A problem was found during back port of JDK-8130150 (JDK-8150152) on Solaris-x86 which looks like caused by SunStudio C++.
There is difference from jdk9 because of issue with code generated by SunStudio C++ version used to build jdk 8u and 7u. As result next changes where made for JDK-8130150 back port:

+ //montgomery_square fails to pass BigIntegerTest on solaris amd64
+ //on jdk7 and jdk8.
+#ifndef SOLARIS
   if (len >= MONTGOMERY_SQUARING_THRESHOLD) {
+#else
+ if (0) {
+#endif
     ::montgomery_square(a, n, m, (unsigned long)inv, longwords);

Note, this change is fine since it affects only performance for some range of values.