gcc/testsuite/gcc.dg/tree-ssa/clz-complement-long-long.c

   1 /* { dg-do run } */
   2 /* { dg-require-effective-target clzll } */
   3 /* { dg-options "-O2 -fdump-tree-optimized" } */
   4
   5 #define PREC (__CHAR_BIT__ * __SIZEOF_LONG_LONG__)
   6
   7 int
   8 __attribute__ ((noinline, noclone))
   9 foo (unsigned long long b) {
  10     int c = 0;
  11
  12     while (b) {
  13         b >>= 1;
  14         c++;
  15     }
  16
  17     return c;
  18 }
  19
  20 int main()
  21 {
  22   if (foo(0) != 0)
  23     __builtin_abort ();
  24   if (foo(5) != 3)
  25     __builtin_abort ();
  26   if (foo(1LL << (PREC - 1)) != PREC)
  27     __builtin_abort ();
  28   return 0;
  29 }
  30
  31 /* { dg-final { scan-tree-dump-times "__builtin_clz|\\.CLZ" 1 "optimized" } } */