This would zero the first 4 or 8 bytes of the array because it is declared as a pointer
rockbox/lib/rbcodec/codecs/libasap/asap.c:1229:44: warning: argument to 'sizeof' in 'memset' call is the same expression as the destination; did you mean to provide an explicit length? [-Wsizeof-pointer-memaccess]
memset(ast -> memory, 0, sizeof(ast -> memory));
~~~~~~~~~~~~~ ~~~~~~~^~~~~~