Thanks to @waltl for reporting this issue.
I have also added an assert to check for invalid null strategy objects, and I
have reworded a couple of code comments in Scheduler.h
llvm-svn: 340545
With this patch, users can now customize the pipeline selection strategy for
scheduler resources. The resource selection strategy can be defined at processor
resource granularity. This enables the definition of different strategies for
different hardware schedulers.
To override the strategy associated with a processor resource, users can call
method ResourceManager::setCustomStrategy(), and pass a 'ResourceStrategy'
object in input.
Class ResourceStrategy is an abstract class which declares virtual method
`ResourceStrategy::select()`. Method select() is meant to implement the actual
strategy; it is responsible for picking the next best resource from a set of
available pipeline resources. Custom strategy must simply override that method.
By default, processor resources are associated with instances of
'DefaultResourceStrategy'. A 'DefaultResourceStrategy' internally implements a
simple round-robin selector. For more details, please refer to the code comments
in Scheduler.h.
llvm-svn: 340536
Both DWARFDebugLine and DWARFDebugAddr used the same callback mechanism
for handling recoverable errors. They both implemented similar warn() function
to be used as such callbacks.
In this revision we get rid of code duplication and move this warn() function
to DWARFContext as DWARFContext::dumpWarning().
Reviewers: lhames, jhenderson, aprantl, probinson, dblaikie, JDevlieghere
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D51033
llvm-svn: 340528
The format is the same as in ELF: a sequence of ULEB128-encoded
symbol indexes.
Differential Revision: https://reviews.llvm.org/D51047
llvm-svn: 340499
There are several places where we use CMAKE_CONFIGURATION_TYPES to determine if we are using an IDE generator and in turn decide not to generate some of the convenience targets (like all the install-* and check-llvm-* targets). This decision is made because IDEs don't always deal well with the thousands of targets LLVM can generate.
This approach does not work for Visual Studio 15's new CMake integration. Because VS15 uses a Ninja generator, it isn't a multi-configuration build, and generating all these extra targets mucks up the UI and adds little value.
With this change we still don't generate these targets by default for Visual Studio and Xcode generators, and LLVM_ENABLE_IDE becomes a switch that can be enabled on the VS15 CMake builds, to improve the IDE experience.
llvm-svn: 340435
Summary: This is to be consistent with lld behavior since rLLD340364.
Reviewers: tejohnson
Reviewed By: tejohnson
Subscribers: steven_wu, eraman, mehdi_amini, inglorion, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D51060
llvm-svn: 340380
The constructor of Scheduler now accepts a SchedulerStrategy object, which is
used internally by method Scheduler::select() to drive the instruction selection
process.
The goal of this patch is to enable the definition of custom selection
strategies while reusing the same algorithms implemented by class Scheduler.
The motivation is that, on some targets, the default strategy may not well
approximate the selection logic in the hardware schedulers.
This patch also adds the ability to pass a ResourceManager object to the
constructor of Scheduler. This gives a bit more flexibility to the design, and
potentially it allows to expose processor resources to SchedulerStrategy
objects.
Differential Revision: https://reviews.llvm.org/D51051
llvm-svn: 340314
The goal of this patch is to simplify the Scheduler's interface in preparation
for D50929.
Some methods in the Scheduler's interface should not be exposed to external
users, since their presence makes it hard to both understand, and extend the
Scheduler's interface.
This patch removes the following two methods from the public Scheduler's API:
- reclaimSimulatedResources()
- updatePendingQueue()
Their logic has been migrated to a new method named 'cycleEvent()'.
Methods 'updateIssuedSet()' and 'promoteToReadySet()' still exist. However,
they are now private members of class Scheduler.
This simplifies the interaction with the Scheduler from the ExecuteStage.
llvm-svn: 340273
Summary: Before, llvm-strip accepted a second argument but it would just be ignored.
Reviewers: alexshap, jhenderson, paulsemel
Reviewed By: alexshap
Subscribers: jakehehrlich, rupprecht, llvm-commits
Differential Revision: https://reviews.llvm.org/D51004
llvm-svn: 340229
The LSUnit is now a HardwareUnit, and it is owned by the mca::Context.
Derived classes can now implement a different consistency model by overriding
method `LSUnit::isReady()`.
