xref: /reactos/sdk/lib/crt/math/i386/allshl_asm.s (revision 8a978a17)
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/allshl_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 __allshl
40
41/* FUNCTIONS ***************************************************************/
42.code
43
44//
45// llshl - long shift left
46//
47// Purpose:
48//       Does a Long Shift Left (signed and unsigned are identical)
49//       Shifts a long left 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__allshl:
63
64//
65// Handle shifts of 64 or more bits (all get 0)
66//
67        cmp     cl, 64
68        jae     short RETZERO
69
70//
71// Handle shifts of between 0 and 31 bits
72//
73        cmp     cl, 32
74        jae     short MORE32
75        shld    edx,eax,cl
76        shl     eax,cl
77        ret
78
79//
80// Handle shifts of between 32 and 63 bits
81//
82MORE32:
83        mov     edx,eax
84        xor     eax,eax
85        and     cl,31
86        shl     edx,cl
87        ret
88
89//
90// return 0 in edx:eax
91//
92RETZERO:
93        xor     eax,eax
94        xor     edx,edx
95        ret
96
97END
98