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/*
Copyright 2022 Gabriel Jensen
This file is part of rgo.
rgo is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
rgo is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with rgo. If not, see <https://www.gnu.org/licenses/>.
*/
#include <rgo.h>
.global rgo_fndbyte
rgo_fndbyte:
/*
void const * ptr
size_t num
uint8_t byte
*/
#if defined(__x86_64__)
/* rax: Address of the current element. */
movq %rdi,%rax
/* rsi: Address of the element after the last element. */
addq %rdi,%rsi
/* rcx: Current element. */
.loop:
cmpq %rax,%rsi
je .nfnd /* We have went through the entire array without finding the byte. */
movb (%rax),%cl
cmpb %cl,%dl
je .fnd /* We have found the byte. */
incq %rax
jmp .loop
.fnd:
subq %rdi,%rax
ret
.nfnd:
movq $0xFFFFFFFFFFFFFFFF,%rax
ret
#endif
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