Enable use of ExecutionEngine JITEventListeners in RTDyldObjectLinkingLayer.
This allows existing MCJIT clients to more easily migrate to LLJIT / ORCv2.
Example usage in llvm/examples/OrcV2Examples/LLJITWithGDBRegistrationListener.
Differential Revision: https://reviews.llvm.org/D75838
GCC when configured with --enable-gnu-unique (default on glibc>=2.11)
emits STB_GNU_UNIQUE for certain objects which are otherwise emitted as
STT_OBJECT, such as an inline function's static local variable or its
guard variable, and a static data member of a template.
Clang does not implement -fgnu-unique.
Implementing it as a binding is strange and the feature itself is
considered by some as a misfeature.
Reviewed By: grimar, jhenderson
Differential Revision: https://reviews.llvm.org/D75797
In order for dsymutil to collect .apinotes files (which capture
attributes such as nullability, Swift import names, and availability),
I want to propose adding an apinotes: field to DIModule that gets
translated into a DW_AT_LLVM_apinotes (path) nested inside
DW_TAG_module. This will be primarily used by LLDB to indirectly
extract the Swift names of Clang declarations that were deserialized
from DWARF.
<rdar://problem/59514626>
Differential Revision: https://reviews.llvm.org/D75585
This is part of PR44213 https://bugs.llvm.org/show_bug.cgi?id=44213
When importing (system) Clang modules, LLDB needs to know which SDK
(e.g., MacOSX, iPhoneSimulator, ...) they came from. While the sysroot
attribute contains the absolute path to the SDK, this doesn't work
well when the debugger is run on a different machine than the
compiler, and the SDKs are installed in different directories. It thus
makes sense to just store the name of the SDK instead of the absolute
path, so it can be found relative to LLDB.
rdar://problem/51645582
Differential Revision: https://reviews.llvm.org/D75646
According to the Twine.h comment, the Twines should only
be used as const references in arguments.
Differential Revision: https://reviews.llvm.org/D75727
Summary:
Bugzilla: https://bugs.llvm.org/show_bug.cgi?id=39701
This patch is to convert certain characters to their XML escape sequences when generating labels for a DOT graph.
I had trouble reproducing the exact issue described on the tracker. I ran `llvm-xray graph` on a log from a test program that included function templates but wasn't able to get the `dot` tool to complain about the `<` and `>` characters. The documentation also suggests that the escape sequences should only be necessary when using HTML string labels which XRay doesn't use (`label=<...>` as opposed to `label="..."`). Perhaps newer versions of Graphviz silently handle this in the case of quoted-string labels.
In any case, the generated labels still look correct after this patch and should also fix the reporter's issue.
I was a bit unsure how to add a test for this since the existing tests seem to only care about `func-id` rather than giving an actual name. If you could give me a hint on the best way to go about this, that'd be much appreciated!
Reviewers: dberris
Reviewed By: dberris
Subscribers: lebedev.ri, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69461
Summary: The wrong variable was being checked for an error, which mean a llvm::Error went unchecked and crashes dsymutil. Discovered this when trying to feed an ELF file to "dsymutil --update" and running into the crash.
Reviewers: aprantl, JDevlieghere
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75777
With the addition of the LLD time tracing it made sense to include coverage
for LLVM's various passes. Doing so ensures that ThinLTO is also covered
with a time trace.
Before:
{F11333974}
After:
{F11333928}
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D74516
The new behavior matches GNU objdump. A pair of angle brackets makes tests slightly easier.
`.foo:` is not unique and thus cannot be used in a `CHECK-LABEL:` directive.
Without `-LABEL`, the CHECK line can match the `Disassembly of section`
line and causes the next `CHECK-NEXT:` to fail.
```
Disassembly of section .foo:
0000000000001634 .foo:
```
Bdragon: <> has metalinguistic connotation. it just "feels right"
Reviewed By: rupprecht
Differential Revision: https://reviews.llvm.org/D75713
* Delete boilerplate
* Change functions to return `Error`
* Test parsing errors
* Update callers of ARMAttributeParser::parse() to check the `Error` return value.
