gcc/testsuite/gcc.dg/tree-ssa/pr114760-1.c

   1 /* PR tree-optimization/114760 */
   2 /* { dg-do compile } */
   3 /* { dg-require-effective-target clz } */
   4 /* { dg-require-effective-target ctz } */
   5 /* { dg-options "-O3 -fdump-tree-optimized" } */
   6
   7 unsigned
   8 ntz32_1 (unsigned x)
   9 {
  10   int n = 32;
  11   while (x != 0)
  12     {
  13       n = n - 1;
  14       x = x * 2;
  15     }
  16   return n;
  17 }
  18
  19 unsigned
  20 ntz32_2 (unsigned x)
  21 {
  22   int n = 32;
  23   while (x != 0)
  24     {
  25       n = n - 1;
  26       x = x + x;
  27     }
  28   return n;
  29 }
  30
  31 unsigned
  32 ntz32_3 (unsigned x)
  33 {
  34   int n = 32;
  35   while (x != 0)
  36     {
  37       n = n - 1;
  38       x = x << 1;
  39     }
  40   return n;
  41 }
  42
  43 #define PREC (__CHAR_BIT__ * __SIZEOF_INT__)
  44 int
  45 nlz32_1 (unsigned int b) {
  46     int c = PREC;
  47
  48     while (b != 0) {
  49         b >>= 1;
  50         c --;
  51     }
  52
  53     return c;
  54 }
  55
  56 int
  57 nlz32_2 (unsigned int b) {
  58     int c = PREC;
  59
  60     while (b != 0) {
  61         b /= 2;
  62         c --;
  63     }
  64
  65     return c;
  66 }
  67
  68 /* { dg-final { scan-tree-dump-times "__builtin_ctz|\\.CTZ" 3 "optimized" } } */
  69 /* { dg-final { scan-tree-dump-times "__builtin_clz|\\.CLZ" 2 "optimized" } } */