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# --------------------------------------------
# FUNCTION: strcmp
# PURPOSE : compares twos strings, and returns
# if they are equal
# INPUTS : rdi = address of first string
# rsi = address of second string
# OUTPUTS : rax = 1 if equals else 0
# CLOBBERS:
# --------------------------------------------
.section .text
.globl strcmp
.type strcmp, @function
strcmp:
xorq %rax, %rax # i = 0
loop:
movb (%rdi, %rax, 1), %r8b
movb (%rsi, %rax, 1), %r9b
cmpb %r8b, %r9b # compare each byte
jne .strcmp_fail
testb %r8b, %r8b # if any is null,
jz .strcmp_success # both are null here
incq %rax
jmp loop
.strcmp_fail:
xorq %rax, %rax
ret
.strcmp_success:
movq $1, %rax
ret
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