[PATCH 1/1] ntdll: Implement NtGetCurrentProcessorNumber for macOS on x86_64.

[Marc-Aurel Zent]

From: Marc-Aurel Zent

See _os_cpu_number at xnu/libsyscall/os/tsd.h.
The arm and arm64 implementations are not stable across kernel releases (yet).
---
 dlls/ntdll/unix/thread.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/dlls/ntdll/unix/thread.c b/dlls/ntdll/unix/thread.c
index a7114825118..5eaf3bf85b8 100644
--- a/dlls/ntdll/unix/thread.c
+++ b/dlls/ntdll/unix/thread.c
@@ -2563,6 +2563,12 @@ ULONG WINAPI NtGetCurrentProcessorNumber(void)
 #if defined(__linux__) && defined(__NR_getcpu)
     int res = syscall(__NR_getcpu, &processor, NULL, NULL);
     if (res != -1) return processor;
+#elif defined(__APPLE__) && (defined(__x86_64__) || defined(__i386__))
+    struct {
+        unsigned long p1, p2;
+    } p;
+    __asm__ __volatile__("sidt %[p]" : [p] "=&m"(p));
+    return (ULONG)(p.p1 & 0xfff);
 #endif

if (peb->NumberOfProcessors > 1)