Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 127 insertions, 0 deletions

diff --git a/src/VBox/Runtime/common/asm/ASMBitFirstClear.asm b/src/VBox/Runtime/common/asm/ASMBitFirstClear.asm
new file mode 100644
index 00000000..86cad421
--- /dev/null
+++ b/src/VBox/Runtime/common/asm/ASMBitFirstClear.asm
@@ -0,0 +1,127 @@
+; $Id: ASMBitFirstClear.asm $
+;; @file
+; IPRT - ASMBitFirstClear().
+;
+
+;
+; 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                                                                *
+;*******************************************************************************
+%include "iprt/asmdefs.mac"
+
+BEGINCODE
+
+;;
+; Finds the first clear bit in a bitmap.
+;
+; @returns (32/64:eax, 16:ax+dx)   Index of the first zero bit.
+; @returns (32/64:eax, 16:ax+dx)  -1 if no clear bit was found.
+; @param   msc:rcx gcc:rdi pvBitmap    Pointer to the bitmap.
+; @param   msc:edx gcc:rsi cBits       The number of bits in the bitmap. Multiple of 32.
+;
+BEGINPROC_EXPORTED ASMBitFirstClear
+        ;
+        ; if (cBits)
+        ; Put cBits in ecx first.
+        ;
+%if    ARCH_BITS == 64
+ %ifdef ASM_CALL64_GCC
+        mov     ecx, esi
+ %else
+        xchg    rcx, rdx                ; rdx=pvDst, ecx=cBits
+ %endif
+%elif ARCH_BITS == 32
+        mov     ecx, [esp + 4 + 4]
+%elif ARCH_BITS == 16
+        push    bp
+        mov     bp, sp
+        mov     ecx, [bp + 4 + 4]
+%endif
+        or      ecx, ecx
+        jz      short .failed
+        ;{
+        push    xDI
+
+        ;    asm {...}
+%if    ARCH_BITS == 64
+ %ifdef ASM_CALL64_GCC
+                                        ; rdi = start of scasd - already done
+ %else
+        mov     rdi, rdx                ; rdi = start of scasd (Note! xchg rdx,rcx above)
+ %endif
+%elif ARCH_BITS == 32
+        mov     edi, [esp + 8]
+%elif ARCH_BITS == 16
+        mov     ax, [bp + 4 + 2]
+        mov     di, [bp + 4]
+        mov     es, ax                  ; es is volatile, no need to save.
+%endif
+        add     ecx, 31                 ; 32 bit aligned
+        shr     ecx, 5                  ; number of dwords to scan.
+        mov     xDX, xDI                ; xDX = saved pvBitmap
+        mov     eax, 0ffffffffh
+        repe scasd                      ; Scan for the first dword with any clear bit.
+        je      .failed_restore
+
+        ; find the bit in question
+        sub     xDI, 4                  ; one step back.
+%if ARCH_BITS == 16
+        movzx   edi, di
+        xor     eax, [es:xDI]           ; eax = NOT [rdi]
+%else
+        xor     eax, [xDI]              ; eax = NOT [rdi]
+%endif
+        sub     xDI, xDX
+        shl     edi, 3                  ; calc bit offset.
+
+        bsf     ecx, eax
+        jz      .failed_restore         ; race paranoia
+        add     ecx, edi
+        mov     eax, ecx
+
+        ; return success
+        pop     xDI
+%if ARCH_BITS == 16
+        mov     edx, eax
+        shr     edx, 16
+        leave
+%endif
+        ret
+
+        ; failure
+        ;}
+        ;return -1;
+.failed_restore:
+        pop     xDI
+.failed:
+%if ARCH_BITS != 16
+        mov     eax, 0ffffffffh
+%else
+        mov     ax, 0ffffh
+        mov     dx, ax
+        leave
+%endif
+        ret
+ENDPROC ASMBitFirstClear
+