Since this patch touches nearly everything in the file, I apply
http://llvm.org/docs/Proposals/VariableNames.html and change variable
names to lower case.
Reviewed By: compnerd
Differential Revision: https://reviews.llvm.org/D75015
This fixes several issues. The behavior changes are:
A SHN_COMMON symbol does not have the 'g' flag.
An undefined symbol does not have 'g' or 'l' flag.
A STB_GLOBAL SymbolRef::ST_Unknown symbol has the 'g' flag.
A STB_LOCAL SymbolRef::ST_Unknown symbol has the 'l' flag.
Reviewed By: rupprecht
Differential Revision: https://reviews.llvm.org/D75659
This changes the output of `llvm-readelf -n` from:
```
Displaying notes found at file offset 0x<...> with length 0x<...>:
```
to:
```
Displaying notes found in: .note.foo
```
And similarly, adds a `Name:` field to the `llvm-readobj -n` output for notes.
This change not only increases GNU compatibility, it also makes it much easier to read notes. Note that we still fall back to printing the file offset/length in cases where we don't have a section name, such as when printing notes in program headers or printing notes in a partially stripped file (GNU readelf does the same).
Fixes llvm.org/PR41339.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D75647
YAML files were not being run during lit testing as there was no lit.local.cfg file. Once this was fixed, some buildbots would fail due to a StringRef that pointed to a std::string inside of a temporary llvm::Triple object. These issues are fixed here by making a local triple object that stays around long enough so the StringRef points to valid data. Fixed memory sanitizer bot bugs as well.
Differential Revision: https://reviews.llvm.org/D75390
Summary:
getInitialLength is a *DWARF*DataExtractor method so I had to "upgrade"
some DataExtractors to be able to make use of it.
Reviewers: ikudrin, jhenderson, probinson
Subscribers: aprantl, hiraditya, llvm-commits, dblaikie
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75535
This option can be used to for JITLink to link as-if the target memory slab were
allocated at a specific start address. This can be used to both verify that
cross-address space linking is working correctly, and to ensure that certain
address-sensitive optimizations (e.g. GOT and stub elimination) either do or do
not fire, depending on the requirements of the test case.
This argument is only valid for testing in conjunction with -noexec -slab-alloc,
and will produce an error if used without those arguments.
Summary: This patch renames the "llvm-gsym" tool directory to "llvm-gsymutil". Dependencies are also reduced to the bare minimum for llvm-gsymutil.
Reviewers: aprantl, thakis
Subscribers: mgorny, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75291
Response files where not being correctly read on Windows, this change
fixes the issue and adds some tests.
Differential Revision: https://reviews.llvm.org/D69665
Sometimes we need to dump an object and build it again from a YAML
description produced. The problem is that obj2yaml does not dump some
of sections, like string tables and symbol tables.
Because of that yaml2obj implicitly creates them and sections created
are not placed at their original locations. They are added to the end of a section list.
That makes a preparing test cases task harder than it can be.
This patch teaches obj2yaml to dump parts of allocatable SHT_STRTAB, SHT_SYMTAB
and SHT_DYNSYM sections to print placeholders for them.
This also allows to preserve usefull parameters, like virtual address.
Differential revision: https://reviews.llvm.org/D74955
YAML files were not being run during lit testing as there was no lit.local.cfg file. Once this was fixed, some buildbots would fail due to a StringRef that pointed to a std::string inside of a temporary llvm::Triple object. These issues are fixed here by making a local triple object that stays around long enough so the StringRef points to valid data. Also fixed an issue where strings for files in the file table could be added in opposite order due to parameters to function calls not having a strong ordering, which caused tests to fail. Added new arch specfic directories so when targets are not enabled, we continue to function just fine.
