xref: /csrg-svn/old/as.vax/assyms.h (revision 19826)
1604Sbill /*
2*19826Sdist  * Copyright (c) 1982 Regents of the University of California.
3*19826Sdist  * All rights reserved.  The Berkeley software License Agreement
4*19826Sdist  * specifies the terms and conditions for redistribution.
5*19826Sdist  *
6*19826Sdist  *	@(#)assyms.h	5.1 (Berkeley) 04/30/85
75830Srrh  */
8*19826Sdist 
95830Srrh /*
10604Sbill  *	To speed up walks through symbols defined in a particular
11604Sbill  *	segment, we buil up a table of pointers into the symbol table
12604Sbill  *	and a table of delimiters for each segment.  The delimiter for
13604Sbill  *	the particular segment points to the first word in that segment.
14604Sbill  */
15604Sbill 
16604Sbill extern	struct	symtab	**symptrs;		/*dynamically allocated*/
17604Sbill extern	struct	symtab	**symdelim[NLOC + NLOC + 1];
18604Sbill extern	struct	symtab	**symptrub;
19604Sbill extern	int	nsyms;			/*number in the symbol table*/
20604Sbill extern	int	njxxx;			/*the number of jxxx entries in the table*/
21604Sbill extern	int	nforgotten;		/*how many entries erroneously entered*/
22604Sbill extern	int	nlabels;		/*how many labels in the symbol table*/
23604Sbill extern	int	hshused;		/*how many hash slots used*/
24604Sbill 
25604Sbill #define SEGITERATE(segno, start, end, copointer, walkpointer, ubpointer, direction) \
26604Sbill 	for(copointer = start == 0? symdelim[segno]:start,\
27604Sbill 	    ubpointer = end == 0 ? *symdelim[segno+1] : *(symdelim[segno]-1),\
28604Sbill 	    walkpointer = *copointer;\
29604Sbill 	    walkpointer != ubpointer;\
30604Sbill 	    walkpointer = * direction copointer)
31604Sbill 
32604Sbill #define SYMITERATE(copointer, walkpointer) \
33604Sbill 	for(copointer = symptrs, \
34604Sbill 	    walkpointer = *copointer; \
35604Sbill 	    copointer < symptrub; \
36604Sbill 	    walkpointer = * ++ copointer)
37604Sbill /*
38604Sbill  *	Symbols are allocated in non contiguous chunks by extending
3913461Srrh  *	the data area.
40604Sbill  */
41604Sbill 
42604Sbill #define SYMDALLOP	200
43604Sbill struct 	allocbox{
44604Sbill 	struct		allocbox	*nextalloc;
45604Sbill 	struct		symtab		symslots[SYMDALLOP];
46604Sbill };
47604Sbill 
48604Sbill /*
4913461Srrh  *	Names are allocated in a dynamically extensible string pool.
50604Sbill  */
51604Sbill struct	strpool{
52604Sbill 	struct	strpool	*str_next;
53604Sbill 	int		str_nalloc;
54604Sbill 	char		str_names[STRPOOLDALLOP];
55604Sbill };
56604Sbill 
57604Sbill extern	struct	strpool *strplhead;
58604Sbill 
59604Sbill extern	struct	allocbox	*allochead;
60604Sbill extern	struct	allocbox	*alloctail;
61604Sbill extern	struct	symtab		*nextsym;
62604Sbill extern	struct	allocbox	*newbox;
63604Sbill extern	char			*namebuffer;
64604Sbill extern	int			symsleft;
65604Sbill 
66604Sbill #define ALLOCQTY 	sizeof (struct allocbox)
67604Sbill /*
68604Sbill  *	Iterate through all symbols in the symbol table in declaration
69604Sbill  *	order
70604Sbill  */
71604Sbill #define DECLITERATE(allocwalk, walkpointer, ubpointer) \
72604Sbill 	for(allocwalk = allochead; \
73604Sbill 	    allocwalk != 0; \
74604Sbill 	    allocwalk = allocwalk->nextalloc) \
75604Sbill 		for (walkpointer = &allocwalk->symslots[0],\
76604Sbill 		        ubpointer = &allocwalk->symslots[SYMDALLOP], \
77604Sbill 		        ubpointer = ubpointer > ( (struct symtab *)alloctail) \
78604Sbill 				 ? nextsym : ubpointer ;\
79604Sbill 		     walkpointer < ubpointer; \
80604Sbill 		     walkpointer++ )
81604Sbill /*
82604Sbill  *	The hash table is segmented, and dynamically extendable.
83604Sbill  *	We have a linked list of hash table segments; within each
84604Sbill  *	segment we use a quadratic rehash that touches no more than 1/2
85604Sbill  *	of the buckets in the hash table when probing.
86604Sbill  *	If the probe does not find the desired symbol, it moves to the
87604Sbill  *	next segment, or allocates a new segment.
88604Sbill  *
89604Sbill  *	Hash table segments are kept on the linked list with the first
90604Sbill  *	segment always first (that contains the reserved words) and
91604Sbill  *	the last added segment immediately after the first segment
92604Sbill  *	to hopefully gain something by locality of reference.
93604Sbill  */
94604Sbill struct hashdallop {
95604Sbill 	int	h_nused;
96604Sbill 	struct	hashdallop	*h_next;
97604Sbill 	struct	symtab		*h_htab[NHASH];
98604Sbill };
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