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tuttlem/strlen.asm

Created January 7, 2013 21:44
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strlen - nasm
Raw
strlen.asm
_strlen:
push rcx ; save and clear out counter
xor rcx, rcx
_strlen_next:
cmp [rdi], byte 0 ; null byte yet?
jz _strlen_null ; yes, get out
inc rcx ; char is ok, count it
inc rdi ; move to next char
jmp _strlen_next ; process again
_strlen_null:
mov rax, rcx ; rcx = the length (put in rax)
pop rcx ; restore rcx
ret ; get out
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