so introduce
a proper configure check to detect if it is available on the target platform.
In a similar manner, std::is_copy_assignable is not fully supported for gcc4.9.
Provide a portable (?) implementation instead.
Differential Revision: https://reviews.llvm.org/D57018
llvm-svn: 351820
Summary:
getLastAccessedTime() and getLastModificationTime() provided times in nanoseconds but with only 1 second resolution, even when the underlying file system could provide more precise times than that.
These changes add sub-second precision for unix platforms that support improved precision.
Also add some comments to make sure people are aware that the resolution of times can vary across different file systems.
Reviewers: labath, zturner, aaron.ballman, kristina
Reviewed By: aaron.ballman, kristina
Subscribers: lebedev.ri, mgorny, kristina, llvm-commits
Differential Revision: https://reviews.llvm.org/D54826
llvm-svn: 347530
Since crash dumping landed in r268519, May 2016, I have not once seen
anyone use an uploaded minidump to debug a compiler crash. Therefore,
I'm turning this off by default. The dumps clutter up user and buildbot
temp directories. Each file is only about 56KB, but it adds up.
In the context of clang, the extra line about the minidump confuses
users, when what we really want from them is the pre-processed source
code.
llvm-svn: 340185
See thread "Replacing LLVM_ON_WIN32 with just _WIN32" on llvm-dev and cfe-dev.
I replaced all uses of LLVM_ON_WIN32 with _WIN32 in r331127 (llvm),
r331069 (clang), r329697 (lldb), r329696 (lld), r329696 (clang-tools-extra).
If your out-of-tree program used LLVM_ON_WIN32, just use _WIN32 instead, which
is set at exactly the same time to exactly the same value.
https://reviews.llvm.org/D46264
llvm-svn: 331224
Summary:
[llvm-exegesis][RFC] Automatic Measurement of Instruction Latency/Uops
This is the code corresponding to the RFC "llvm-exegesis Automatic Measurement of Instruction Latency/Uops".
The RFC is available on the LLVM mailing lists as well as the following document
for easier reading:
https://docs.google.com/document/d/1QidaJMJUyQdRrFKD66vE1_N55whe0coQ3h1GpFzz27M/edit?usp=sharing
Subscribers: mgorny, gchatelet, orwant, llvm-commits
Differential Revision: https://reviews.llvm.org/D44519
llvm-svn: 329156
These used to be set in the old autoconf build, but the cmake build has had a
"TODO: actually check for these" comment since it was checked in, and they
were set to 1 on mingw unconditionally. It seems safe to say that they always
exist under mingw, so just remove them and assume they're set exactly when on
mingw (with msvc, we use `pragma comment` instead of linking these via flags).
llvm-svn: 328992
The autoconf manual: "This macro is obsolescent, as all current systems with
directory libraries have <dirent.h>. New programs need not use this macro."
llvm-svn: 328989
These should exist in all toolchains LLVM supports nowadays.
Enables making DataTypes.h a regular header instead of a .h.cmake file and
allows deleting a bunch of cmake goop (which should also speed up cmake
configure time a bit).
All the code this removes is 9+ years old.
https://reviews.llvm.org/D45155
llvm-svn: 328970
Found by looking through the output of
for f in $(grep -o '\bHAVE_[A-Z0-9_]*\b' llvm/cmake/config-ix.cmake); do
echo $f $(git grep $f '*' | wc -l);
done
in the monorepo.
llvm-svn: 328957
Summary: Make LLVM_ENABLE_DUMP independent LLVM_ENABLE_ASSERTIONS,
move it to llvm-config.h, and update description.
Differential Revision: https://reviews.llvm.org/D38406
llvm-svn: 320111
Summary:
This patch adds a LLVM_ENABLE_GISEL_COV which, like LLVM_ENABLE_DAGISEL_COV,
causes TableGen to instrument the generated table to collect rule coverage
information. However, LLVM_ENABLE_GISEL_COV goes a bit further than
LLVM_ENABLE_DAGISEL_COV. The information is written to files
(${CMAKE_BINARY_DIR}/gisel-coverage-* by default). These files can then be
concatenated into ${LLVM_GISEL_COV_PREFIX}-all after which TableGen will
read this information and use it to emit warnings about untested rules.
This technique could also be used by SelectionDAG and can be further
extended to detect hot rules and give them priority over colder rules.
Usage:
* Enable LLVM_ENABLE_GISEL_COV in CMake
* Build the compiler and run some tests
* cat gisel-coverage-[0-9]* > gisel-coverage-all
* Delete lib/Target/*/*GenGlobalISel.inc*
* Build the compiler
Known issues:
* ${LLVM_GISEL_COV_PREFIX}-all must be generated as a manual
step due to a lack of a portable 'cat' command. It should be the
concatenation of all ${LLVM_GISEL_COV_PREFIX}-[0-9]* files.
* There's no mechanism to discard coverage information when the ruleset
changes
Depends on D39742
Reviewers: ab, qcolombet, t.p.northover, aditya_nandakumar, rovka
Reviewed By: rovka
Subscribers: vsk, arsenm, nhaehnle, mgorny, kristof.beyls, javed.absar, igorb, llvm-commits
Differential Revision: https://reviews.llvm.org/D39747
llvm-svn: 318356
Summary:
Add LLVM_FORCE_ENABLE_DUMP cmake option, and use it along with
LLVM_ENABLE_ASSERTIONS to set LLVM_ENABLE_DUMP.
Remove NDEBUG and only use LLVM_ENABLE_DUMP to enable dump methods.
Move definition of LLVM_ENABLE_DUMP from config.h to llvm-config.h so
it'll be picked up by public headers.
