Alexandre Julliard (@julliard) commented about dlls/ntdll/unix/signal_x86_64.c:
"movl 0xb0(%rcx),%r14d\n\t" /* frame->syscall_flags */ "testl $3,%r14d\n\t" /* SYSCALL_HAVE_XSAVE | SYSCALL_HAVE_XSAVEC */ "jz 2f\n\t" - "movl $7,%eax\n\t" - "xorl %edx,%edx\n\t" - "movq %rdx,0x2c0(%rcx)\n\t" - "movq %rdx,0x2c8(%rcx)\n\t" - "movq %rdx,0x2d0(%rcx)\n\t" + "movl %gs:0x340,%eax\n\t" /* amd64_thread_data()->xstate_features_mask */ + "movl %gs:0x344,%edx\n\t" /* amd64_thread_data()->xstate_features_mask high dword */
macOS needs an extra indirection for TEB accesses. -- https://gitlab.winehq.org/wine/wine/-/merge_requests/4987#note_61487