Differential Revision: https://reviews.llvm.org/D75390
YAML files were not being run during lit testing as there was no lit.local.cfg file. Once this was fixed, some buildbots would fail due to a StringRef that pointed to a std::string inside of a temporary llvm::Triple object. These issues are fixed here by making a local triple object that stays around long enough so the StringRef points to valid data. Also fixed an issue where strings for files in the file table could be added in opposite order due to parameters to function calls not having a strong ordering, which caused tests to fail.
Differential Revision: https://reviews.llvm.org/D75390
Lots of headers pass around MemoryBuffer objects, but very few open
them. Let those that do include FileSystem.h.
Saves ~250 includes of Chrono.h & FileSystem.h:
$ diff -u thedeps-before.txt thedeps-after.txt | grep '^[-+] ' | sort | uniq -c | sort -nr
254 - ../llvm/include/llvm/Support/FileSystem.h
253 - ../llvm/include/llvm/Support/Chrono.h
237 - ../llvm/include/llvm/Support/NativeFormatting.h
237 - ../llvm/include/llvm/Support/FormatProviders.h
192 - ../llvm/include/llvm/ADT/StringSwitch.h
190 - ../llvm/include/llvm/Support/FormatVariadicDetails.h
...
This requires duplicating the file_t typedef, which is unfortunate. I
sunk the choice of mapping mode down into the cpp file using variable
template specializations instead of class members in headers.
Summary: YAML files were not being run during lit testing as there was no lit.local.cfg file. Once this was fixed, some buildbots would fail due to a StringRef that pointed to a std::string inside of a temporary llvm::Triple object. These issues are fixed here by making a local triple object that stays around long enough so the StringRef points to valid data.
Reviewers: aprantl, thakis, MaskRay, aadsm, wallace
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75390
Tools working with object files on Darwin (e.g. lipo) may need to know
properties like the CPU type and subtype of a bitcode file. The logic of
converting a triple to a Mach-O CPU_(SUB_)TYPE should be provided by
LLVM instead of relying on tools to re-implement it.
Differential Revision: https://reviews.llvm.org/D75067
Summary:
DWARFContext has all the required information to access source debug info.
It is not necessary to use "const object::ObjectFile" to create DWARFContext.
Thus this patch removes all usages of "const object::ObjectFile"
from DWARFLinker. Instead, already created DWARFContext is passed
to DWARFLinker. The purpose is to not depend on "const object::ObjectFile".
The patch looks big, but most of changes are renamings and movements.
Testing: it passes "check-all" lit testing. MD5 checksum for clang .dSYM bundle
matches for the dsymutil with/without that patch.
Reviewers: JDevlieghere, friss, dblaikie, aprantl
Reviewed By: JDevlieghere
Subscribers: hiraditya, llvm-commits
Tags: #llvm, #debug-info
Differential Revision: https://reviews.llvm.org/D75029
llvm-ar is using CompareStringOrdinal which is available
only starting with Windows Vista (WINVER 0x600).
Fix this by hoising WindowsSupport.h, which sets _WIN32_WINNT
to 0x0601, up to llvm/include/llvm/Support and use it in llvm-ar.
Patch by Cristian Adam!
Differential revision: https://reviews.llvm.org/D74599
Summary:
This patch creates the llvm-gsymutil binary that can convert object files to GSYM using the --convert <path> option. It can also dump and lookup addresses within GSYM files that have been saved to disk.
To dump a file:
llvm-gsymutil /path/to/a.gsym
To perform address lookups, like with atos, on GSYM files:
llvm-gsymutil --address 0x1000 --address 0x1100 /path/to/a.gsym
To convert a mach-o or ELF file, including any DWARF debug info contained within the object files:
llvm-gsymutil --convert /path/to/a.out --out-file /path/to/a.out.gsym
Conversion highlights:
- convert DWARF debug info in mach-o or ELF files to GSYM
- convert symbols in symbol table to GSYM and don't convert symbols that overlap with DWARF debug info
- extract UUID from object files
- extract .text (read + execute) section address ranges and filter out any DWARF or symbols that don't fall in those ranges.
