1 files changed, 67 insertions, 0 deletions
diff --git a/configure b/configure
index e076bc43c5e..118562c4973 100755
--- a/configure
+++ b/configure
@@ -2437,6 +2437,73 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 if test "$ac_env_CFLAGS_set" = set; then
   CFLAGS=$ac_env_CFLAGS_value
 fi
+
+# Need to specify -fno-strict-aliasing too in case it's gcc 3.3 or later.
+echo "$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}$pgac_cv_prog_cc_no_strict_aliasing" >&6
+
+if test x"$pgac_cv_prog_cc_no_strict_aliasing" != x""; then
+  CFLAGS="$CFLAGS $pgac_cv_prog_cc_no_strict_aliasing"
+fi
+
+# supply -g if --enable-debug
 if test "$enable_debug" = yes && test "$ac_cv_prog_cc_g" = yes; then
   CFLAGS="$CFLAGS -g"
 fi