Make extended binary the default output format for CSSPGO. This avoids having to pass flag every time when generating profile. It also matches llvm-profdata where binary profile is the default (should we switch to extbinary as default for llvm-profdata?).
We plan to compress name table for context profile, which depends on the built-in compression of extbinary.
Differential Revision: https://reviews.llvm.org/D103650
This patch introduces a new tool, llvm-tapi-diff, that compares and returns the diff of two TBD files.
Reviewed By: ributzka, JDevlieghere
Differential Revision: https://reviews.llvm.org/D101835
This is a followup to D103422. The DenseMapInfo implementations for
ArrayRef and StringRef are moved into the ArrayRef.h and StringRef.h
headers, which means that these two headers no longer need to be
included by DenseMapInfo.h.
This required adding a few additional includes, as many files were
relying on various things pulled in by ArrayRef.h.
Differential Revision: https://reviews.llvm.org/D103491
This patch updates llvm-dwp to include rnglists and loclists
when parsing debug sections.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D101894
This patch adds support for DWARFv5 type units: parsing from
the .debug_info section, and writing index to the type unit index.
Previously, the type units were part of the .debug_types section
which is no longer used in DWARFv5.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D101818
This patch adds general support for DWARFv5 index writing.
In particular, this means only allowing inputs with one version,
either DWARFv5 or DWARFv4.
This patch adds the .debug_macro section as an example,
but the DWARFv5 type support and loc and rangelists are still
missing (and upcoming).
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D102315
This patch makes llvm-dwp skip debug info sections that may not be encoding a compile unit.
In DWARF5, debug info sections are also used for type units. As in preparation to support type units,
make llvm-dwp aware of other uses of debug info sections but skip them for now.
The patch first records all .debug_info sections, then goes through them one by one and records
the cu debug info section for writing the index unit, and copies that section to the final dwp output
info section. If it's not a compile unit, skip.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D102312
This patch uses the `getSymbolIndexForFunctionAddress` helper function to print function names for BB address map entries.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D102900
This change adds tests specifically for --parent-recurse-depth, --quiet
and -o. The test for -o found a typo in an error message which is also
fixed in this change.
Differential Revision: https://reviews.llvm.org/D103250
This is based on the assumption that most simulated instructions don't define
more than one or two registers. This is true for example on x86, where
most instruction definitions don't declare more than one register write.
The default code region size has been increased from 8 to 16. This is based on
the assumption that, for small microbenchmarks, the typical code snippet size is
often less than 16 instructions.
mca::Instruction now uses bitfields to pack flags.
No functional change intended.
During reviewing D102277 it was decided to remove lazy options processing
from llvm-objcopy CopyConfig structure. This patch transforms processing of ELF
lazy options into the in-place processing.
Differential Revision: https://reviews.llvm.org/D103260
Moved the logic that checks for RAW hazards from the InOrderIssueStage to the
RegisterFile.
Changed how the InOrderIssueStage keeps track of backend stalls. Stall events
are now generated from method notifyStallEvent().
No functional change intended.
Summary: Under the option --section-headers, we can only
print the section types of TEXT, DATA, and BSS for now.
This patch adds the DEBUG type.
Reviewed By: jhenderson, Higuoxing
Differential Revision: https://reviews.llvm.org/D102603
Currently, each function name lookup is a linear iteration over all symbols defined in the object file which makes the total running time quadratic.
This patch optimizes the function name lookup by populating an **address to index** map upon the first function name lookup which is used to lookup each function name in O(1).
**impact**: For the clang binary built with `-fstack-size-section`, this improves the running time of `llvm-readobj --stack-size` from 7 minutes to 0.25 seconds.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D103072
In objdump, many targets support `-M no-aliases`. Instead of having a
`-*-no-aliases` for each target when LLVM adds the support, it makes more sense
to introduce objdump style `-M`.
-riscv-arch-reg-names is removed. -riscv-no-aliases has too many uses and thus is retained for now.
