Returning `std::array<uint8_t, N>` is better ergonomics for the hashing functions usage, instead of a `StringRef`:
* When returning `StringRef`, client code is "jumping through hoops" to do string manipulations instead of dealing with fixed array of bytes directly, which is more natural
* Returning `std::array<uint8_t, N>` avoids the need for the hasher classes to keep a field just for the purpose of wrapping it and returning it as a `StringRef`
As part of this patch also:
* Introduce `TruncatedBLAKE3` which is useful for using BLAKE3 as the hasher type for `HashBuilder` with non-default hash sizes.
* Make `MD5Result` inherit from `std::array<uint8_t, 16>` which improves & simplifies its API.
Differential Revision: https://reviews.llvm.org/D123100
Add !isTailCall in isUnconditionalBranch check in order to sync the x86
and aarch64 and fix the fixDoubleJumps pass on aarch64.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Differential Revision: https://reviews.llvm.org/D122929
The bfd linker adds the symbol versioning string to the symbol name in symtab.
Skip the versioning part in order to find the registered PLT function.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Differential Revision: https://reviews.llvm.org/D122039
Check for supported target architecture instead of the host arch when
deciding to execute non-runtime tests.
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D122498
Read static relocs on the same address, as dynamic in order to update
constant island data address properly.
Differential Revision: https://reviews.llvm.org/D122100
Check that the function will be emitted in the final binary. Preserving
old function address is needed in case it is PLT trampiline, that is
currently not moved by the BOLT.
Differential Revision: https://reviews.llvm.org/D122098
BOLT treats aarch64 objects located in text as empty functions with
contant islands. Emit them with at least 8-byte alignment to the new
text section.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Differential Revision: https://reviews.llvm.org/D122097
AArch64 requires CI to be aligned to 8 bytes due to access instructions
restrictions. E.g. the ldr with imm, where imm must be aligned to 8 bytes.
Differential Revision: https://reviews.llvm.org/D122065
It seems the earlier implementation does not follow the description
in LoopRotationPass.h: It rotates loops even if they are already laid out
correctly. The diff adjusts the behaviour.
Given that the impact of LoopInversionPass is minor, this change won't
yield significant perf differences. Tested on clang-10: there seems to be a
0.1%-0.3% cpu win and a small reduction of branch misses.
**Before:**
BOLT-INFO: 120 Functions were reordered by LoopInversionPass
**After:**
BOLT-INFO: 79 Functions were reordered by LoopInversionPass
Reviewed By: yota9
Differential Revision: https://reviews.llvm.org/D121921
Run tentativeLayoutRelocMode twice only if UseOldText option was passed.
Refactor BF loop to break on condtition met.
Differential Revision: https://reviews.llvm.org/D121825
Remove tables from X86MCPlusBuilder, make use of llvm::X86 mnemonic tables.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D121573
Since LLVM MC now preserves redundant AdSize override prefix (0x67), remove it
in BOLT explicitly (-x86-strip-redundant-adsize, on by default).
Test Plan:
`bin/llvm-lit -a bolt/test/X86/addr32.s`
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D120975
The BinaryEmitter uses opts::AlignText value to align the hot text
section. Also check that the opts::AlignText is at least
equal opts::AlignFunctions for the same reason, as described in D121392.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Differential Revision: https://reviews.llvm.org/D121728
The cold text section alignment is set using the maximum alignment value
passed to the emitCodeAlignment. In order to calculate tentetive layout
right we will set the minimum alignment of such sections to the maximum
possible function alignment explicitly.
Differential Revision: https://reviews.llvm.org/D121392
This clarifies that this is an LLVM specific variable and avoids
potential conflicts with other projects.
Differential Revision: https://reviews.llvm.org/D119918
For AArch64 in some cases/some distributions ld uses 64K alignment of LOAD segments by default.
