+
+* MIT-style license :
+
+xchg() privimitive has been rewritten from scratch starting from atomic_ops 1.2
+which has a MIT-style license that is intended to allow use in both free and
+proprietary software:
+ http://www.hpl.hp.com/research/linux/atomic_ops/LICENSING.txt
+ http://www.hpl.hp.com/personal/Hans_Boehm/gc/gc_source/
+
+This license applies to :
+
+arch_atomic_x86.h
+arch_atomic_ppc.h
+
+
+* GPLv2
+