fixed simX multicore support, added shared memory

simX/util.h

@@ -10,6 +10,14 @@ void unused(Args&&...) {}
 
 #define __unused(...) unused(__VA_ARGS__)
 
+constexpr bool ispow2(uint32_t value) {
+  return value && !(value & (value - 1));
+}
+
+constexpr unsigned log2ceil(uint32_t value) {
+  return 32 - __builtin_clz(value - 1);
+}
+
 Word signExt(Word w, Size bit, Word mask);
 
 Word bytesToWord(const Byte *b, Size wordSize);