Reviewed By: yota9, maksfb
Differential Revision: https://reviews.llvm.org/D119267
The aarch64 uses the trampolines located in .iplt section, which
contains plt-like trampolines on the value stored in .got. In this case
we don't have JUMP_SLOT relocation, but we have a symbol that belongs to
ifunc trampoline, so use it and set set plt symbol for such functions.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Differential Revision: https://reviews.llvm.org/D120850
Address fuzzer crash on malformed input:
```
BOLT-ERROR: cannot get section contents for .dynsym: The end of the file was unexpectedly encountered.
```
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D121068
This patch enables PLT analysis for aarch64. It is used by the static
relocations in order to provide final symbol address of PLT entry for some
instructions like ADRP.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Differential Revision: https://reviews.llvm.org/D118088
Reassigning the operand didn't update the operand type which resulted in an
assertion (`Assertion `isReg() && "This is not a register operand!"' failed.`)
Reset the instruction instead.
Test Plan:
```
ninja check-bolt
...
PASS: BOLT-Unit :: Core/./CoreTests/X86/MCPlusBuilderTester.ReplaceRegWithImm/0 (90 of 136)
```
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D120263
We were not handling correctly conversion from DW_AT_high_pc into DW_AT_ranges,
when size of DW_AT_high_pc is not 4/8 bytes.
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D120528
PC-relative memory operand could reference a different object from
the one located at the target address, e.g. when a negative offset
is used. Check relocations for the real referenced object.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D120379
Further improve error handling in BOLT by reporting `RewriteInstance` errors in
a library and fuzzer-friendly way instead of exiting.
Follow-up to D119658
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D120224
Fix data race reported by ThreadSanitizer in clang.test:
```
ThreadSanitizer: data race /data/llvm-project/bolt/lib/Passes/ShrinkWrapping.cpp:1359:28
in llvm::bolt::ShrinkWrapping::moveSaveRestores()
```
The issue is with incrementing global counters from multiple threads.
Reviewed By: yota9
Differential Revision: https://reviews.llvm.org/D120218
Refactor createBinaryContext and RewriteInstance/MachORewriteInstance
constructors to report an error in a library and fuzzer-friendly way instead of
returning a nullptr or exiting.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D119658
This patch changes patchELFAllocatableRelaSections from going through
old relocations sections and update the relocation offsets to emitting
the relocations stored in binary sections. This is needed in case we
would like to remove and add dynamic relocations during BOLT work and it
is used by golang support pass. Note: Currently we emit relocations in
the old sections, so the total number of them should be equal or less
of old number.
Testing: No special tests are neeeded, since this patch does not fix
anything or add new functionality (it only prepares to add). Every
PIC-compiled test binary will use this code and thus become a test.
But just in case the aarch64 dynamic relocations tests were added.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D117612
Added ability to append new entries to DIE. This is useful to standadize DWARF4
Split Dwarf, and simplify implementation of DWARF5.
Multiple DIEs can share an abbrev. So currently limitation is that only unique
Attributes can be added.
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D119577
After "Remove caching of ranges/abbrevs" patch the dwarf offsets are a
bit changed and the subprograms high pc is replaced with AT_RANGES.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D119733
As usual with that header cleanup series, some implicit dependencies now need to
be explicit:
llvm/DebugInfo/DWARF/DWARFContext.h no longer includes:
- "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
- "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
- "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
- "llvm/DebugInfo/DWARF/DWARFDebugAranges.h"
- "llvm/DebugInfo/DWARF/DWARFDebugFrame.h"
- "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
- "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
- "llvm/DebugInfo/DWARF/DWARFGdbIndex.h"
- "llvm/DebugInfo/DWARF/DWARFSection.h"
- "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
- "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
Plus llvm/Support/Errc.h not included by a bunch of llvm/DebugInfo/DWARF/DWARF*.h files
Preprocessed lines to build llvm on my setup:
after: 1065629059
before: 1066621848
Which is a great diff!
Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D119723
When a jump table is recovered in postProcessIndirectBranches(),
successors for the containing basic block are added in random order.
Make the order deterministic.
