diff --git a/configure b/configure
index 74e34ebae7..0165c3c9b7 100755
--- a/configure
+++ b/configure
@@ -15326,113 +15326,6 @@ $as_echo "$as_me: error: unknown endianness
    { (exit 1); exit 1; }; } ;;
  esac
 
-{ $as_echo "$as_me:$LINENO: checking for an ANSI C-conforming const" >&5
-$as_echo_n "checking for an ANSI C-conforming const... " >&6; }
-if test "${ac_cv_c_const+set}" = set; then
-  $as_echo_n "(cached) " >&6
-else
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-
-int
-main ()
-{
-/* FIXME: Include the comments suggested by Paul. */
-#ifndef __cplusplus
-  /* Ultrix mips cc rejects this.  */
-  typedef int charset[2];
-  const charset cs;
-  /* SunOS 4.1.1 cc rejects this.  */
-  char const *const *pcpcc;
-  char **ppc;
-  /* NEC SVR4.0.2 mips cc rejects this.  */
-  struct point {int x, y;};
-  static struct point const zero = {0,0};
-  /* AIX XL C 1.02.0.0 rejects this.
-     It does not let you subtract one const X* pointer from another in
-     an arm of an if-expression whose if-part is not a constant
-     expression */
-  const char *g = "string";
-  pcpcc = &g + (g ? g-g : 0);
-  /* HPUX 7.0 cc rejects these. */
-  ++pcpcc;
-  ppc = (char**) pcpcc;
-  pcpcc = (char const *const *) ppc;
-  { /* SCO 3.2v4 cc rejects this.  */
-    char *t;
-    char const *s = 0 ? (char *) 0 : (char const *) 0;
-
-    *t++ = 0;
-    if (s) return 0;
-  }
-  { /* Someone thinks the Sun supposedly-ANSI compiler will reject this.  */
-    int x[] = {25, 17};
-    const int *foo = &x[0];
-    ++foo;
-  }
-  { /* Sun SC1.0 ANSI compiler rejects this -- but not the above. */
-    typedef const int *iptr;
-    iptr p = 0;
-    ++p;
-  }
-  { /* AIX XL C 1.02.0.0 rejects this saying
-       "k.c", line 2.27: 1506-025 (S) Operand must be a modifiable lvalue. */
-    struct s { int j; const int *ap[3]; };
-    struct s *b; b->j = 5;
-  }
-  { /* ULTRIX-32 V3.1 (Rev 9) vcc rejects this */
-    const int foo = 10;
-    if (!foo) return 0;
-  }
-  return !cs[0] && !zero.x;
-#endif
-
-  ;
-  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
-  ac_cv_c_const=yes
-else
-  $as_echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-	ac_cv_c_const=no
-fi
-
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:$LINENO: result: $ac_cv_c_const" >&5
-$as_echo "$ac_cv_c_const" >&6; }
-if test $ac_cv_c_const = no; then
-
-cat >>confdefs.h <<\_ACEOF
-#define const /**/
-_ACEOF
-
-fi
-
 { $as_echo "$as_me:$LINENO: checking for inline" >&5
 $as_echo_n "checking for inline... " >&6; }
 if test "${ac_cv_c_inline+set}" = set; then
@@ -15570,40 +15463,6 @@ cat >>confdefs.h <<_ACEOF
 #define PG_USE_INLINE 1
 _ACEOF
 
-fi
-
-{ $as_echo "$as_me:$LINENO: checking for preprocessor stringizing operator" >&5
-$as_echo_n "checking for preprocessor stringizing operator... " >&6; }
-if test "${ac_cv_c_stringize+set}" = set; then
-  $as_echo_n "(cached) " >&6
-else
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-#define x(y) #y
-
-char *s = x(teststring);
-_ACEOF
-if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
-  $EGREP "#teststring" >/dev/null 2>&1; then
-  ac_cv_c_stringize=no
-else
-  ac_cv_c_stringize=yes
-fi
-rm -f conftest*
-
-fi
-{ $as_echo "$as_me:$LINENO: result: $ac_cv_c_stringize" >&5
-$as_echo "$ac_cv_c_stringize" >&6; }
-if test $ac_cv_c_stringize = yes; then
-
-cat >>confdefs.h <<\_ACEOF
-#define HAVE_STRINGIZE 1
-_ACEOF
-
 fi
 