This patch also slightly refactors the Scheduler interface in the attempt to
simplifying the interaction between ExecuteStage and the underlying Scheduler.
llvm-svn: 340176
This patch significantly improves performance of the YAML serializer by
optimizing `YAML::isNumeric` function. This function is called on the
most strings and is highly inefficient for two reasons:
* It uses `Regex`, which is parsed and compiled each time this
function is called
* It uses multiple passes which are not necessary
This patch introduces stateful ad hoc YAML number parser which does not
rely on `Regex`. It also fixes YAML number format inconsistency: current
implementation supports C-stile octal number format (`01234567`) which
was present in YAML 1.0 specialization (http://yaml.org/spec/1.0/),
[Section 2.4. Tags, Example 2.19] but was deprecated and is no longer
present in latest YAML 1.2 specification
(http://yaml.org/spec/1.2/spec.html), see [Section 10.3.2. Tag
Resolution]. Since the rest of the rest of the implementation does not
support other deprecated YAML 1.0 numeric features such as sexagecimal
numbers, commas as delimiters it is treated as inconsistency and not
longer supported. This patch also adds unit tests to ensure the validity
of proposed implementation.
This performance bottleneck was identified while profiling Clangd's
global-symbol-builder tool with my colleague @ilya-biryukov. The
substantial part of the runtime was spent during a single-thread Reduce
phase, which concludes with YAML serialization of collected symbol
collection. Regex matching was accountable for approximately 45% of the
whole runtime (which involves sharded Map phase), now it is reduced to
18% (which is spent in `clang::clangd::CanonicalIncludes` and can be
also optimized because all used regexes are in fact either suffix
matches or exact matches).
`llvm-yaml-numeric-parser-fuzzer` was used to ensure the validity of the
proposed regex replacement. Fuzzing for ~60 hours using 10 threads did
not expose any bugs.
Benchmarking `global-symbol-builder` (using `hyperfine --warmup 2
--min-runs 5 'command 1' 'command 2'`) tool by processing a reasonable
amount of code (26 source files matched by
`clang-tools-extra/clangd/*.cpp` with all transitive includes) confirmed
our understanding of the performance bottleneck nature as it speeds up
the command by the factor of 1.6x:
| Command | Mean [s] | Min…Max [s] |
| this patch (D50839) | 84.7 ± 0.6 | 83.3…84.7 |
| master (rL339849) | 133.1 ± 0.8 | 132.4…134.6 |
Using smaller samples (e.g. by collecting symbols from
`clang-tools-extra/clangd/AST.cpp` only) yields even better performance
improvement, which is expected because Map phase takes less time
compared to Reduce and is 2.05x faster and therefore would significantly
improve the performance of standalone YAML serializations.
| Command | Mean [ms] | Min…Max [ms] |
| this patch (D50839) | 3702.2 ± 48.7 | 3635.1…3752.3 |
| master (rL339849) | 7607.6 ± 109.5 | 7533.3…7796.4 |
Reviewed by: zturner, ilya-biryukov
Differential revision: https://reviews.llvm.org/D50839
llvm-svn: 340154
Added DIFlags in LLVMDIBuilderCreateBasicType to add optional DWARF
attributes, such as DW_AT_endianity.
Patch by Chirag Patel.
Differential Revision: https://reviews.llvm.org/D50832
llvm-svn: 340146
Summary:
Port GNU Objcopy -G/--keep-global-symbol(s).
This is slightly different than the already-implemented --globalize-symbol, which marks a symbol as global when copying. When --keep-global-symbol (alias -G) is used, *only* those symbols marked will stay global, and all other globals are demoted to local. (Also note that it doesn't *promote* a symbol to global). Additionally, there is a pluralized version of the flag --keep-global-symbols, which effectively applies --keep-global-symbol for every non-comment in a file.
Reviewers: jakehehrlich, jhenderson, alexshap
Reviewed By: jhenderson
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D50589
llvm-svn: 340105
VSO was a little close to VDSO (an acronym on Linux for Virtual Dynamic Shared
Object) for comfort. It also risks giving the impression that instances of this
class could be shared between ExecutionSessions, which they can not.
JITDylib seems moderately less confusing, while still hinting at how this
class is intended to be used, i.e. as a JIT-compiled stand-in for a dynamic
library (code that would have been a dynamic library if you had wanted to
compile it ahead of time).
llvm-svn: 340084
Summary:
The -I (--input-target) and -B (--binary-architecture) flags exist but are currently silently ignored. This adds support for -I binary for architectures i386, x86-64 (and alias i386:x86-64), arm, aarch64, sparc, and ppc (powerpc:common64). This is largely based on D41687.
This is done by implementing an additional subclass of Reader, BinaryReader, which works by interpreting the input file as contents for .data field, sets up a synthetic header, and adds additional sections/symbols (e.g. _binary__tmp_data_txt_start).
