Merge branch 'rickard/atomics-api/OTP-9014' into major

* rickard/atomics-api/OTP-9014:
  Use new atomic API in runtime system
  Improve ethread atomics

1 files changed, 250 insertions, 184 deletions

diff --git a/erts/aclocal.m4 b/erts/aclocal.m4
index b64380e817..3ebea66d30 100644
--- a/erts/aclocal.m4
+++ b/erts/aclocal.m4
@@ -679,6 +679,55 @@ AC_SUBST(ERTS_INTERNAL_X_LIBS)
 
 ])
 
+AC_DEFUN(ETHR_CHK_SYNC_OP,
+[
+    AC_MSG_CHECKING([for $3-bit $1()])
+    case "$2" in
+	"1") sync_call="$1(&var);";;
+	"2") sync_call="$1(&var, ($4) 0);";;
+	"3") sync_call="$1(&var, ($4) 0, ($4) 0);";;
+    esac
+    have_sync_op=no
+    AC_TRY_LINK([],
+	[
+	    $4 res;
+	    volatile $4 var;
+	    res = $sync_call
+	],
+	[have_sync_op=yes])
+    test $have_sync_op = yes && $5
+    AC_MSG_RESULT([$have_sync_op])
+])
+
+AC_DEFUN(ETHR_CHK_INTERLOCKED,
+[
+    ilckd="$1"
+    AC_MSG_CHECKING([for ${ilckd}()])
+    case "$2" in
+	"1") ilckd_call="${ilckd}(var);";;
+	"2") ilckd_call="${ilckd}(var, ($3) 0);";;
+	"3") ilckd_call="${ilckd}(var, ($3) 0, ($3) 0);";;
+	"4") ilckd_call="${ilckd}(var, ($3) 0, ($3) 0, arr);";;
+    esac
+    have_interlocked_op=no
+    AC_TRY_LINK(
+	[
+	#define WIN32_LEAN_AND_MEAN
+	#include <windows.h>
+	#include <intrin.h>
+	],
+	[
+	    volatile $3 *var;
+	    volatile $3 arr[2];
+
+	    $ilckd_call
+	    return 0;
+	],
+	[have_interlocked_op=yes])
+    test $have_interlocked_op = yes && $4
+    AC_MSG_RESULT([$have_interlocked_op])
+])
+
 dnl ----------------------------------------------------------------------
 dnl
 dnl ERL_FIND_ETHR_LIB
@@ -750,121 +799,41 @@ case "$THR_LIB_NAME" in
 
 	AC_DEFINE(ETHR_WIN32_THREADS, 1, [Define if you have win32 threads])
 
