audk/MdePkg/Library/BaseLib/Ia32/RRotU64.asm

50 lines
1.5 KiB
NASM

;------------------------------------------------------------------------------
;
; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
; This program and the accompanying materials
; are licensed and made available under the terms and conditions of the BSD License
; which accompanies this distribution. The full text of the license may be found at
; http://opensource.org/licenses/bsd-license.php
;
; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
;
; Module Name:
;
; RRotU64.asm
;
; Abstract:
;
; 64-bit right rotation for Ia32
;
;------------------------------------------------------------------------------
.686
.model flat,C
.code
;------------------------------------------------------------------------------
; UINT64
; EFIAPI
; InternalMathRRotU64 (
; IN UINT64 Operand,
; IN UINTN Count
; );
;------------------------------------------------------------------------------
InternalMathRRotU64 PROC USES ebx
mov cl, [esp + 16]
mov eax, [esp + 8]
mov edx, [esp + 12]
shrd ebx, eax, cl
shrd eax, edx, cl
rol ebx, cl
shrd edx, ebx, cl
test cl, 32 ; Count >= 32?
cmovnz ecx, eax ; switch eax & edx if Count >= 32
cmovnz eax, edx
cmovnz edx, ecx
ret
InternalMathRRotU64 ENDP
END