1 extern void abort (void);
2 
3 typedef unsigned long HARD_REG_SET[2];
4 HARD_REG_SET reg_class_contents[2];
5 
6 struct du_chain
7 {
8   struct du_chain *next_use;
9   int cl;
10 };
11 
12 void __attribute__((noinline))
merge_overlapping_regs(HARD_REG_SET * p)13 merge_overlapping_regs (HARD_REG_SET *p)
14 {
15   if ((*p)[0] != -1 || (*p)[1] != -1)
16     abort ();
17 }
18 
19 void __attribute__((noinline))
regrename_optimize(struct du_chain * this)20 regrename_optimize (struct du_chain *this)
21 {
22   HARD_REG_SET this_unavailable;
23   unsigned long *scan_fp_;
24   int n_uses;
25   struct du_chain *last;
26 
27   this_unavailable[0] = 0;
28   this_unavailable[1] = 0;
29 
30   n_uses = 0;
31   for (last = this; last->next_use; last = last->next_use)
32     {
33       scan_fp_ = reg_class_contents[last->cl];
34       n_uses++;
35       this_unavailable[0] |= ~ scan_fp_[0];
36       this_unavailable[1] |= ~ scan_fp_[1];
37     }
38   if (n_uses < 1)
39     return;
40 
41   scan_fp_ = reg_class_contents[last->cl];
42   this_unavailable[0] |= ~ scan_fp_[0];
43   this_unavailable[1] |= ~ scan_fp_[1];
44 
45   merge_overlapping_regs (&this_unavailable);
46 }
47 
main()48 int main()
49 {
50   struct du_chain du1 = { 0, 0 };
51   struct du_chain du0 = { &du1, 1 };
52   reg_class_contents[0][0] = -1;
53   reg_class_contents[0][1] = -1;
54   reg_class_contents[1][0] = 0;
55   reg_class_contents[1][1] = 0;
56   regrename_optimize (&du0);
57   return 0;
58 }
59