Reviewed By: yota9
Differential Revision: https://reviews.llvm.org/D119672
Most notably,
llvm/Object/Binary.h no longer includes llvm/Support/MemoryBuffer.h
llvm/Object/MachOUniversal*.h no longer include llvm/Object/Archive.h
llvm/Object/TapiUniversal.h no longer includes llvm/Object/TapiFile.h
llvm-project preprocessed size:
before: 1068185081
after: 1068324320
Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D119457
We are moving away from building the runtimes with LLVM_ENABLE_PROJECTS,
however the documentation was largely outdated. This commit updates all
the documentation I could find to use LLVM_ENABLE_RUNTIMES instead of
LLVM_ENABLE_PROJECTS for building runtimes.
Note that in the near future, libcxx, libcxxabi and libunwind will stop
supporting being built with LLVM_ENABLE_PROJECTS altogether. I don't know
what the plans are for other runtimes like libc, openmp and compiler-rt,
so I didn't make any changes to the documentation that would imply
something for those projects.
Once this lands, I will also cherry-pick this on the release/14.x branch
to make sure that LLVM's documentation is up-to-date and reflects what
we intend to support in the future.
Differential Revision: https://reviews.llvm.org/D119351
Removing caching of ranges/abbrevs to simplify the code.
Before we were doing it to get around a gdb limitation.
FBD34015613
Reviewed By: Amir, maksfb
Differential Revision: https://reviews.llvm.org/D119276
Add the script to set up llvm-bolt-wrapper. The intended use is to run NFC
checks manually and automatically on a buildbot.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D118516
Summary:
- variable 'TotalSize' set but not used
- variable 'TotalCallsTopN' set but not used
- use of bitwise '|' with boolean operands
Reviewed By: maksfb
FBD33911129
clang-10 complains about changed section flags in two tests:
- X86/shrinkwrapping.test
- X86/exceptions-args.test
Fix that by adding the missing flags.
Reviewed By: yota9
Differential Revision: https://reviews.llvm.org/D119014
Only enable --emit-relocs linker option for merge-fdata target if tests are enabled.
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D118580
We can have a scenario where multiple CUs share an abbrev table.
We modify or don't modify one CU, which leads to other CUs having invalid abbrev section.
Example that caused it.
All of CUs shared the same abbrev table. First CU just had compile_unit and sub_program.
It was not modified. Next CU had DW_TAG_lexical_block with
DW_AT_low_pc/DW_AT_high_pc converted to DW_AT_low_pc/DW_AT_ranges.
We used unmodified abbrev section for first and subsequent CUs.
So when parsing subsequent CUs debug info was corrupted.
In this patch we will now duplicate all sections that are modified and are different.
This also means that if .debug_types is present and it shares Abbrev table, and
they usually are, we now can have two Abbrev tables. One for CU that was modified,
and unmodified one for TU.
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D118517
Commit history in chronological order:
[BOLT] llvm-bolt-wrapper: added wrapper for bolt binary matching
Summary:
Wrapper to compare two versions of BOLT to see if they produce the same output
binary given the same input.
(cherry picked from FBD26626137)
[BOLT] llvm-bolt-wrapper: support for no-output tests and heatmap mode
Summary:
- Added an option `skip_binary_cmp` to support invocations that don't output
a binary
- Minor fixes for heatmap mode, timeout, log comparison
- Rearranged in-line config example to be copy-pasteable
(cherry picked from FBD26822016)
[BOLT] llvm-bolt-wrapper: merge stdout/stderr, search for config in script dir
(cherry picked from FBD27529335)
[BOLT] llvm-bolt-wrapper: handle /dev/null
Summary:
Fixed the wrapper to preserve `-o /dev/null` and skip binary matching for such
invocations.
(cherry picked from FBD28013747)
[BOLT] llvm-bolt-wrapper: handle cases where output binary doesn't exist
Summary:
Handle invocations where output binary is not generated (e.g. due to an expected
assertion or exit with BOLT-ERROR) and skip binary comparison in such cases.
(cherry picked from FBD28080158)
[BOLT] llvm-bolt-wrapper: handle boltdiff mode
Summary:
Handle `llvm-boltdiff` invocation similarly to `perf2bolt`
(cherry picked from FBD28080157)
[BOLT] llvm-bolt-wrapper: find section with mismatch
Summary:
For mismatching ELF files, find section with mismatch and print sections table
with highlighted mismatch section.
