diff --git a/config/c-compiler.m4 b/config/c-compiler.m4
index 5d72e1377b..1649b105aa 100644
--- a/config/c-compiler.m4
+++ b/config/c-compiler.m4
@@ -1,5 +1,5 @@
 # Macros to detect C compiler features
-# $Header: /cvsroot/pgsql/config/c-compiler.m4,v 1.8 2003/04/24 21:16:42 tgl Exp $
+# $Header: /cvsroot/pgsql/config/c-compiler.m4,v 1.9 2003/10/25 15:32:11 petere Exp $
 
 
 # PGAC_C_SIGNED
@@ -97,7 +97,7 @@ AC_DEFINE_UNQUOTED(AS_TR_CPP(alignof_$1),
 
 
 # PGAC_C_FUNCNAME_SUPPORT
-# -------------
+# -----------------------
 # Check if the C compiler understands __func__ (C99) or __FUNCTION__ (gcc).
 # Define HAVE_FUNCNAME__FUNC or HAVE_FUNCNAME__FUNCTION accordingly.
 AC_DEFUN([PGAC_C_FUNCNAME_SUPPORT],
@@ -120,3 +120,32 @@ AC_DEFINE(HAVE_FUNCNAME__FUNCTION, 1,
           [Define to 1 if your compiler understands __FUNCTION__.])
 fi
 fi])# PGAC_C_FUNCNAME_SUPPORT
+
+
+# PGAC_PROG_CC_NO_STRICT_ALIASING
+# -------------------------------
+# Find out how to turn off strict aliasing in the C compiler.
+AC_DEFUN([PGAC_PROG_CC_NO_STRICT_ALIASING],
+[AC_CACHE_CHECK([how to turn off strict aliasing in $CC],
+                pgac_cv_prog_cc_no_strict_aliasing,
+[pgac_save_CFLAGS=$CFLAGS
+if test "$GCC" = yes; then
+  pgac_try="-fno-strict-aliasing"
+else
+  # Maybe fill in later...
+  pgac_try=
+fi
+
+for pgac_flag in $pgac_try; do
+  CFLAGS="$pgac_save_CFLAGS $pgac_flag"
+  _AC_COMPILE_IFELSE([AC_LANG_PROGRAM()],
+                     [pgac_cv_prog_cc_no_strict_aliasing=$pgac_try
+break])
+done
+
+CFLAGS=$pgac_save_CFLAGS
+])
+
+if test "$ac_env_CFLAGS_set" != set; then
+  CFLAGS="$CFLAGS $pgac_cv_prog_cc_no_strict_aliasing"
+fi])# PGAC_PROG_CC_NO_STRICT_ALIASING
diff --git a/configure b/configure
index 7aae5f6270..284d231db9 100755
--- a/configure
+++ b/configure
@@ -841,7 +841,7 @@ Optional Features:
   --enable-nls[=LANGUAGES]  enable Native Language Support
   --disable-shared        do not build shared libraries
   --disable-rpath         do not embed shared library search path in executables
-  --disable-spinlocks     do not use Spinlocks
+  --disable-spinlocks     do not use spinlocks
   --enable-debug          build with debugging symbols (-g)
   --enable-depend         turn on automatic dependency tracking
   --enable-cassert        enable assertion checks (for debugging)
@@ -2384,40 +2384,105 @@ ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $
 ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 
+pgac_CFLAGS_before_template=$CFLAGS
+
 #
 # Read the template
 #
 . "$srcdir/src/template/$template" || exit
 