- if .text sections are extracted, and if the last gsym::FunctionInfo object has no size, cap the size to the end of the section the function was contained in
Dumping GSYM files will dump all sections of the GSYM file in textual format.
Reviewers: labath, aadsm, serhiy.redko, jankratochvil, xiaobai, wallace, aprantl, JDevlieghere, jdoerfert
Subscribers: mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74883
Only MCAsmStreamer (assembly output) needs to keep names of temporary labels created by
MCContext::createTempSymbol().
This change made the rL236642 optimization available for cc2as and
probably some other users.
This eliminates a behavior difference between llvm-mc -filetype=obj and cc1as, which caused
https://reviews.llvm.org/D74006#1890487
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D75097
The GenericLLVMIRPlatformSupport class runs a transform on all LLVM IR added to
the LLJIT instance to replace instances of llvm.global_ctors with a specially
named function that runs the corresponing static initializers (See
(GlobalCtorDtorScraper from lib/ExecutionEngine/Orc/LLJIT.cpp). This patch
updates the GenericIRPlatform class to check for this specially named function
in other materialization units that are added to the JIT and, if found, add
the function to the initializer work queue. Doing this allows object files
that were compiled from IR and cached to be reloaded in subsequent JIT sessions
without their initializers being skipped.
To enable testing this patch also updates the lli tool's -jit-kind=orc-lazy mode
to respect the -enable-cache-manager and -object-cache-dir options, and modifies
the CompileOnDemandLayer to rename extracted submodules to include a hash of the
names of their symbol definitions. This allows a simple object caching scheme
based on module names (which was already implemented in lli) to work with the
lazy JIT.
I've noticed that it is not convenient to create YAMLs from
binaries (using obj2yaml) that have to be test cases for obj2yaml
later (after applying yaml2obj).
The problem, for example is that obj2yaml emits "DynamicSymbols:"
key instead of .dynsym. It also does not create .dynstr.
And when a YAML document without explicitly defined .dynsym/.dynstr
is given to yaml2obj, we have issues:
1) These sections are placed after non-allocatable sections (I've fixed it in D74756).
2) They have VA == 0. User needs create descriptions for such sections explicitly manually
to set a VA.
This patch addresses (2). I suggest to let yaml2obj assign virtual addresses by itself.
It makes an output binary to be much closer to "normal" ELF.
(It is still possible to use "Address: 0x0" for a section to get the original behavior
if it is needed)
Differential revision: https://reviews.llvm.org/D74764
Summary:
GNU objdump prints the method name in disassembly output, and upon further investigation this seems to come from debug info, not the symbol table.
Some additional refactoring is necessary to make this work even when the line number is 0/the filename is unknown. The added test case includes a note for this scenario.
See http://llvm.org/PR41341 for more info.
Reviewers: dblaikie, MaskRay, jhenderson
Reviewed By: MaskRay
Subscribers: ormris, jvesely, aprantl, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74507
In this diff we change the storage of a section to unique_ptr.
This refactoring was factored out from D71647.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D74946
isPrefix was added to support the patches to align branches.
it relies on a switch over instruction names.
This moves those opcodes to a new format so the information is
tablegen and we can just check for a specific value in some bits
in TSFlags instead.
I've left the other function in place for now so that the
existing patches in phabricator will still work. I'll work with
the owner to get them migrated.
The changes the in-memory representation of wasm symbols such that their
optional ImportName and ImportModule use llvm::Optional.
ImportName is set whenever WASM_SYMBOL_EXPLICIT_NAME flag is set.
ImportModule (for imports) is currently always set since it defaults to
"env".
In the future we can possibly extent to binary format distingish
import which have explit module names.
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74109
Initializers and deinitializers are used to implement C++ static constructors
and destructors, runtime registration for some languages (e.g. with the
Objective-C runtime for Objective-C/C++ code) and other tasks that would
typically be performed when a shared-object/dylib is loaded or unloaded by a
statically compiled program.
