src/jemalloc/include/msvc_compat/strings.h

   1 #ifndef strings_h
   2 #define strings_h
   3
   4 /* MSVC doesn't define ffs/ffsl. This dummy strings.h header is provided
   5  * for both */
   6 #ifdef _MSC_VER
   7 #  include <intrin.h>
   8 #  pragma intrinsic(_BitScanForward)
   9 static __forceinline int ffsl(long x)
  10 {
  11         unsigned long i;
  12
  13         if (_BitScanForward(&i, x))
  14                 return (i + 1);
  15         return (0);
  16 }
  17
  18 static __forceinline int ffs(int x)
  19 {
  20
  21         return (ffsl(x));
  22 }
  23
  24 #else
  25 #  define ffsl(x) __builtin_ffsl(x)
  26 #  define ffs(x) __builtin_ffs(x)
  27 #endif
  28
  29 #endif /* strings_h */