-	have_ilckd=no
-	AC_MSG_CHECKING([for _InterlockedCompareExchange64()])
-	AC_TRY_LINK([
-			#define WIN32_LEAN_AND_MEAN
-			#include <windows.h>
-		    ],
-		    [
-			volatile __int64 *var;
-			_InterlockedCompareExchange64(var, (__int64) 1, (__int64) 0);
-			return 0;
-		    ],
-		    have_ilckd=yes)
-	AC_MSG_RESULT([$have_ilckd])
-	test $have_ilckd = yes && AC_DEFINE(ETHR_HAVE__INTERLOCKEDCOMPAREEXCHANGE64, 1, [Define if you have _InterlockedCompareExchange64()])
-
-	AC_CHECK_SIZEOF(void *)
-	case "$ac_cv_sizeof_void_p-$have_ilckd" in
-	    8-no)
-		ethr_have_native_atomics=no
-	  	ethr_have_native_spinlock=no;;
-	    *)
-		ethr_have_native_atomics=yes
-	  	ethr_have_native_spinlock=yes;;
-	esac
-
-	have_ilckd=no
-	AC_MSG_CHECKING([for _InterlockedDecrement64()])
-	AC_TRY_LINK([
-			#define WIN32_LEAN_AND_MEAN
-			#include <windows.h>
-		    ],
-		    [
-			volatile __int64 *var;
-			_InterlockedDecrement64(var);
-			return 0;
-		    ],
-		    have_ilckd=yes)
-	AC_MSG_RESULT([$have_ilckd])
-	test $have_ilckd = yes && AC_DEFINE(ETHR_HAVE__INTERLOCKEDDECREMENT64, 1, [Define if you have _InterlockedDecrement64()])
-
-	have_ilckd=no
-	AC_MSG_CHECKING([for _InterlockedIncrement64()])
-	AC_TRY_LINK([
-			#define WIN32_LEAN_AND_MEAN
-			#include <windows.h>
-		    ],
-		    [
-			volatile __int64 *var;
-			_InterlockedIncrement64(var);
-			return 0;
-		    ],
-		    have_ilckd=yes)
-	AC_MSG_RESULT([$have_ilckd])
-	test $have_ilckd = yes && AC_DEFINE(ETHR_HAVE__INTERLOCKEDINCREMENT64, 1, [Define if you have _InterlockedIncrement64()])
-
-	have_ilckd=no
-	AC_MSG_CHECKING([for _InterlockedExchangeAdd64()])
-	AC_TRY_LINK([
-			#define WIN32_LEAN_AND_MEAN
-			#include <windows.h>
-		    ],
-		    [
-			volatile __int64 *var;
-			_InterlockedExchangeAdd64(var, (__int64) 1);
-			return 0;
-		    ],
-		    have_ilckd=yes)
-	AC_MSG_RESULT([$have_ilckd])
-	test $have_ilckd = yes && AC_DEFINE(ETHR_HAVE__INTERLOCKEDEXCHANGEADD64, 1, [Define if you have _InterlockedExchangeAdd64()])
-
-	have_ilckd=no
-	AC_MSG_CHECKING([for _InterlockedExchange64()])
-	AC_TRY_LINK([
-			#define WIN32_LEAN_AND_MEAN
-			#include <windows.h>
-		    ],
-		    [
-			volatile __int64 *var;
-			_InterlockedExchange64(var, (__int64) 1);
-			return 0;
-		    ],
-		    have_ilckd=yes)
-	AC_MSG_RESULT([$have_ilckd])
-	test $have_ilckd = yes && AC_DEFINE(ETHR_HAVE__INTERLOCKEDEXCHANGE64, 1, [Define if you have _InterlockedExchange64()])
-
-	have_ilckd=no
-	AC_MSG_CHECKING([for _InterlockedAnd64()])
-	AC_TRY_LINK([
-			#define WIN32_LEAN_AND_MEAN
-			#include <windows.h>
-		    ],
-		    [
-			volatile __int64 *var;
-			_InterlockedAnd64(var, (__int64) 1);
-			return 0;
-		    ],
-		    have_ilckd=yes)
-	AC_MSG_RESULT([$have_ilckd])
-	test $have_ilckd = yes && AC_DEFINE(ETHR_HAVE__INTERLOCKEDAND64, 1, [Define if you have _InterlockedAnd64()])
-
-	have_ilckd=no
-	AC_MSG_CHECKING([for _InterlockedOr64()])
-	AC_TRY_LINK([
-			#define WIN32_LEAN_AND_MEAN
-			#include <windows.h>
-		    ],
-		    [
-			volatile __int64 *var;
-			_InterlockedOr64(var, (__int64) 1);
-			return 0;
-		    ],
-		    have_ilckd=yes)
-	AC_MSG_RESULT([$have_ilckd])
-	test $have_ilckd = yes && AC_DEFINE(ETHR_HAVE__INTERLOCKEDOR64, 1, [Define if you have _InterlockedOr64()])
-
+	ETHR_CHK_INTERLOCKED([_InterlockedDecrement], [1], [long], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDDECREMENT, 1, [Define if you have _InterlockedDecrement()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedDecrement_rel], [1], [long], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDDECREMENT_REL, 1, [Define if you have _InterlockedDecrement_rel()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedIncrement], [1], [long], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDINCREMENT, 1, [Define if you have _InterlockedIncrement()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedIncrement_acq], [1], [long], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDINCREMENT_ACQ, 1, [Define if you have _InterlockedIncrement_acq()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedExchangeAdd], [2], [long], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDEXCHANGEADD, 1, [Define if you have _InterlockedExchangeAdd()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedExchangeAdd_acq], [2], [long], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDEXCHANGEADD_ACQ, 1, [Define if you have _InterlockedExchangeAdd_acq()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedAnd], [2], [long], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDAND, 1, [Define if you have _InterlockedAnd()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedOr], [2], [long], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDOR, 1, [Define if you have _InterlockedOr()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedExchange], [2], [long], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDEXCHANGE, 1, [Define if you have _InterlockedExchange()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedCompareExchange], [3], [long], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDCOMPAREEXCHANGE, 1, [Define if you have _InterlockedCompareExchange()]))
+	test "$have_interlocked_op" = "yes" && ethr_have_native_atomics=yes
+	ETHR_CHK_INTERLOCKED([_InterlockedCompareExchange_acq], [3], [long], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDCOMPAREEXCHANGE_ACQ, 1, [Define if you have _InterlockedCompareExchange_acq()]))
+	test "$have_interlocked_op" = "yes" && ethr_have_native_atomics=yes
+	ETHR_CHK_INTERLOCKED([_InterlockedCompareExchange_rel], [3], [long], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDCOMPAREEXCHANGE_REL, 1, [Define if you have _InterlockedCompareExchange_rel()]))
+	test "$have_interlocked_op" = "yes" && ethr_have_native_atomics=yes
+
+	ETHR_CHK_INTERLOCKED([_InterlockedDecrement64], [1], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDDECREMENT64, 1, [Define if you have _InterlockedDecrement64()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedDecrement64_rel], [1], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDDECREMENT64_REL, 1, [Define if you have _InterlockedDecrement64_rel()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedIncrement64], [1], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDINCREMENT64, 1, [Define if you have _InterlockedIncrement64()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedIncrement64_acq], [1], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDINCREMENT64_ACQ, 1, [Define if you have _InterlockedIncrement64_acq()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedExchangeAdd64], [2], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDEXCHANGEADD64, 1, [Define if you have _InterlockedExchangeAdd64()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedExchangeAdd64_acq], [2], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDEXCHANGEADD64_ACQ, 1, [Define if you have _InterlockedExchangeAdd64_acq()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedAnd64], [2], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDAND64, 1, [Define if you have _InterlockedAnd64()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedOr64], [2], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDOR64, 1, [Define if you have _InterlockedOr64()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedExchange64], [2], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDEXCHANGE64, 1, [Define if you have _InterlockedExchange64()]))
+	ETHR_CHK_INTERLOCKED([_InterlockedCompareExchange64], [3], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDCOMPAREEXCHANGE64, 1, [Define if you have _InterlockedCompareExchange64()]))
+	test "$have_interlocked_op" = "yes" && ethr_have_native_atomics=yes
+	ETHR_CHK_INTERLOCKED([_InterlockedCompareExchange64_acq], [3], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDCOMPAREEXCHANGE64_ACQ, 1, [Define if you have _InterlockedCompareExchange64_acq()]))
+	test "$have_interlocked_op" = "yes" && ethr_have_native_atomics=yes
+	ETHR_CHK_INTERLOCKED([_InterlockedCompareExchange64_rel], [3], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDCOMPAREEXCHANGE64_REL, 1, [Define if you have _InterlockedCompareExchange64_rel()]))
+	test "$have_interlocked_op" = "yes" && ethr_have_native_atomics=yes
+
+	ETHR_CHK_INTERLOCKED([_InterlockedCompareExchange128], [4], [__int64], AC_DEFINE_UNQUOTED(ETHR_HAVE__INTERLOCKEDCOMPAREEXCHANGE128, 1, [Define if you have _InterlockedCompareExchange128()]))
+
+	test "$ethr_have_native_atomics" = "yes" && ethr_have_native_spinlock=yes
 	;;
 
