gcc/testsuite/gcc.dg/tree-ssa/popcount4.c

   1 /* { dg-do compile } */
   2 /* { dg-require-effective-target popcount } */
   3 /* { dg-require-effective-target int32plus } */
   4 /* { dg-options "-O2 -fdump-tree-optimized" } */
   5
   6 const unsigned m1  = 0x55555555UL;
   7 const unsigned m2  = 0x33333333UL;
   8 const unsigned m4  = 0x0F0F0F0FUL;
   9 const unsigned h01 = 0x01010101UL;
  10 const int shift = 24;
  11
  12 int popcount64c(unsigned x)
  13 {
  14     x -= (x >> 1) & m1;
  15     x = (x & m2) + ((x >> 2) & m2);
  16     x = (x + (x >> 4)) & m4;
  17     return (x * h01) >> shift;
  18 }
  19
  20 /* { dg-final { scan-tree-dump-times "\.POPCOUNT" 1 "optimized" } } */
  21
  22