return (r1-surr1)<<10 | (r2 - surr2) + surrSelf
	}
	return replacementChar
}

// EncodeRune returns the UTF-16 surrogate pair r1, r2 for the given rune.
// If the rune is not a valid Unicode code point or does not need encoding,
// EncodeRune returns U+FFFD, U+FFFD.
func EncodeRune(r rune) (r1, r2 rune) {
	if r < surrSelf || r > maxRune {
		return replacementChar, replacementChar
	}
	r -= surrSelf

	for i, tt := range encodeTests {
		j := 0
		for _, r := range tt.in {
			r1, r2 := EncodeRune(r)
			if r < 0x10000 || r > unicode.MaxRune {
				if j >= len(tt.out) {
					t.Errorf("#%d: ran out of tt.out", i)
					break
				}
				if r1 != unicode.ReplacementChar || r2 != unicode.ReplacementChar {
					t.Errorf("EncodeRune(%#x) = %#x, %#x; want 0xfffd, 0xfffd", r, r1, r2)
				}
				j++
			} else {