diff options
Diffstat (limited to 'src/u_utils.S')
| -rw-r--r-- | src/u_utils.S | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/src/u_utils.S b/src/u_utils.S new file mode 100644 index 0000000..a460701 --- /dev/null +++ b/src/u_utils.S @@ -0,0 +1,58 @@ +/* + * ======================== + * ===== =============== + * ====== ================ + * ====== ================ + * ====== ==== ==== == + * ====== === == = = + * ====== === = == = + * = === === = == ==== + * = === === = == = = + * == ===== ==== == + * ======================== + * + * SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 2022 Joe + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the organization nor the + * names of its contributors may be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY JOE ''AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL JOE BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * asm-cgi-example: src/u_utils.S + * Sun May 22 18:12:26 CEST 2022 + * Joe + */ + +.text +.globl u_strlen + +u_strlen: + movq $-1, %rax + pushq %rdi +loop: + addq $0x1, %rax + cmpb $0x0, (%rdi) + leaq 1(%rdi), %rdi + jne loop + popq %rdi + retq |