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 = (RAA_BLKSHIFT-RAA_LAYERSHIFT) + layers*RAA_LAYERSHIFT;
  23     }
  24     return r;
  25 }
  26
  27 struct RAA *raa_init(void)
  28 {
  29     return real_raa_init(0);
  30 }
  31
  32 void raa_free(struct RAA *r)
  33 {
  34     if (r->layers) {
  35         struct RAA **p;
  36         for (p = r->u.b.data; p - r->u.b.data < RAA_LAYERSIZE; p++)
  37             if (*p)
  38                 raa_free(*p);
  39     }
  40     nasm_free(r);
  41 }
  42
  43 int64_t raa_read(struct RAA *r, int32_t posn)
  44 {
  45     if ((uint32_t)posn >= (UINT32_C(1) << (r->shift + LAYERSHIFT(r))))
  46         return 0;               /* Return 0 for undefined entries */
  47     while (r->layers > 0) {
  48         int32_t l = posn >> r->shift;
  49         posn &= (UINT32_C(1) << r->shift)-1;
  50         r = r->u.b.data[l];
  51         if (!r)
  52             return 0;           /* Return 0 for undefined entries */
  53     }
  54     return r->u.l.data[posn];
  55 }
  56
  57 struct RAA *raa_write(struct RAA *r, int32_t posn, int64_t value)
  58 {
  59     struct RAA *result;
  60
  61     if (posn < 0)
  62         nasm_malloc_error(ERR_PANIC, "negative position in raa_write");
  63
  64     while ((UINT32_C(1) << (r->shift+LAYERSHIFT(r))) <= (uint32_t)posn) {
  65         /*
  66          * Must add a layer.
  67          */
  68         struct RAA *s;
  69         int i;
  70
  71         s = nasm_malloc(BRANCHSIZ);
  72         for (i = 0; i < RAA_LAYERSIZE; i++)
  73             s->u.b.data[i] = NULL;
  74         s->layers = r->layers + 1;
  75         s->shift = LAYERSHIFT(r) + r->shift;
  76         s->u.b.data[0] = r;
  77         r = s;
  78     }
  79
  80     result = r;
  81
  82     while (r->layers > 0) {
  83         struct RAA **s;
  84         int32_t l = posn >> r->shift;
  85         posn &= (UINT32_C(1) << r->shift)-1;
  86         s = &r->u.b.data[l];
  87         if (!*s)
  88             *s = real_raa_init(r->layers - 1);
  89         r = *s;
  90     }
  91
  92     r->u.l.data[posn] = value;
  93
  94     return result;
  95 }