raa.c

   1 #include "nasmlib.h"
   2 #include "raa.h"
   3
   4 #define LEAFSIZ (sizeof(RAA)-sizeof(RAA_UNION)+sizeof(RAA_LEAF))
   5 #define BRANCHSIZ (sizeof(RAA)-sizeof(RAA_UNION)+sizeof(RAA_BRANCH))
   6
   7 #define LAYERSHIFT(r) ( (r)->layers==0 ? RAA_BLKSHIFT : RAA_LAYERSHIFT )
   8
   9 static struct RAA *real_raa_init(int layers)
  10 {
  11     struct RAA *r;
  12     int i;
  13
  14     if (layers == 0) {
  15         r = nasm_zalloc(LEAFSIZ);
  16         r->shift = 0;
  17     } else {
  18         r = nasm_malloc(BRANCHSIZ);
  19         r->layers = layers;
  20         for (i = 0; i < RAA_LAYERSIZE; i++)
  21             r->u.b.data[i] = NULL;
  22         r->shift =
  23             (RAA_BLKSHIFT - RAA_LAYERSHIFT) + layers * RAA_LAYERSHIFT;
  24     }
  25     return r;
  26 }
  27
  28 struct RAA *raa_init(void)
  29 {
  30     return real_raa_init(0);
  31 }
  32
  33 void raa_free(struct RAA *r)
  34 {
  35     if (r->layers) {
  36         struct RAA **p;
  37         for (p = r->u.b.data; p - r->u.b.data < RAA_LAYERSIZE; p++)
  38             if (*p)
  39                 raa_free(*p);
  40     }
  41     nasm_free(r);
  42 }
  43
  44 int64_t raa_read(struct RAA *r, int32_t posn)
  45 {
  46     if ((uint32_t) posn >= (UINT32_C(1) << (r->shift + LAYERSHIFT(r))))
  47         return 0;               /* Return 0 for undefined entries */
  48     while (r->layers > 0) {
  49         int32_t l = posn >> r->shift;
  50         posn &= (UINT32_C(1) << r->shift) - 1;
  51         r = r->u.b.data[l];
  52         if (!r)
  53             return 0;           /* Return 0 for undefined entries */
  54     }
  55     return r->u.l.data[posn];
  56 }
  57
  58 struct RAA *raa_write(struct RAA *r, int32_t posn, int64_t value)
  59 {
  60     struct RAA *result;
  61
  62     if (posn < 0)
  63         nasm_malloc_error(ERR_PANIC, "negative position in raa_write");
  64
  65     while ((UINT32_C(1) << (r->shift + LAYERSHIFT(r))) <= (uint32_t) posn) {
  66         /*
  67          * Must add a layer.
  68          */
  69         struct RAA *s;
  70         int i;
  71
  72         s = nasm_malloc(BRANCHSIZ);
  73         for (i = 0; i < RAA_LAYERSIZE; i++)
  74             s->u.b.data[i] = NULL;
  75         s->layers = r->layers + 1;
  76         s->shift = LAYERSHIFT(r) + r->shift;
  77         s->u.b.data[0] = r;
  78         r = s;
  79     }
  80
  81     result = r;
  82
  83     while (r->layers > 0) {
  84         struct RAA **s;
  85         int32_t l = posn >> r->shift;
  86         posn &= (UINT32_C(1) << r->shift) - 1;
  87         s = &r->u.b.data[l];
  88         if (!*s)
  89             *s = real_raa_init(r->layers - 1);
  90         r = *s;
  91     }
  92
  93     r->u.l.data[posn] = value;
  94
  95     return result;
  96 }