MCJIT and ORC have historically provided limited support for discovering and
running initializers/deinitializers by scanning the llvm.global_ctors and
llvm.global_dtors variables and recording the functions to be run. This approach
suffers from several drawbacks: (1) It only works for IR inputs, not for object
files (including cached JIT'd objects). (2) It only works for initializers
described by llvm.global_ctors and llvm.global_dtors, however not all
initializers are described in this way (Objective-C, for example, describes
initializers via specially named metadata sections). (3) To make the
initializer/deinitializer functions described by llvm.global_ctors and
llvm.global_dtors searchable they must be promoted to extern linkage, polluting
the JIT symbol table (extra care must be taken to ensure this promotion does
not result in symbol name clashes).
This patch introduces several interdependent changes to ORCv2 to support the
construction of new initialization schemes, and includes an implementation of a
backwards-compatible llvm.global_ctor/llvm.global_dtor scanning scheme, and a
MachO specific scheme that handles Objective-C runtime registration (if the
Objective-C runtime is available) enabling execution of LLVM IR compiled from
Objective-C and Swift.
The major changes included in this patch are:
(1) The MaterializationUnit and MaterializationResponsibility classes are
extended to describe an optional "initializer" symbol for the module (see the
getInitializerSymbol method on each class). The presence or absence of this
symbol indicates whether the module contains any initializers or
deinitializers. The initializer symbol otherwise behaves like any other:
searching for it triggers materialization.
(2) A new Platform interface is introduced in llvm/ExecutionEngine/Orc/Core.h
which provides the following callback interface:
- Error setupJITDylib(JITDylib &JD): Can be used to install standard symbols
in JITDylibs upon creation. E.g. __dso_handle.
- Error notifyAdding(JITDylib &JD, const MaterializationUnit &MU): Generally
used to record initializer symbols.
- Error notifyRemoving(JITDylib &JD, VModuleKey K): Used to notify a platform
that a module is being removed.
Platform implementations can use these callbacks to track outstanding
initializers and implement a platform-specific approach for executing them. For
example, the MachOPlatform installs a plugin in the JIT linker to scan for both
__mod_inits sections (for C++ static constructors) and ObjC metadata sections.
If discovered, these are processed in the usual platform order: Objective-C
registration is carried out first, then static initializers are executed,
ensuring that calls to Objective-C from static initializers will be safe.
This patch updates LLJIT to use the new scheme for initialization. Two
LLJIT::PlatformSupport classes are implemented: A GenericIR platform and a MachO
platform. The GenericIR platform implements a modified version of the previous
llvm.global-ctor scraping scheme to provide support for Windows and
Linux. LLJIT's MachO platform uses the MachOPlatform class to provide MachO
specific initialization as described above.
Reviewers: sgraenitz, dblaikie
Subscribers: mgorny, hiraditya, mgrang, ributzka, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74300
Summary: Commit 63bb9fee52 was reverted in
7603bfb4b0 because it broke builds that treat
warnings as errors.
This commit updates the calls to `assembleToStream()` in tests to check that
the return value is valid.
Original commit message:
Followup to D74084.
Replace the use of `report_fatal_error()` with returning the error to
`llvm-exegesis.cpp` and handling it there.
Differential Revision: https://reviews.llvm.org/D74325
Summary:
Depends on https://reviews.llvm.org/D71901.
The fifth in a series of patches that ports the LLVM coroutines passes
to the new pass manager infrastructure.
The first 4 patches allow users to run coroutine passes by invoking, for
example `opt -passes=coro-early`. However, most of LLVM's tests for
coroutines use an option, `opt -enable-coroutines`, which adds all 4
coroutine passes to the appropriate legacy pass manager extension points.
This patch does the same, but using the new pass manager: when
coroutine features are enabled and the new pass manager is being used,
this adds the new-pass-manager-compliant coroutine passes to the pass
builder's pipeline.