     pthread)
@@ -1100,35 +1069,51 @@ case "$THR_LIB_NAME" in
 	AC_MSG_RESULT([$linux_futex])
 	test $linux_futex = yes && AC_DEFINE(ETHR_HAVE_LINUX_FUTEX, 1, [Define if you have a linux futex implementation.])
 
-	AC_MSG_CHECKING([for GCC atomic operations])
-	ethr_have_gcc_atomic_ops=no
-	AC_TRY_LINK([],
-		    [
-			long res;
-			volatile long val;
-			res = __sync_val_compare_and_swap(&val, (long) 1, (long) 0);
-			res = __sync_add_and_fetch(&val, (long) 1);
-			res = __sync_sub_and_fetch(&val, (long) 1);
-			res = __sync_fetch_and_and(&val, (long) 1);
-			res = __sync_fetch_and_or(&val, (long) 1);
-		    ],
-		    [ethr_have_native_atomics=yes
-		     ethr_have_gcc_atomic_ops=yes])
-	AC_MSG_RESULT([$ethr_have_gcc_atomic_ops])
-	test $ethr_have_gcc_atomic_ops = yes && AC_DEFINE(ETHR_HAVE_GCC_ATOMIC_OPS, 1, [Define if you have gcc atomic operations])
+	AC_CHECK_SIZEOF(int)
+	AC_CHECK_SIZEOF(long)
+	AC_CHECK_SIZEOF(long long)
+	AC_CHECK_SIZEOF(__int128_t)
+
+	if test "$ac_cv_sizeof_int" = "4"; then
+	    int32="int"
+	elif test "$ac_cv_sizeof_long" = "4"; then
+	    int32="long"
+	elif test "$ac_cv_sizeof_long_long" = "4"; then
+	    int32="long long"
+	else
+	    AC_MSG_ERROR([No 32-bit type found])
+	fi
 
-	case "$host_cpu" in
-	  sun4u | sparc64 | sun4v)
-		ethr_have_native_atomics=yes;; 
-	  i86pc | i*86 | x86_64 | amd64)
-		ethr_have_native_atomics=yes;;
-	  macppc | ppc | "Power Macintosh")
-		ethr_have_native_atomics=yes;;
-	  tile)
-		ethr_have_native_atomics=yes;;
-	  *)
-		;;
-	esac
+	if test "$ac_cv_sizeof_int" = "8"; then
+	    int64="int"
+	elif test "$ac_cv_sizeof_long" = "8"; then
+	    int64="long"
+	elif test "$ac_cv_sizeof_long_long" = "8"; then
+	    int64="long long"
+	else
+	    AC_MSG_ERROR([No 64-bit type found])
+	fi
+
+	int128=no
+	if test "$ac_cv_sizeof___int128_t" = "16"; then
+	    int128="__int128_t"
+	fi
+
+	ETHR_CHK_SYNC_OP([__sync_val_compare_and_swap], [3], [32], [$int32], AC_DEFINE(ETHR_HAVE___SYNC_VAL_COMPARE_AND_SWAP32, 1, [Define if you have __sync_val_compare_and_swap() for 32-bit integers]))
+	test "$have_sync_op" = "yes" && ethr_have_native_atomics=yes
+	ETHR_CHK_SYNC_OP([__sync_add_and_fetch], [2], [32], [$int32], AC_DEFINE(ETHR_HAVE___SYNC_ADD_AND_FETCH32, 1, [Define if you have __sync_add_and_fetch() for 32-bit integers]))
+	ETHR_CHK_SYNC_OP([__sync_fetch_and_and], [2], [32], [$int32], AC_DEFINE(ETHR_HAVE___SYNC_FETCH_AND_AND32, 1, [Define if you have __sync_fetch_and_and() for 32-bit integers]))
+	ETHR_CHK_SYNC_OP([__sync_fetch_and_or], [2], [32], [$int32], AC_DEFINE(ETHR_HAVE___SYNC_FETCH_AND_OR32, 1, [Define if you have __sync_fetch_and_or() for 32-bit integers]))
+
+	ETHR_CHK_SYNC_OP([__sync_val_compare_and_swap], [3], [64], [$int64], AC_DEFINE(ETHR_HAVE___SYNC_VAL_COMPARE_AND_SWAP64, 1, [Define if you have __sync_val_compare_and_swap() for 64-bit integers]))
+	test "$have_sync_op" = "yes" && ethr_have_native_atomics=yes
+	ETHR_CHK_SYNC_OP([__sync_add_and_fetch], [2], [64], [$int64], AC_DEFINE(ETHR_HAVE___SYNC_ADD_AND_FETCH64, 1, [Define if you have __sync_add_and_fetch() for 64-bit integers]))
+	ETHR_CHK_SYNC_OP([__sync_fetch_and_and], [2], [64], [$int64], AC_DEFINE(ETHR_HAVE___SYNC_FETCH_AND_AND64, 1, [Define if you have __sync_fetch_and_and() for 64-bit integers]))
+	ETHR_CHK_SYNC_OP([__sync_fetch_and_or], [2], [64], [$int64], AC_DEFINE(ETHR_HAVE___SYNC_FETCH_AND_OR64, 1, [Define if you have __sync_fetch_and_or() for 64-bit integers]))
+
+	if test $int128 != no; then
+	    ETHR_CHK_SYNC_OP([__sync_val_compare_and_swap], [3], [128], [$int128], AC_DEFINE(ETHR_HAVE___SYNC_VAL_COMPARE_AND_SWAP128, 1, [Define if you have __sync_val_compare_and_swap() for 128-bit integers]))
+	fi
 
