[llvm-objcopy][MachO] Use alignToPowerOf2 instead of alignTo (#204033)
During the review of #203680 I noticed that Mach-O objcopy files seems
to use `alignTo` and import `Alignment.h` to align some offsets to page
boundaries and similar requirements. However, the `alignTo` in
`Alignment.h`, while being intended for powers of 2, requires using an
alignment of type `llvm::Align`, and needs explicit conversion from
`uint64_t` and similar. Single `Alignment.h` includes `MathExtras.h`,
the `alignTo` being invoked ends up being a generic `alignTo` that does
not require powers of 2, and perform divisions and multiplications.
While some of those might be optimized by the compiler into efficient
power of 2 operations, there's an explicit `alignToPowerOf2` version
that is optimized and asserts the alignment is a power of 2 (with
asserts enabled). Since all the alignments should be power of 2 for the
Mach-O binary format, change from `alignTo` to `alignToPowerOf2` to make
the fact more visible (and get the extra safety net of the assertions).
As expected, the test suite of objcopy doesn't show any regressions, but
I have not done a performance benchmark around this either.
[llvm-objcopy][MachO] Align __LINKEDIT entries to pointer size (#203680)
Align Mach-O __LINKEDIT entries to the target pointer size when building
the tail layout. This matches the behavior of ld64 and lld-macho.
dyld on macOS 27 rejects loading dylibs with misaligned __LINKEDIT
entries.
See #203678 for details and the motivation of this fix.
AI Tool Use Disclosure:
Regarding the PR and the linked issue, I have personally wrote every
single part of the PR by myself, and have/ran/verified every single part
of the issue report as well without any AI tool usage.
I have used LLM-based coding agents only for debugging purposes, e.g. to
figure out why the dylib was not loading (from the original bug report),
and figuring out how to build, run, and test my local `llvm-objcopy`.
databases/clickhouse-devel: New port
ClickHouse is an open-source column-oriented database management
system that allows generating analytical data reports in real time.
This is based on the the stable series.
WWW: https://clickhouse.com/
[VPlan] Skip shl->mul SCEV rewrite for out-of-range shift amounts. (#204921)
getSCEVExprForVPValue rewrites `shl x, c` as `x * (1 << c)` using
ScalarEvolution::getPowerOfTwo, which asserts that the power is less
than the type's bit width.
Only perform the rewrite when the shift amount is less than the
operand's bit width, to avoid assertion.
