does not compile on non-x86 platforms (e.g. arm)

/tmp/ccE5S8Kh.s: Assembler messages:
/tmp/ccE5S8Kh.s:4818: Error: bad instruction bsfq r2,r3' /tmp/ccE5S8Kh.s:7391: Error: bad instruction bsfq r2,ip'
/tmp/ccE5S8Kh.s:7423: Error: bad instruction bsfq r0,r3' /tmp/ccE5S8Kh.s:7503: Error: bad instruction bsfq [sp,#104],r8'
/tmp/ccE5S8Kh.s:8201: Error: bad instruction `bsfq r4,r3'

and so on

Index: tbprobe.c

--- tbprobe.c (revision 3989)
+++ tbprobe.c (working copy)
@@ -30,7 +30,6 @@
#include "tbprobe.h"

#ifdef GNUC
-#include <x86intrin.h>
#endif

#define WHITE_KING (TB_WPAWN + 5)
@@ -127,12 +126,9 @@
#ifdef TB_CUSTOM_LSB
#define lsb(b) TB_CUSTOM_LSB(b)
#else
-static inline unsigned lsb(uint64_t b)
-{

• size_t idx;
• asm("bsfq %1, %0": "=r"(idx): "rm"(b));
• return idx;
  -}
  +// from http://cb2pgn.googlecode.com/svn/trunk/jni/mstl/m_bit_functions.ipp
  +inline unsigned ctz(unsigned long long x) { return __builtin_ctzll(x); }
  +inline unsigned lsb(uint64_t x) { return ctz(x); }
  #endif
  #define square(r, f) (8 * (r) + (f))