sys/src/cmd/cc/pswt.c

   1 #include "gc.h"
   2
   3 int
   4 swcmp(const void *a1, const void *a2)
   5 {
   6         C1 *p1, *p2;
   7
   8         p1 = (C1*)a1;
   9         p2 = (C1*)a2;
  10         if(p1->val < p2->val)
  11                 return -1;
  12         return p1->val > p2->val;
  13 }
  14
  15 void
  16 doswit(Node *n)
  17 {
  18         Case *c;
  19         C1 *q, *iq;
  20         long def, nc, i, isv;
  21         int dup;
  22
  23         def = 0;
  24         nc = 0;
  25         isv = 0;
  26         for(c = cases; c->link != C; c = c->link) {
  27                 if(c->def) {
  28                         if(def)
  29                                 diag(n, "more than one default in switch");
  30                         def = c->label;
  31                         continue;
  32                 }
  33                 isv |= c->isv;
  34                 nc++;
  35         }
  36         if(isv && !typev[n->type->etype])
  37                 warn(n, "32-bit switch expression with 64-bit case constant");
  38
  39         iq = alloc(nc*sizeof(C1));
  40         q = iq;
  41         for(c = cases; c->link != C; c = c->link) {
  42                 if(c->def)
  43                         continue;
  44                 q->label = c->label;
  45                 if(isv)
  46                         q->val = c->val;
  47                 else
  48                         q->val = (long)c->val;  /* cast ensures correct value for 32-bit switch on 64-bit architecture */
  49                 q++;
  50         }
  51         qsort(iq, nc, sizeof(C1), swcmp);
  52         if(debug['W'])
  53         for(i=0; i<nc; i++)
  54                 print("case %2ld: = %.8llux\n", i, (vlong)iq[i].val);
  55         dup = 0;
  56         for(i=0; i<nc-1; i++)
  57                 if(iq[i].val == iq[i+1].val) {
  58                         diag(n, "duplicate cases in switch %lld", (vlong)iq[i].val);
  59                         dup = 1;
  60                 }
  61         if(dup)
  62                 return;
  63         if(def == 0) {
  64                 def = breakpc;
  65                 nbreak++;
  66         }
  67         swit1(iq, nc, def, n);
  68 }
  69
  70 void
  71 casf(void)
  72 {
  73         Case *c;
  74
  75         c = alloc(sizeof(*c));
  76         c->link = cases;
  77         cases = c;
  78 }
  79
  80 long
  81 outlstring(ushort *s, long n)
  82 {
  83         char buf[2];
  84         int c;
  85         long r;
  86
  87         if(suppress)
  88                 return nstring;
  89         while(nstring & 1)
  90                 outstring("", 1);
  91         r = nstring;
  92         while(n > 0) {
  93                 c = *s++;
  94                 if(align(0, types[TCHAR], Aarg1)) {
  95                         buf[0] = c>>8;
  96                         buf[1] = c;
  97                 } else {
  98                         buf[0] = c;
  99                         buf[1] = c>>8;
 100                 }
 101                 outstring(buf, 2);
 102                 n -= sizeof(ushort);
 103         }
 104         return r;
 105 }
 106
 107 void
 108 nullwarn(Node *l, Node *r)
 109 {
 110         warn(Z, "result of operation not used");
 111         if(l != Z)
 112                 cgen(l, Z);
 113         if(r != Z)
 114                 cgen(r, Z);
 115 }
 116
 117 void
 118 ieeedtod(Ieee *ieee, double native)
 119 {
 120         double fr, ho, f;
 121         int exp;
 122
 123         if(native < 0) {
 124                 ieeedtod(ieee, -native);
 125                 ieee->h |= 0x80000000L;
 126                 return;
 127         }
 128         if(native == 0) {
 129                 ieee->l = 0;
 130                 ieee->h = 0;
 131                 return;
 132         }
 133         fr = frexp(native, &exp);
 134         f = 2097152L;           /* shouldnt use fp constants here */
 135         fr = modf(fr*f, &ho);
 136         ieee->h = ho;
 137         ieee->h &= 0xfffffL;
 138         ieee->h |= (exp+1022L) << 20;
 139         f = 65536L;
 140         fr = modf(fr*f, &ho);
 141         ieee->l = ho;
 142         ieee->l <<= 16;
 143         ieee->l |= (long)(fr*f);
 144 }