Before we always used DW_RLE_startx_length. This is not very efficient and leads
to bigger .debug_addr section. Changed it to use
DW_RLE_base_addressx/DW_RLE_offset_pair.
clang-16 build in debug mode
llvm-bolt ran on it with --update-debug-sections
| section | before | after | diff | % decrease |
| .debug_rnglists | 32732292 | 31986051 | -746241 | 2.3% |
| .debug_addr | 14415808 | 14184128 | -231680 | 1.6% |
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D140439
Use llvm::reverse instead of `for (auto I = rbegin(), E = rend(); I != E; ++I)`
Reviewed By: #bolt, rafauler
Differential Revision: https://reviews.llvm.org/D140516
Linker might relax adrp + ldr got address loading to adrp + add for
local non-preemptible symbols (e.g. hidden/protected symbols in
executable). As usually linker doesn't change relocations properly after
relaxation, so we have to handle such cases by ourselves. To do that
during relocations reading we change LD64 reloc to ADD if instruction
mismatch found and introduce FixRelaxationPass that searches for ADRP+ADD
pairs and after performing some checks we're replacing ADRP target symbol
to already fixed ADDs one.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Differential Revision: https://reviews.llvm.org/D138097
With ThinLTO mutliple CUs can share the same .debug_str_offsets contribution. We
were creating a new one for each CU. This lead to a binary size increase.
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D139214
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
This patch makes code less readable but it will clean itself after all functions are converted.
Differential Revision: https://reviews.llvm.org/D138665
This has the following advantages:
- std::shared_timed_mutex is macOS 10.12+ only. llvm::sys::RWMutex
automatically switches to a different implementation internally
when targeting older macOS versions.
- bolt only needs std::shared_mutex, not std::shared_timed_mutex.
llvm::sys::RWMutex automatically uses std::shared_mutex internally
where available.
std::shared_mutex and RWMutex have the same API, so no code changes
other than types and includes are needed.
Differential Revision: https://reviews.llvm.org/D138423
This patch replaces NoneType() and NoneType::None with None in
preparation for migration from llvm::Optional to std::optional.
In the std::optional world, we are not guranteed to be able to
default-construct std::nullopt_t or peek what's inside it, so neither
NoneType() nor NoneType::None has a corresponding expression in the
std::optional world.
Once we consistently use None, we should even be able to replace the
contents of llvm/include/llvm/ADT/None.h with something like:
using NoneType = std::nullopt_t;
inline constexpr std::nullopt_t None = std::nullopt;
to ease the migration from llvm::Optional to std::optional.
Differential Revision: https://reviews.llvm.org/D138376
This patch adds the huge pages support (-hugify) for PIE/no-PIE
binaries. Also returned functionality to support the kernels < 5.10
where there is a problem in a dynamic loader with the alignment of
pages addresses.
Differential Revision: https://reviews.llvm.org/D129107
Some distribution install libraries under lib64. LLVM supports this
through LLVM_LIBDIR_SUFFIX, have bolt do the same.
Differential Revision: https://reviews.llvm.org/D137039
Always use non-symbolizing disassembler for instruction encoding
validation as symbols will be treated as undefined/zeros be the encoder
and causing byte sequence mismatches.
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D136118
Simplify the logic of handling sections in BOLT. This change brings more
direct and predictable mapping of BinarySection instances to sections in
the input and output files.
* Only sections from the input binary will have a non-null SectionRef.
When a new section is created as a copy of the input section,
its SectionRef is reset to null.
* RewriteInstance::getOutputSectionName() is removed as the section name
in the output file is now defined by BinarySection::getOutputName().
* Querying BinaryContext for sections by name uses their original name.
E.g., getUniqueSectionByName(".rodata") will return the original
section even if the new .rodata section was created.
* Input file sections (with relocations applied) are emitted via MC with
".bolt.org" prefix. However, their name in the output binary is
unchanged unless a new section with the same name is created.