 	AC_MSG_CHECKING([for a usable libatomic_ops implementation])
 	case "x$with_libatomic_ops" in
@@ -1175,6 +1160,34 @@ case "$THR_LIB_NAME" in
 	    AC_MSG_ERROR([No usable libatomic_ops implementation found])
 	fi
 
+	case "$host_cpu" in
+	  sparc | sun4u | sparc64 | sun4v)
+		case "$with_sparc_memory_order" in
+		    "TSO")
+			AC_DEFINE(ETHR_SPARC_TSO, 1, [Define if only run in Sparc TSO mode]);;
+		    "PSO")
+			AC_DEFINE(ETHR_SPARC_PSO, 1, [Define if only run in Sparc PSO, or TSO mode]);;
+		    "RMO"|"")
+			AC_DEFINE(ETHR_SPARC_RMO, 1, [Define if run in Sparc RMO, PSO, or TSO mode]);;
+		    *)
+			AC_MSG_ERROR([Unsupported Sparc memory order: $with_sparc_memory_order]);;
+		esac
+		ethr_have_native_atomics=yes;; 
+	  i86pc | i*86 | x86_64 | amd64)
+		if test "$enable_x86_out_of_order" = "yes"; then
+			AC_DEFINE(ETHR_X86_OUT_OF_ORDER, 1, [Define if x86/x86_64 out of order instructions should be synchronized])
+		fi
+		ethr_have_native_atomics=yes;;
+	  macppc | ppc | "Power Macintosh")
+		ethr_have_native_atomics=yes;;
+	  tile)
+		ethr_have_native_atomics=yes;;
+	  *)
+		;;
+	esac
+
+	test ethr_have_native_atomics = "yes" && ethr_have_native_spinlock=yes
+
 	dnl Restore LIBS
 	LIBS=$saved_libs
 	dnl restore CPPFLAGS
@@ -1210,6 +1223,8 @@ AC_CHECK_SIZEOF(long long)
 AC_DEFINE_UNQUOTED(ETHR_SIZEOF_LONG_LONG, $ac_cv_sizeof_long_long, [Define to the size of long long])
 AC_CHECK_SIZEOF(__int64)
 AC_DEFINE_UNQUOTED(ETHR_SIZEOF___INT64, $ac_cv_sizeof___int64, [Define to the size of __int64])
+AC_CHECK_SIZEOF(__int128_t)
+AC_DEFINE_UNQUOTED(ETHR_SIZEOF___INT128_T, $ac_cv_sizeof___int128_t, [Define to the size of __int128_t])
 
 
 case X$erl_xcomp_bigendian in
@@ -1232,6 +1247,10 @@ AC_ARG_ENABLE(native-ethr-impls,
     *)  disable_native_ethr_impls=no ;;
   esac ], disable_native_ethr_impls=no)
 