(cherry picked from FBD28087231)
[BOLT] llvm-bolt-wrapper: ignore-build-id in perf2bolt mode
Summary:
When perf2bolt fails to match build-id from perf output for cmp binary, we need
to use -ignore-build-id option to override the strict checking behavior.
(cherry picked from FBD28087232)
[BOLT] llvm-bolt-wrapper: suppress -bolt-info=0 in heatmap mode
Summary:
Heatmap mode is incompatible with `-bolt-info=0` used to suppress binary
differences. Remove it.
(cherry picked from FBD28087230)
[BOLT] llvm-bolt-wrapper: add config-generator mode
Summary:
llvm-bolt-wrapper config can be generated by the script itself.
It makes the workflow more reliable compared to preparing the config manually.
(cherry picked from FBD28358939)
[BOLT] llvm-bolt-wrapper: fix mismatch reporting
Summary:
1. Fixed header comparison issue where headers were skipped due to
`skip_end == 0` (`lst[:-n]` does not work if n==0).
2. Detect color support while printing mismatching section:
- use bold color if terminal supports ANSI escape codes,
- otherwise print ">" at mismatching section.
3. Remove extra 0x before mismatching offset.
(cherry picked from FBD28691979)
[BOLT] llvm-bolt-wrapper: handle perf2bolt tests with ignore-build-id
Summary:
`ignore-build-id` must be passed not more than once. Account for that.
(cherry picked from FBD29830266)
[BOLT] llvm-bolt-wrapper: fix running subprocesses in parallel
Summary:
The commands were running sequentially due to the use of blocking `communicate`
call, which is needed when stdout/stderr are directed to a pipe.
Fix this behavior by directing the output to a file.
(cherry picked from FBD29951863)
The aarch64 platform has special registers like X0_X1_X2_X3_X4_X5_X6_X7.
Using the downwards propagation this register will become a super
register for all X0..X7 and its super registers which is not right. This
patch replaces the downwards propagation with caching all the aliases using MCRegAliasIterator.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D117394
Since we now re-write .debug_info the DWARF CU Offsets can change.
Just like for .debug_aranges the GDB Index will need to be updated.
Reviewed By: Amir, maksfb
Differential Revision: https://reviews.llvm.org/D118273
This patch reverts patch "DWARFv5 default: Switch bolt tests to use
DWARFv4 since Bolt doesn't support v5 yet" and places the -gdwarf-4 flag
to the global cflags config file.
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D118283
This patch adds unit testing support for BOLT. In order to do this we will need at least do this changes on the code level:
* Make createMCPlusBuilder accessible externally
* Remove positional InputFilename argument to bolt utlity sources
And prepare the cmake and lit for the new tests.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Reviewed By: maksfb, Amir
Differential Revision: https://reviews.llvm.org/D118271
<memory> is no longer included as a result of 5f290c090a
("Move STLFunctionalExtras out of STLExtras").
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D118064
This patch fixes the removal of unreachable uncondtional branch located
after return instruction.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D117677
Summary:
Move the annotation to avoid dynamic memory allocations.
Improves the CPU time of instrumenting a large binary by 1% (+-0.8%, p-value 0.01)
Test Plan: NFC
Reviewers: maksfb
FBD30091656
In case the case the DW_AT_ranges tag already exists for the object the
low pc values won't be updated and will be incorrect in
after-bolt binaries.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Differential Revision: https://reviews.llvm.org/D117216
Matching an exact byte offset is fragile if a different version of compiler
is used (e.g. distro clang).
Resolves an issue with running with BOLT_CLANG_EXE + clang-12
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D117440
This is a follow up to Fix size mismatch error with jemalloc.
4243b6582c
Although that fix works it increased memory footprint.
With this patch we go back to original memory footprint.
