1 files changed, 87 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/math/watcom/U8M-I8M-x86-32.asm b/src/VBox/Runtime/common/math/watcom/U8M-I8M-x86-32.asm
new file mode 100644
index 00000000..3b01cd5c
--- /dev/null
+++ b/src/VBox/Runtime/common/math/watcom/U8M-I8M-x86-32.asm
@@ -0,0 +1,87 @@
+; $Id: U8M-I8M-x86-32.asm $
+;; @file
+; BS3Kit - 32-bit Watcom C/C++, 64-bit unsigned integer division.
+;
+
+;
+; Copyright (C) 2007-2023 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
+
+
+;;
+; 64-bit signed & unsigned integer multiplication.
+;
+; @returns  EDX:EAX product
+; @param    EDX:EAX     Factor #1.
+; @param    ECX:EBX     Factor #2.
+; @uses     ECX, EBX
+;
+global __U8M
+__U8M:
+global __I8M
+__I8M:
+        ;
+        ; See if this is a pure 32-bit multiplication.  We might get lucky.
+        ;
+        test    edx, edx
+        jnz     .complicated
+        test    ecx, ecx
+        jnz     .complicated
+
+        mul     ebx                     ; eax * ebx -> edx:eax
+        ret
+
+.complicated:
+        push    eax
+        push    edx
+
+        ; ecx = F1.lo * F2.hi  (edx contains overflow here can be ignored)
+        mul     ecx
+        mov     ecx, eax
+
+        ; ecx += F1.hi * F2.lo (edx can be ignored again)
+        pop     eax
+        mul     ebx
+        add     ecx, eax
+
+        ; edx:eax = F1.lo * F2.lo
+        pop     eax
+        mul     ebx
+
+        ; Add ecx to the high part (edx).
+        add     edx, ecx
+
+        ret
+