nasm/raa.c

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/* ----------------------------------------------------------------------- *
*
* Copyright 1996-2009 The NASM Authors - All Rights Reserved
* See the file AUTHORS included with the NASM distribution for
* the specific copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* ----------------------------------------------------------------------- */
#include "nasmlib.h"
#include "raa.h"
#define LEAFSIZ (sizeof(RAA)-sizeof(RAA_UNION)+sizeof(RAA_LEAF))
#define BRANCHSIZ (sizeof(RAA)-sizeof(RAA_UNION)+sizeof(RAA_BRANCH))
#define LAYERSHIFT(r) ( (r)->layers==0 ? RAA_BLKSHIFT : RAA_LAYERSHIFT )
static struct RAA *real_raa_init(int layers)
{
struct RAA *r;
int i;
if (layers == 0) {
r = nasm_zalloc(LEAFSIZ);
r->shift = 0;
} else {
r = nasm_malloc(BRANCHSIZ);
r->layers = layers;
for (i = 0; i < RAA_LAYERSIZE; i++)
r->u.b.data[i] = NULL;
r->shift =
(RAA_BLKSHIFT - RAA_LAYERSHIFT) + layers * RAA_LAYERSHIFT;
}
return r;
}
struct RAA *raa_init(void)
{
return real_raa_init(0);
}
void raa_free(struct RAA *r)
{
if (r->layers) {
struct RAA **p;
for (p = r->u.b.data; p - r->u.b.data < RAA_LAYERSIZE; p++)
if (*p)
raa_free(*p);
}
nasm_free(r);
}
int64_t raa_read(struct RAA *r, int32_t posn)
{
if ((uint32_t) posn >= (UINT32_C(1) << (r->shift + LAYERSHIFT(r))))
return 0; /* Return 0 for undefined entries */
while (r->layers > 0) {
int32_t l = posn >> r->shift;
posn &= (UINT32_C(1) << r->shift) - 1;
r = r->u.b.data[l];
if (!r)
return 0; /* Return 0 for undefined entries */
}
return r->u.l.data[posn];
}
struct RAA *raa_write(struct RAA *r, int32_t posn, int64_t value)
{
struct RAA *result;
nasm_assert(posn >= 0);
while ((UINT32_C(1) << (r->shift + LAYERSHIFT(r))) <= (uint32_t) posn) {
/*
* Must add a layer.
*/
struct RAA *s;
int i;
s = nasm_malloc(BRANCHSIZ);
for (i = 0; i < RAA_LAYERSIZE; i++)
s->u.b.data[i] = NULL;
s->layers = r->layers + 1;
s->shift = LAYERSHIFT(r) + r->shift;
s->u.b.data[0] = r;
r = s;
}
result = r;
while (r->layers > 0) {
struct RAA **s;
int32_t l = posn >> r->shift;
posn &= (UINT32_C(1) << r->shift) - 1;
s = &r->u.b.data[l];
if (!*s)
*s = real_raa_init(r->layers - 1);
r = *s;
}
r->u.l.data[posn] = value;
return result;
}