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D117341
Summary:
Address @smeenai feedback https://reviews.llvm.org/D117061#inline-1122106:
>CMake has if(IN_LIST) now, which you can use instead of the string(FIND)
IN_LIST is available since CMake 3.3 released in 2015.
Reviewed By: smeenai
FBD33590959
The DW_FORM_addr form of highPC address is written in absolute addres,
the data form is written in offset-from-low pc format.
Due to the large test binary the test is prepared separately in
https://github.com/rafaelauler/bolt-tests/pull/8
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Reviewed By: ayermolo
Differential Revision: https://reviews.llvm.org/D117217
Summary:
Follow the clang-tidy suggestion to replace reset-release with move assignment.
Move assignment's effect for unique_ptr:
> Effects: Transfers ownership from `u` to `*this` as if by calling `reset(u.release())`
followed by an assignment from `std::forward<D>(u.get_deleter())`.
Summary:
Remove X86MCPlusBuilder code that duplicates checks in X86BaseInfo.
Remove isINC and isDEC as redundant.
The new code of `X86MCPlusBuilder::isMacroOpFusionPair` is functionally
equivalent to `X86AsmBackend::isMacroFused`. However, as the method is
declared/defined in X86AsmBackend.cpp and not exported in a header file,
there's no way to use it in BOLT without changes in LLVM code.
(cherry picked from FBD33440373)
Summary:
Remove patterns ineligible for macro-fusion:
- First instruction has a memory destination
This is a temporary commit to align BOLT with LLVM MC interfaces.
(cherry picked from FBD33479340)
Summary:
When building with GCC and linking against jemalloc there is an
assertion when Debug Patches unique pointers are being freed from an std vector.
The base destructor gets invoked which results in type mismatch.
Added virtual destructor to the base class.
(cherry picked from FBD33489259)
Summary:
Reformat code and put options in lexicographical order.
Comparing to clang-format output, manual formatting looks cleaner to me.
(cherry picked from FBD33481692)
Summary:
Adding support for DW_FORM_data_2, DW_FORM_data_1, DW_FORM_udata.
With new .debug_info code only need to modify the check.
(cherry picked from FBD33302731)
Summary:
Now that we are re-writing .debug_info we are not longer restricted to have same size patches.
Simplifying logic to use direct forms.
(cherry picked from FBD32971159)
Summary:
If `addUnknownControlFlow` in `BinaryFunction::postProcessIndirectBranches`
is invoked with a basic block that has multiple edges to the same successor,
it leads to an assertion in `BinaryBasicBlock::removePredecessor`.
For basic blocks with multiple edges to the same successor, the default
behavior of removePredecessor is to remove all occurrences of the
predecessor block in its predecessor list (Multiple=true).
Example:
```A -> B (two edges)
A->removeAllSuccessors()
for each successor of block A: // B twice
// this removes both occurrences of A in B's predecessors list
B->removePredecessor(A);
// this invocation triggers an assert as A is no longer in B's
// predecessor list
B->removePredecessor(A);
```
This issue is not fixed by NormalizeCFG as `removeAllSuccessor` is called
earlier (from `buildCFG` -> `postProcessIndirectBranches`).
Solve this issue by collecting the successors into a set (`SmallPtrSet`) first,
before invoking `SuccessorBB->removePredecessor(this)`.
GitHub issue: https://github.com/facebookincubator/BOLT/issues/187
(cherry picked from FBD30796979)
Summary:
Changed the behavior of how we handle .debug_info section.
Instead of patching it will now rewrite it.
With this approach we are no longer constrained to having new values
of the same size.
It handles re-writing by treating .debug_info as raw data.
It copies chunks of data between patches, with new data written in
between.
(cherry picked from FBD32519952)
Summary:
Refactor remaining bolt sources to follow the braces rule for if/else/loop from
[LLVM Coding Standards](https://llvm.org/docs/CodingStandards.html).
(cherry picked from FBD33345885)
Summary:
Refactor bolt/*/Profile to follow the braces rule for if/else/loop from
[LLVM Coding Standards](https://llvm.org/docs/CodingStandards.html).
