projects / apple / libc.git / blame
| Commit | Line | Data |
|---|---|---|
| 224c7076 A |
1 | --- rand48.h.orig 2003-05-20 15:21:02.000000000 -0700 |
| 2 | +++ rand48.h 2005-11-03 14:06:17.000000000 -0800 | |
| 3 | @@ -19,8 +19,6 @@ | |
| 4 | #include <math.h> | |
| 5 | #include <stdlib.h> | |
| 6 | ||
| 7 | -void _dorand48(unsigned short[3]); | |
| 8 | - | |
| 9 | #define RAND48_SEED_0 (0x330e) | |
| 10 | #define RAND48_SEED_1 (0xabcd) | |
| 11 | #define RAND48_SEED_2 (0x1234) | |
| 12 | @@ -29,4 +27,55 @@ | |
| 13 | #define RAND48_MULT_2 (0x0005) | |
| 14 | #define RAND48_ADD (0x000b) | |
| 15 | ||
| 16 | +typedef unsigned long long uint48; | |
| 17 | + | |
| 18 | +extern uint48 _rand48_seed; | |
| 19 | +extern uint48 _rand48_mult; | |
| 20 | +extern uint48 _rand48_add; | |
| 21 | + | |
| 22 | +#define TOUINT48(x,y,z) \ | |
| 23 | + ((uint48)(x) + (((uint48)(y)) << 16) + (((uint48)(z)) << 32)) | |
| 24 | + | |
| 25 | +#define RAND48_SEED TOUINT48(RAND48_SEED_0, RAND48_SEED_1, RAND48_SEED_2) | |
| 26 | +#define RAND48_MULT TOUINT48(RAND48_MULT_0, RAND48_MULT_1, RAND48_MULT_2) | |
| 27 | + | |
| 28 | +#define LOADRAND48(l,x) \ | |
| 29 | + (l) = TOUINT48((x)[0], (x)[1], (x)[2]) | |
| 30 | + | |
| 31 | +#define STORERAND48(l,x) \ | |
| 32 | + (x)[0] = (unsigned short)(l); \ | |
| 33 | + (x)[1] = (unsigned short)((l) >> 16); \ | |
| 34 | + (x)[2] = (unsigned short)((l) >> 32) | |
| 35 | + | |
| 36 | +#define _DORAND48(l) \ | |
| 37 | + (l) = (l) * _rand48_mult + _rand48_add | |
| 38 | + | |
| 39 | +#define DORAND48(l,x) \ | |
| 40 | + LOADRAND48(l, x); \ | |
| 41 | + _DORAND48(l); \ | |
| 42 | + STORERAND48(l, x) | |
| 43 | + | |
| 44 | +#include "fpmath.h" | |
| 45 | + | |
| 46 | +/* | |
| 47 | + * Optimization for speed: avoid int-to-double conversion. Assume doubles | |
| 48 | + * are IEEE-754 and insert the bits directly. To normalize, the (1 << 52) | |
| 49 | + * is the hidden bit, which the first set bit is shifted to. | |
| 50 | + */ | |
| 51 | +#define ERAND48_BEGIN \ | |
| 52 | + union { \ | |
| 53 | + union IEEEd2bits ieee; \ | |
| 54 | + unsigned long long l; \ | |
| 55 | + } u; \ | |
| 56 | + int s | |
| 57 | + | |
| 58 | +#define ERAND48_END(x) \ | |
| 59 | + u.l = ((x) & 0xffffffffffffULL); \ | |
| 60 | + if (u.l == 0) \ | |
| 61 | + return 0.0; \ | |
| 62 | + u.l <<= 5; \ | |
| 63 | + for(s = 0; !(u.l & (1LL << 52)); s++, u.l <<= 1) {} \ | |
| 64 | + u.ieee.bits.exp = 1022 - s; \ | |
| 65 | + return u.ieee.d | |
| 66 | + | |
| 67 | #endif /* _RAND48_H_ */ |