1 files changed, 56 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/asm/ASMGetXcr0.asm b/src/VBox/Runtime/common/asm/ASMGetXcr0.asm
new file mode 100644
index 00000000..e6306f66
--- /dev/null
+++ b/src/VBox/Runtime/common/asm/ASMGetXcr0.asm
@@ -0,0 +1,56 @@
+; $Id: ASMGetXcr0.asm $
+;; @file
+; IPRT - ASMGetXcr0().
+;
+
+;
+; 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.
+;
+
+;*******************************************************************************
+;* Header Files                                                                *
+;*******************************************************************************
+%define RT_ASM_WITH_SEH64
+%include "iprt/asmdefs.mac"
+
+BEGINCODE
+
+;;
+; Gets the content of the XCR0 CPU register.
+; @returns XCR0 value in rax (amd64) / edx:eax (x86).
+;
+BEGINPROC_EXPORTED ASMGetXcr0
+SEH64_END_PROLOGUE
+        xor     ecx, ecx                ; XCR0
+        xgetbv
+%ifdef RT_ARCH_AMD64
+        shl     rdx, 32
+        or      rax, rdx
+%endif
+%if ARCH_BITS == 16 ; DX:CX:BX:AX - DX=15:0, CX=31:16, BX=47:32, AX=63:48
+        mov     ebx, edx
+        mov     ecx, eax
+        shr     ecx, 16
+        xchg    eax, edx
+        shr     eax, 16
+%endif
+        ret
+ENDPROC ASMGetXcr0
+