| 1 | /*++␍␊ |
| 2 | ␍␊ |
| 3 | Copyright (c) 2004 - 2010, Intel Corporation. All rights reserved.<BR>␍␊ |
| 4 | This program and the accompanying materials ␍␊ |
| 5 | are licensed and made available under the terms and conditions of the BSD License ␍␊ |
| 6 | which accompanies this distribution. The full text of the license may be found at ␍␊ |
| 7 | http://opensource.org/licenses/bsd-license.php ␍␊ |
| 8 | ␍␊ |
| 9 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, ␍␊ |
| 10 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. ␍␊ |
| 11 | ␍␊ |
| 12 | Module Name:␍␊ |
| 13 | ␍␊ |
| 14 | Math.c␍␊ |
| 15 | ␍␊ |
| 16 | Abstract:␍␊ |
| 17 | ␍␊ |
| 18 | Math worker functions. ␍␊ |
| 19 | ␍␊ |
| 20 | --*/␍␊ |
| 21 | ␍␊ |
| 22 | #include <efi.h>␍␊ |
| 23 | ␍␊ |
| 24 | UINT64␍␊ |
| 25 | LShiftU64 (␍␊ |
| 26 | IN UINT64 Operand,␍␊ |
| 27 | IN UINTN Count␍␊ |
| 28 | )␍␊ |
| 29 | /*++␍␊ |
| 30 | ␍␊ |
| 31 | Routine Description:␍␊ |
| 32 | ␍␊ |
| 33 | This routine allows a 64 bit value to be left shifted by 32 bits and ␍␊ |
| 34 | returns the shifted value.␍␊ |
| 35 | Count is valid up 63. (Only Bits 0-5 is valid for Count)␍␊ |
| 36 | ␍␊ |
| 37 | Arguments:␍␊ |
| 38 | ␍␊ |
| 39 | Operand - Value to be shifted␍␊ |
| 40 | Count - Number of times to shift left.␍␊ |
| 41 | ␍␊ |
| 42 | Returns:␍␊ |
| 43 | ␍␊ |
| 44 | Value shifted left identified by the Count.␍␊ |
| 45 | ␍␊ |
| 46 | --*/␍␊ |
| 47 | {␍␊ |
| 48 | return Operand << Count;␍␊ |
| 49 | }␍␊ |
| 50 | ␍␊ |
| 51 | UINT64␍␊ |
| 52 | MultU64x32 (␍␊ |
| 53 | IN UINT64 Multiplicand,␍␊ |
| 54 | IN UINTN Multiplier␍␊ |
| 55 | )␍␊ |
| 56 | /*++ ␍␊ |
| 57 | ␍␊ |
| 58 | Routine Description:␍␊ |
| 59 | ␍␊ |
| 60 | This routine allows a 64 bit value to be multiplied with a 32 bit ␍␊ |
| 61 | value returns 64bit result.␍␊ |
| 62 | No checking if the result is greater than 64bits␍␊ |
| 63 | ␍␊ |
| 64 | Arguments:␍␊ |
| 65 | ␍␊ |
| 66 | Multiplicand - multiplicand␍␊ |
| 67 | Multiplier - multiplier␍␊ |
| 68 | ␍␊ |
| 69 | Returns:␍␊ |
| 70 | ␍␊ |
| 71 | Multiplicand * Multiplier␍␊ |
| 72 | ␍␊ |
| 73 | --*/␍␊ |
| 74 | {␍␊ |
| 75 | return Multiplicand * Multiplier;␍␊ |
| 76 | }␍␊ |
| 77 | ␍␊ |
| 78 | UINT64␍␊ |
| 79 | Power10U64 (␍␊ |
| 80 | IN UINT64 Operand,␍␊ |
| 81 | IN UINTN Power␍␊ |
| 82 | )␍␊ |
| 83 | {␍␊ |
| 84 | UINT64 Result;␍␊ |
| 85 | ␍␊ |
| 86 | Result = Operand;␍␊ |
| 87 | while (Power-- > 0) {␍␊ |
| 88 | Result *= 10;␍␊ |
| 89 | }␍␊ |
| 90 | return Result;␍␊ |
| 91 | }␍␊ |
| 92 | ␍␊ |
| 93 | UINT64␍␊ |
| 94 | RShiftU64 (␍␊ |
| 95 | IN UINT64 Operand,␍␊ |
| 96 | IN UINTN Count␍␊ |
| 97 | )␍␊ |
| 98 | /*++␍␊ |
| 99 | ␍␊ |
| 100 | Routine Description:␍␊ |
| 101 | ␍␊ |
| 102 | This routine allows a 64 bit value to be right shifted by 32 bits and returns the ␍␊ |
| 103 | shifted value.␍␊ |
| 104 | Count is valid up 63. (Only Bits 0-5 is valid for Count)␍␊ |
| 105 | ␍␊ |
| 106 | Arguments:␍␊ |
| 107 | ␍␊ |
| 108 | Operand - Value to be shifted␍␊ |
| 109 | Count - Number of times to shift right.␍␊ |
| 110 | ␍␊ |
| 111 | Returns:␍␊ |
| 112 | ␍␊ |
| 113 | Value shifted right identified by the Count.␍␊ |
