Adding upstream version 7.0.6-dfsg.upstream/7.0.6-dfsgupstream

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

1 files changed, 137 insertions, 0 deletions

diff --git a/src/VBox/Runtime/common/asm/ASMBitFirstSet.asm b/src/VBox/Runtime/common/asm/ASMBitFirstSet.asm
new file mode 100644
index 00000000..0f2c87a0
--- /dev/null
+++ b/src/VBox/Runtime/common/asm/ASMBitFirstSet.asm
@@ -0,0 +1,137 @@
+; $Id: ASMBitFirstSet.asm $
+;; @file
+; IPRT - ASMBitFirstSet().
+;
+
+;
+; Copyright (C) 2006-2022 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
+;
+
+
+;*******************************************************************************
+;* Header Files                                                                *
+;*******************************************************************************
+%include "iprt/asmdefs.mac"
+
+BEGINCODE
+
+;;
+; Finds the first set 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 set 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.
+;
+RT_BEGINPROC ASMBitFirstSet
+        ;
+        ; 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 + 4]
+%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
+        xor     eax, eax
+        repe scasd                      ; Scan for the first dword with any bit set.
+        je      .failed_restore
+
+        ; find the bit in question
+        sub     xDI, 4                  ; one step back.
+%if ARCH_BITS == 16
+        movzx   edi, di
+        mov     eax, [es:xDI]
+%else
+        mov     eax, [xDI]
+%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 ASMBitFirstSet
+