diff -Nrup a/m4/ac_check_fpu_control.m4 b/m4/ac_check_fpu_control.m4
--- a/m4/ac_check_fpu_control.m4 2016-02-11 05:31:26.000000000 -0700
+++ b/m4/ac_check_fpu_control.m4 2020-05-21 13:19:45.448773119 -0600
@@ -49,9 +49,9 @@ main() {
#else
- float nf1 = -3, pf1 = 3, f2 = 5;
- double nd1 = -7, pd1 = 7, d2 = 11;
-long double nl1 = -13, pl1 = 13, l2 = 17;
+ volatile float nf1 = -3, pf1 = 3, f2 = 5;
+ volatile double nd1 = -7, pd1 = 7, d2 = 11;
+volatile long double nl1 = -13, pl1 = 13, l2 = 17;
float nf[2], pf[2];
double nd[2], pd[2];