 
@@ -15734,67 +15593,6 @@ cat >>confdefs.h <<\_ACEOF
 _ACEOF
 
 fi
-{ $as_echo "$as_me:$LINENO: checking for working volatile" >&5
-$as_echo_n "checking for working volatile... " >&6; }
-if test "${ac_cv_c_volatile+set}" = set; then
-  $as_echo_n "(cached) " >&6
-else
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-
-int
-main ()
-{
-
-volatile int x;
-int * volatile y = (int *) 0;
-return !x && !y;
-  ;
-  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
-  ac_cv_c_volatile=yes
-else
-  $as_echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-	ac_cv_c_volatile=no
-fi
-
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-{ $as_echo "$as_me:$LINENO: result: $ac_cv_c_volatile" >&5
-$as_echo "$ac_cv_c_volatile" >&6; }
-if test $ac_cv_c_volatile = no; then
-
-cat >>confdefs.h <<\_ACEOF
-#define volatile /**/
-_ACEOF
-
-fi
-
 { $as_echo "$as_me:$LINENO: checking for __func__" >&5
 $as_echo_n "checking for __func__... " >&6; }
 if test "${pgac_cv_funcname_func_support+set}" = set; then
@@ -28897,101 +28695,6 @@ operating system;  use --disable-thread-safety to disable thread safety." >&2;}
 fi
 fi
 
-# SunOS doesn't handle negative byte comparisons properly with +/- return
-{ $as_echo "$as_me:$LINENO: checking for working memcmp" >&5
-$as_echo_n "checking for working memcmp... " >&6; }
-if test "${ac_cv_func_memcmp_working+set}" = set; then
-  $as_echo_n "(cached) " >&6
-else
-  if test "$cross_compiling" = yes; then
-  ac_cv_func_memcmp_working=no
-else
-  cat >conftest.$ac_ext <<_ACEOF
-/* confdefs.h.  */
-_ACEOF
-cat confdefs.h >>conftest.$ac_ext
-cat >>conftest.$ac_ext <<_ACEOF
-/* end confdefs.h.  */
-$ac_includes_default
-int
-main ()
-{
-
-  /* Some versions of memcmp are not 8-bit clean.  */
-  char c0 = '\100', c1 = '\200', c2 = '\201';
-  if (memcmp(&c0, &c2, 1) >= 0 || memcmp(&c1, &c2, 1) >= 0)
-    return 1;
-
-  /* The Next x86 OpenStep bug shows up only when comparing 16 bytes
-     or more and with at least one buffer not starting on a 4-byte boundary.
-     William Lewis provided this test program.   */
-  {
-    char foo[21];
-    char bar[21];
-    int i;
-    for (i = 0; i < 4; i++)
-      {
-	char *a = foo + i;
-	char *b = bar + i;
-	strcpy (a, "--------01111111");
-	strcpy (b, "--------10000000");
-	if (memcmp (a, b, 16) >= 0)
-	  return 1;
-      }
-    return 0;
-  }
-
-  ;
-  return 0;
-}
-_ACEOF
-rm -f conftest$ac_exeext
-if { (ac_try="$ac_link"
-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_link") 2>&5
-  ac_status=$?
-  $as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); } && { ac_try='./conftest$ac_exeext'
-  { (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_try") 2>&5
-  ac_status=$?
-  $as_echo "$as_me:$LINENO: \$? = $ac_status" >&5
-  (exit $ac_status); }; }; then
-  ac_cv_func_memcmp_working=yes
-else
-  $as_echo "$as_me: program exited with status $ac_status" >&5
-$as_echo "$as_me: failed program was:" >&5
-sed 's/^/| /' conftest.$ac_ext >&5
-
-( exit $ac_status )
-ac_cv_func_memcmp_working=no
-fi
-rm -rf conftest.dSYM
-rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext conftest.$ac_objext conftest.$ac_ext
-fi
-
-
-fi
-{ $as_echo "$as_me:$LINENO: result: $ac_cv_func_memcmp_working" >&5
-$as_echo "$ac_cv_func_memcmp_working" >&6; }
-test $ac_cv_func_memcmp_working = no && case " $LIBOBJS " in
-  *" memcmp.$ac_objext "* ) ;;
-  *) LIBOBJS="$LIBOBJS memcmp.$ac_objext"
- ;;
-esac
-
-
-
 
 # Select semaphore implementation type.
 if test "$PORTNAME" != "win32"; then
diff --git a/configure.in b/configure.in
index 304399e75f..5479eab75c 100644
--- a/configure.in
+++ b/configure.in
@@ -1114,12 +1114,9 @@ fi
 
 m4_defun([AC_PROG_CC_STDC], []) dnl We don't want that.
 AC_C_BIGENDIAN
-AC_C_CONST
 PGAC_C_INLINE
-AC_C_STRINGIZE
 AC_C_FLEXIBLE_ARRAY_MEMBER
 PGAC_C_SIGNED
-AC_C_VOLATILE
 PGAC_C_FUNCNAME_SUPPORT
 PGAC_C_STATIC_ASSERT
 PGAC_C_TYPES_COMPATIBLE
@@ -1749,9 +1746,6 @@ operating system;  use --disable-thread-safety to disable thread safety.])
 fi
 fi
 
-# SunOS doesn't handle negative byte comparisons properly with +/- return
-AC_FUNC_MEMCMP
-
 
