// double-width CAS support - only for libc++
+// You can manually suppress wide-atomic support by defining in compiler command line:
+// for 64bit platform: -DCDS_DISABLE_128BIT_ATOMIC
+// for 32bit platform: -DCDS_DISABLE_64BIT_ATOMIC
#ifdef _LIBCPP_VERSION
# if CDS_BUILD_BITS == 64
-# ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16
+# if !defined( CDS_DISABLE_128BIT_ATOMIC ) && defined( __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 )
# define CDS_DCAS_SUPPORT
# endif
# else
-# ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8
+# if !defined( CDS_DISABLE_64BIT_ATOMIC ) && defined( __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 )
# define CDS_DCAS_SUPPORT
# endif
# endif
// double-width CAS support
// note: gcc-4.8 does not support double-word atomics
// gcc-4.9: a lot of crashes when use DCAS
+// You can manually suppress wide-atomic support by defining in compiler command line:
+// for 64bit platform: -DCDS_DISABLE_128BIT_ATOMIC
+// for 32bit platform: -DCDS_DISABLE_64BIT_ATOMIC
#if CDS_COMPILER_VERSION >= 50000
# if CDS_BUILD_BITS == 64
-# ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16
+# if !defined( CDS_DISABLE_128BIT_ATOMIC ) && defined( __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 )
# define CDS_DCAS_SUPPORT
# endif
# else
-# ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8
+# if !defined( CDS_DISABLE_64BIT_ATOMIC ) && defined( __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8 )
# define CDS_DCAS_SUPPORT
# endif
# endif