(cherry picked from FBD33345741)
Summary:
Refactor bolt/lib/Target to follow the braces rule for if/else/loop from
[LLVM Coding Standards](https://llvm.org/docs/CodingStandards.html).
(cherry picked from FBD33345353)
Summary:
Refactor bolt/*/Passes to follow the braces rule for if/else/loop from
[LLVM Coding Standards](https://llvm.org/docs/CodingStandards.html).
(cherry picked from FBD33344642)
Summary:
The lower_bound might return the end iterator, the ignoring of which will
cause memory corruption.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD33307803)
Summary:
Fix missing string header file inclusion and link_fdata find
problem in lit tests. Change root-level tests to require
linux. Re-enable Windows in our root CMakeLists.txt.
(cherry picked from FBD33296290)
Summary:
Fix according to Coding Standards doc, section Don't Use
Braces on Simple Single-Statement Bodies of if/else/loop Statements.
This set of changes applies to lib Core only.
(cherry picked from FBD33240028)
Summary:
Since nops are now removed in a separate pass, the profile is consumed
on a CFG with nops. If previously a profile was generated without nops,
the offsets in the profile could be different if branches included nops
either as a source or a destination.
This diff adjust offsets to make the profile reading backwards
compatible.
(cherry picked from FBD33231254)
Summary:
The patch moves the shortenInstructions and nop remove to separate binary
passes. As a result when llvm-bolt optimizations stage will begin the
instructions of the binary functions will be absolutely the same as it
was in the binary. This is needed for the golang support by llvm-bolt.
Some of the tests must be changed, since bb alignment nops might create
unreachable BBs in original functions.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD32896517)
Summary:
This patch adds AArch64 relocations handling in case updating of
debug sections is enabled
Elvina Yakubova,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD33077609)
Summary:
Create a new high-level target named bolt that builds all
BOLT artifacts, as well as a install-bolt target that installs them.
(cherry picked from FBD33133002)
Summary:
Gracefully handle binaries with split functions where two fragments are folded
into one, resulting in a fragment with two parent functions.
This behavior is expected in GCC8+ with -O2 optimization level, where both
function splitting and ICF are enabled by default.
On the BOLT side, the changes are:
- BinaryFunction: allow multiple parent fragments:
- `ParentFragment` --> `ParentFragments`,
- `setParentFragment` --> `addParentFragment`.
- BinaryContext:
- `populateJumpTables`: mark fragments to be skipped later,
- `registerFragment`: add a name heuristic check, return false if it failed,
- `processInterproceduralReferences`: check if `registerFragment`
succeeded, otherwise issue a warning,
- `skipMarkedFragments`: move out fragment traversal and skipping from
`populateJumpTables` into a separate function.
This change fixes an issue where unrelated functions might be registered
as fragments:
```
BOLT-WARNING: interprocedural reference between unrelated fragments:
bad_gs/1(*2) and amd_decode_mce.cold.27/1(*2)
```
(Linux kernel binary)
(cherry picked from FBD32786688)
Summary:
Refactor members of BinaryBasicBlock. Replace some std containers with
ADT equivalents. The size of BinaryBasicBlock on x86-64 Linux is reduced
from 232 bytes to 192 bytes.
(cherry picked from FBD33081850)
Summary:
Build is already broken because VS fails to locate
llvm-boltdiff when running tests, and VS also complains that
include/bolt/Passes/InstrumentationSummary.h is lacking an include
string header. Disable this until we have a Windows buildbot to make
sure this build is sane.
(cherry picked from FBD33039972)
Summary:
Switched members of BinaryFunction to ADT where it was possible and
made sense. As a result, the size of BinaryFunction on x86-64 Linux
reduced from 1624 bytes to 1448.
(cherry picked from FBD32981555)
Summary:
For DWP case the AbbreviationsOffset is the offset of the abbrev
contribution in the DWP file, so can be none zero.
(cherry picked from FBD32961240)
Summary:
Currently, RuntimeDyld will not allocate a section without relocations
even if such a section is marked allocatable and defines symbols.
