diff options
Diffstat (limited to 'src/lib/libc/stdlib/_rand48.c')
| -rw-r--r-- | src/lib/libc/stdlib/_rand48.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/src/lib/libc/stdlib/_rand48.c b/src/lib/libc/stdlib/_rand48.c new file mode 100644 index 0000000000..7c950f7cee --- /dev/null +++ b/src/lib/libc/stdlib/_rand48.c | |||
| @@ -0,0 +1,47 @@ | |||
| 1 | /* $OpenBSD: _rand48.c,v 1.3 2005/08/08 08:05:36 espie Exp $ */ | ||
| 2 | /* | ||
| 3 | * Copyright (c) 1993 Martin Birgmeier | ||
| 4 | * All rights reserved. | ||
| 5 | * | ||
| 6 | * You may redistribute unmodified or modified versions of this source | ||
| 7 | * code provided that the above copyright notice and this and the | ||
| 8 | * following conditions are retained. | ||
| 9 | * | ||
| 10 | * This software is provided ``as is'', and comes with no warranties | ||
| 11 | * of any kind. I shall in no event be liable for anything that happens | ||
| 12 | * to anyone/anything when using this software. | ||
| 13 | */ | ||
| 14 | |||
| 15 | #include "rand48.h" | ||
| 16 | |||
| 17 | unsigned short __rand48_seed[3] = { | ||
| 18 | RAND48_SEED_0, | ||
| 19 | RAND48_SEED_1, | ||
| 20 | RAND48_SEED_2 | ||
| 21 | }; | ||
| 22 | unsigned short __rand48_mult[3] = { | ||
| 23 | RAND48_MULT_0, | ||
| 24 | RAND48_MULT_1, | ||
| 25 | RAND48_MULT_2 | ||
| 26 | }; | ||
| 27 | unsigned short __rand48_add = RAND48_ADD; | ||
| 28 | |||
| 29 | void | ||
| 30 | __dorand48(unsigned short xseed[3]) | ||
| 31 | { | ||
| 32 | unsigned long accu; | ||
| 33 | unsigned short temp[2]; | ||
| 34 | |||
| 35 | accu = (unsigned long) __rand48_mult[0] * (unsigned long) xseed[0] + | ||
| 36 | (unsigned long) __rand48_add; | ||
| 37 | temp[0] = (unsigned short) accu; /* lower 16 bits */ | ||
| 38 | accu >>= sizeof(unsigned short) * 8; | ||
| 39 | accu += (unsigned long) __rand48_mult[0] * (unsigned long) xseed[1] + | ||
| 40 | (unsigned long) __rand48_mult[1] * (unsigned long) xseed[0]; | ||
| 41 | temp[1] = (unsigned short) accu; /* middle 16 bits */ | ||
| 42 | accu >>= sizeof(unsigned short) * 8; | ||
| 43 | accu += __rand48_mult[0] * xseed[2] + __rand48_mult[1] * xseed[1] + __rand48_mult[2] * xseed[0]; | ||
| 44 | xseed[0] = temp[0]; | ||
| 45 | xseed[1] = temp[1]; | ||
| 46 | xseed[2] = (unsigned short) accu; | ||
| 47 | } | ||
