/* 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 . */ #include .global rgo_strcpy rgo_strcpy: #if defined(__x86_64__) /* rdi: char const * lstr rsi: char const * rstr */ /* rax: Address of the current input character. */ movq %rdi,%rax /* rdx: Address of the current output character. */ movq %rsi,%rdx /* cl: Current character. */ .loop: movb (%rax),%cl movb %cl,(%rdx) testb %cl,%cl jz .done incq %rax incq %rdx jmp .loop .done: subq %rdi,%rax ret #endif