diff options
Diffstat (limited to 'zap/source/amd64/mem/strfnd.S')
| -rw-r--r-- | zap/source/amd64/mem/strfnd.S | 48 |
1 files changed, 0 insertions, 48 deletions
diff --git a/zap/source/amd64/mem/strfnd.S b/zap/source/amd64/mem/strfnd.S deleted file mode 100644 index f2f94fa..0000000 --- a/zap/source/amd64/mem/strfnd.S +++ /dev/null @@ -1,48 +0,0 @@ -# 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/. - -.globl zap_strfnd - -zap_strfnd: -# Address of the first character: -#define start %rdi -# Character to be found: -#define cmp %sil -# Address of the current character: -#define addr %rax -# Current character: -#define chr %dl - - movq start,addr # addr = start - - # Iterate over the string: -.loop: - - # Copy the character into a register: - movb (addr),chr # chr = *addr - - # Check if we have found the character: - cmpb chr,cmp # if (chr == cmp) - je .fnd # goto fnd - - # Check if we have found the null-terminator: - testb chr,chr # if (chr == 0x0) - jz .nfnd # goto nfnd - - # Continue to the next character: - incq addr # ++addr - jmp .loop # goto loop - - # Found: -.fnd: - - # Get the offset of the character: - subq start,addr # addr -= start - ret # return addr - - # Not found: -.nfnd: - - movq $0xFFFFFFFFFFFFFFFF,addr # addr = 0xFFFFFFFFFFFFFFFF - ret # return addr |