memcpy asm for i386 and x86_64

2012-08-11 21:33:13 -04:00 · 2012-08-11 21:33:13 -04:00 · aaa9eb5101
commit aaa9eb5101
parent 036eaa24cf
2 changed files with 51 additions and 0 deletions
--- a/src/string/x86_64/memcpy.s
+++ b/src/string/x86_64/memcpy.s
@ -0,0 +1,22 @@
+.global memcpy
+.type memcpy,@function
+memcpy:
+	mov %rdi,%rax
+	cmp $8,%rdx
+	jc 1f
+	test $7,%edi
+	jz 1f
+2:	movsb
+	dec %rdx
+	test $7,%edi
+	jnz 2b
+1:	mov %rdx,%rcx
+	shr $3,%rcx
+	rep
+	movsq
+	and $7,%edx
+	jz 1f
+2:	movsb
+	dec %edx
+	jnz 2b
+1:	ret