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nuttx/libs/libc/machine/risc-v
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ganjing a0fcbb7957 libs/libc/risc-v: Refresh memcpy and memset with XLEN-adaptive loops. 
Rewrite arch_memcpy.S and arch_memset.S to be register-width aware on
both RV32 and RV64 using REG_L/REG_S/SZREG macros from asm.h.

memcpy gains:
 - 16xSZREG unrolled main loop (128B/iter on RV64, 64B on RV32).
 - Shift-merge path for misaligned src: reads two aligned words
   straddling each output word and shifts them together, so no load
   or store is ever misaligned.
 - Single SZREG and byte loops for remainder and small copies.

memset gains:
 - 32xSZREG unrolled main loop (256B/iter on RV64, 128B on RV32)
   using Duff's device for non-power-of-two remainders.
 - .option norvc ensures fixed 4-byte instruction width for correct
   jump offset calculation in the Duff's device entry.
 - Zero-length input handled correctly (branch to guarded tail).

The old memcpy always used lw/sw even on RV64, wasting half the
memory bandwidth. The old memset unrolled only 16 bytes per iteration.

Signed-off-by: ganjing <ganjing@xiaomi.com>
2026-08-12 10:24:01 +08:00
..
arch_elf.c include/debug.h: Move to include/nuttx/debug.h 2026-04-07 07:50:06 -03:00
arch_memchr.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
arch_memcmp.S libs/libc/risc-v: Unroll memcmp with 4-word XOR|OR folding. 2026-08-12 10:23:47 +08:00
arch_memcpy.S libs/libc/risc-v: Refresh memcpy and memset with XLEN-adaptive loops. 2026-08-12 10:24:01 +08:00
arch_memmove.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
arch_memset.S libs/libc/risc-v: Refresh memcpy and memset with XLEN-adaptive loops. 2026-08-12 10:24:01 +08:00
arch_setjmp.S
arch_stpcpy.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
arch_stpncpy.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
arch_strcat.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
arch_strchr.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
arch_strchrnul.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
arch_strcmp.S libs/risc-v:add cfi for optimized compilation func 2025-12-18 22:05:12 +08:00
arch_strcpy.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
arch_strlcpy.S libs/libc/risc-v: Add optimized strlcpy. 2026-08-12 10:23:47 +08:00
arch_strlen.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
arch_strncmp.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
arch_strncpy.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
arch_strnlen.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
arch_strrchr.S libs/libc/risc-v: Add optimized string and memory functions. 2026-08-12 10:23:47 +08:00
asm.h
CMakeLists.txt libs/libc/risc-v: Add optimized strlcpy. 2026-08-12 10:23:47 +08:00
Kconfig libs/libc/risc-v: Add optimized strlcpy. 2026-08-12 10:23:47 +08:00
Make.defs libs/libc/risc-v: Add optimized strlcpy. 2026-08-12 10:23:47 +08:00