| 114 | ␍␊ |
| 115 | --*/␍␊ |
| 116 | {␍␊ |
| 117 | return Operand >> Count;␍␊ |
| 118 | }␍␊ |
| 119 | ␍␊ |
| 120 | UINT64␍␊ |
| 121 | DivU64x32 (␍␊ |
| 122 | IN UINT64 Dividend,␍␊ |
| 123 | IN UINTN Divisor,␍␊ |
| 124 | OUT UINTN *Remainder OPTIONAL␍␊ |
| 125 | )␍␊ |
| 126 | /*++␍␊ |
| 127 | ␍␊ |
| 128 | Routine Description:␍␊ |
| 129 | ␍␊ |
| 130 | This routine allows a 64 bit value to be divided with a 32 bit value returns ␍␊ |
| 131 | 64bit result and the Remainder.␍␊ |
| 132 | ␍␊ |
| 133 | Arguments:␍␊ |
| 134 | ␍␊ |
| 135 | Dividend - dividend␍␊ |
| 136 | Divisor - divisor␍␊ |
| 137 | Remainder - buffer for remainder␍␊ |
| 138 | ␍␊ |
| 139 | Returns:␍␊ |
| 140 | ␍␊ |
| 141 | Dividend / Divisor␍␊ |
| 142 | Remainder = Dividend mod Divisor␍␊ |
| 143 | ␍␊ |
| 144 | --*/␍␊ |
| 145 | {␍␊ |
| 146 | if (Remainder != NULL) {␍␊ |
| 147 | *Remainder = Dividend % Divisor;␍␊ |
| 148 | }␍␊ |
| 149 | ␍␊ |
| 150 | return Dividend / Divisor;␍␊ |
| 151 | }␍␊ |
| 152 | ␍␊ |
| 153 | UINT8␍␊ |
| 154 | Log2 (␍␊ |
| 155 | IN UINT64 Operand␍␊ |
| 156 | )␍␊ |
| 157 | /*++␍␊ |
| 158 | ␍␊ |
| 159 | Routine Description:␍␊ |
| 160 | ␍␊ |
| 161 | This function computes rounded down log2 of the Operand. This is an equivalent␍␊ |
| 162 | of the position of the highest bit set in the Operand treated as a mask.␍␊ |
| 163 | E.g., Log2 (0x0001) == 0, Log2 (0x0002) == 1, Log2 (0x0003) == 1, Log2 (0x0005) == 2␍␊ |
| 164 | Log2 (0x4000) == 14, Log2 (0x8000) == 15, Log2 (0xC000) == 15, Log2 (0xFFFF) == 15, etc.␍␊ |
| 165 | ␍␊ |
| 166 | Arguments:␍␊ |
| 167 | Operand - value of which the Log2 is to be computed.␍␊ |
| 168 | ␍␊ |
| 169 | Returns:␍␊ |
| 170 | Rounded down log2 of the Operand or 0xFF if zero passed in.␍␊ |
| 171 | ␍␊ |
| 172 | --*/␍␊ |
| 173 | {␍␊ |
| 174 | UINT8 Bitpos;␍␊ |
| 175 | Bitpos = 0;␍␊ |
| 176 | ␍␊ |
| 177 | if (Operand == 0) {␍␊ |
| 178 | return (0xff);␍␊ |
| 179 | }␍␊ |
| 180 | ␍␊ |
| 181 | while (Operand != 0) {␍␊ |
| 182 | Operand >>= 1;␍␊ |
| 183 | Bitpos++;␍␊ |
| 184 | }␍␊ |
| 185 | return (UINT8)(Bitpos - 1);␍␊ |
| 186 | ␍␊ |
| 187 | }␍␊ |
| 188 | ␍␊ |
| 189 | UINT64␍␊ |
| 190 | GetPowerOfTwo (␍␊ |
| 191 | IN UINT64 Operand␍␊ |
| 192 | )␍␊ |
| 193 | /*++␍␊ |
| 194 | ␍␊ |
| 195 | Routine Description:␍␊ |
| 196 | ␍␊ |
| 197 | Calculates the largest integer that is both ␍␊ |
| 198 | a power of two and less than Input␍␊ |
| 199 | ␍␊ |
| 200 | Arguments:␍␊ |
| 201 | ␍␊ |
| 202 | Operand - value to calculate power of two␍␊ |
| 203 | ␍␊ |
| 204 | Returns:␍␊ |
| 205 | ␍␊ |
| 206 | the largest integer that is both a power of ␍␊ |
| 207 | two and less than Input␍␊ |
| 208 | ␍␊ |
| 209 | --*/␍␊ |
| 210 | {␍␊ |
| 211 | UINT8 Bitpos;␍␊ |
| 212 | Bitpos = 0;␍␊ |
| 213 | ␍␊ |
| 214 | if (Operand == 0) {␍␊ |
| 215 | return 0;␍␊ |
| 216 | }␍␊ |
| 217 | ␍␊ |
| 218 | while (Operand != 0) {␍␊ |
| 219 | Operand >>= 1;␍␊ |
| 220 | Bitpos++;␍␊ |
| 221 | }␍␊ |
| 222 | ␍␊ |
| 223 | Operand = 1;␍␊ |
| 224 | Bitpos--;␍␊ |
| 225 | while (Bitpos != 0) {␍␊ |
| 226 | Operand <<= 1;␍␊ |
| 227 | Bitpos--;␍␊ |
| 228 | }␍␊ |
| 229 | ␍␊ |
| 230 | return Operand;␍␊ |
| 231 | }␍␊ |
| 232 | |
