String.equalsIgnoreCase(...) optimization

[Andrey]

Hello! 

I read source code equalsIgnoreCase(...) in String class and saw that it is not optimal. This method check length and call regionMatches(...)  with 'constant' values

http://hg.openjdk.java.net/jdk8/jdk8/jdk/file/687fd7c7986d/src/share/classes/java/lang/String.java#l1095 

...

   && (anotherString.value.length == value.length)
    && regionMatches(true, 0, anotherString, 0, value.length);
...

But regionMatches(...) check 'constant' values

http://hg.openjdk.java.net/jdk8/jdk8/jdk/file/687fd7c7986d/src/share/classes/java/lang/String.java#l1338

// Note: toffset, ooffset, or len might be near -1>>>1.
if ((ooffset < 0) || (toffset < 0)
    || (toffset > (long)value.length - len)
    || (ooffset > (long)other.value.length - len)) {
  return false;
}

and increment equalent variables to==po in loop

http://hg.openjdk.java.net/jdk8/jdk8/jdk/file/687fd7c7986d/src/share/classes/java/lang/String.java#l1344

while (len-- > 0) {

  char c1 = ta[to++];

  char c2 = pa[po++];

...

}

and use if(...) in while loop

http://hg.openjdk.java.net/jdk8/jdk8/jdk/file/687fd7c7986d/src/share/classes/java/lang/String.java#l1349

if (ignoreCase) {

...

}



May be can create optimized regionMatches(...) for use in equalsIgnoreCase(...)?