gcc/libobjc/objc/sarray.h

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/* Sparse Arrays for Objective C dispatch tables
Copyright (C) 1993, 1995, 1996, 2004, 2009 Free Software Foundation, Inc.
Contributed by Kresten Krab Thorup.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#ifndef __sarray_INCLUDE_GNU
#define __sarray_INCLUDE_GNU
#include "thr.h"
#define OBJC_SPARSE2 /* 2-level sparse array */
/* #define OBJC_SPARSE3 */ /* 3-level sparse array */
#ifdef OBJC_SPARSE2
extern const char* __objc_sparse2_id;
#endif
#ifdef OBJC_SPARSE3
extern const char* __objc_sparse3_id;
#endif
#include <stddef.h>
#include <assert.h>
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
extern int nbuckets; /* for stats */
extern int nindices;
extern int narrays;
extern int idxsize;
/* An unsigned integer of same size as a pointer */
#define SIZET_BITS (sizeof(size_t)*8)
#if defined(__sparc__) || defined(OBJC_SPARSE2)
#define PRECOMPUTE_SELECTORS
#endif
#ifdef OBJC_SPARSE3
/* Buckets are 8 words each */
#define BUCKET_BITS 3
#define BUCKET_SIZE (1<<BUCKET_BITS)
#define BUCKET_MASK (BUCKET_SIZE-1)
/* Indices are 16 words each */
#define INDEX_BITS 4
#define INDEX_SIZE (1<<INDEX_BITS)
#define INDEX_MASK (INDEX_SIZE-1)
#define INDEX_CAPACITY (BUCKET_SIZE*INDEX_SIZE)
#else /* OBJC_SPARSE2 */
/* Buckets are 32 words each */
#define BUCKET_BITS 5
#define BUCKET_SIZE (1<<BUCKET_BITS)
#define BUCKET_MASK (BUCKET_SIZE-1)
#endif /* OBJC_SPARSE2 */
typedef size_t sidx;
#ifdef PRECOMPUTE_SELECTORS
struct soffset {
#ifdef OBJC_SPARSE3
unsigned int unused : SIZET_BITS/4;
unsigned int eoffset : SIZET_BITS/4;
unsigned int boffset : SIZET_BITS/4;
unsigned int ioffset : SIZET_BITS/4;
#else /* OBJC_SPARSE2 */
#ifdef __sparc__
unsigned long boffset : (SIZET_BITS - 2) - BUCKET_BITS;
unsigned int eoffset : BUCKET_BITS;
unsigned int unused : 2;
#else
unsigned int boffset : SIZET_BITS/2;
unsigned int eoffset : SIZET_BITS/2;
#endif
#endif /* OBJC_SPARSE2 */
};
union sofftype {
struct soffset off;
sidx idx;
};
#endif /* not PRECOMPUTE_SELECTORS */
union sversion {
int version;
void *next_free;
};
struct sbucket {
void* elems[BUCKET_SIZE]; /* elements stored in array */
union sversion version; /* used for copy-on-write */
};
#ifdef OBJC_SPARSE3
struct sindex {
struct sbucket* buckets[INDEX_SIZE];
union sversion version; /* used for copy-on-write */
};
#endif /* OBJC_SPARSE3 */
struct sarray {
#ifdef OBJC_SPARSE3
struct sindex** indices;
struct sindex* empty_index;
#else /* OBJC_SPARSE2 */
struct sbucket** buckets;
#endif /* OBJC_SPARSE2 */
struct sbucket* empty_bucket;
union sversion version; /* used for copy-on-write */
short ref_count;
struct sarray* is_copy_of;
size_t capacity;
};
struct sarray* sarray_new(int, void* default_element);
void sarray_free(struct sarray*);
struct sarray* sarray_lazy_copy(struct sarray*);
void sarray_realloc(struct sarray*, int new_size);
void sarray_at_put(struct sarray*, sidx indx, void* elem);
void sarray_at_put_safe(struct sarray*, sidx indx, void* elem);
struct sarray* sarray_hard_copy(struct sarray*); /* ... like the name? */
void sarray_remove_garbage(void);
#ifdef PRECOMPUTE_SELECTORS
/* Transform soffset values to ints and vica verca */
static inline unsigned int
soffset_decode(sidx indx)
{
union sofftype x;
x.idx = indx;
#ifdef OBJC_SPARSE3
return x.off.eoffset
+ (x.off.boffset*BUCKET_SIZE)
+ (x.off.ioffset*INDEX_CAPACITY);
#else /* OBJC_SPARSE2 */
return x.off.eoffset + (x.off.boffset*BUCKET_SIZE);
#endif /* OBJC_SPARSE2 */
}
static inline sidx
soffset_encode(size_t offset)
{
union sofftype x;
x.off.eoffset = offset%BUCKET_SIZE;
#ifdef OBJC_SPARSE3
x.off.boffset = (offset/BUCKET_SIZE)%INDEX_SIZE;
x.off.ioffset = offset/INDEX_CAPACITY;
#else /* OBJC_SPARSE2 */
x.off.boffset = offset/BUCKET_SIZE;
#endif
return (sidx)x.idx;
}
#else /* not PRECOMPUTE_SELECTORS */
static inline size_t
soffset_decode(sidx indx)
{
return indx;
}
static inline sidx
soffset_encode(size_t offset)
{
return offset;
}
#endif /* not PRECOMPUTE_SELECTORS */
/* Get element from the Sparse array `array' at offset `indx' */
static inline void* sarray_get(struct sarray* array, sidx indx)
{
#ifdef PRECOMPUTE_SELECTORS
union sofftype x;
x.idx = indx;
#ifdef OBJC_SPARSE3
return
array->
indices[x.off.ioffset]->
buckets[x.off.boffset]->
elems[x.off.eoffset];
#else /* OBJC_SPARSE2 */
return array->buckets[x.off.boffset]->elems[x.off.eoffset];
#endif /* OBJC_SPARSE2 */
#else /* not PRECOMPUTE_SELECTORS */
#ifdef OBJC_SPARSE3
return array->
indices[indx/INDEX_CAPACITY]->
buckets[(indx/BUCKET_SIZE)%INDEX_SIZE]->
elems[indx%BUCKET_SIZE];
#else /* OBJC_SPARSE2 */
return array->buckets[indx/BUCKET_SIZE]->elems[indx%BUCKET_SIZE];
#endif /* not OBJC_SPARSE3 */
#endif /* not PRECOMPUTE_SELECTORS */
}
static inline void* sarray_get_safe(struct sarray* array, sidx indx)
{
if(soffset_decode(indx) < array->capacity)
return sarray_get(array, indx);
else
return (array->empty_bucket->elems[0]);
}
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* __sarray_INCLUDE_GNU */