Commit Graph

264 Commits

Author SHA1 Message Date
Amir Ayupov
f8c7fb499b [BOLT][NFC] Reduce includes with include-what-you-use
Summary: Removed redundant includes with IWYU

Test Plan: ninja bolt

Reviewers: maksfb

FBD32043568
2022-01-21 12:05:47 -08:00
Amir Ayupov
a9cd49d50e [BOLT][NFC] Move Offset annotation to Group 1
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
2022-01-18 13:24:50 -08:00
Amir Ayupov
29fe14c78d [BOLT][NFC] Remove redundant dependent template type
Summary:
Reduce code size by removing redundant dependent template type
from RewriteInstance methods.

Code size savings (via bloaty on llvm-bolt Debug build):
```
symbol,vmsize,filesize -> vmsize,filesize (delta vmsize,filesize)
updateELFSymbolTable         57096,59600 -> 56656,59048 (440,552)
updateELFSymbolTable::lambda 35957,55277 -> 35949,54485   (8,792)
getOutputSections            20592,21440 -> 20372,21156 (220,284)
getOutputSections::lambda      1792,5300 ->   1792,5372   (0,-72)

total delta (668,1556)
```

Reviewed By: maksfb

FBD33589393
2022-01-14 15:47:15 -08:00
Maksim Panchenko
df288e8487 [BOLT][NFC] Refactor if statements in RewriteInstance
(cherry picked from FBD33341796)
2021-12-28 13:46:45 -08:00
Alexander Yermolovich
1c2f4bbe99 [BOLT] Rewrite of .debug_info section
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)
2021-11-15 17:19:24 -08:00
Maksim Panchenko
ee0e9ccb52 [BOLTRewrite][NFC] Fix braces usages
Summary:
Refactor bolt/*/Rewrite to follow the braces rule for if/else/loop from
LLVM Coding Standards.

(cherry picked from FBD33305364)
2021-12-23 12:38:33 -08:00
Maksim Panchenko
2f09f445b2 [BOLT][NFC] Fix file-description comments
Summary: Fix comments at the start of source files.

(cherry picked from FBD33274597)
2021-12-21 10:21:41 -08:00
Maksim Panchenko
ccb99dd126 [BOLT] Fix profile and tests for nop-removal pass
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)
2021-12-18 17:05:00 -08:00
Maksim Panchenko
40c2e0fafe [BOLT][NFC] Reformat with clang-format
Summary: Selectively apply clang-format to BOLT code base.

(cherry picked from FBD33119052)
2021-12-14 16:52:51 -08:00
Amir Ayupov
6aa735ceaf [BOLT] Split functions: support fragments with multiple parents
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)
2021-12-01 21:14:56 -08:00
Rafael Auler
a23726bb33 [BOLT] Fix crash when trying to resolve external symbols for runtime libs
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)
2021-11-16 16:47:02 -08:00
Amir Ayupov
d474dbdfcb [BOLT][NFC] Use function names passed in -funcs-no-regex as-is
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)
2021-06-04 18:49:29 -07:00
Rafael Auler
ae585be11c [BOLT] Fix Windows build
Summary:
Make BOLT build in VisualStudio compiler and run without
crashing on a simple test. Other tests are not running.

(cherry picked from FBD32378736)
2021-11-11 18:14:53 -08:00
Rafael Auler
a34c753fe7 Rebase: [NFC] Refactor sources to be buildable in shared mode
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)
2021-10-08 11:47:10 -07:00