From 5278f6def4248391a481382bd7b0042b04c829f2 Mon Sep 17 00:00:00 2001 From: Richard Qin Date: Tue, 21 Apr 2026 23:16:50 +0800 Subject: feat: add string manipulation functions derived from musl libc This commit introduces a variety of string manipulation functions, including: - `memmem`: Searches for a substring in a memory area. - `memmove`: Safely copies memory areas, handling overlaps. - `mempcpy`: Copies memory and returns a pointer to the end of the destination. - `memrchr`: Finds the last occurrence of a character in a memory area. - `memset`: Fills a memory area with a specified value. - `rindex`: Returns the last occurrence of a character in a string. - `stpcpy` and `stpncpy`: Copies strings and returns a pointer to the end. - `strcat`, `strchr`, `strcspn`, `strlcat`, `strlcpy`, `strlen`, `strncat`, `strncmp`, `strncpy`, `strnlen`, `strpbrk`, `strrchr`, `strstr`, `strtok`, and `strtok_r`: Various string manipulation functions for concatenation, searching, and tokenization. Assembly implementations for `memcpy`, `memmove`, and `memset` are also included for optimized performance on x86_64 architectures. --- na/lib/string/i386/memcpy.s | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 na/lib/string/i386/memcpy.s (limited to 'na/lib/string/i386/memcpy.s') diff --git a/na/lib/string/i386/memcpy.s b/na/lib/string/i386/memcpy.s new file mode 100644 index 0000000..0608dd8 --- /dev/null +++ b/na/lib/string/i386/memcpy.s @@ -0,0 +1,32 @@ +.global memcpy +.global __memcpy_fwd +.hidden __memcpy_fwd +.type memcpy,@function +memcpy: +__memcpy_fwd: + push %esi + push %edi + mov 12(%esp),%edi + mov 16(%esp),%esi + mov 20(%esp),%ecx + mov %edi,%eax + cmp $4,%ecx + jc 1f + test $3,%edi + jz 1f +2: movsb + dec %ecx + test $3,%edi + jnz 2b +1: mov %ecx,%edx + shr $2,%ecx + rep + movsl + and $3,%edx + jz 1f +2: movsb + dec %edx + jnz 2b +1: pop %edi + pop %esi + ret -- cgit v1.2.3