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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/.
*/
#include <rgo.h>
.global rgo_fndchr
rgo_fndchr:
/*
char const * str
char chr
*/
#if defined(__i386__)
/* eax: Address of the current character. */
movl 0x4(%esp),%eax
/* ecx: Character. */
movb 0x8(%esp),%cl
/* edx: Current character. */
.loop:
movb (%eax),%dl
cmpb %dl,%cl
je .fnd /* Exit loop if we have found the character. */
testb %dl,%dl
je .nfnd /* We encountered the null-terminator but not the specified character. */
incl %eax
jmp .loop
.fnd:
subl 0x4(%esp),%eax
ret
.nfnd:
movl $0xFFFFFFFF,%eax
ret
#elif defined(__x86_64__)
/* rax: Address of the current character. */
movq %rdi,%rax
/* rdx: Current character. */
.loop:
movb (%rax),%dl
cmpb %dl,%sil
je .fnd /* Exit loop if we have found the character. */
testb %dl,%dl
je .nfnd /* We encountered the null-terminator but not the specified character. */
incq %rax
jmp .loop
.fnd:
subq %rdi,%rax
ret
.nfnd:
movq $0xFFFFFFFFFFFFFFFF,%rax
ret
#endif
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