1/* 2 * COPYRIGHT: See COPYING in the top level directory 3 * PROJECT: ReactOS kernel 4 * PURPOSE: Run-Time Library 5 * FILE: lib/sdk/crt/math/i386/aullshr_asm.s 6 * PROGRAMER: Alex Ionescu (alex@relsoft.net) 7 * 8 * Copyright (C) 2002 Michael Ringgaard. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the project nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES// LOSS OF USE, DATA, OR PROFITS// OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37#include <asm.inc> 38 39PUBLIC __aullshr 40 41/* FUNCTIONS ***************************************************************/ 42.code 43 44// 45// ullshr - long shift right 46// 47// Purpose: 48// Does a unsigned Long Shift Right 49// Shifts a long right any number of bits. 50// 51// Entry: 52// EDX:EAX - long value to be shifted 53// CL - number of bits to shift by 54// 55// Exit: 56// EDX:EAX - shifted value 57// 58// Uses: 59// CL is destroyed. 60// 61 62__aullshr: 63 64// 65// Handle shifts of 64 bits or more (if shifting 64 bits or more, the result 66// depends only on the high order bit of edx). 67// 68 cmp cl,64 69 jae short .RETZERO 70 71// 72// Handle shifts of between 0 and 31 bits 73// 74 cmp cl, 32 75 jae short .MORE32 76 shrd eax,edx,cl 77 shr edx,cl 78 ret 79 80// 81// Handle shifts of between 32 and 63 bits 82// 83.MORE32: 84 mov eax,edx 85 xor edx,edx 86 and cl,31 87 shr eax,cl 88 ret 89 90// 91// return 0 in edx:eax 92// 93.RETZERO: 94 xor eax,eax 95 xor edx,edx 96 ret 97 98END 99