~mdw / catacomb / blame
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| a3ad4421 MW |
1 | /// -*- mode: asm; asm-comment-char: ?/ -*- |
| 2 | /// | |
| 3 | /// Random-number support for x86 | |
| 4 | /// | |
| 5 | /// (c) 2019 Straylight/Edgeware | |
| 6 | /// | |
| 7 | ||
| 8 | ///----- Licensing notice --------------------------------------------------- | |
| 9 | /// | |
| 10 | /// This file is part of Catacomb. | |
| 11 | /// | |
| 12 | /// Catacomb is free software: you can redistribute it and/or modify it | |
| 13 | /// under the terms of the GNU Library General Public License as published | |
| 14 | /// by the Free Software Foundation; either version 2 of the License, or | |
| 15 | /// (at your option) any later version. | |
| 16 | /// | |
| 17 | /// Catacomb is distributed in the hope that it will be useful, but | |
| 18 | /// WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 19 | /// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 20 | /// Library General Public License for more details. | |
| 21 | /// | |
| 22 | /// You should have received a copy of the GNU Library General Public | |
| 23 | /// License along with Catacomb. If not, write to the Free Software | |
| 24 | /// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, | |
| 25 | /// USA. | |
| 26 | ||
| 27 | ///-------------------------------------------------------------------------- | |
| 28 | /// Preliminaries. | |
| 29 | ||
| 30 | #include "config.h" | |
| 31 | #include "asm-common.h" | |
| 32 | ||
| 33 | .extern F(rand_add) | |
| 34 | ||
| 35 | .text | |
| 36 | ||
| 37 | ///-------------------------------------------------------------------------- | |
| 38 | /// Quick random generation. | |
| 39 | ||
| dc2adc88 MW |
40 | // Common register allocation. |
| 41 | #if CPUFAM_X86 | |
| 42 | # define COUNT ecx | |
| 43 | #endif | |
| 44 | #if CPUFAM_AMD64 && ABI_SYSV | |
| 45 | # define COUNT ecx | |
| 46 | #endif | |
| 47 | #if CPUFAM_AMD64 && ABI_WIN | |
| 48 | # define COUNT r8d | |
| 49 | #endif | |
| 50 | ||
| a3ad4421 MW |
51 | FUNC(rand_quick_x86ish_rdrand) |
| 52 | // Enter with a pointer to the random context in the first argument. | |
| 53 | // Return zero on success, or -1 on error. | |
| 54 | ||
| 55 | #if CPUFAM_X86 | |
| a90d420c | 56 | mov edx, [SP + 4] |
| a3ad4421 | 57 | stalloc 28 |
| a3ad4421 MW |
58 | #endif |
| 59 | #if CPUFAM_AMD64 && ABI_SYSV | |
| 60 | stalloc 8 | |
| a3ad4421 MW |
61 | #endif |
| 62 | #if CPUFAM_AMD64 && ABI_WIN | |
| 63 | stalloc 40 | |
| a3ad4421 MW |
64 | #endif |
| 65 | endprologue | |
| 66 | ||
| 67 | // Try to fetch a random number. | |
| 68 | mov COUNT, 16 | |
| a90d420c | 69 | 0: rdrand AX |
| a3ad4421 MW |
70 | jc 1f |
| 71 | dec COUNT | |
| 72 | jnz 0b | |
| 73 | ||
| 74 | // Failed. | |
| 75 | mov eax, -1 | |
| 76 | jmp 9f | |
| 6c0946ef MW |
77 | ENDFUNC |
| 78 | ||
| 79 | FUNC(rand_quick_x86ish_rdseed) | |
| 80 | // Enter with a pointer to the random context in the first argument. | |
| 81 | // Return zero on success, or -1 on error. | |
| 82 | ||
| 83 | #if CPUFAM_X86 | |
| 84 | mov edx, [SP + 4] | |
| 85 | stalloc 28 | |
| 86 | #endif | |
| 87 | #if CPUFAM_AMD64 && ABI_SYSV | |
| 88 | stalloc 8 | |
| 89 | #endif | |
| 90 | #if CPUFAM_AMD64 && ABI_WIN | |
| 91 | stalloc 40 | |
| 92 | #endif | |
| 93 | endprologue | |
| 94 | ||
| 95 | // Try to fetch a random number. | |
| 96 | mov COUNT, 16 | |
| 97 | 0: rdseed AX | |
| 98 | jc 1f | |
| 99 | dec COUNT | |
| 100 | jnz 0b | |
| 101 | ||
| 102 | // Failed. | |
| 103 | mov eax, -1 | |
| 104 | jmp 9f | |
| a3ad4421 MW |
105 | |
| 106 | // Success. | |
| 107 | 1: | |
| 108 | #if CPUFAM_X86 | |
| a90d420c MW |
109 | mov [SP + 16], AX |
| 110 | lea ecx, [SP + 16] | |
| 111 | mov dword ptr [SP + 12], 32 | |
| 112 | mov dword ptr [SP + 8], 4 | |
| 113 | mov [SP + 4], ecx | |
| 114 | mov [SP + 0], edx | |
| a3ad4421 MW |
115 | #endif |
| 116 | #if CPUFAM_AMD64 && ABI_SYSV | |
| a90d420c MW |
117 | mov [SP + 0], AX |
| 118 | mov rsi, SP | |
| a3ad4421 MW |
119 | mov edx, 8 |
| 120 | mov ecx, 64 | |
| 121 | #endif | |
| 122 | #if CPUFAM_AMD64 && ABI_WIN | |
| a90d420c MW |
123 | mov [SP + 32], AX |
| 124 | lea rdx, [SP + 32] | |
| a3ad4421 MW |
125 | mov r8d, 8 |
| 126 | mov r9d, 64 | |
| 127 | #endif | |
| 128 | callext F(rand_add) | |
| 129 | xor eax, eax | |
| 130 | ||
| 131 | // Done. | |
| 132 | 9: | |
| 133 | #if CPUFAM_X86 | |
| 134 | stfree 28 | |
| 135 | #endif | |
| 136 | #if CPUFAM_AMD64 && ABI_SYSV | |
| 137 | stfree 8 | |
| 138 | #endif | |
| 139 | #if CPUFAM_AMD64 && ABI_WIN | |
| 140 | stfree 40 | |
| 141 | #endif | |
| 142 | ret | |
| dc2adc88 | 143 | ENDFUNC |
| 89dbb5fd MW |
144 | |
| 145 | #undef COUNT | |
| 146 | ||
| a3ad4421 | 147 | ///----- That's all, folks -------------------------------------------------- |