When we emit .debug_line for compile units with unchanged code, we
output original (input) data, without relocations. If all units are
emitted in this way, we will have no relocations in the emitted
.debug_line. RuntimeDyld will not allocate the section and as a result
we will write an empty .debug_line section.
To workaround the issue, always emit a relocation of RELOC_NONE type
when emitting raw contents to debug_line.
(cherry picked from FBD32909869)
Summary:
Some optimizations may remove all instructions in a basic block.
The pass will cleanup the CFG afterwards by removing empty basic
blocks and merging duplicate CFG edges.
The normalized CFG is printed under '-print-normalized' option.
(cherry picked from FBD32774360)
Summary:
The debug message for the last fall-through block was printed under the
reverse condition, i.e. when the block was not a fall-through. Remove
the debug message. If we'll need such information, we can add a pass
with more analysis, i.e. checking the last instruction, if the block is
reachable, etc.
(cherry picked from FBD32670816)
Summary:
TailDuplication::isInCacheLine makes the assumption that the block
has a valid layout index, which is not the case for unreachable blocks.
Add a check for a valid layout index.
(cherry picked from FBD32659755)
Summary:
In some of the system stack protection is enabled by default, which will
lead in extra symbols dependencies, which we want to avoid.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD32478426)
Summary:
As pointed out by Vladislav in issue 217, if our RTDyld-based
linker fails to locate a symbol, it will crash with segfault. Fix that.
(cherry picked from FBD32481543)
Summary:
Currently there are two issues rendering the use of bughunter/BOLT on a binary
with a large number of functions (100k) impossible:
1) `selectFunctionsToProcess` has O(binary_fn * force_fn) run-time, which is up
to quadratic with the number of functions in the binary.
2) It unnecessarily treats supplied function names as regexes.
This diff proposes the following changes to address the issue:
1. Add two options that treat function names as is, not as regexes, matching
bughunter usage model: `-funcs-no-regex`/`-funcs-file-no-regex`.
These options are complementary to `-funcs`/`-funcs-file` and `-skip-funcs`/
`-skip-funcs-file`. `funcs` takes precedence over `funcs-no-regex`.
2. Use string set to speed up function eligibility checking with
`-funcs-file-no-regex` to O(binary_fn * log force_fn).
(cherry picked from FBD28917225)
Summary:
The push and pop instructions might have wrong reorder due to this
error. Thanks rafaelauler for the provided test case.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD32478348)
Summary:
We were not tracking -DBUILD_SHARED_LIBS=ON and we introduced
some commits that break that by not specifying the correct dependencies.
Fix that.
(cherry picked from FBD32453377)
Summary: In some cases __open() is returning 0 for me. The open
syscall will return a negative number (-1) on error so 0 should be
valid.
This happens when one compiles a BOLT instrumented executable of
pyston (python implementation) and afterwards pip installs a package
which needs to be compiled and sets CFLAGS=-pipe. I could not reduce
it down to a small testcase but I guess it one can trigger when
manually closing std{in, out, err}. Everything seems to work
normally when disabling the assert for 0 in getBinaryPath() - I
decided to also modify the second case in readDescriptions() even
though I did not run into that one yet.
(cherry picked from FBD32409548)
Summary:
Make BOLT build in VisualStudio compiler and run without
crashing on a simple test. Other tests are not running.
(cherry picked from FBD32378736)
Summary:
Moved the FDATA printing under the condition of non-empty profile data.
The change reduces the assembly dumps.
(cherry picked from FBD32262675)
Summary:
Import the test. The assembly input has three functions with associated fdata.
The old link_fdata.sh script only replaces the symbol names with symbol values,
whereas fdata format expects to have symbol offsets against the anchor symbol.
Introduce the link_fdata.py script which is able to parse the input and produce
either an offset or an absolute symbol value.
(cherry picked from FBD32256351)
Summary:
The majority of tests in LLVM projects are using - instead of _ in the name,
i.e. `check-something.test` is preferred over `check_something.test`.
It makes sense for us to adopt the same naming scheme for our future tests and
to rename existing ones.
