diff options
Diffstat (limited to 'src/VBox/Runtime/common/string/strchr.asm')
| -rw-r--r-- | src/VBox/Runtime/common/string/strchr.asm | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/string/strchr.asm b/src/VBox/Runtime/common/string/strchr.asm new file mode 100644 index 00000000..59a8203a --- /dev/null +++ b/src/VBox/Runtime/common/string/strchr.asm @@ -0,0 +1,152 @@ +; $Id: strchr.asm $ +;; @file +; IPRT - No-CRT strchr - AMD64 & X86. +; + +; +; Copyright (C) 2006-2022 Oracle and/or its affiliates. +; +; This file is part of VirtualBox base platform packages, as +; available from https://www.virtualbox.org. +; +; This program is free software; you can redistribute it and/or +; modify it under the terms of the GNU General Public License +; as published by the Free Software Foundation, in version 3 of the +; License. +; +; This program 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 +; General Public License for more details. +; +; You should have received a copy of the GNU General Public License +; along with this program; if not, see <https://www.gnu.org/licenses>. +; +; The contents of this file may alternatively be used under the terms +; of the Common Development and Distribution License Version 1.0 +; (CDDL), a copy of it is provided in the "COPYING.CDDL" file included +; in the VirtualBox distribution, in which case the provisions of the +; CDDL are applicable instead of those of the GPL. +; +; You may elect to license modified versions of this file under the +; terms and conditions of either the GPL or the CDDL or both. +; +; SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 +; + +%include "iprt/asmdefs.mac" + +BEGINCODE + +;; +; @param psz gcc: rdi msc: rcx x86:[esp+4] wcall: eax +; @param ch gcc: esi msc: edx x86:[esp+8] wcall: edx +RT_NOCRT_BEGINPROC strchr + cld + + ; check for ch == 0 and setup normal strchr. +%ifdef RT_ARCH_AMD64 + %ifdef ASM_CALL64_MSC + or dl, dl + jz near .strlen + mov r9, rsi ; save rsi + mov rsi, rcx + %else + or sil, sil + jz near .strlen + mov edx, esi + mov rsi, rdi + %endif +%else + %ifndef ASM_CALL32_WATCOM + mov edx, [esp + 8] + %endif + or dl, dl + jz near .strlen + mov ecx, esi ; save esi + %ifdef ASM_CALL32_WATCOM + mov esi, eax + %else + mov esi, [esp + 4] + %endif +%endif + + ; do the search +.next: + lodsb + cmp al, dl + je .found + test al, al + jz .not_found + + lodsb + cmp al, dl + je .found + test al, al + jz .not_found + + lodsb + cmp al, dl + je .found + test al, al + jz .not_found + + lodsb + cmp al, dl + je .found + test al, al + jz .not_found + jmp .next + +.found: + lea xAX, [xSI - 1] +%ifdef ASM_CALL64_MSC + mov rsi, r9 +%endif +%ifdef RT_ARCH_X86 + mov esi, ecx +%endif + ret + +.not_found: +%ifdef ASM_CALL64_MSC + mov rsi, r9 +%endif +%ifdef RT_ARCH_X86 + mov esi, ecx +%endif + xor eax, eax + ret + +; +; Special case: strchr(str, '\0'); +; +align 16 +.strlen: +%ifdef RT_ARCH_AMD64 + %ifdef ASM_CALL64_MSC + mov r9, rdi ; save rdi + mov rdi, rcx + %endif +%else + mov edx, edi ; save edi + %ifdef ASM_CALL32_WATCOM + mov edi, eax + %else + mov edi, [esp + 4] + %endif +%endif + mov xCX, -1 + xor eax, eax + repne scasb + + lea xAX, [xDI - 1] +%ifdef ASM_CALL64_MSC + mov rdi, r9 +%endif +%ifdef RT_ARCH_X86 + mov edi, edx +%endif + ret +ENDPROC RT_NOCRT(strchr) + |