summaryrefslogtreecommitdiffstats
path: root/src/VBox/Runtime/common/string/memrchr.asm
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 03:01:46 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 03:01:46 +0000
commitf8fe689a81f906d1b91bb3220acde2a4ecb14c5b (patch)
tree26484e9d7e2c67806c2d1760196ff01aaa858e8c /src/VBox/Runtime/common/string/memrchr.asm
parentInitial commit. (diff)
downloadvirtualbox-upstream.tar.xz
virtualbox-upstream.zip
Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/VBox/Runtime/common/string/memrchr.asm')
-rw-r--r--src/VBox/Runtime/common/string/memrchr.asm97
1 files changed, 97 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/string/memrchr.asm b/src/VBox/Runtime/common/string/memrchr.asm
new file mode 100644
index 00000000..39af08f1
--- /dev/null
+++ b/src/VBox/Runtime/common/string/memrchr.asm
@@ -0,0 +1,97 @@
+; $Id: memrchr.asm $
+;; @file
+; IPRT - No-CRT memrchr - AMD64 & X86.
+;
+
+;
+; Copyright (C) 2006-2019 Oracle Corporation
+;
+; This file is part of VirtualBox Open Source Edition (OSE), as
+; available from http://www.virtualbox.org. This file is free software;
+; you can redistribute it and/or modify it under the terms of the GNU
+; General Public License (GPL) as published by the Free Software
+; Foundation, in version 2 as it comes in the "COPYING" file of the
+; VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+;
+; The contents of this file may alternatively be used under the terms
+; of the Common Development and Distribution License Version 1.0
+; (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+; VirtualBox OSE 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.
+;
+
+%include "iprt/asmdefs.mac"
+
+BEGINCODE
+
+;;
+; @param pv gcc: rdi msc: ecx x86:[esp+4] wcall: eax
+; @param ch gcc: esi msc: edx x86:[esp+8] wcall: edx
+; @param cb gcc: rdx msc: r8 x86:[esp+0ch] wcall: ebx
+RT_NOCRT_BEGINPROC memrchr
+ std
+%ifdef RT_ARCH_AMD64
+ %ifdef ASM_CALL64_MSC
+ or r8, r8
+ jz .not_found_early
+
+ mov r9, rdi ; save rdi
+ mov eax, edx
+ lea rdi, [rcx + r8 - 1]
+ mov rcx, r8
+ %else
+ mov rcx, rdx
+ jrcxz .not_found_early
+
+ mov eax, esi
+ lea rdi, [rdi + rcx - 1]
+ %endif
+
+%else
+ %ifdef ASM_CALL32_WATCOM
+ mov ecx, ebx
+ jecxz .not_found_early
+ xchg eax, edx
+ xchg edi, edx ; load + save edi
+ %else
+ mov ecx, [esp + 0ch]
+ jecxz .not_found_early
+ mov edx, edi ; save edi
+ mov eax, [esp + 8]
+ mov edi, [esp + 4]
+ %endif
+ lea edi, [edi + ecx - 1]
+%endif
+
+ ; do the search
+ repne scasb
+ jne .not_found
+
+ ; found it
+ lea xAX, [xDI + 1]
+%ifdef ASM_CALL64_MSC
+ mov rdi, r9
+%endif
+%ifdef RT_ARCH_X86
+ mov edi, edx
+%endif
+ cld
+ ret
+
+.not_found:
+%ifdef ASM_CALL64_MSC
+ mov rdi, r9
+%endif
+%ifdef RT_ARCH_X86
+ mov edi, edx
+%endif
+.not_found_early:
+ xor eax, eax
+ cld
+ ret
+ENDPROC RT_NOCRT(memrchr)
+