Reviewed By: luismarques
Differential Revision: https://reviews.llvm.org/D103004
Summary: This is a NFC patch to change the input parameter of the method SectionRef::isDebugSection(), by replacing the StringRef SectionName with DataRefImpl Sec. This allows us to determine if a section is debug type in more ways than just by section name.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D102601
llvm-profgen uses profile summary based cold threshold to merge and trim cold context profile. This is to strike a good balance between profile size and performance.
We've been using 99.9% as the cutoff to save profile size without affecting performance. This change switch to use 99.9% instead of 99.9999% as default cold threshold cutoff for llvm-profgen.
Redundant switch csprof-cold-thres is also removed and tests cleaned up.
Differential Revision: https://reviews.llvm.org/D103071
The parseInputFile function returns an empty unique_ptr to signal an
error, like when the input file doesn't exist, or is malformed. In this
case, the tool should exit immediately rather than segfault by
dereferencing the unique_ptr later.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D102891
I really needed this, like, factually, yesterday,
when verifying dependency breaking idioms for AMD Zen 3 scheduler model.
Consider the following example:
```
$ ./bin/llvm-exegesis --mode=inverse_throughput --snippets-file=/tmp/snippet.s --num-repetitions=1000000 --repetition-mode=duplicate
Check generated assembly with: /usr/bin/objdump -d /tmp/snippet-4a7e50.o
---
mode: inverse_throughput
key:
instructions:
- 'VPXORYrr YMM0 YMM0 YMM0'
config: ''
register_initial_values: []
cpu_name: znver3
llvm_triple: x86_64-unknown-linux-gnu
num_repetitions: 1000000
measurements:
- { key: inverse_throughput, value: 0.31025, per_snippet_value: 0.31025 }
error: ''
info: ''
assembled_snippet: C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C5FDEFC0C3
...
```
What does it tell us?
So wait, it can only execute ~3 x86 AVX YMM PXOR zero-idioms per cycle?
That doesn't seem right. That's even less than there are pipes supporting this type of op.
Now, second example:
```
$ ./bin/llvm-exegesis --mode=inverse_throughput --snippets-file=/tmp/snippet.s --num-repetitions=1000000 --repetition-mode=loop
Check generated assembly with: /usr/bin/objdump -d /tmp/snippet-2418b5.o
---
mode: inverse_throughput
key:
instructions:
- 'VPXORYrr YMM0 YMM0 YMM0'
config: ''
register_initial_values: []
cpu_name: znver3
llvm_triple: x86_64-unknown-linux-gnu
num_repetitions: 1000000
measurements:
- { key: inverse_throughput, value: 1.00011, per_snippet_value: 1.00011 }
error: ''
info: ''
assembled_snippet: 49B80800000000000000C5FDEFC0C5FDEFC04983C0FF75F2C3
...
```
Now that's just worse. Due to the looping, the throughput completely plummeted,
and now we can only do a single instruction/cycle!?
That's not great.
And final example:
```
$ ./bin/llvm-exegesis --mode=inverse_throughput --snippets-file=/tmp/snippet.s --num-repetitions=1000000 --repetition-mode=loop --loop-body-size=1000
Check generated assembly with: /usr/bin/objdump -d /tmp/snippet-c402e2.o
---
mode: inverse_throughput
key:
instructions:
- 'VPXORYrr YMM0 YMM0 YMM0'
config: ''
register_initial_values: []
cpu_name: znver3
llvm_triple: x86_64-unknown-linux-gnu
num_repetitions: 1000000
measurements:
- { key: inverse_throughput, value: 0.167087, per_snippet_value: 0.167087 }
error: ''
info: ''
assembled_snippet: 49B80800000000000000C5FDEFC0C5FDEFC04983C0FF75F2C3
...
```
So if we merge the previous two approaches, do duplicate this single-instruction snippet 1000x
(loop-body-size/instruction count in snippet), and run a loop with 1000 iterations
over that duplicated/unrolled snippet, the measured throughput goes through the roof,
up to 5.9 instructions/cycle, which finally tells us that this idiom is zero-cycle!
Reviewed By: courbet
Differential Revision: https://reviews.llvm.org/D102522
The Mach-O object file format is limited to 4GB because its used of
32-bit offsets in the header. It is possible for dsymutil to (silently)
emit an invalid binary. Instead of having consumers deal with this, emit
an error instead.