+AC_ARG_ENABLE(x86-out-of-order,
+	      AS_HELP_STRING([--enable-x86-out-of-order],
+                             [enable x86/x84_64 out of order support (default disabled)]))
+
 test "X$disable_native_ethr_impls" = "Xyes" &&
   AC_DEFINE(ETHR_DISABLE_NATIVE_IMPLS, 1, [Define if you want to disable native ethread implementations])
 
@@ -1250,55 +1269,101 @@ AC_ARG_WITH(libatomic_ops,
 	    AS_HELP_STRING([--with-libatomic_ops=PATH],
 			   [specify and prefer usage of libatomic_ops in the ethread library]))
 
-AC_ARG_ENABLE(ethread-pre-pentium4-compatibility,
-	      AS_HELP_STRING([--enable-ethread-pre-pentium4-compatibility],
-			     [enable compatibility with x86 processors before pentium 4 (back to 486) in the ethread library]),
-[
-  case "$enable_ethread_pre_pentium4_compatibility" in
-    yes|no) ;;
-    *) enable_ethread_pre_pentium4_compatibility=check;;
-  esac
-],
-[enable_ethread_pre_pentium4_compatibility=check])
-
-test "$cross_compiling" != "yes" || enable_ethread_pre_pentium4_compatibility=no
-
-case "$enable_ethread_pre_pentium4_compatibility-$host_cpu" in
-  check-i86pc | check-i*86)
-    AC_MSG_CHECKING([whether pre pentium 4 compatibility should forced])
-    AC_RUN_IFELSE([
-#if defined(__GNUC__)
-#  if defined(ETHR_PREFER_LIBATOMIC_OPS_NATIVE_IMPLS)
-#    define CHECK_LIBATOMIC_OPS__
-#  else
-#    define CHECK_GCC_ASM__
-#  endif
-#elif defined(ETHR_HAVE_LIBATOMIC_OPS)
-#  define CHECK_LIBATOMIC_OPS__
+AC_ARG_WITH(with_sparc_memory_order,
+	    AS_HELP_STRING([--with-sparc-memory-order=TSO|PSO|RMO],
+			   [specify sparc memory order (defaults to RMO)]))
+
+ETHR_X86_SSE2_ASM=no
+case "$GCC-$ac_cv_sizeof_void_p-$host_cpu" in
+  yes-4-i86pc | yes-4-i*86 | yes-4-x86_64 | yes-4-amd64)
+    AC_MSG_CHECKING([for gcc sse2 asm support])
+    save_CFLAGS="$CFLAGS"
+    CFLAGS="$CFLAGS -msse2"
+    gcc_sse2_asm=no
+    AC_TRY_COMPILE([],
+	[
+		long long x, *y;
+		__asm__ __volatile__("movq %1, %0\n\t" : "=x"(x) : "m"(*y) : "memory");
+	],
+	[gcc_sse2_asm=yes])
+    CFLAGS="$save_CFLAGS"
+    AC_MSG_RESULT([$gcc_sse2_asm])
+    if test "$gcc_sse2_asm" = "yes"; then
+      AC_DEFINE(ETHR_GCC_HAVE_SSE2_ASM_SUPPORT, 1, [Define if you use a gcc that supports -msse2 and understand sse2 specific asm statements])
+      ETHR_X86_SSE2_ASM=yes
+    fi
+    ;;
+  *)
+    ;;
+esac
+
+case "$GCC-$host_cpu" in
+  yes-i86pc | yes-i*86 | yes-x86_64 | yes-amd64)
+    gcc_dw_cmpxchg_asm=no
+    AC_MSG_CHECKING([for gcc double word cmpxchg asm support])    
+    AC_TRY_COMPILE([],
+	[
+    char xchgd;
