From 8eede5fd642db2c56a1f5185973815fbd2b0afa4 Mon Sep 17 00:00:00 2001 From: Anton Kling Date: Fri, 27 Oct 2023 16:32:13 +0200 Subject: LibC: Optimize memcpy function Instead of copying byte by byte it now copies in 64, 32, 16, 8 bit chunks. --- libc/string/memcpy.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'libc/string/memcpy.c') diff --git a/libc/string/memcpy.c b/libc/string/memcpy.c index 70a60c1..5c04407 100644 --- a/libc/string/memcpy.c +++ b/libc/string/memcpy.c @@ -1,10 +1,19 @@ #include "../include/string.h" -void *__attribute__((optimize("O0"))) +void * memcpy(void *dest, const void *src, uint32_t n) { unsigned char *d = dest; const unsigned char *s = src; - // for(;n--;) *d++ = *s++; + + for (; n >= 8; n -= 8, d += 8, s += 8) + *(uint64_t *)d = *(uint64_t *)s; + + for (; n >= 4; n -= 4, d += 4, s += 4) + *(uint32_t *)d = *(uint32_t *)s; + + for (; n >= 2; n -= 2, d += 2, s += 2) + *(uint16_t *)d = *(uint16_t *)s; + for (; n; n--) *d++ = *s++; return dest; -- cgit v1.2.3