+$echo "Checking whether NV 0.0 is all bits zero in memory..." >&4
+: volatile so that the compiler has to store it out to memory.
+if test X"$d_volatile" = X"$define"; then
+ volatile=volatile
+fi
+$cat <<EOP >try.c
+#include <stdio.h>
+#$i_stdlib I_STDLIB
+#ifdef I_STDLIB
+#include <stdlib.h>
+#endif
+#$i_string I_STRING
+#ifdef I_STRING
+# include <string.h>
+#else
+# include <strings.h>
+#endif
+#include <sys/types.h>
+#include <signal.h>
+#ifdef SIGFPE
+$volatile int bletched = 0;
+$signal_t blech(s) int s; { bletched = 1; }
+#endif
+
+int checkit($nvtype d, char *where) {
+ unsigned char *p = (char *)&d;
+ unsigned char *end = p + sizeof(d);
+ int fail = 0;
+
+ while (p < end)
+ fail += *p++;
+
+ if (!fail)
+ return 0;
+
+ p = (char *)&d;
+ printf("No - %s: 0x", where);
+ while (p < end)
+ printf ("%02X", *p++);
+ printf("\n");
+ return 1;
+}
+
+int main(int argc, char **argv) {
+ $nvtype d = 0.0;
+ int fail = 0;
+ fail += checkit(d, "0.0");
+
+ /* The compiler shouldn't be assuming that bletched is 0 */
+ d = bletched;
+
+ fail += checkit(d, "bleched");
+
+#ifdef SIGFPE
+ signal(SIGFPE, blech);
+#endif
+
+ /* Paranoia - the compiler should have no way of knowing that ANSI says
+ that argv[argc] will always be NULL. Actually, if it did assume this it
+ would be buggy, as this is C and main() can be called from elsewhere in
+ the program. */
+ d = argv[argc] ? 1 : 0;
+
+ if (d) {
+ printf("Odd argv[argc]=%p, d=%g\n", argv[argc], d);
+ }
+
+ fail += checkit(d, "ternary");
+
+ memset(&d, sizeof(d), argv[argc] ? 1 : 0);
+
+ if (d != 0.0) {
+ printf("No - memset doesn't give 0.0\n");
+ /* This might just blow up: */
+ printf("(gives %g)\n", d);
+ return 1;
+ }
+
+#ifdef SIGFPE
+ if (bletched) {
+ printf("No - something bleched\n");
+ return 1;
+ }
+#endif
+ if (fail) {
+ printf("No - %d fail(s)\n", fail);
+ return 1;
+ }
+ printf("Yes\n");
+ return 0;
+}
+EOP
+set try
+
+d_nv_zero_is_allbits_zero="$undef"
+if eval $compile; then
+ xxx="`$run ./try`"
+ case "$?" in
+ 0)
+ case "$xxx" in
+ Yes) cat >&4 <<EOM
+0.0 is represented as all bits zero in memory
+EOM
+ d_nv_zero_is_allbits_zero="$define"
+ ;;
+ *) cat >&4 <<EOM
+0.0 is not represented as all bits zero in memory
+EOM
+ d_nv_zero_is_allbits_zero="$undef"
+ ;;
+ esac
+ ;;
+ *) cat >&4 <<EOM
+0.0 is not represented as all bits zero in memory
+EOM
+ d_nv_zero_is_allbits_zero="$undef"
+ ;;
+ esac
+fi
+
+$rm -f try.* try
+