Refactor MCPlusBuilder's create{Instruction}() functions that used to
return bool. We almost never check the return value as we rely on
llvm_unreachable() to detect unimplemented functionality. There were a
couple of cases that checked the return value, but they would hit the
unreachable condition first (at least in debug builds) before the return
value gets checked.
Make core BOLT functionality more friendly to being used as a
library instead of in our standalone driver llvm-bolt. To
accomplish this, we augment BinaryContext with journaling streams
that are to be used by most BOLT code whenever something needs to
be logged to the screen. Users of the library can decide if logs
should be printed to a file, no file or to the screen, as
before. To illustrate this, this patch adds a new option
`--log-file` that allows the user to redirect BOLT logging to a
file on disk or completely hide it by using
`--log-file=/dev/null`. Future BOLT code should now use
`BinaryContext::outs()` for printing important messages instead of
`llvm::outs()`. A new test log.test enforces this by verifying that
no strings are print to screen once the `--log-file` option is
used.
In previous patches we also added a new BOLTError class to report
common and fatal errors, so code shouldn't call exit(1) now. To
easily handle problems as before (by quitting with exit(1)),
callers can now use
`BinaryContext::logBOLTErrorsAndQuitOnFatal(Error)` whenever code
needs to deal with BOLT errors. To test this, we have fatal.s
that checks we are correctly quitting and printing a fatal error
to the screen.
Because this is a significant change by itself, not all code was
yet ported. Code from Profiler libs (DataAggregator and friends)
still print errors directly to screen.
Co-authored-by: Rafael Auler <rafaelauler@fb.com>
Test Plan: NFC
As part of the effort to refactor old error handling code that
would directly call exit(1), in this patch continue the migration
on libCore, libRewrite and libPasses to use the new BOLTError
class whenever a failure occurs.
Test Plan: NFC
Co-authored-by: Rafael Auler <rafaelauler@fb.com>
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
Closes https://github.com/llvm/llvm-project/issues/63097
Before merging please make sure the change to
bolt/include/bolt/Passes/StokeInfo.h is correct.
bolt/include/bolt/Passes/StokeInfo.h
```diff
// This Pass solves the two major problems to use the Stoke program without
- // proting its code:
+ // probing its code:
```
I'm still not happy about the awkward wording in this comment.
bolt/include/bolt/Passes/FixRelaxationPass.h
```
$ ed -s bolt/include/bolt/Passes/FixRelaxationPass.h <<<'9,12p'
// This file declares the FixRelaxations class, which locates instructions with
// wrong targets and fixes them. Such problems usually occures when linker
// relaxes (changes) instructions, but doesn't fix relocations types properly
// for them.
$
```
bolt/docs/doxygen.cfg.in
bolt/include/bolt/Core/BinaryContext.h
bolt/include/bolt/Core/BinaryFunction.h
bolt/include/bolt/Core/BinarySection.h
bolt/include/bolt/Core/DebugData.h
bolt/include/bolt/Core/DynoStats.h
bolt/include/bolt/Core/Exceptions.h
bolt/include/bolt/Core/MCPlusBuilder.h
bolt/include/bolt/Core/Relocation.h
bolt/include/bolt/Passes/FixRelaxationPass.h
bolt/include/bolt/Passes/InstrumentationSummary.h
bolt/include/bolt/Passes/ReorderAlgorithm.h
bolt/include/bolt/Passes/StackReachingUses.h
bolt/include/bolt/Passes/StokeInfo.h
bolt/include/bolt/Passes/TailDuplication.h
bolt/include/bolt/Profile/DataAggregator.h
bolt/include/bolt/Profile/DataReader.h
bolt/lib/Core/BinaryContext.cpp
bolt/lib/Core/BinarySection.cpp
bolt/lib/Core/DebugData.cpp
bolt/lib/Core/DynoStats.cpp
bolt/lib/Core/Relocation.cpp
bolt/lib/Passes/Instrumentation.cpp
bolt/lib/Passes/JTFootprintReduction.cpp
bolt/lib/Passes/ReorderData.cpp
bolt/lib/Passes/RetpolineInsertion.cpp
bolt/lib/Passes/ShrinkWrapping.cpp
bolt/lib/Passes/TailDuplication.cpp
bolt/lib/Rewrite/BoltDiff.cpp
bolt/lib/Rewrite/DWARFRewriter.cpp
bolt/lib/Rewrite/RewriteInstance.cpp
bolt/lib/Utils/CommandLineOpts.cpp
bolt/runtime/instr.cpp
bolt/test/AArch64/got-ld64-relaxation.test
bolt/test/AArch64/unmarked-data.test
bolt/test/X86/Inputs/dwarf5-cu-no-debug-addr-helper.s
bolt/test/X86/Inputs/linenumber.cpp
bolt/test/X86/double-jump.test
bolt/test/X86/dwarf5-call-pc-function-null-check.test
bolt/test/X86/dwarf5-split-dwarf4-monolithic.test
bolt/test/X86/dynrelocs.s
bolt/test/X86/fallthrough-to-noop.test
bolt/test/X86/tail-duplication-cache.s
bolt/test/runtime/X86/instrumentation-ind-calls.s
As discussed in D159266, for some instructions it's impossible to know
statically if they will load/store (e.g., predicated instructions).
Therefore, mayLoad/mayStore are more appropriate names.
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
This patch adds a dedicated class to keep track of each function's
layout. It also lays the groundwork for splitting functions into
multiple fragments (as opposed to a strict hot/cold split).
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D129518
Add -experimental-shrink-wrapping flag to control when we
want to move callee-saved registers even when addresses of the stack
frame are captured and used in pointer arithmetic, making it more
challenging to do alias analysis to prove that we do not access
optimized stack positions. This alias analysis is not yet implemented,
hence, it is experimental. In practice, though, no compiler would emit
code to do pointer arithmetic to access a saved callee-saved register
unless there is a memory bug or we are failing to identify a
callee-saved reg, so I'm not sure how useful it would be to formally
prove that.
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D126115
Change shrink-wrapping to try a priority list of save
positions, instead of trying the best one and giving up if it doesn't
work. This also increases coverage.
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D126114
Add the option to run -equalize-bb-counts before shrink
wrapping to avoid unnecessarily optimizing some CFGs where profile is
inaccurate but we can prove two blocks have the same frequency.
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D126113
Change how function score is calculated and provide more
detailed statistics when reporting back frame optimizer and shrink
wrapping results. In this new statistics, we provide dynamic coverage
numbers. The main metric for shrink wrapping is the number of executed
stores that were saved because of shrink wrapping (push instructions
that were either entirely moved away from the hot block or converted
to a stack adjustment instruction). There is still a number of reduced
load instructions (pop) that we are not counting at the moment. Also
update alloc combiner to report dynamic numbers, as well as frame
optimizer.
For debugging purposes, we also include a list of top 10 functions
optimized by shrink wrapping. These changes are aimed at better
understanding the impact of shrink wrapping in a given binary.
We also remove an assertion in dataflow analysis to do not choke on
empty functions (which makes no sense).
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D126111
Fix a bug where shrink-wrapping would use wrong stack offsets
because the stack was being aligned with an AND instruction, hence,
making its true offsets only available during runtime (we can't
statically determine where are the stack elements and we must give up
on this case).
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D126110
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
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:
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:
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:
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:
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)
