[all-commits] [llvm/llvm-project] f35bd3: [libc][aarch64] Use inline_memcpy_aligned_access_6...

[PiJoules via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f35bd33e2d9037a2dab48c8231355e01b9c4a722
      https://github.com/llvm/llvm-project/commit/f35bd33e2d9037a2dab48c8231355e01b9c4a722
  Author: PiJoules <leonardchan at google.com>
  Date:   2026-09-29 (Tue, 29 Sep 2026)

  Changed paths:
    M libc/src/string/memory_utils/aarch64/inline_memcpy.h

  Log Message:
  -----------
  [libc][aarch64] Use inline_memcpy_aligned_access_64bit under -mstrict-align (#227428)

Under `-mstrict-align`, clang cannot determine both `src` and `dst` are
aligned. The end of `inline_memcpy_aarch64` aligns `src` but it cannot
confirm `dst` is aligned. As a result,
`builtin::Memcpy<64>::loop_and_tail(dst, src, count)` lowers to
`__builtin_memcpy_inline(..., 64)` but clang emits many many single-byte
load/store instructions to ensure correctness. This can be very slow, so
if unaligned accesses are not supported, opt for adjusting both `src`
and `dst` such that we can use 8-byte loads/stores.
`inline_memcpy_aligned_access_64bit` already does this so we can just
reuse that.



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