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| Rev | Author | Line No. | Line |
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| 2726 | vana | 1 | /*++ |
| 2 | |||
| 3 | Copyright (c) 1998 Intel Corporation |
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| 4 | |||
| 5 | Module Name: |
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| 6 | |||
| 7 | math.c |
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| 8 | |||
| 9 | Abstract: |
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| 10 | |||
| 11 | |||
| 12 | |||
| 13 | |||
| 14 | Revision History |
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| 15 | |||
| 16 | --*/ |
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| 17 | |||
| 18 | #include "lib.h" |
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| 19 | |||
| 20 | |||
| 21 | // |
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| 22 | // Declare runtime functions |
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| 23 | // |
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| 24 | |||
| 25 | #ifdef RUNTIME_CODE |
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| 26 | #pragma RUNTIME_CODE(LShiftU64) |
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| 27 | #pragma RUNTIME_CODE(RShiftU64) |
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| 28 | #pragma RUNTIME_CODE(MultU64x32) |
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| 29 | #pragma RUNTIME_CODE(DivU64x32) |
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| 30 | #endif |
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| 31 | |||
| 32 | // |
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| 33 | // |
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| 34 | // |
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| 35 | |||
| 36 | UINT64 |
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| 37 | LShiftU64 ( |
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| 38 | IN UINT64 Operand, |
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| 39 | IN UINTN Count |
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| 40 | ) |
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| 41 | // Left shift 64bit by 32bit and get a 64bit result |
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| 42 | { |
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| 43 | #ifdef __GNUC__ |
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| 44 | return Operand << Count; |
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| 45 | #else |
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| 46 | UINT64 Result; |
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| 47 | _asm { |
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| 48 | mov eax, dword ptr Operand[0] |
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| 49 | mov edx, dword ptr Operand[4] |
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| 50 | mov ecx, Count |
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| 51 | and ecx, 63 |
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| 52 | |||
| 53 | shld edx, eax, cl |
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| 54 | shl eax, cl |
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| 55 | |||
| 56 | cmp ecx, 32 |
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| 57 | jc short ls10 |
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| 58 | |||
| 59 | mov edx, eax |
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| 60 | xor eax, eax |
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| 61 | |||
| 62 | ls10: |
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| 63 | mov dword ptr Result[0], eax |
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| 64 | mov dword ptr Result[4], edx |
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| 65 | } |
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| 66 | |||
| 67 | return Result; |
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| 68 | #endif |
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| 69 | } |
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| 70 | |||
| 71 | UINT64 |
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| 72 | RShiftU64 ( |
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| 73 | IN UINT64 Operand, |
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| 74 | IN UINTN Count |
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| 75 | ) |
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| 76 | // Right shift 64bit by 32bit and get a 64bit result |
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| 77 | { |
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| 78 | #ifdef __GNUC__ |
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| 79 | return Operand >> Count; |
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| 80 | #else |
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| 81 | UINT64 Result; |
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| 82 | _asm { |
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| 83 | mov eax, dword ptr Operand[0] |
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| 84 | mov edx, dword ptr Operand[4] |
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| 85 | mov ecx, Count |
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| 86 | and ecx, 63 |
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| 87 | |||
| 88 | shrd eax, edx, cl |
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| 89 | shr edx, cl |
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| 90 | |||
| 91 | cmp ecx, 32 |
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| 92 | jc short rs10 |
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| 93 | |||
| 94 | mov eax, edx |
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| 95 | xor edx, edx |
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| 96 | |||
| 97 | rs10: |
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| 98 | mov dword ptr Result[0], eax |
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| 99 | mov dword ptr Result[4], edx |
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| 100 | } |
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| 101 | |||
| 102 | return Result; |
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| 103 | #endif |
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| 104 | } |
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| 105 | |||
| 106 | |||
| 107 | UINT64 |
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| 108 | MultU64x32 ( |
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| 109 | IN UINT64 Multiplicand, |
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| 110 | IN UINTN Multiplier |
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| 111 | ) |
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| 112 | // Multiple 64bit by 32bit and get a 64bit result |
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| 113 | { |
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| 114 | #ifdef __GNUC__ |
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| 115 | return Multiplicand * Multiplier; |
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| 116 | #else |
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| 117 | UINT64 Result; |
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| 118 | _asm { |
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| 119 | mov eax, dword ptr Multiplicand[0] |
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| 120 | mul Multiplier |
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| 121 | mov dword ptr Result[0], eax |
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| 122 | mov dword ptr Result[4], edx |
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| 123 | mov eax, dword ptr Multiplicand[4] |
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| 124 | mul Multiplier |
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| 125 | add dword ptr Result[4], eax |
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| 126 | } |
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| 127 | |||
| 128 | return Result; |
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| 129 | #endif |
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| 130 | } |
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| 131 | |||
| 132 | UINT64 |
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| 133 | DivU64x32 ( |
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| 134 | IN UINT64 Dividend, |
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| 135 | IN UINTN Divisor, |
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| 136 | OUT UINTN *Remainder OPTIONAL |
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| 137 | ) |
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| 138 | // divide 64bit by 32bit and get a 64bit result |
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| 139 | // N.B. only works for 31bit divisors!! |
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| 140 | { |
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| 141 | #ifdef __GNUC__ |
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| 142 | if (Remainder) |
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| 143 | *Remainder = Dividend % Divisor; |
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| 144 | return Dividend / Divisor; |
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| 145 | #else |
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| 146 | UINT32 Rem; |
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| 147 | UINT32 bit; |
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| 148 | |||
| 149 | ASSERT (Divisor != 0); |
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| 150 | ASSERT ((Divisor >> 31) == 0); |
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| 151 | |||
| 152 | // |
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| 153 | // For each bit in the dividend |
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| 154 | // |
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| 155 | |||
| 156 | Rem = 0; |
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| 157 | for (bit=0; bit < 64; bit++) { |
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| 158 | _asm { |
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| 159 | shl dword ptr Dividend[0], 1 ; shift rem:dividend left one |
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| 160 | rcl dword ptr Dividend[4], 1 |
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| 161 | rcl dword ptr Rem, 1 |
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| 162 | |||
| 163 | mov eax, Rem |
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| 164 | cmp eax, Divisor ; Is Rem >= Divisor? |
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| 165 | cmc ; No - do nothing |
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| 166 | sbb eax, eax ; Else, |
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| 167 | sub dword ptr Dividend[0], eax ; set low bit in dividen |
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| 168 | and eax, Divisor ; and |
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| 169 | sub Rem, eax ; subtract divisor |
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| 170 | } |
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| 171 | } |
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| 172 | |||
| 173 | if (Remainder) { |
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| 174 | *Remainder = Rem; |
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| 175 | } |
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| 176 | |||
| 177 | return Dividend; |
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| 178 | #endif |
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| 179 | } |