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# 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_strfill
zap_strfill:
# Address of the current character:
#define addr %rax
# Address of the first character of the string:
#define start %rdi
# Fill character:
#define chr %sil
movq start,addr
# Iterate over string:
.loop:
# Check if we have reached the null-terminator:
cmpb $0x0,(addr) # if (*addr == 0x0)
je .done # goto done
# Set the value of the current element:
movb chr,(addr) # *addr = chr
# Continue to next character:
incq addr # ++addr
jmp .loop # goto loop
# Finish:
.done:
# Get the length of the string:
subq start,addr # addr -= start
ret # return addr
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