+/// StrInStrNoCase - Portable version of strcasestr. Locates the first
+/// occurrence of string 's1' in string 's2', ignoring case. Returns
+/// the offset of s2 in s1 or npos if s2 cannot be found.
+StringRef::size_type llvm::StrInStrNoCase(StringRef s1, StringRef s2) {
+ size_t N = s2.size(), M = s1.size();
+ if (N > M)
+ return StringRef::npos;
+ for (size_t i = 0, e = M - N + 1; i != e; ++i)
+ if (s1.substr(i, N).equals_lower(s2))
+ return i;
+ return StringRef::npos;
+}
+