 # Select semaphore implementation type.
 if test "$PORTNAME" != "win32"; then
diff --git a/src/include/c.h b/src/include/c.h
index 6e19c6df87..beb20b0e6c 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -130,28 +130,12 @@
  * CppConcat
  *		Concatenate two arguments together, using the C preprocessor.
  *
- * Note: the standard Autoconf macro AC_C_STRINGIZE actually only checks
- * whether #identifier works, but if we have that we likely have ## too.
+ * Note: There used to be support here for pre-ANSI C compilers that didn't
+ * support # and ##.  Nowadays, these macros are just for clarity and/or
+ * backward compatibility with existing PostgreSQL code.
  */
-#if defined(HAVE_STRINGIZE)
-
 #define CppAsString(identifier) #identifier
 #define CppConcat(x, y)			x##y
-#else							/* !HAVE_STRINGIZE */
-
-#define CppAsString(identifier) "identifier"
-
-/*
- * CppIdentity -- On Reiser based cpp's this is used to concatenate
- *		two tokens.  That is
- *				CppIdentity(A)B ==> AB
- *		We renamed it to _private_CppIdentity because it should not
- *		be referenced outside this file.  On other cpp's it
- *		produces  A  B.
- */
-#define _priv_CppIdentity(x)x
-#define CppConcat(x, y)			_priv_CppIdentity(x)y
-#endif   /* !HAVE_STRINGIZE */
 
 /*
  * dummyret is used to set return values in macros that use ?: to make
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 5eac52d93a..d482e58fe5 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -457,9 +457,6 @@
 /* Define to 1 if you have the `strerror_r' function. */
 #undef HAVE_STRERROR_R
 
-/* Define to 1 if cpp supports the ANSI # stringizing operator. */
-#undef HAVE_STRINGIZE
-
 /* Define to 1 if you have the <strings.h> header file. */
 #undef HAVE_STRINGS_H
 
@@ -839,9 +836,6 @@
 /* Define for large files, on AIX-style hosts. */
 #undef _LARGE_FILES
 
-/* Define to empty if `const' does not conform to ANSI C. */
-#undef const
-
 /* Define to `__inline__' or `__inline' if that's what the C compiler
    calls it, or to nothing if 'inline' is not supported under any name.  */
 #ifndef __cplusplus
@@ -858,7 +852,3 @@
 /* Define to the type of an unsigned integer type wide enough to hold a
    pointer, if such a type exists, and if the system does not define it. */
 #undef uintptr_t
-
-/* Define to empty if the keyword `volatile' does not work. Warning: valid
-   code using `volatile' can become incorrect without. Disable with care. */
-#undef volatile
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index 54db287aff..b69414fd48 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -360,9 +360,6 @@
 /* Define to 1 if you have the `strerror_r' function. */
 /* #undef HAVE_STRERROR_R */
 
-/* Define to 1 if cpp supports the ANSI # stringizing operator. */
-#define HAVE_STRINGIZE 1
-
 /* Define to 1 if you have the <strings.h> header file. */
 /*#define HAVE_STRINGS_H 1 */
 
@@ -674,9 +671,6 @@
 /* Define for large files, on AIX-style hosts. */
 /* #undef _LARGE_FILES */
 
-/* Define to empty if `const' does not conform to ANSI C. */
-/* #undef const */
-
 /* Define to `__inline__' or `__inline' if that's what the C compiler
    calls it, or to nothing if 'inline' is not supported under any name.  */
 #ifndef __cplusplus
@@ -685,7 +679,3 @@
 
 /* Define to empty if the C compiler does not understand signed types. */
 /* #undef signed */
-
-/* Define to empty if the keyword `volatile' does not work. Warning: valid
-   code using `volatile' can become incorrect without. Disable with care. */
-/* #undef volatile */
diff --git a/src/port/memcmp.c b/src/port/memcmp.c
deleted file mode 100644
index dc8fa4a797..0000000000
--- a/src/port/memcmp.c
+++ /dev/null
@@ -1,70 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * memcmp.c
- *	  compares memory bytes
- *
- * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
- *
- *
- * IDENTIFICATION
- *	  src/port/memcmp.c
- *
- * This file was taken from NetBSD and is used by SunOS because memcmp
- * on that platform does not properly compare negative bytes. The
- * NetBSD copyright terms follow.
- */
-
-/*-
- * Copyright (c) 1990, 1993
- *	The Regents of the University of California.  All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * Chris Torek.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *	  notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *	  notice, this list of conditions and the following disclaimer in the
- *	  documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the University nor the names of its contributors
- *	  may be used to endorse or promote products derived from this software
- *	  without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.	IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include "c.h"
-
-
-/*
- * Compare memory regions.
- */
-int
-memcmp(const void *s1, const void *s2, size_t n)
-{
-	if (n != 0)
-	{
-		const unsigned char *p1 = s1,
-				   *p2 = s2;
-
-		do
-		{
-			if (*p1++ != *p2++)
-				return (*--p1 - *--p2);
-		} while (--n != 0);
-	}
-	return 0;
-}