This allows us to run all coroutine tests using the new pass manager
(besides those that use the coroutine retcon ABI used by the Swift
compiler, which is not yet supported in the new pass manager).
Reviewers: GorNishanov, lewissbaker, chandlerc, junparser, wenlei
Subscribers: wenlei, EricWF, Prazek, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71902
Summary:
This patch teaches llvm-dwp to parse DWARFv5 info section header.
Tested this using asm test case caontaining DWARFv5 info.
Assemling it to DWO object, checking corresponding content using llvm-dwarfdump. Then finally, packaging it
to DWP using llvm-dwp and again checking corresponding content using llvm-dwarfdump.
Reviewers: dblaikie, aprantl, probinson.
Reviewed By: dblaikie.
Differential Revision: https://reviews.llvm.org/D74425
Followup to D74085.
Replace the use of `report_fatal_error()` with returning the error to
`llvm-exegesis.cpp` and handling it there.
Differential Revision: https://reviews.llvm.org/D74325
There was a short discussion about this:
https://reviews.llvm.org/D73484#inline-676942
To summarize:
It is a bit unclear to me why the `DT_SYMENT` tag exist.
LLD has the code that does:
"addInt(DT_SYMENT, sizeof(Elf_Sym));" and I guess other linkers has the same logic.
It is unclear why it can be possible to have other values rather than values of
a size of platform symbol. Seems it is not possible, and atm for me it looks that
this tag should not be used. This patch starts reporting the warning when the
value it contains differs from a symbol size for a 32/64 bit platform for safety.
It keeps the rest of the logic we have unchanged. Before this patch we did not handle
the tag at all.
Differential review: https://reviews.llvm.org/D74479
Summary:
Many directives are unavailable, and support for others may be limited.
This first draft has preliminary support for:
- conditional directives (including errors),
- data allocation (unsigned types up to 8 bytes, and ALIGN),
- equates/variables (numeric and text),
- and procedure directives (without parameters),
as well as COMMENT, ECHO, INCLUDE, INCLUDELIB, PUBLIC, and EXTERN. Text variables (aka text macros) are expanded in-place wherever the identifier occurs.
We deliberately ignore all ml.exe processor directives.
Prominent features not yet supported:
- structs
- macros (both procedures and functions)
- procedures (with specified parameters)
- substitution & expansion operators
Conditional directives are complicated by the fact that "ifdef rax" is a valid way to check if a file is being assembled for a 64-bit x86 processor; we add support for "ifdef <register>" in general, which requires adding a tryParseRegister method to all MCTargetAsmParsers. (Some targets require backtracking in the non-register case.)
Reviewers: rnk, thakis
Reviewed By: thakis
Subscribers: kerbowa, merge_guards_bot, wuzish, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, mgorny, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Jim, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72680
The current code has following issues:
1) It has a duplicated logic part.
2) This logic relies on unwrapOrError calls, but if we want to convert
them to warnings, we will need to change all of them what is hard to do
because of the duplication.
In this patch I've created a new method that returns Expected<> what allows
now to catch all errors in a single place and remove the code duplication.
Note: this change is itself a refactor NFC. It does not change the current logic
anyhow. It prepares the code for the follow-up(s).
Differential revision: https://reviews.llvm.org/D74545
I was reported that with commit:
https://github.com/llvm/llvm-project/commit/d3963051c490
gcc-9.2 is giving the warning below.
This should help (I have no gcc 9.2 to test).