Fixing an issue where samples collected for an untrackable frame is not reported. An untrackable frame refers to a frame whose caller is untrackable due to missing debug info or pseudo probe. Though the frame is connected to its parent frame through the frame pointer chain at runtime, the compiler cannot build the connection without debug info or pseudo probe. In such case we just need to report the untrackable frame as the base frame and all of its child frames.
With more samples reported I'm seeing this improves the performance of an internal benchmark by 2.5%.
Reviewed By: wenlei, wlei
Differential Revision: https://reviews.llvm.org/D102961
This makes it possible for targets to define their own MCObjectFileInfo.
This MCObjectFileInfo is then used to determine things like section alignment.
This is a follow up to D101462 and prepares for the RISCV backend defining the
text section alignment depending on the enabled extensions.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D101921
This will allow to use llvm-strip with file names that begin with dashes.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D102825
This patch prepares llvm-objcopy to move its implementation
into a separate library. To make it possible it is necessary
to minimize internal dependencies.
Differential Revision: https://reviews.llvm.org/D99055
In order to create the code regions for llvm-mca to analyze, llvm-mca creates an
AsmCodeRegionGenerator and calls AsmCodeRegionGenerator::parseCodeRegions().
Within this function, both an MCAsmParser and MCTargetAsmParser are created so
that MCAsmParser::Run() can be used to create the code regions for us.
These parser classes were created for llvm-mc so they are designed to emit code
with an MCStreamer and MCTargetStreamer that are expected to be setup and passed
into the MCAsmParser constructor. Because llvm-mca doesn’t want to emit any
code, an MCStreamerWrapper class gets created instead and passed into the
MCAsmParser constructor. This wrapper inherits from MCStreamer and overrides
many of the emit methods to just do nothing. The exception is the
emitInstruction() method which calls Regions.addInstruction(Inst).
This works well and allows llvm-mca to utilize llvm-mc’s MCAsmParser to build
our code regions, however there are a few directives which rely on the
MCTargetStreamer. llvm-mc assumes that the MCStreamer that gets passed into the
MCAsmParser’s constructor has a valid pointer to an MCTargetStreamer. Because
llvm-mca doesn’t setup an MCTargetStreamer, when the parser encounters one of
those directives, a segfault will occur.
In x86, each one of these 7 directives will cause this segfault if they exist in
the input assembly to llvm-mca:
.cv_fpo_proc
.cv_fpo_setframe
.cv_fpo_pushreg
.cv_fpo_stackalloc
.cv_fpo_stackalign
.cv_fpo_endprologue
.cv_fpo_endproc
I haven’t looked at other targets, but I wouldn’t be surprised if some of the
other ones also have certain directives which could result in this same
segfault.
My proposed solution is to simply initialize an MCTargetStreamer after we
initialize the MCStreamerWrapper. The MCTargetStreamer requires an ostream
object, but we don’t actually want any of these directives to be emitted
anywhere, so I use an ostream created with the nulls() function. Since this
needs to happen after the MCStreamerWrapper has been initialized, it needs to
happen within the AsmCodeRegionGenerator::parseCodeRegions() function. The
MCTargetStreamer also needs an MCInstPrinter which is easiest to initialize
within the main() function of llvm-mca. So this MCInstPrinter gets constructed
within main() then passed into the parseCodeRegions() function as a parameter.
(If you feel like it would be appropriate and possible to create the
MCInstPrinter within the parseCodeRegions() function, then feel free to modify
my solution. That would stop us from having to pass it into the function and
would limit its scope / lifetime.)
My solution stops the segfault from happening and still passes all of the
current (expected) llvm-mca tests. I also added a new test for x86 that checks
for this segfault on an input that includes one of the .cv_fpo directives (this
test fails without my solution, but passes with it).
As far as I can tell, all of the functions that I modified are only called from
within llvm-mca so there shouldn’t be any worries about breaking other tools.
Differential Revision: https://reviews.llvm.org/D102709
lld/MachO/Driver.cpp and lld/MachO/SyntheticSections.cpp include
llvm/Config/config.h which doesn't exist when building standalone lld.
