| … | |
… | |
| 48 | */ |
48 | */ |
| 49 | #ifndef FRST |
49 | #ifndef FRST |
| 50 | # define FRST(p) (((p[0]) << 8) | p[1]) |
50 | # define FRST(p) (((p[0]) << 8) | p[1]) |
| 51 | # define NEXT(v,p) (((v) << 8) | p[2]) |
51 | # define NEXT(v,p) (((v) << 8) | p[2]) |
| 52 | # define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
52 | # define IDX(h) ((((h ^ (h << 5)) >> (3*8 - HLOG)) - h*5) & (HSIZE - 1)) |
|
|
53 | //# define IDX(h) ((ip[0] * 121 ^ ip[1] * 33 ^ ip[2] * 1) & (HSIZE-1)) |
| 53 | #endif |
54 | #endif |
| 54 | /* |
55 | /* |
| 55 | * IDX works because it is very similar to a multiplicative hash, e.g. |
56 | * IDX works because it is very similar to a multiplicative hash, e.g. |
| 56 | * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1)) |
57 | * ((h * 57321 >> (3*8 - HLOG)) & (HSIZE - 1)) |
| 57 | * the latter is also quite fast on newer CPUs, and sligthly better |
58 | * the latter is also quite fast on newer CPUs, and compresses similarly. |
| 58 | * |
59 | * |
| 59 | * the next one is also quite good, albeit slow ;) |
60 | * the next one is also quite good, albeit slow ;) |
| 60 | * (int)(cos(h & 0xffffff) * 1e6) |
61 | * (int)(cos(h & 0xffffff) * 1e6) |
| 61 | */ |
62 | */ |
| 62 | |
63 | |
| … | |
… | |
| 67 | # define IDX(h) ((h) & (HSIZE - 1)) |
68 | # define IDX(h) ((h) & (HSIZE - 1)) |
| 68 | #endif |
69 | #endif |
| 69 | |
70 | |
| 70 | #define MAX_LIT (1 << 5) |
71 | #define MAX_LIT (1 << 5) |
| 71 | #define MAX_OFF (1 << 13) |
72 | #define MAX_OFF (1 << 13) |
| 72 | #define MAX_REF ((1 << 8) + (1 << 3)) |
73 | #define MAX_REF ((1 << 8) + (1 << 3)) |
| 73 | |
74 | |
| 74 | /* |
75 | /* |
| 75 | * compressed format |
76 | * compressed format |
| 76 | * |
77 | * |
| 77 | * 000LLLLL <L+1> ; literal |
78 | * 000LLLLL <L+1> ; literal |
