u3: moves loom base on linux-64 to accomodate ASan
# else
#error "port: headers"
+# endif
+
+# ifndef __has_feature
+# define __has_feature(x) 0
+# endif
+# if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
+# define ASAN_ENABLED
# endif
/** Address space layout.
**/
# if defined(U3_OS_linux)
+# ifdef __LP64__
+# ifdef ASAN_ENABLED
+# define U3_OS_LoomBase 0x10007ffff000
+# else
+# define U3_OS_LoomBase 0x200000000
+# endif
+# else
# define U3_OS_LoomBase 0x36000000
+# endif
# define U3_OS_LoomBits 29 // ie, 2^29 words == 2GB
# elif defined(U3_OS_osx)
# ifdef __LP64__
