[PATCH v3 0/1] riscv: add vectorized memset, memcpy and memmove

[Pincheng Wang]

Hi all,

This v3 patch adds RISC-V Vector (RVV) optimized implementations for
memset, memcpy and memmove.

Changes since v2:
- Changed conditional compilation order, so vector path will not be
  chosen when optimizing for size.

Changes since v1:
- Switch the conditional compilation macro from __riscv_v to
  __riscv_vector.
- Replaced '.option arch,+v' with '.option arch,+zve32x'.
- Removed an unnecessary unconditional jump instruction in
  memmove-asm.S.
- In memcpy and memmove, when __riscv_misaligned_fast is not defined,
  the destination address is now aligned to SZREG to improve performance
  on systems with slow misaligned accesses.

These implementations use the RVV extension with e8 element size and m8
LMUL, and are conditionally compiled only when __riscv_vector is
defined, ensuring compatibility with non-vector RISC-V systems.

Benchmark results on Spacemit X60 (Muse-pi) and Canaan K230 show
significant improvements.

memcpy: Up to 4.84x on Muse-pi and 4.66x on K230.
memset: Up to 4.31x on Muse-pi and 3.14x on K230.
memmove: Up to 2.87x on Muse-pi and 1.48x on K230.

Comments and suggestions are greatly appreciated. Thank you for your
time and review!

Best regards,
Pincheng Wang

Pincheng Wang (1):
  riscv: add vectorized memset, memcpy and memmove

 newlib/libc/machine/riscv/memcpy-asm.S  | 52 ++++++++++++++
 newlib/libc/machine/riscv/memcpy.c      |  2 +-
 newlib/libc/machine/riscv/memmove-asm.S | 93 +++++++++++++++++++++++++
 newlib/libc/machine/riscv/memmove.c     |  2 +-
 newlib/libc/machine/riscv/memset.S      | 18 +++++
 5 files changed, 165 insertions(+), 2 deletions(-)

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2.39.5