Differential Revision: https://reviews.llvm.org/D38406
llvm-svn: 315590
But now include a check for CPU_COUNT so we still build on 10 year old
versions of glibc.
Original message:
Use sched_getaffinity instead of std:🧵:hardware_concurrency.
The issue with std:🧵:hardware_concurrency is that it forwards
to libc and some implementations (like glibc) don't take thread
affinity into consideration.
With this change a llvm program that can execute in only 2 cores will
use 2 threads, even if the machine has 32 cores.
This makes benchmarking a lot easier, but should also help if someone
doesn't want to use all cores for compilation for example.
llvm-svn: 314931
Summary:
This reverts D38481. The change breaks systems with older versions of glibc. It
injects a use of CPU_COUNT() from sched.h without checking to ensure that the
function exists first.
Reviewers:
Subscribers:
llvm-svn: 314922
The issue with std:🧵:hardware_concurrency is that it forwards
to libc and some implementations (like glibc) don't take thread
affinity into consideration.
With this change a llvm program that can execute in only 2 cores will
use 2 threads, even if the machine has 32 cores.
This makes benchmarking a lot easier, but should also help if someone
doesn't want to use all cores for compilation for example.
llvm-svn: 314809
Summary: Implement parsing and writing of a single xml manifest file.
Subscribers: mgorny, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D35425
llvm-svn: 308679
No behavior is changed if LLVM_TARGET_TRIPLE_ENV is blank or undefined.
If LLVM_TARGET_TRIPLE_ENV is "TEST_TARGET_TRIPLE" and $TEST_TARGET_TRIPLE is not blank,
llvm::sys::getDefaultTargetTriple() returns $TEST_TARGET_TRIPLE.
Lit resets config.target_triple and config.environment[LLVM_TARGET_TRIPLE_ENV] to change the default target.
Without changing LLVM_DEFAULT_TARGET_TRIPLE nor rebuilding, lit can be run;
TEST_TARGET_TRIPLE=i686-pc-win32 bin/llvm-lit -sv path/to/test/
TEST_TARGET_TRIPLE=i686-pc-win32 ninja check-clang-tools
Differential Revision: https://reviews.llvm.org/D33662
llvm-svn: 305632
Summary:
Since LLVM_NATIVE_ARCH, LLVM_NATIVE_ASMPARSER, LLVM_NATIVE_ASMPRINTER,
LLVM_NATIVE_DISASSEMBLER, LLVM_NATIVE_TARGET, LLVM_NATIVE_TARGETINFO and
LLVM_NATIVE_TARGETMC are already defined in llvm-config.h, there seems
to be no reason to also define them in config.h. Also, I can only find
usage of these macros in files that include llvm-config.h.
So let's remove the duplicated macros from config.h.
Reviewers: chandlerc, rnk, mehdi_amini, joerg
Reviewed By: rnk
Subscribers: chapuni, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D33881
llvm-svn: 304714
Summary:
VersionPrinter by default outputs information about the Host CPU
and Default target. Printing this information requires linking in
a large amount of data, such as supported target triples as C
strings, which in turn bloats the binary size.
Enable a new CMake option LLVM_VERSION_PRINTER_SHOW_HOST_TARGET_INFO
which controls printing of the host and target info. This allows
the target triple names to be dead-code stripped. This is a nice
win for LLVM clients that wish to minimize their binary size, such
as graphics drivers.
By default this is ON, so there is no change in the default behavior.
Clients who wish to suppress this printing can do so by setting this
option to off via CMake.
A test app on Linux that uses ParseCommandLineOptions() shows a binary
size reduction of 23KB (from 149K to 126K) for a Release build, and 24KB
(from 135K to 111K) in a MinSizeRel build.
Reviewers: klimek, beanz, bogner, chandlerc, compnerd
Reviewed By: compnerd
Patch by pammon (Peter Ammon) !
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D30904
llvm-svn: 300630
On FreeBSD backtrace is not part of libc and depends on libexecinfo
being available. Instead of using manual checks we can use the builtin
CMake module FindBacktrace.cmake to detect availability of backtrace()
in a portable way.
Patch By: Alex Richardson
Differential Revision: https://reviews.llvm.org/D27143
llvm-svn: 300062
Committing after fixing suggested changes and tested release/debug builds on
x86_64-linux and arm/aarch64 builds.
Differential revision: https://reviews.llvm.org/D29042
llvm-svn: 293850
Add an explicit LLVM_ENABLE_DIA_SDK option to control building support
for DIA SDK-based debugging. Control its value to match whether DIA SDK
support was found and expose it in LLVMConfig (alike LLVM_ENABLE_ZLIB).
Its value is needed for LLDB to determine whether to run tests requiring
DIA support. Currently it is obtained from llvm/Config/config.h;
however, this file is not available for standalone builds. Following
this change, LLDB will be modified to use the value from LLVMConfig.
Differential Revision: https://reviews.llvm.org/D26255
llvm-svn: 290818
The macro LLVM_ENABLE_ABI_BREAKING_CHECKS is moved to a new header
abi-breaking.h, from llvm-config.h. Only headers that are using the
macro are including this new header.
LLVM will define a symbol, either EnableABIBreakingChecks or
DisableABIBreakingChecks depending on the configuration setting for
LLVM_ABI_BREAKING_CHECKS.
The abi-breaking.h header will add weak references to these symbols in
every clients that includes this header. This should ensure that
a mismatch triggers a link failure (or a load time failure for DSO).
On MSVC, the pragma "detect_mismatch" is used instead.
Differential Revision: https://reviews.llvm.org/D26876
llvm-svn: 288082