* New sections are emitted internally with ".bolt.new" prefix if there's
a name conflict with an input file section. Their original name is
preserved in the output file.
* Section header string table is properly populated with section names
that are actually used. Previously we used to include discarded
section names as well.
* Fix the problem when dynamic relocations were propagated to a new
section with a name that matched a section in the input binary.
E.g., the new .rodata with jump tables had dynamic relocations from
the original .rodata.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D135494
This adds a round of checks to memory references, looking for
incorrect references to jump table objects. Fix them by replacing the
jump table reference with another object reference + offset.
This solves bugs related to regular data references in code
accidentally being bound to a jump table, and this reference being
updated to a new (incorrect) location because we moved this jump
table.
Fixes#55004
Reviewed By: #bolt, maksfb
Differential Revision: https://reviews.llvm.org/D134098
Put code that creates references to symbol+addend behind MCPlusBuilder.
Will use this later in validate memory references pass.
Reviewed By: #bolt, maksfb, yota9
Differential Revision: https://reviews.llvm.org/D134097
While the order of new sections in the output binary was deterministic
in the past (i.e. there was no run-to-run variation), it wasn't always
rational as we used size to define the precedence of allocatable
sections within "code" or "data" groups (probably unintentionally).
Fix that by defining stricter section-ordering rules.
Other than the order of sections, this should be NFC.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D135235
I went over the output of the following mess of a command:
`(ulimit -m 2000000; ulimit -v 2000000; git ls-files -z | parallel --xargs -0 cat | aspell list --mode=none --ignore-case | grep -E '^[A-Za-z][a-z]*$' | sort | uniq -c | sort -n | grep -vE '.{25}' | aspell pipe -W3 | grep : | cut -d' ' -f2 | less)`
and proceeded to spend a few days looking at it to find probable typos
and fixed a few hundred of them in all of the llvm project (note, the
ones I found are not anywhere near all of them, but it seems like a
good start).
Reviewed By: Amir, maksfb
Differential Revision: https://reviews.llvm.org/D130824
In perf2bolt and `-aggregate-only` BOLT mode, the output profile file is written
in fdata format by default. Provide a knob `-profile-format=[fdata,yaml]` to
control the format.
Note that `-w` option still dumps in YAML format.
Reviewed By: #bolt, maksfb
Differential Revision: https://reviews.llvm.org/D133995
After BOLT's merge to LLVM, there are two (almost identical) versions of the
code layout algorithm. The diff unifies the implementations by keeping the one
in LLVM.
There are mild changes in the resulting block orders. I tested the changes
extensively both on the clang binary and on prod services. Didn't see stat sig
differences on average.
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D129895
I'm planning to deprecate and eventually remove llvm::empty.
Note that no use of llvm::empty requires the ability of llvm::empty to
determine the emptiness from begin/end only.
When we derive EFMM from SectionMemoryManager, it brings into EFMM extra
functionality, such as the registry of exception handling sections,
page permission management, etc. Such functionality is of no use to
llvm-bolt and can even be detrimental (see
https://github.com/llvm/llvm-project/issues/56726).
Change the base class of ExecutableFileMemoryManager to MemoryManager,
avoid registering EH sections, and skip memory finalization.
Fixes#56726
Reviewed By: yota9
Differential Revision: https://reviews.llvm.org/D133994
In non-relocation mode, every function is emitted in its own section. If
a function is empty, RuntimeDyld will still allocate 1-byte section
for the function and initialize it with zero. As a result, we will
overwrite the first byte of the original function contents with zero.
Such scenario can happen when the input function had only NOP
instructions which BOLT removes by default. Even though such functions
likely cause undefined behavior, it's better to preserve their contents.
Reviewed By: yota9
Differential Revision: https://reviews.llvm.org/D133978
For functions with references to internal offsets from data, verify externally
referenced blocks against the set of jump table targets. Mark the function
as non-simple if there are any unclaimed data to code references.
Reviewed By: #bolt, maksfb
Differential Revision: https://reviews.llvm.org/D132495