Reviewers: jakehehrlich, alexshap, jhenderson, javed.absar
Reviewed By: jhenderson
Subscribers: jyknight, nemanjai, kbarton, fedor.sergeev, jrtc27, kristof.beyls, paulsemel, llvm-commits
Differential Revision: https://reviews.llvm.org/D50343
llvm-svn: 340070
class Scheduler should not know anything of hardware event listeners and
hardware stall events (HWStallEvent). HWStallEvent objects should only be
constructed by pipeline stages to notify listeners of hardware events.
No functional change intended.
llvm-svn: 340036
This patch changes how instruction execution is orchestrated by the Pipeline.
In particular, this patch makes it more explicit how instructions transition
through the various pipeline stages during execution.
The main goal is to simplify both the stage API and the Pipeline execution. At
the same time, this patch fixes some design issues which are currently latent,
but that are likely to cause problems in future if people start defining custom
pipelines.
The new design assumes that each pipeline stage knows the "next-in-sequence".
The Stage API has gained three new methods:
- isAvailable(IR)
- checkNextStage(IR)
- moveToTheNextStage(IR).
An instruction IR can be executed by a Stage if method `Stage::isAvailable(IR)`
returns true.
Instructions can move to next stages using method moveToTheNextStage(IR).
An instruction cannot be moved to the next stage if method checkNextStage(IR)
(called on the current stage) returns false.
Stages are now responsible for moving instructions to the next stage in sequence
if necessary.
Instructions are allowed to transition through multiple stages during a single
cycle (as long as stages are available, and as long as all the calls to
`checkNextStage(IR)` returns true).
Methods `Stage::preExecute()` and `Stage::postExecute()` have now become
redundant, and those are removed by this patch.
Method Pipeline::runCycle() is now simpler, and it correctly visits stages
on every begin/end of cycle.
Other changes:
- DispatchStage no longer requires a reference to the Scheduler.
- ExecuteStage no longer needs to directly interact with the
RetireControlUnit. Instead, executed instructions are now directly moved to the
next stage (i.e. the retire stage).
- RetireStage gained an execute method. This allowed us to remove the
dependency with the RCU in ExecuteStage.
- FecthStage now updates the "program counter" during cycleBegin() (i.e.
before we start executing new instructions).
- We no longer need Stage::Status to be returned by method execute(). It has
been dropped in favor of a more lightweight llvm::Error.
Overally, I measured a ~11% performance gain w.r.t. the previous design. I also
think that the Stage interface is probably easier to read now. That being said,
code comments have to be improved, and I plan to do it in a follow-up patch.
Differential revision: https://reviews.llvm.org/D50849
llvm-svn: 339923
The main difference is that now `cycleStart()` and `cycleEnd()` return an
llvm::Error.
This patch implements a few minor style changes, and adds missing 'const' to
some methods.
llvm-svn: 339885
This allows to set custom Info field value for SHT_GROUP sections.
It is useful to allow this because we would be able to replace at least one binary
object committed in LLD and replace it with the yaml2obj based test.
Differential revision: https://reviews.llvm.org/D50776
llvm-svn: 339772
This patch fixes a regression introduced at revision 338702.
A processor resource mask was incorrectly implicitly truncated to an unsigned
quantity. Later on, the truncated mask was used to initialize an element of a
vector of processor resource descriptors.
On targets with more than 32 processor resources, some elements of the vector
are left uninitialized. As a consequence, this bug might have eventually caused
a crash due to null dereference in the Scheduler.
This patch fixes PR38575, and adds a test for it.
llvm-svn: 339768
Currently, it is possible to use yaml2obj for producing SHT_GROUP sections
of type GRP_COMDAT. For LLD test case I need to produce an object with
a broken (different from GRP_COMDAT) type.
The patch teaches tool to do such things.
Differential revision: https://reviews.llvm.org/D50761
llvm-svn: 339764
Summary:
Add an overload to sys::fs::setLastModificationAndAccessTime that allows setting last access and modification times separately. This will allow tools to use this API when they want to preserve both the access and modification times from an input file, which may be different.
Also note that both the POSIX (futimens/futimes) and Windows (SetFileTime) APIs take the two timestamps in the order of (1) access (2) modification time, so this renames the method to "setLastAccessAndModificationTime" to make it clear which timestamp is which.
For existing callers, the 1-arg overload just sets both timestamps to the same thing.
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D50521
llvm-svn: 339628
Summary:
This patch introduces error handling to propagate the errors from llvm-mca library classes (or what will become library classes) up to the driver. This patch also introduces an enum to make clearer the intention of the return value for Stage::execute.
This supports PR38101.
Reviewers: andreadb, courbet, RKSimon
Reviewed By: andreadb
Subscribers: llvm-commits, tschuett, gbedwell
Differential Revision: https://reviews.llvm.org/D50561
llvm-svn: 339594