-# The template may have supplied a default setting for CFLAGS.
-# Override this if CFLAGS was set in the original environment.
+# CFLAGS are selected so:
+# If the user specifies something in the environment, that is used.
+# else:  If the template file set something, that is used.
+# else:  If the compiler is GCC, then we use -O2.
+# else:  If the compiler is something else, then we use -0.
+
 if test "$ac_env_CFLAGS_set" = set; then
   CFLAGS=$ac_env_CFLAGS_value
+elif test "$pgac_CFLAGS_before_template" != "$CFLAGS"; then
+  : # (keep what template set)
+elif test "$GCC" = yes; then
+  CFLAGS="-O2"
 else
-  # autoconf already set the default CFLAGS for gcc to be -O2, but we
-  # need to specify -fno-strict-aliasing too in case it's gcc 3.3 or later.
-  if test "$GCC" = yes; then
-    CFLAGS="$CFLAGS -fno-strict-aliasing"
-  fi
+  CFLAGS="-O"
 fi
+
+# Need to specify -fno-strict-aliasing too in case it's gcc 3.3 or later.
+echo "$as_me:$LINENO: checking how to turn off strict aliasing in $CC" >&5
+echo $ECHO_N "checking how to turn off strict aliasing in $CC... $ECHO_C" >&6
+if test "${pgac_cv_prog_cc_no_strict_aliasing+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+if test "$GCC" = yes; then
+  pgac_try="-fno-strict-aliasing"
+else
+  # Maybe fill in later...
+  pgac_try=
+fi
+
+for pgac_flag in $pgac_try; do
+  CFLAGS="$pgac_save_CFLAGS $pgac_flag"
+  cat >conftest.$ac_ext <<_ACEOF
+#line $LINENO "configure"
+#include "confdefs.h"
+
+#ifdef F77_DUMMY_MAIN
+#  ifdef __cplusplus
+     extern "C"
+#  endif
+   int F77_DUMMY_MAIN() { return 1; }
+#endif
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext
+if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5
+  (eval $ac_compile) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+         { ac_try='test -s conftest.$ac_objext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  pgac_cv_prog_cc_no_strict_aliasing=$pgac_try
+break
+else
+  echo "$as_me: failed program was:" >&5
+cat conftest.$ac_ext >&5
+fi
+rm -f conftest.$ac_objext conftest.$ac_ext
+done
+
+CFLAGS=$pgac_save_CFLAGS
+
+fi
+echo "$as_me:$LINENO: result: $pgac_cv_prog_cc_no_strict_aliasing" >&5
+echo "${ECHO_T}$pgac_cv_prog_cc_no_strict_aliasing" >&6
+
+if test "$ac_env_CFLAGS_set" != set; then
+  CFLAGS="$CFLAGS $pgac_cv_prog_cc_no_strict_aliasing"
+fi
+
 # supply -g if --enable-debug
 if test "$enable_debug" = yes -a "$ac_cv_prog_cc_g" = yes; then
   CFLAGS="$CFLAGS -g"
 fi
-# default to -O rather than empty CFLAGS; this path will not be taken for
-# gcc (since autoconf supplies -O2), nor if --enable-debug (because -O -g
-# doesn't work on most non-gcc compilers), nor if the template provided
-# some CFLAGS.
-if test "$ac_env_CFLAGS_set" != set -a x"$CFLAGS" = x""; then
-  CFLAGS="-O"
-fi
+
 { echo "$as_me:$LINENO: using CFLAGS=$CFLAGS" >&5
 echo "$as_me: using CFLAGS=$CFLAGS" >&6;}
 
 # We already have this in Makefile.win32, but configure needs it too
-if test "$PORTNAME" = "win32"
-then
-	CPPFLAGS="$CPPFLAGS -I$srcdir/src/include/port/win32"
+if test "$PORTNAME" = "win32"; then
+  CPPFLAGS="$CPPFLAGS -I$srcdir/src/include/port/win32"
 fi
 
 # Check if the compiler still works with the template settings
diff --git a/configure.in b/configure.in
index 3b25a2b6fe..67c23b638f 100644
--- a/configure.in
+++ b/configure.in
@@ -1,5 +1,5 @@
 dnl Process this file with autoconf to produce a configure script.
-dnl $Header: /cvsroot/pgsql/configure.in,v 1.297 2003/10/22 04:16:39 pgsql Exp $
+dnl $Header: /cvsroot/pgsql/configure.in,v 1.298 2003/10/25 15:32:11 petere Exp $
 dnl
 dnl Developers, please strive to achieve this order:
 dnl
@@ -203,7 +203,7 @@ AC_SUBST(enable_rpath)
 # Spinlocks
 #
 PGAC_ARG_BOOL(enable, spinlocks, yes,
-              [  --disable-spinlocks     do not use Spinlocks])
+              [  --disable-spinlocks     do not use spinlocks])
 
 #
 # --enable-debug adds -g to compiler flags
@@ -229,39 +229,42 @@ esac
 
 AC_PROG_CC([$pgac_cc_list])
 
+pgac_CFLAGS_before_template=$CFLAGS
+
 #
 # Read the template
 #
 . "$srcdir/src/template/$template" || exit
 
-# The template may have supplied a default setting for CFLAGS.
-# Override this if CFLAGS was set in the original environment.
+# CFLAGS are selected so:
+# If the user specifies something in the environment, that is used.
+# else:  If the template file set something, that is used.
+# else:  If the compiler is GCC, then we use -O2.
+# else:  If the compiler is something else, then we use -0.
+
 if test "$ac_env_CFLAGS_set" = set; then
   CFLAGS=$ac_env_CFLAGS_value
+elif test "$pgac_CFLAGS_before_template" != "$CFLAGS"; then
+  : # (keep what template set)
+elif test "$GCC" = yes; then
+  CFLAGS="-O2"
 else
-  # autoconf already set the default CFLAGS for gcc to be -O2, but we
-  # need to specify -fno-strict-aliasing too in case it's gcc 3.3 or later.
-  if test "$GCC" = yes; then
-    CFLAGS="$CFLAGS -fno-strict-aliasing"
-  fi
+  CFLAGS="-O"
 fi
+
+# Need to specify -fno-strict-aliasing too in case it's gcc 3.3 or later.
+PGAC_PROG_CC_NO_STRICT_ALIASING
+
 # supply -g if --enable-debug
 if test "$enable_debug" = yes -a "$ac_cv_prog_cc_g" = yes; then
   CFLAGS="$CFLAGS -g"
 fi
-# default to -O rather than empty CFLAGS; this path will not be taken for
-# gcc (since autoconf supplies -O2), nor if --enable-debug (because -O -g
-# doesn't work on most non-gcc compilers), nor if the template provided
-# some CFLAGS.
-if test "$ac_env_CFLAGS_set" != set -a x"$CFLAGS" = x""; then
-  CFLAGS="-O"
-fi
+
 AC_MSG_NOTICE([using CFLAGS=$CFLAGS])
 