(cherry picked from FBD32185879)
Summary:
BOLT meta test using merge-fdata tool.
This tests BOLT instrumentation for a non-trivial binary, running instrumented
binary, and using the instrumentation profile for BOLT optimizations.
The results are verified between original, instrumented, and optimized binaries.
Additional tested features: boltdiff mode and merge-fdata for two profiles.
merge-fdata tool is linked with relocs on Linux to support this test.
(cherry picked from FBD32141812)
Summary:
Replace erroneous check for function eligibility from `Function.isIgnored()`
to `shouldOptimize(Function)`. This prevents non-simple functions from being
processed.
(cherry picked from FBD32301958)
Summary:
With LTO, it's possible for multiple DWARF compile units to share the
same abbreviation section set, i.e. to have the same abbrev_offset.
When units sharing the same abbrev set are located next to each other
and neither of them is being processed (i.e. contain processed
functions), it can trigger a bug in BOLT. When this happened,
the abbrev set is considered empty. Additionally, different units
may patch abbrev section differently.
The fix is to not rely on the next unit offset when detecting
abbreviation set boundaries and to delay writing abbrev section
until all units are processed.
(cherry picked from FBD31985046)
Summary:
This commit uses reviews.llvm.org/D6629 as a reference to optimize
X86::EFLAGS load/store in the instrumentation snippet by using lahf/sahf
instructions instead of pushf/popf.
(cherry picked from FBD31662303)
Summary:
Added new functionality of dumping simple functions into assembly.
This includes:
- function control flow (basic blocks, instructions),
- profile information as `FDATA` directives, to be consumed by link_fdata,
- data labels,
- CFI directives,
- symbols for callee functions,
- jump table symbols.
Envisioned usage:
1. Find a function that triggers BOLT crash (e.g. with `bughunter.sh`).
2. Generate reproducer asm source for that function (using `-funcs`).
3. Attach it to an issue.
4. Reduce and include as a test case.
Current limitations:
1. Emitted assembly won't match input file relocations.
2. No DWARF support.
3. Data is not emitted.
(cherry picked from FBD32746857)
Summary:
BinaryContext is available via BinaryFunction::getBinaryContext(),
hence there's no reason to pass both as arguments to a function.
In a similar fashion, BinaryBasicBlock has an access to BinaryFunction
via getFunction(). Eliminate unneeded arguments.
(cherry picked from FBD31921680)
Summary:
Change cmake config in BOLT to only support Linux. In other
platforms, we print a warning that we won't build BOLT. Change
configs to determine whether we will build BOLT runtime libs. This
only happens in x86 hosts. If true, we will build the runtime and
enable bolt-runtime tests. New tests that depend on the bolt_rt lib
needs to be marked REQUIRES:bolt-runtime. I updated the relevant
tests. Fix cmake to do not crash when building llvm with a target
that BOLT does not support.
(cherry picked from FBD31935760)
Summary:
Moves source files into separate components, and make explicit
component dependency on each other, so LLVM build system knows how to
build BOLT in BUILD_SHARED_LIBS=ON.
Please use the -c merge.renamelimit=230 git option when rebasing your
work on top of this change.
To achieve this, we create a new library to hold core IR files (most
classes beginning with Binary in their names), a new library to hold
Utils, some command line options shared across both RewriteInstance
and core IR files, a new library called Rewrite to hold most classes
concerned with running top-level functions coordinating the binary
rewriting process, and a new library called Profile to hold classes
dealing with profile reading and writing.
To remove the dependency from BinaryContext into X86-specific classes,
we do some refactoring on the BinaryContext constructor to receive a
reference to the specific backend directly from RewriteInstance. Then,
the dependency on X86 or AArch64-specific classes is transfered to the
Rewrite library. We can't have the Core library depend on targets
because targets depend on Core (which would create a cycle).
Files implementing the entry point of a tool are transferred to the
tools/ folder. All header files are transferred to the include/
folder. The src/ folder was renamed to lib/.
(cherry picked from FBD32746834)
Rahman Lavaee