+    long new[2], xchg[2], *p;		  
+    __asm__ __volatile__(
+#if ETHR_SIZEOF_PTR == 4 && defined(__PIC__) && __PIC__
+	"pushl %%ebx\n\t"
+	"movl %8, %%ebx\n\t"
 #endif
-#if defined(CHECK_LIBATOMIC_OPS__)
-#include "atomic_ops.h"
+#if ETHR_SIZEOF_PTR == 4
+	"lock; cmpxchg8b %0\n\t"
+#else
+	"lock; cmpxchg16b %0\n\t"
 #endif
-int main(void)
-{
-#if defined(CHECK_GCC_ASM__)
-    __asm__ __volatile__("mfence" : : : "memory");
-#elif defined(CHECK_LIBATOMIC_OPS__)
-    AO_nop_full();
+	"setz %3\n\t"
+#if ETHR_SIZEOF_PTR == 4 && defined(__PIC__) && __PIC__
+	"popl %%ebx\n\t"
 #endif
-    return 0;
-}
+	: "=m"(*p), "=d"(xchg[1]), "=a"(xchg[0]), "=c"(xchgd)
+	: "m"(*p), "1"(xchg[1]), "2"(xchg[0]), "3"(new[1]),
+#if ETHR_SIZEOF_PTR == 4 && defined(__PIC__) && __PIC__
+	  "r"(new[0])
+#else
+	  "b"(new[0])
+#endif
+	: "cc", "memory");
+
 	],
-	[enable_ethread_pre_pentium4_compatibility=no],
-	[enable_ethread_pre_pentium4_compatibility=yes],
-	[enable_ethread_pre_pentium4_compatibility=no])
-    AC_MSG_RESULT([$enable_ethread_pre_pentium4_compatibility]);;
+	[gcc_dw_cmpxchg_asm=yes])
+    if test $gcc_dw_cmpxchg_asm = no && test $ac_cv_sizeof_void_p = 4; then
+      AC_TRY_COMPILE([],
+	  [
+      char xchgd;
+      long new[2], xchg[2], *p;
+#if !defined(__PIC__) || !__PIC__
+#  error nope
+#endif
+      __asm__ __volatile__(
+    	  "pushl %%ebx\n\t"
+	  "movl (%7), %%ebx\n\t"
+	  "movl 4(%7), %%ecx\n\t"
+	  "lock; cmpxchg8b %0\n\t"
+  	  "setz %3\n\t"
+	  "popl %%ebx\n\t"
+	  : "=m"(*p), "=d"(xchg[1]), "=a"(xchg[0]), "=c"(xchgd)
+	  : "m"(*p), "1"(xchg[1]), "2"(xchg[0]), "3"(new)
+	: "cc", "memory");
+
+	],
+	[gcc_dw_cmpxchg_asm=yes])
+      if test "$gcc_dw_cmpxchg_asm" = "yes"; then
+        AC_DEFINE(ETHR_CMPXCHG8B_REGISTER_SHORTAGE, 1, [Define if you get a register shortage with cmpxchg8b and position independent code])
+      fi
+    fi
+    AC_MSG_RESULT([$gcc_dw_cmpxchg_asm])
+    if test "$gcc_dw_cmpxchg_asm" = "yes"; then
+      AC_DEFINE(ETHR_GCC_HAVE_DW_CMPXCHG_ASM_SUPPORT, 1, [Define if you use a gcc that supports the double word cmpxchg instruction])
+    fi;;
   *)
     ;;
 esac
 
-test $enable_ethread_pre_pentium4_compatibility = yes &&
-  AC_DEFINE(ETHR_PRE_PENTIUM4_COMPAT, 1, [Define if you want compatibilty with x86 processors before pentium4.])
+
 
 AC_DEFINE(ETHR_HAVE_ETHREAD_DEFINES, 1, \
 [Define if you have all ethread defines])
@@ -1309,6 +1374,7 @@ AC_SUBST(ETHR_LIB_NAME)
 AC_SUBST(ETHR_DEFS)
 AC_SUBST(ETHR_THR_LIB_BASE)
 AC_SUBST(ETHR_THR_LIB_BASE_DIR)
+AC_SUBST(ETHR_X86_SSE2_ASM)
 
 ])