diff --git a/configure b/configure
index 6f30b03a41b..359d359eba6 100755
--- a/configure
+++ b/configure
@@ -25392,60 +25392,6 @@ cat >>confdefs.h <<_ACEOF
 _ACEOF
 
 
-
-if test x"$HAVE_LONG_LONG_INT_64" = xyes ; then
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-
-#define INT64CONST(x)  x##LL
-long long int foo = INT64CONST(0x1234567890123456);
-
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest.$ac_objext
-if { (ac_try="$ac_compile"
-case "(($ac_try" in
-  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
-  *) ac_try_echo=$ac_try;;
-esac
-eval ac_try_echo="\"\$as_me:$LINENO: $ac_try_echo\""
-$as_echo "$ac_try_echo") >&5
-  (eval "$ac_compile") 2>conftest.er1
-  ac_status=$?
-  grep -v '^ *+' conftest.er1 >conftest.err
-  rm -f conftest.er1
-  cat conftest.err >&5
-  $as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } && {
-	 test -z "$ac_c_werror_flag" ||
-	 test ! -s conftest.err
-       } && test -s conftest.$ac_objext; then
-
-cat >>confdefs.h <<\_ACEOF
-#define HAVE_LL_CONSTANTS 1
-_ACEOF
-
-else
-  $as_echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-
-fi
-
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-
-
 # If we found "long int" is 64 bits, assume snprintf handles it.  If
 # we found we need to use "long long int", better check.  We cope with
 # snprintfs that use %lld, %qd, or %I64d as the format.  If none of these
diff --git a/configure.in b/configure.in
index 832e23cde66..e68fe7d3874 100644
--- a/configure.in
+++ b/configure.in
@@ -1667,19 +1667,6 @@ fi
 AC_DEFINE_UNQUOTED(PG_INT64_TYPE, $pg_int64_type,
   [Define to the name of a signed 64-bit integer type.])
 
-dnl If we need to use "long long int", figure out whether nnnLL notation works.
-
-if test x"$HAVE_LONG_LONG_INT_64" = xyes ; then
-  AC_TRY_COMPILE([
-#define INT64CONST(x)  x##LL
-long long int foo = INT64CONST(0x1234567890123456);
-],
-	[],
-	[AC_DEFINE(HAVE_LL_CONSTANTS, 1, [Define to 1 if constants of type 'long long int' should have the suffix LL.])],
-	[])
-fi
-
-
 # If we found "long int" is 64 bits, assume snprintf handles it.  If
 # we found we need to use "long long int", better check.  We cope with
 # snprintfs that use %lld, %qd, or %I64d as the format.  If none of these
diff --git a/src/include/c.h b/src/include/c.h
index 47c5e8db112..2d1576016ab 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -272,6 +272,8 @@ typedef long int int64;
 #ifndef HAVE_UINT64
 typedef unsigned long int uint64;
 #endif
+#define INT64CONST(x)  (x##L)
+#define UINT64CONST(x) (x##UL)
 #elif defined(HAVE_LONG_LONG_INT_64)
 /* We have working support for "long long int", use that */
 
@@ -281,23 +283,20 @@ typedef long long int int64;
 #ifndef HAVE_UINT64
 typedef unsigned long long int uint64;
 #endif
+#define INT64CONST(x)  (x##LL)
+#define UINT64CONST(x) (x##ULL)
 #else
 /* neither HAVE_LONG_INT_64 nor HAVE_LONG_LONG_INT_64 */
 #error must have a working 64-bit integer datatype
 #endif
 
-/* Decide if we need to decorate 64-bit constants */
-#ifdef HAVE_LL_CONSTANTS
-#define INT64CONST(x)  ((int64) x##LL)
-#define UINT64CONST(x) ((uint64) x##ULL)
-#else
-#define INT64CONST(x)  ((int64) x)
-#define UINT64CONST(x) ((uint64) x)
-#endif
-
 /* Max value of size_t might be missing if we don't have stdint.h */
 #ifndef SIZE_MAX
-#define SIZE_MAX ((size_t) -1)
+#if SIZEOF_SIZE_T == 8
+#define SIZE_MAX UINT64CONST(0xFFFFFFFFFFFFFFFF)
+#else
+#define SIZE_MAX (0xFFFFFFFFU)
+#endif
 #endif
 
 /* Select timestamp representation (float8 or int64) */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 872d39fb819..c1b7e299b9c 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -326,10 +326,6 @@
 /* Define to 1 if you have the `z' library (-lz). */
 #undef HAVE_LIBZ
 
-/* Define to 1 if constants of type 'long long int' should have the suffix LL.
-   */
-#undef HAVE_LL_CONSTANTS
-
 /* Define to 1 if the system has the type `locale_t'. */
 #undef HAVE_LOCALE_T
 
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 7fd2a346eec..06c5b534324 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -232,12 +232,6 @@
 /* Define to 1 if you have the `z' library (-lz). */
 /* #undef HAVE_LIBZ */
 
-/* Define to 1 if constants of type 'long long int' should have the suffix LL.
-   */
-#if (_MSC_VER > 1200)
-#define HAVE_LL_CONSTANTS 1
-#endif
-
 /* Define to 1 if the system has the type `locale_t'. */
 #define HAVE_LOCALE_T 1
 
@@ -246,7 +240,7 @@
 
 /* Define to 1 if `long long int' works and is 64 bits. */
 #if (_MSC_VER > 1200)
-#define HAVE_LONG_LONG_INT_64
+#define HAVE_LONG_LONG_INT_64 1
 #endif
 
 /* Define to 1 if you have the `mbstowcs_l' function. */