diff options
Diffstat (limited to 'rgo/src/streq.S')
| -rw-r--r-- | rgo/src/streq.S | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/rgo/src/streq.S b/rgo/src/streq.S new file mode 100644 index 0000000..f530d54 --- /dev/null +++ b/rgo/src/streq.S @@ -0,0 +1,45 @@ +/* + 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_streq + +rgo_streq: +#if defined(__x86_64__) + /* + rdi: char const * lstr + rsi: char const * rstr + */ + /* rdx: Address of the current input character. */ + movq %rdi,%rdx + /* rcx: Address of the current output character. */ + movq %rsi,%rcx + /* r8b: Current input character. */ + /* r9b: Current output character. */ +.loop: + movb (%rdx),%r8b + movb (%rcx),%r9b + cmpb %r8b,%r9b + jne .neq + testb %r8b,%r8b /* Check if we have reached the null-terminator. */ + jz .eq + incq %rdx + incq %rcx + jmp .loop +.eq: + mov $0x1,%rax + ret +.neq: + mov $0x0,%rax + ret +#endif |