blob: e8739e2616b65aaa33f532f7fc33f6375121bc3b (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
|
# Copyright 2022 Gabriel Jensen.
# This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
# If a copy of the MPL was not distributed with this file, You can obtain one at https://mozilla.org/MPL/2.0/.
.globl zap_strlen
zap_strlen:
# rax: Address of the current character.
# rdi: Address of the first character.
# rdx: Current character.
movq %rdi,%rax
# Iterate over the string:
.loop:
# Move the character into a register:
movb (%rax),%dl
# Check if we have reached the null-terminator:
testb %dl,%dl
jz .done # If so, we are done.
# Continue to the next character:
incq %rax
jmp .loop
# Done:
.done:
# Get the length:
subq %rdi,%rax
ret
|
