Index: configure.in
===================================================================
--- configure.in	(revision 1902266)
+++ configure.in	(working copy)
@@ -457,17 +457,23 @@ case "$host:$CC" in
         ;;
 esac
 
-AC_CACHE_CHECK([whether the compiler provides atomic builtins], [ap_cv_atomic_builtins],
+AC_CACHE_CHECK([whether the compiler provides 32bit atomic builtins], [ap_cv_atomic_builtins],
 [AC_TRY_RUN([
-int main()
+#if HAVE_STDINT_H
+#include <stdint.h>
+#endif
+int main(int argc, const char *const *argv)
 {
-    unsigned long val = 1010, tmp, *mem = &val;
+#if HAVE_STDINT_H
+    uint32_t val = 1010, tmp, *mem = &val;
+#else
+    unsigned int val = 1010, tmp, *mem = &val;
+#endif
 
     if (__sync_fetch_and_add(&val, 1010) != 1010 || val != 2020)
         return 1;
 
     tmp = val;
-
     if (__sync_fetch_and_sub(mem, 1010) != tmp || val != 1010)
         return 1;
 
@@ -475,28 +481,59 @@ esac
         return 1;
 
     tmp = 3030;
-
     if (__sync_val_compare_and_swap(mem, 0, tmp) != 0 || val != tmp)
         return 1;
 
+    __sync_synchronize();
     if (__sync_lock_test_and_set(&val, 4040) != 3030)
         return 1;
 
-    mem = &tmp;
+    if (__sync_val_compare_and_swap(&mem, &val, &tmp) != &val || mem != &tmp)
+        return 1;
 
-    if (__sync_val_compare_and_swap(&mem, &tmp, &val) != &tmp)
+    return 0;
+}], [ap_cv_atomic_builtins=yes], [ap_cv_atomic_builtins=no], [ap_cv_atomic_builtins=no])])
+
+if test "$ap_cv_atomic_builtins" = "yes"; then
+    AC_DEFINE(HAVE_ATOMIC_BUILTINS, 1, [Define if compiler provides 32bit atomic builtins])
+fi
+
+AC_CACHE_CHECK([whether the compiler provides 64bit atomic builtins], [ap_cv_atomic_builtins64],
+[AC_TRY_RUN([
+#if HAVE_STDINT_H
+#include <stdint.h>
+#endif
+int main(int argc, const char *const *argv)
+{
+#if HAVE_STDINT_H
+    uint64_t val = 1010, tmp, *mem = &val;
+#else
+    unsigned long long val = 1010, tmp, *mem = &val;
+#endif
+
+    if (__sync_fetch_and_add(&val, 1010) != 1010 || val != 2020)
         return 1;
 
-    __sync_synchronize();
+    tmp = val;
+    if (__sync_fetch_and_sub(mem, 1010) != tmp || val != 1010)
+        return 1;
 
-    if (mem != &val)
+    if (__sync_sub_and_fetch(&val, 1010) != 0 || val != 0)
         return 1;
 
+    tmp = 3030;
+    if (__sync_val_compare_and_swap(mem, 0, tmp) != 0 || val != tmp)
+        return 1;
+
+    __sync_synchronize();
+    if (__sync_lock_test_and_set(&val, 4040) != 3030)
+        return 1;
+
     return 0;
-}], [ap_cv_atomic_builtins=yes], [ap_cv_atomic_builtins=no], [ap_cv_atomic_builtins=no])])
+}], [ap_cv_atomic_builtins64=yes], [ap_cv_atomic_builtins64=no], [ap_cv_atomic_builtins64=no])])
 
-if test "$ap_cv_atomic_builtins" = "yes"; then
-    AC_DEFINE(HAVE_ATOMIC_BUILTINS, 1, [Define if compiler provides atomic builtins])
+if test "$ap_cv_atomic_builtins64" = "yes"; then
+    AC_DEFINE(HAVE_ATOMIC_BUILTINS64, 1, [Define if compiler provides 64bit atomic builtins])
 fi
 
 case $host in
Index: include/arch/unix/apr_arch_atomic.h
===================================================================
--- include/arch/unix/apr_arch_atomic.h	(revision 1902266)
+++ include/arch/unix/apr_arch_atomic.h	(working copy)
@@ -26,6 +26,11 @@
 /* noop */
 #elif HAVE_ATOMIC_BUILTINS
 #   define USE_ATOMICS_BUILTINS
+#   if HAVE_ATOMIC_BUILTINS64
+#   define USE_ATOMICS_BUILTINS64
+#   else
+#   define NEED_ATOMICS_GENERIC64
+#   endif
 #elif defined(SOLARIS2) && SOLARIS2 >= 10
 #   define USE_ATOMICS_SOLARIS
 #   define NEED_ATOMICS_GENERIC64
@@ -36,7 +41,9 @@
 #elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
 #   define USE_ATOMICS_IA32
 #   define NEED_ATOMICS_GENERIC64
-#elif defined(__GNUC__) && (defined(__PPC__) || defined(__ppc__))
+#elif defined(__GNUC__) && (defined(__powerpc__) \
+                            || defined(__PPC__) \
+                            || defined(__ppc__))
 #   define USE_ATOMICS_PPC
 #   define NEED_ATOMICS_GENERIC64
 #elif defined(__GNUC__) && (defined(__s390__) || defined(__s390x__))
Index: atomic/unix/builtins64.c
===================================================================
--- atomic/unix/builtins64.c	(revision 1902266)
+++ atomic/unix/builtins64.c	(working copy)
@@ -16,7 +16,7 @@
 
 #include "apr_arch_atomic.h"
 
-#ifdef USE_ATOMICS_BUILTINS
+#ifdef USE_ATOMICS_BUILTINS64
 
 APR_DECLARE(apr_uint64_t) apr_atomic_read64(volatile apr_uint64_t *mem)
 {
@@ -61,4 +61,4 @@ APR_DECLARE(apr_uint64_t) apr_atomic_xchg64(volati
     return __sync_lock_test_and_set(mem, val);
 }
 
-#endif /* USE_ATOMICS_BUILTINS */
+#endif /* USE_ATOMICS_BUILTINS64 */