fix getting the unique thread id on the Apple M1, see issue
@@ -707,7 +707,7 @@ static inline void* mi_tls_slot(size_t slot) mi_attr_noexcept {
res = tcb[slot];
#elif defined(__aarch64__)
void** tcb; UNUSED(ofs);
-#if defined(__APPLE__) // issue #343
+#if defined(__APPLE__) // M1, issue #343
__asm__ volatile ("mrs %0, tpidrro_el0" : "=r" (tcb));
#else
__asm__ volatile ("mrs %0, tpidr_el0" : "=r" (tcb));
@@ -734,7 +734,7 @@ static inline void mi_tls_slot_set(size_t slot, void* value) mi_attr_noexcept {
tcb[slot] = value;
#elif defined(__aarch64__)
void** tcb; UNUSED(ofs);
-#if defined(__APPLE__) // issue #343
+#if defined(__APPLE__) // M1, issue #343
__asm__ volatile ("mrs %0, tpidrro_el0" : "=r" (tcb));
#else
__asm__ volatile ("mrs %0, tpidr_el0" : "=r" (tcb));
@@ -744,8 +744,13 @@ static inline void mi_tls_slot_set(size_t slot, void* value) mi_attr_noexcept {
}
static inline uintptr_t _mi_thread_id(void) mi_attr_noexcept {
- // in all our targets, slot 0 is the pointer to the thread control block
+#if defined(__aarch64__) && defined(__APPLE__) // M1
+ // on macOS on the M1, slot 0 does not seem to work, so we fall back to portable C for now. See issue #354
+ return (uintptr_t)&_mi_heap_default;
+#else
+ // in all our other targets, slot 0 is the pointer to the thread control block
return (uintptr_t)mi_tls_slot(0);
+#endif
}
#else
// otherwise use standard C