This patch replaces llvm/Config/config.h include with llvm/Config/llvm-config.h
just like it is in lld/ELF/Driver.cpp and HAVE_LIBXAR with LLVM_HAVE_LIXAR and
moves LLVM_HAVE_LIBXAR from config.h to llvm-config.h
Also it adds LLVM_HAVE_LIBXAR to LLVMConfig.cmake and links liblldMachO2.so
with XAR_LIB if LLVM_HAVE_LIBXAR is set.
Differential Revision: https://reviews.llvm.org/D102084
This will allow to use llvm-objcopy with file names that begin with dashes.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D102665
To bring D99599's implementation in line with the existing
PrintPassInstrumentation, and to fix a FIXME, add more customizability
to PrintPassInstrumentation.
Introduce three new options. The first takes over the existing
"-debug-pass-manager-verbose" cl::opt.
The second and third option are specific to -fdebug-pass-structure. They
allow indentation, and also don't print analysis queries.
To avoid more golden file tests than necessary, prune down the
-fdebug-pass-structure tests.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D102196
The system's network API is in libnetwork.so, so we explicitly need to link to
them on Haiku. This patch is similar to https://reviews.llvm.org/D97633.
Patch by Niels Reedijk. Thanks Niels!
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D98405
llvm-dev message: https://lists.llvm.org/pipermail/llvm-dev/2021-May/150465.html
In an ELF shared object, a default visibility defined symbol is preemptible by
default. This creates some missed optimization opportunities.
-Bsymbolic-functions is more aggressive than our current -fvisibility-inlines-hidden
(present since 2012) as it applies to all function definitions. It can
* avoid PLT for cross-TU function calls && reduce dynamic symbol lookup
* reduce dynamic symbol lookup for taking function addresses and optimize out GOT/TOC on x86-64/ppc64
In a -DLLVM_TARGETS_TO_BUILD=X86 build, the number of JUMP_SLOT decreases from 12716 to 1628, and the number of GLOB_DAT decreases from 1918 to 1313
The built clang with `-DLLVM_LINK_LLVM_DYLIB=on -DCLANG_LINK_CLANG_DYLIB=on` is significantly faster.
See the Linux kernel build result https://bugs.archlinux.org/task/70697
Note: the performance of -fno-semantic-interposition -Bsymbolic-functions
libLLVM.so and libclang-cpp.so is close to a PIE binary linking against
`libLLVM*.a` and `libclang*.a`. When the host compiler is Clang,
-Bsymbolic-functions is the major contributor. On x86-64 (with GOTPCRELX) and
ppc64 ELFv2, the GOT/TOC relocations can be optimized.
Some implication:
Interposing a subset of functions is no longer supported.
(This is fragile on ELF and unsupported on Mach-O at all. For Mach-O we don't
use `ld -interpose` or `-flat_namespace`)
Compiling a program which takes the address of any LLVM function with
`{gcc,clang} -fno-pic` and expects the address to equal to the address taken
from libLLVM.so or libclang-cpp.so is unsupported. I am fairly confident that
llvm-project shouldn't have different behaviors depending on such pointer
equality (as we've been using -fvisibility-inlines-hidden which applies to
inline functions for a long time), but if we accidentally do, users should be
aware that they should not make assumption on pointer equality in `-fno-pic`
mode.
See more on https://maskray.me/blog/2021-05-09-fno-semantic-interposition
Reviewed By: phosek
Differential Revision: https://reviews.llvm.org/D102090
llvm-dev message: https://lists.llvm.org/pipermail/llvm-dev/2021-May/150465.html
In an ELF shared object, a default visibility defined symbol is preemptible by default.
This creates some missed optimization opportunities. -fno-semantic-interposition can optimize -fPIC:
* in Clang: avoid GOT/PLT cost for variable access/function calls to external linkage definition in the same TU
* in GCC: enable interprocedural optimizations (including inlining) and avoid PLT
See https://gist.github.com/MaskRay/2d4dfcfc897341163f734afb59f689c6 for more information.