 # We already have this in Makefile.win32, but configure needs it too
-if test "$PORTNAME" = "win32"
-then
-	CPPFLAGS="$CPPFLAGS -I$srcdir/src/include/port/win32"
+if test "$PORTNAME" = "win32"; then
+  CPPFLAGS="$CPPFLAGS -I$srcdir/src/include/port/win32"
 fi
 
 # Check if the compiler still works with the template settings
diff --git a/src/template/aix b/src/template/aix
index f72be4f9a0..1e3d226195 100644
--- a/src/template/aix
+++ b/src/template/aix
@@ -1,7 +1,7 @@
 if test "$GCC" != yes ; then
   case $host_os in
     aix3.2.5 | aix4.1*) ;;
-    *) CFLAGS="$CFLAGS -O2 -qlonglong";;
+    *) CFLAGS="-O2 -qlonglong";;
   esac
-  CFLAGS="$CFLAGS -qmaxmem=16384 -qsrcmsg"
+  CFLAGS="-O -qmaxmem=16384 -qsrcmsg"
 fi
diff --git a/src/template/bsdi b/src/template/bsdi
index 70b27910a1..4c62ce4421 100644
--- a/src/template/bsdi
+++ b/src/template/bsdi
@@ -1,7 +1,3 @@
-case $host_cpu in
-  i?86)  CFLAGS="$CFLAGS -m486";;
-esac
-
 case $host_os in
   bsdi2.0 | bsdi2.1 | bsdi3*) CC=gcc2;;
 esac
diff --git a/src/template/freebsd b/src/template/freebsd
index fbf01fcd8a..2b155d12db 100644
--- a/src/template/freebsd
+++ b/src/template/freebsd
@@ -1,5 +1,5 @@
 case $host_cpu in
-  alpha*)   CFLAGS="$CFLAGS -O";;  # alpha has problems with -O2
+  alpha*)   CFLAGS="-O";;  # alpha has problems with -O2
 esac
 
 THREAD_SUPPORT=yes
diff --git a/src/template/hpux b/src/template/hpux
index a461df0dcd..28d836e012 100644
--- a/src/template/hpux
+++ b/src/template/hpux
@@ -2,5 +2,5 @@ CPPFLAGS="-D_XOPEN_SOURCE_EXTENDED"
 
 if test "$GCC" != yes ; then
   CC="$CC -Ae"
-  CFLAGS="$CFLAGS +O2"
+  CFLAGS="+O2"
 fi
diff --git a/src/template/osf b/src/template/osf
index 2b4dee1546..312d6cdfa5 100644
--- a/src/template/osf
+++ b/src/template/osf
@@ -1,6 +1,6 @@
 if test "$GCC" != yes ; then
   CC="$CC -std"
-  CFLAGS="$CFLAGS -O4 -Olimit 2000"
+  CFLAGS="-O4 -Olimit 2000"
 fi
 
 THREAD_SUPPORT=yes
diff --git a/src/template/qnx4 b/src/template/qnx4
index fc55af2c57..4ab0ae1db9 100644
--- a/src/template/qnx4
+++ b/src/template/qnx4
@@ -1,2 +1 @@
-CFLAGS="$CFLAGS -I/usr/local/include"
 LIBS="-lunix"
diff --git a/src/template/solaris b/src/template/solaris
index 5264f74985..7609d0e2cb 100644
--- a/src/template/solaris
+++ b/src/template/solaris
@@ -1,9 +1,8 @@
 if test "$GCC" != yes ; then
   CC="$CC -Xa"			# relaxed ISO C mode
-  CFLAGS="$CFLAGS -O -v"	# -v is like gcc -Wall
+  CFLAGS="-O -v"		# -v is like gcc -Wall
 fi
 
 THREAD_SUPPORT=yes
 NEED_REENTRANT_FUNCS=yes	# 5.6 2003-09-13
 THREAD_LIBS="-pthread"
-
diff --git a/src/template/univel b/src/template/univel
index 12d1149673..30980fee0a 100644
--- a/src/template/univel
+++ b/src/template/univel
@@ -1,2 +1,2 @@
-CFLAGS="$CFLAGS -v -O -K i486,host,inline,loop_unroll -Dsvr4"
+CFLAGS="-v -O -K i486,host,inline,loop_unroll -Dsvr4"
 LIBS="-lc89"
diff --git a/src/template/unixware b/src/template/unixware
index 8ad4a745d2..1b420c81c4 100644
--- a/src/template/unixware
+++ b/src/template/unixware
@@ -4,7 +4,7 @@ else
 # the -Kno_host is temporary for a bug in the compiler.  See -hackers
 # discussion on 7-8/Aug/2003.
 # when the 7.1.3UP3 or later compiler is out, we can do a version check.
-  CFLAGS="$CFLAGS -O -Kinline,no_host"
+  CFLAGS="-O -Kinline,no_host"
   THREAD_CPPFLAGS="-K pthread"
 fi