AIX xlc has to have strict aliasing turned off. If not, the optimizer

assumes that pointers can only point to an object of the same type.

diff --git a/configure.ac b/configure.ac
index 5e16564ea195eb093c80613fe3b1b2b204581e82..dcc53dc6da84f934d152d229012216cd63268973 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1459,6 +1459,10 @@ if test "x$RECENTAIX" = "xyes"; then
          XLC="yes"
          AC_MSG_RESULT([yes])
          CFLAGS="$CFLAGS -qthreaded"
+         dnl AIX xlc has to have strict aliasing turned off. If not,
+         dnl the optimizer assumes that pointers can only point to
+         dnl an object of the same type.
+         CFLAGS="$CFLAGS -qnoansialias"
        )