-Bsymbolic-functions is more aggressive than -fvisibility-inlines-hidden (present since 2012) as it applies
to all function definitions. It can
* avoid PLT for cross-TU function calls && reduce dynamic symbol lookup
* reduce dynamic symbol lookup for taking function addresses and optimize out GOT/TOC on x86-64/ppc64
With both options, the libLLVM.so and libclang-cpp.so performance should
be closer to PIE binary linking against `libLLVM*.a` and `libclang*.a`
(In a -DLLVM_TARGETS_TO_BUILD=X86 build, the number of JUMP_SLOT decreases from 12716 to 1628, and the number of GLOB_DAT decreases from 1918 to 1313
The built clang with `-DLLVM_LINK_LLVM_DYLIB=on -DCLANG_LINK_CLANG_DYLIB=on` is significantly faster.
See the Linux kernel build result https://bugs.archlinux.org/task/70697
)
Some implication:
Interposing a subset of functions is no longer supported.
(This is fragile anyway and cannot really be supported. For Mach-O we don't use
`ld -interpose`, so interposition is not supported on Mach-O at all.)
Compiling a program which takes the address of any LLVM function with
`{gcc,clang} -fno-pic` and expects the address to equal to the address taken
from libLLVM.so or libclang-cpp.so is unsupported. I am fairly confident that
llvm-project shouldn't have different behaviors depending on such pointer
equality (as we've been using -fvisibility-inlines-hidden which applies to
inline functions for a long time), but if we accidentally do, users should be
aware that they should not make assumption on pointer equality in `-fno-pic`
mode.
Reviewed By: phosek
Differential Revision: https://reviews.llvm.org/D102090
`__mh_(execute|dylib|dylinker|bundle|preload|object)_header` are special symbols whose values hold the VMA of the Mach header to support introspection. They are attached to the first section in `__TEXT`, even though their addresses are outside `__TEXT`, and they do not refer to code.
It is normally harmless, but when the first section of `__TEXT` has no other symbols, `__mh_*_header` is considered by the disassembler when determing function boundaries. Since `__mh_*_header` refers to an address outside `__TEXT`, the boundary determination fails and disassembly quits.
Since `__TEXT,__text` normally has symbols, this bug is obscured. Experiments placing `__stubs` and `__stub_helper` first exposed the bug, since neither has symbols.
Differential Revision: https://reviews.llvm.org/D101786
The readelf command guide shows the short options used as aliases but
these are not found in the help text unless --show-hidden is used, other
tools show aliases with --help. This change fixes the help output to be
consistent with the command guide.
Differential Revision: https://reviews.llvm.org/D102173
In the help output of other tools and in the symbolizer command guide,
Mach-O specific options are in their own section. This change fixes the
symbolizer help output to be consistent.
Differential Revision: https://reviews.llvm.org/D102178
When making compilation relocatable, for example in distributed
compilation scenarios, we want to set compilation dir to a relative
value like `.` but this presents a problem when generating reports
because if the file path is relative as well, for example `..`, you
may end up writing files outside of the output directory.
This change introduces a flag that allows overriding the compilation
directory that's stored inside the profile with a different value that
is absolute.
Differential Revision: https://reviews.llvm.org/D100232
Originally landed in: 6400905a615282c83a2fc6e49e57ff716aa8b4de
Reverted in: 668dccc396da4f593ac87c92dc0eb7bc983b5762
Fix branch coverage merging in FunctionCoverageSummary::get() for instantiation
groups.
This change corrects the implementation for the branch coverage summary to do
the same thing for branches that is done for lines and regions. That is,
across function instantiations in an instantiation group, the maximum branch
coverage found in any of those instantiations is returned, with the total
number of branches being the same across instantiations.
Differential Revision: https://reviews.llvm.org/D102193
groups.
This change corrects the implementation for the branch coverage
summary to do the same thing for branches that is done for lines and regions.
That is, across function instantiations in an instantiation group, the maximum
branch coverage found in any of those instantiations is returned, with the
total number of branches being the same across instantiations.
Differential Revision: https://reviews.llvm.org/D102193
