In lite mode (default for X86), BOLT optimizes and relocates functions
with profile. The rest of the code is preserved, but if it references
relocated code such references have to be updated. The update is handled
by scanExternalRefs() function. Note that we cannot solely rely on
relocations written by the linker, as not all code references are
exposed to the linker. Additionally, the linker can modify certain
instructions and relocations will no longer match the code.
With this change, start using symbolic disassembler for scanning code
for references in scanExternalRefs(). Unlike the previous approach, the
symbolizer properly detects and creates references for instructions with
multiple/ambiguous symbolic operands and handles cases where a
relocation doesn't match any operand. See test cases for examples.
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D152631
PUSH[16|32|64]i[8|32] are not arithmetic instructions, so I renamed the
functions.
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D151028
Extending yaml profile format with block hashes, which are used for stale
profile matching. To avoid duplication of the code, created a new class with a
collection of utilities for computing hashes.
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D144306
The two methods don't belong in BinaryFunction methods.
Move the dispatch tables into target-specific MCPlusBuilder methods.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D131813
Leverage move semantics for `std::vector`.
This also makes it consistent with `createInstrumentationSnippet`.
Reviewed By: Elvina
Differential Revision: https://reviews.llvm.org/D145465
When createInstrumentedIndirectCall() was invoked for tail calls, we
attached annotation instruction twice to the new call instruction.
First in createDirectCall(), and then again while copying over the
metadata operands.
As a result, the annotations were not properly stripped for such calls
before the call to freeAnnotations() in LowerAnnotations pass. That lead
to use-after-free while restoring the offsets with setOffset() call.
Reviewed By: yota9
Differential Revision: https://reviews.llvm.org/D144806
Simplify `MCPlusBuilder::evaluateX86MemoryOperand`: make it return a struct
with memory operand analysis struct `X86MemOperand`.
Reviewed By: #bolt, rafauler
Differential Revision: https://reviews.llvm.org/D144310
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 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
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
Refactor isStackAccess() to reflect updates by D126116. Now we only
handle simple stack accesses and delegate the rest of the cases to
getMemDataSize.
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D126112
Generate INSTRINFO_OPERAND_TYPE table in X86GenInstrInfo.inc.
This diff adds support for instructions that were previously reported as having
memory access size 0. It replaces the heuristic of looking at instruction
register width to determine memory access width by instead checking the memory
operand type using tablegen-provided tables.
Reviewed By: skan
Differential Revision: https://reviews.llvm.org/D126116
Summary:
While disassembling instructions, we need to replace certain immediate
operands with symbols. This symbolizing process relies on reading
relocations against instructions. However, some X86 instructions can
have multiple immediate operands and up to two relocations against
them. Thus, correctly matching a relocation to an operand is not
always possible without knowing the operand offset within the
instruction.
Luckily, LLVM provides an interface for passing the required info from
the disassembler via a virtual MCSymbolizer class. Creating a
target-specific version allows a precise matching of relocations to
operands.
This diff adds X86MCSymbolizer class that performs X86-specific
symbolizing (currently limited to non-branch instructions).
Reviewers: yota9, Amir, ayermolo, rafauler, zr33
Differential Revision: https://reviews.llvm.org/D120928
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
Address warnings in Release build without assertions.
Tip @tschuett for reporting the issue #55404.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D125475
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
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
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
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
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:
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 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)
