reactos/sdk/lib/crt/math/i386/aullshr_asm.s

99 lines
2.9 KiB
ArmAsm

/*
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS kernel
* PURPOSE: Run-Time Library
* FILE: lib/sdk/crt/math/i386/aullshr_asm.s
* PROGRAMER: Alex Ionescu (alex@relsoft.net)
*
* Copyright (C) 2002 Michael Ringgaard.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES// LOSS OF USE, DATA, OR PROFITS// OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <asm.inc>
PUBLIC __aullshr
/* FUNCTIONS ***************************************************************/
.code
//
// ullshr - long shift right
//
// Purpose:
// Does a unsigned Long Shift Right
// Shifts a long right any number of bits.
//
// Entry:
// EDX:EAX - long value to be shifted
// CL - number of bits to shift by
//
// Exit:
// EDX:EAX - shifted value
//
// Uses:
// CL is destroyed.
//
__aullshr:
//
// Handle shifts of 64 bits or more (if shifting 64 bits or more, the result
// depends only on the high order bit of edx).
//
cmp cl,64
jae short .RETZERO
//
// Handle shifts of between 0 and 31 bits
//
cmp cl, 32
jae short .MORE32
shrd eax,edx,cl
shr edx,cl
ret
//
// Handle shifts of between 32 and 63 bits
//
.MORE32:
mov eax,edx
xor edx,edx
and cl,31
shr eax,cl
ret
//
// return 0 in edx:eax
//
.RETZERO:
xor eax,eax
xor edx,edx
ret
END