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:
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:
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:
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:
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:
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:
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:
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:
Add lit.local.cfg to X86 and AArch64 folders.
Fix host_arch in lit config for AArch64.
Fix AArch64 and X86 tests.
Elvina Yakubova,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD31702068)
Summary:
When the compiler emits line table program, it emits EOS using the label
at the end of the containing code section. Since each compilation unit
has its own set of code sections it works as expected (* see the excerpt
from the standard below). However, in BOLT the code from many CUs is
combined into a common section, such as hot text or cold text.
As a result, the symbol at the end of the section may point way past the
code sequence for a given unit.
Since we can emit functions in any order, we conservatively emit
end-of-sequence at the end of every emitted function.
Fixes a problem while intermixing source code with disassembly in
binutils' objdump.
(*) DWARF v4 6.2.5.3:
"Every line number program sequence must end with a DW_LNE_end_sequence
instruction which creates a row whose address is that of the byte after
the last target machine instruction of the sequence."
(cherry picked from FBD31347870)
Summary:
Create bolt/test/runtime folder and move tests that execute the binary.
Move lit.local.cfg with host_arch check to the corresponding folder.
Addresses issue facebookincubator/BOLT#132.
AArch64/tls.c shows a different behavior with clang hence marked as XFAIL
TODO: add a check for non-exec tests for a corresponding LLVM_TARGETS_TO_BUILD.
(cherry picked from FBD31132234)
Summary:
LLVM started printing warnings when DWARFDebugInfoEntry::extractFast()
is invoked trying to read a DIE past the current unit limits. This
results in verbose warnings from BOLT which are harmless but confusing
to the user. Check the boundaries before calling the API above.
(cherry picked from FBD31097271)
Summary:
We have a problem where we will emit sections that we are not supposed
to emit (with no output offset assigned). This will make us write at
file offset 0 and corrupt the first sections in the binary (usually
.interp section will be corrupted and bash will refuse to run the
binary).
This only happens in non-reloc mode when using JTS_BASIC and when we
do not emit a function that has a jump table (if it gets too large).
Using -update-debug-sections will trigger the pass
check-large-functions, which will mark large funcs as non-simple
and will hide this bug.
(cherry picked from FBD30882012)
Summary:
This commit introduces TryLock usage for SimpleHashTable getter to
avoid deadlock and relax syscalls usage which causes significant
overhead in runtime.
The old behavior left under -conservative-instrumentation option passed
to instrumentation library.
Also, this commit includes a corresponding test case: instrumentation of
executable which performs indirect calls from common code and signal
handler.
Note: in case if TryLock was failed to acquire the lock - this indirect
call will not be accounted in the resulting profile.
Vasily Leonenko,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD30821949)
Summary:
Three way branches commonly appear
in HHVM. They have one test and then two jumps. The
jump's destinations are not currently optimized.
This pass attempts to optimize which is the first branch.
(cherry picked from FBD30460441)
Summary:
There are 2 problems found when handling ADR instruction:
1. When extracting value from the ADR instruction we need to do
it another way, then we do it for ADRP instruction.
2. When creating target expression the VariantKind should be other for
ADR instruction.
And we introduces R_AARCH64_ADR_PREL_LO21,
R_AARCH64_TLSDESC_ADR_PREL21 and R_AARCH64_ADR_PREL_PG_HI21_NC
relocations support.
Also this patch introduces AdrPass, which will replace non-local
pointing ADR instructions with ADRP + ADD instructions sequence due to
small offset range of ADR instruction, so after BOLT magic there are no
guarantees that ADR instruction will still be in the range of
just +- 1MB from its target. The instruction replacement needs
relocations to be avalailable, so we won't remove "IsFromCode"
relocations after disassembly from BF anymore. Also we need original
offset of ADR instruction to be available so we add offset annotation
for these instructions.
The last thing this patch adds is ARM testing directory, which will be
used only on ARM testing servers. The common tests (non-assembler tests
which are platform-independent) might be moved from the X86 directory to
the parent one in the future, so such tests could be tested on both X86
and ARM machines.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD30497379)
Summary:
Added a function in TailDuplication
that will do Constant and Copy Propagation for blocks that
we duplicated as a part of tail duplication. Added supporting
functions to MCPlusBuilder to find src registers and replace
registers
(cherry picked from FBD30231907)
Summary:
This patch is part of preparation for golang support. The golang symbols
might have spaces in the name (for example "type..eq.[10]interface {}").
Since fdata uses spaces as a field separator such names brakes the fdata
format, so we need to escape whitespaces and backslashes in symbol names
using the backslash character.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD29999491)
Summary:
This commit adds dummy tests for checking instrumentation
support for PIE executables and shared libraries.
Vasily Leonenko,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD30092729)
Summary:
The linker can generate 8- or 16-byte entries in .plt.got and .plt.sec
sections. On X86, the main differentiator is the presence of endbr64
instruction at the beginning of the entry. Detect the instruction and
adjust the size accordingly.
(cherry picked from FBD29847639)
Summary:
Created a binary pass that records how many
times tail duplication would be used and how many cache
misses it would theoretically stop
(cherry picked from FBD29619858)
Summary:
A binary can contain multiple PLT sections with different name and
attributes (such as an entry size). Extend the support to .plt.sec and
refactor the code to make future extensions simpler.
(cherry picked from FBD29502107)
Rafael Auler