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3eb9473e | 1 | /*++\r |
2 | \r | |
4ea9375a HT |
3 | Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>\r |
4 | This program and the accompanying materials \r | |
3eb9473e | 5 | are licensed and made available under the terms and conditions of the BSD License \r |
6 | which accompanies this distribution. The full text of the license may be found at \r | |
7 | http://opensource.org/licenses/bsd-license.php \r | |
8 | \r | |
9 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r | |
10 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r | |
11 | \r | |
12 | Module Name:\r | |
13 | \r | |
14 | LShiftU64.c\r | |
15 | \r | |
16 | Abstract:\r | |
17 | \r | |
18 | 64-bit left shift function for IA-32\r | |
19 | \r | |
20 | --*/\r | |
21 | \r | |
22 | #include "Tiano.h"\r | |
23 | \r | |
24 | UINT64\r | |
25 | LShiftU64 (\r | |
26 | IN UINT64 Operand,\r | |
27 | IN UINTN Count\r | |
28 | )\r | |
29 | /*++\r | |
30 | \r | |
31 | Routine Description:\r | |
32 | \r | |
33 | This routine allows a 64 bit value to be left shifted by 32 bits and \r | |
34 | returns the shifted value.\r | |
35 | Count is valid up 63. (Only Bits 0-5 is valid for Count)\r | |
36 | \r | |
37 | Arguments:\r | |
38 | \r | |
39 | Operand - Value to be shifted\r | |
40 | Count - Number of times to shift left.\r | |
41 | \r | |
42 | Returns:\r | |
43 | \r | |
44 | Value shifted left identified by the Count.\r | |
45 | \r | |
46 | --*/\r | |
47 | {\r | |
48 | __asm {\r | |
49 | \r | |
50 | mov eax, dword ptr Operand[0]\r | |
51 | mov edx, dword ptr Operand[4]\r | |
52 | \r | |
53 | ;\r | |
54 | ; CL is valid from 0 - 31. shld will move EDX:EAX by CL times but EAX is not touched\r | |
55 | ; For CL of 32 - 63, it will be shifted 0 - 31 so we will move eax to edx later. \r | |
56 | ;\r | |
57 | mov ecx, Count\r | |
58 | and ecx, 63\r | |
59 | shld edx, eax, cl\r | |
60 | shl eax, cl\r | |
61 | \r | |
62 | ;\r | |
63 | ; Since Count is 32 - 63, eax will have been shifted by 0 - 31 \r | |
64 | ; If shifted by 32 or more, set lower 32 bits to zero.\r | |
65 | ;\r | |
66 | cmp ecx, 32\r | |
67 | jc short _LShiftU64_Done\r | |
68 | \r | |
69 | mov edx, eax\r | |
70 | xor eax, eax\r | |
71 | \r | |
72 | _LShiftU64_Done:\r | |
73 | }\r | |
74 | }\r |