[ 57%] Building CXX object tools/obj2yaml/CMakeFiles/obj2yaml.dir/elf2yaml.cpp.o
/llvm/tools/obj2yaml/elf2yaml.cpp: In instantiation of ‘llvm::Expected<llvm::ELFYAML::Object*>
{anonymous}::ELFDumper<ELFT>::dump() [with ELFT = llvm::object::ELFType<llvm::support::little, false>]’:
/llvm/tools/obj2yaml/elf2yaml.cpp:1218:31: required from ‘llvm::Error elf2yaml(llvm::raw_ostream&,
const llvm::object::ELFFile<ELFT>&) [with ELFT = llvm::object::ELFType<llvm::support::little, false>]’
/llvm/tools/obj2yaml/elf2yaml.cpp:1231:47: required from here
/llvm/tools/obj2yaml/elf2yaml.cpp:207:41: warning: comparison of integer expressions of different
signedness: ‘llvm::support::detail::packed_endian_specific_integral<unsigned int, llvm::support::little, 1>::value_type’ {aka ‘unsigned int’} and ‘int’ [-Wsign-compare]
207 | if (!SymTab || SymTabShndx->sh_link != SymTab - Sections.begin())
/llvm/tools/obj2yaml/elf2yaml.cpp: In instantiation of ‘llvm::Expected<llvm::ELFYAML::Object*>
{anonymous}::ELFDumper<ELFT>::dump() [with ELFT = llvm::object::ELFType<llvm::support::big, false>]’:
...
Passing '-dlopen <library-path>' to lli will cause the specified library to be
loaded (via llvm::sys::DynamicLibrary::LoadLibraryPermanently) before JIT'd code
is executed, making the library's symbols accessible to JIT'd code.
This avoids questionable code such as taking address of current
range-based for variable and comparing it with vector begin iterator.
While this may not be a problem in itself, it can be written more consice.
This was initially suggested by @aaronpuchert.
It seems like gcc 5.5 wants to iterate over the new variable instead
of the container that lives outside the loop. But of course this
new container is empty.
Plus using a different variable names makes the code more readable.
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
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
function_ref is non-owning, so if we get it as a parameter in constructor,
our reference goes out-of-scope as soon as constructor returns.
Instead, let's just take it as a parameter to the actual `generate()` call
Summary:
Currently, we only have nice exploration for LEA instruction,
while for the rest, we rely on `randomizeUnsetVariables()`
to sometimes generate something interesting.
While that works, it isn't very reliable in coverage :)
Here, i'm making an assumption that while we may want to explore
multi-instruction configs, we are most interested in the
characteristics of the main instruction we were asked about.
Which we can do, by taking the existing `randomizeMCOperand()`,
and turning it on it's head - instead of relying on it to randomly fill
one of the interesting values, let's pregenerate all the possible interesting
values for the variable, and then generate as much `InstructionTemplate`
combinations of these possible values for variables as needed/possible.
Of course, that requires invasive changes to no longer pass just the
naked `Instruction`, but sometimes partially filled `InstructionTemplate`.
As it can be seen from the test, this allows us to explore
`X86::OperandType::OPERAND_COND_CODE` for instructions
that take such an operand.
I'm hoping this will greatly simplify exploration.
Reviewers: courbet, gchatelet
Reviewed By: gchatelet
Subscribers: orodley, mgorny, sdardis, tschuett, jrtc27, atanasyan, mstojanovic, andreadb, RKSimon, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74156
Summary:
GNU objdump prints the file format in lowercase, e.g. `elf64-x86-64`. llvm-objdump prints `ELF64-x86-64` right now, even though piping that into llvm-objcopy refuses that as a valid arch to use.
As an example of a problem this causes, see: https://github.com/ClangBuiltLinux/linux/issues/779
Reviewers: MaskRay, jhenderson, alexshap
Reviewed By: MaskRay
Subscribers: tpimh, sbc100, grimar, jvesely, nhaehnle, kerbowa, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D74433
Summary:
Simplifies the C++11-style "-> decltype(...)" return-type deduction.
Note that you have to be careful about whether the function return type
is `auto` or `decltype(auto)`. The difference is that bare `auto`
strips const and reference, just like lambda return type deduction. In
some cases that's what we want (or more likely, we know that the return
type is a value type), but whenever we're wrapping a templated function
which might return a reference, we need to be sure that the return type
is decltype(auto).
No functional change.
Subscribers: dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74383
Rui Ueyama