1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
|
/**********************************************************************
The OPTYap Prolog system
OPTYap extends the Yap Prolog system to support or-parallel tabling
Copyright: R. Rocha and NCC - University of Porto, Portugal
File: opt.mavar.h
version: $Id: opt.mavar.h,v 1.4 2005/08/05 14:55:03 vsc Exp $
**********************************************************************/
#ifdef MULTI_ASSIGNMENT_VARIABLES
/*
Set of routines to allow restoring updatable variables when we go *up*
in the tree. Required by copying, SBA, and tabling. Not required by ACOW.
*/
#ifndef OPT_MAVAR_STATIC
#define OPT_MAVAR_STATIC inline static
#endif
#define MAVARS_HASH_SIZE 512
typedef struct ma_h_entry {
CELL* addr;
struct ma_h_entry *next;
} ma_h_inner_struct;
typedef struct {
UInt timestmp;
struct ma_h_entry val;
} ma_hash_entry;
extern ma_hash_entry Yap_ma_hash_table[MAVARS_HASH_SIZE];
extern UInt Yap_timestamp; /* an unsigned int */
OPT_MAVAR_STATIC unsigned int Yap_MAVAR_HASH(CELL *);
OPT_MAVAR_STATIC struct ma_h_entry *Yap_ALLOC_NEW_MASPACE(void);
OPT_MAVAR_STATIC int Yap_lookup_ma_var(CELL *);
OPT_MAVAR_STATIC UInt Yap_NEW_MAHASH(ma_h_inner_struct *);
OPT_MAVAR_STATIC unsigned int
Yap_MAVAR_HASH(CELL *addr) {
#if SIZEOF_INT_P==8
return((((unsigned int)((CELL)(addr)))>>3)%MAVARS_HASH_SIZE);
#else
return((((unsigned int)((CELL)(addr)))>>2)%MAVARS_HASH_SIZE);
#endif
}
extern ma_h_inner_struct *Yap_ma_h_top;
OPT_MAVAR_STATIC struct ma_h_entry *
Yap_ALLOC_NEW_MASPACE(void)
{
ma_h_inner_struct *new = Yap_ma_h_top;
Yap_ma_h_top++;
return new;
}
OPT_MAVAR_STATIC int
Yap_lookup_ma_var(CELL *addr) {
unsigned int i = Yap_MAVAR_HASH(addr);
struct ma_h_entry *nptr, *optr;
if (Yap_ma_hash_table[i].timestmp != Yap_timestamp) {
Yap_ma_hash_table[i].timestmp = Yap_timestamp;
Yap_ma_hash_table[i].val.addr = addr;
Yap_ma_hash_table[i].val.next = NULL;
return FALSE;
}
if (Yap_ma_hash_table[i].val.addr == addr)
return TRUE;
optr = &(Yap_ma_hash_table[i].val);
nptr = Yap_ma_hash_table[i].val.next;
while (nptr != NULL) {
if (nptr->addr == addr) {
return TRUE;
}
optr = nptr;
nptr = nptr->next;
}
nptr = Yap_ALLOC_NEW_MASPACE();
nptr->addr = addr;
nptr->next = optr;
return FALSE;
}
OPT_MAVAR_STATIC UInt
Yap_NEW_MAHASH(ma_h_inner_struct *top) {
UInt time = ++Yap_timestamp;
if (time == 0) {
unsigned int i;
/* damn, we overflowed */
for (i = 0; i < MAVARS_HASH_SIZE; i++)
Yap_ma_hash_table[i].timestmp = 0;
time = ++Yap_timestamp;
}
Yap_ma_h_top = top;
return time;
}
#endif /* MULTI_ASSIGNMENT_VARIABLES */
|
