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yap-6.3/OPTYap/opt.mavar.h
2003-11-05 16:12:25 +00:00

94 lines
2.1 KiB
C

#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 ma_hash_table[MAVARS_HASH_SIZE];
extern UInt timestamp; /* an unsigned int */
OPT_MAVAR_STATIC unsigned int MAVAR_HASH(CELL *);
OPT_MAVAR_STATIC struct ma_h_entry *ALLOC_NEW_MASPACE(void);
OPT_MAVAR_STATIC int lookup_ma_var(CELL *);
OPT_MAVAR_STATIC UInt NEW_MAHASH(ma_h_inner_struct *);
OPT_MAVAR_STATIC unsigned int
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 *ma_h_top;
OPT_MAVAR_STATIC struct ma_h_entry *
ALLOC_NEW_MASPACE(void)
{
ma_h_inner_struct *new = ma_h_top;
ma_h_top++;
return(new);
}
OPT_MAVAR_STATIC int
lookup_ma_var(CELL *addr) {
unsigned int i = MAVAR_HASH(addr);
struct ma_h_entry *nptr, *optr;
if (ma_hash_table[i].timestmp != timestamp) {
ma_hash_table[i].timestmp = timestamp;
ma_hash_table[i].val.addr = addr;
ma_hash_table[i].val.next = NULL;
return(FALSE);
}
if (ma_hash_table[i].val.addr == addr)
return(TRUE);
optr = &(ma_hash_table[i].val);
nptr = ma_hash_table[i].val.next;
while (nptr != NULL) {
if (nptr->addr == addr) {
return(TRUE);
}
optr = nptr;
nptr = nptr->next;
}
nptr = ALLOC_NEW_MASPACE();
nptr->addr = addr;
nptr->next = optr;
return(FALSE);
}
OPT_MAVAR_STATIC UInt
NEW_MAHASH(ma_h_inner_struct *top) {
UInt time = ++timestamp;
if (time == 0) {
unsigned int i;
/* damn, we overflowed */
for (i = 0; i < MAVARS_HASH_SIZE; i++)
ma_hash_table[i].timestmp = 0;
time = ++timestamp;
}
ma_h_top = top;
return(time);
}
#endif /* MULTI_ASSIGNMENT_VARIABLES */