+#define likely(x) __builtin_expect(!!(x), 1)
+#define unlikely(x) __builtin_expect(!!(x), 0)
+
+#define __section(name) __attribute__((section(name)))
+#define weak_alias(name) __attribute__((weak, alias(name)))
+#define optimize(opt) __attribute__((optimize(opt)))
+#define weak __attribute__((weak))
+#define noret __attribute__((noreturn))
+#define must_inline __attribute__((always_inline))
+#define must_emit __attribute__((used))
+#define unreachable __builtin_unreachable()
+#define no_inline __attribute__((noinline))
+
+#define clz(bits) __builtin_clz(bits)
+#define sadd_overflow(a, b, of) __builtin_sadd_overflow(a, b, of)
+#define umul_overflow(a, b, of) __builtin_umul_overflow(a, b, of)
+#define offsetof(f, m) __builtin_offsetof(f, m)
+
+#define prefetch_rd(ptr, ll) __builtin_prefetch((ptr), 0, ll)
+#define prefetch_wr(ptr, ll) __builtin_prefetch((ptr), 1, ll)
+
+#define stringify(v) #v
+#define stringify__(v) stringify(v)
+
+#define compact __attribute__((packed))
+#define align(v) __attribute__((aligned (v)))
+
+#define cacheline_size 64
+#define cacheline_align align(cacheline_size)
+
+#define export_symbol(domain, namespace, symbol)\
+ typeof(symbol)* must_emit __SYMEXPORT_Z##domain##_N##namespace##_S##symbol = &(symbol)
+
+inline static void noret
+spin()
+{
+ volatile int __infloop = 1;
+ while (__infloop)
+ ;
+ unreachable;
+}