gcc/testsuite/gcc.target/i386/lzcnt-4.c

   1 /* { dg-do run { target { lzcnt } } } */
   2 /* { dg-options "-O2 -mlzcnt -fno-inline" } */
   3
   4 #include <x86intrin.h>
   5
   6 #include "lzcnt-check.h"
   7
   8 int calc_lzcnt_u32 (int src)
   9 {
  10   int i;
  11   int res = 0;
  12
  13   while ((res < 32) && (((src >> (31 - res)) & 1) == 0))
  14     ++res;
  15
  16   return res;
  17 }
  18
  19 static void
  20 lzcnt_test ()
  21 {
  22   unsigned i;
  23   int src = 0xce7ace0;
  24   int res, res_ref;
  25
  26   for (i=0; i<5; ++i) {
  27     src = src >> i;
  28
  29     res_ref = calc_lzcnt_u32 (src);
  30     res = __lzcnt32 (src);
  31
  32     if (res != res_ref)
  33       abort();
  34   }
  35 }