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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/memmove.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/memmove.asm')
-rw-r--r--src/VBox/Runtime/common/string/memmove.asm145
1 files changed, 145 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/string/memmove.asm b/src/VBox/Runtime/common/string/memmove.asm
new file mode 100644
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+++ b/src/VBox/Runtime/common/string/memmove.asm
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+; $Id: memmove.asm $
+;; @file
+; IPRT - No-CRT memmove - 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 pvDst gcc: rdi msc: rcx x86:[esp+4] wcall: eax
+; @param pvSrc gcc: rsi msc: rdx x86:[esp+8] wcall: edx
+; @param cb gcc: rdx msc: r8 x86:[esp+0ch] wcall: ebx
+RT_NOCRT_BEGINPROC memmove
+ ; Prolog.
+%ifdef RT_ARCH_AMD64
+ %ifdef ASM_CALL64_MSC
+ mov r10, rdi ; save
+ mov r11, rsi ; save
+ mov rdi, rcx
+ mov rsi, rdx
+ mov rcx, r8
+ mov rdx, r8
+ %else
+ mov rcx, rdx
+ %endif
+ mov rax, rdi ; save the return value
+%else
+ push edi
+ push esi
+ %ifdef ASM_CALL32_WATCOM
+ mov edi, eax
+ mov esi, edx
+ mov ecx, ebx
+ mov edx, ebx
+ %else
+ mov edi, [esp + 04h + 8]
+ mov esi, [esp + 08h + 8]
+ mov ecx, [esp + 0ch + 8]
+ mov edx, ecx
+ mov eax, edi ; save the return value
+ %endif
+%endif
+
+ ;
+ ; Decide which direction to perform the copy in.
+ ;
+%if 1 ; keep it simple for now.
+ cmp xDI, xSI
+ jnb .backward
+
+ ;
+ ; Slow/simple forward copy.
+ ;
+ cld
+ rep movsb
+ jmp .epilog
+
+%else ; disabled - it seems to work, but play safe for now.
+ ;sub xAX, xSI
+ ;jnb .backward
+ cmp xDI, xSI
+ jnb .backward
+
+ ;
+ ; Fast forward copy.
+ ;
+.fast_forward:
+ cld
+%ifdef RT_ARCH_AMD64
+ shr rcx, 3
+ rep movsq
+%else
+ shr ecx, 2
+ rep movsd
+%endif
+
+ ; The remaining bytes.
+%ifdef RT_ARCH_AMD64
+ test dl, 4
+ jz .forward_dont_move_dword
+ movsd
+%endif
+.forward_dont_move_dword:
+ test dl, 2
+ jz .forward_dont_move_word
+ movsw
+.forward_dont_move_word:
+ test dl, 1
+ jz .forward_dont_move_byte
+ movsb
+.forward_dont_move_byte:
+
+%endif ; disabled
+
+ ;
+ ; The epilog.
+ ;
+.epilog:
+%ifdef RT_ARCH_AMD64
+ %ifdef ASM_CALL64_MSC
+ mov rdi, r10
+ mov rsi, r11
+ %endif
+%else
+ pop esi
+ pop edi
+%endif
+ ret
+
+ ;
+ ; Slow/simple backward copy.
+ ;
+ALIGNCODE(16)
+.backward:
+ ;; @todo check if they overlap.
+ lea xDI, [xDI + xCX - 1]
+ lea xSI, [xSI + xCX - 1]
+ std
+ rep movsb
+ cld
+ jmp .epilog
+ENDPROC RT_NOCRT(memmove)
+