c0 := s[0]
	if c0 < 0x80 { // is ASCII
		return bidiValues[c0]
	}
	i := bidiIndex[c0]
	if c0 < 0xE0 { // 2-byte UTF-8
		return t.lookupValue(uint32(i), s[1])
	}
	i = bidiIndex[uint32(i)<<6+uint32(s[1])]
	if c0 < 0xF0 { // 3-byte UTF-8
		return t.lookupValue(uint32(i), s[2])
	}
	i = bidiIndex[uint32(i)<<6+uint32(s[2])]
	if c0 < 0xF8 { // 4-byte UTF-8
		return t.lookupValue(uint32(i), s[3])
	}

	c0 := s[0]
	if c0 < 0x80 { // is ASCII
		return bidiValues[c0]
	}
	i := bidiIndex[c0]
	if c0 < 0xE0 { // 2-byte UTF-8
		return t.lookupValue(uint32(i), s[1])
	}
	i = bidiIndex[uint32(i)<<6+uint32(s[1])]
	if c0 < 0xF0 { // 3-byte UTF-8
		return t.lookupValue(uint32(i), s[2])
	}
	i = bidiIndex[uint32(i)<<6+uint32(s[2])]
	if c0 < 0xF8 { // 4-byte UTF-8
		return t.lookupValue(uint32(i), s[3])
	}

	c0 := s[0]
	if c0 < 0x80 { // is ASCII
		return bidiValues[c0]
	}
	i := bidiIndex[c0]
	if c0 < 0xE0 { // 2-byte UTF-8
		return t.lookupValue(uint32(i), s[1])
	}
	i = bidiIndex[uint32(i)<<6+uint32(s[1])]
	if c0 < 0xF0 { // 3-byte UTF-8
		return t.lookupValue(uint32(i), s[2])
	}
	i = bidiIndex[uint32(i)<<6+uint32(s[2])]
	if c0 < 0xF8 { // 4-byte UTF-8
		return t.lookupValue(uint32(i), s[3])
	}

	c0 := s[0]
	if c0 < 0x80 { // is ASCII
		return bidiValues[c0]
	}
	i := bidiIndex[c0]
	if c0 < 0xE0 { // 2-byte UTF-8
		return t.lookupValue(uint32(i), s[1])
	}
	i = bidiIndex[uint32(i)<<6+uint32(s[1])]
	if c0 < 0xF0 { // 3-byte UTF-8
		return t.lookupValue(uint32(i), s[2])
	}
	i = bidiIndex[uint32(i)<<6+uint32(s[2])]
	if c0 < 0xF8 { // 4-byte UTF-8
		return t.lookupValue(uint32(i), s[3])
	}

	c0 := s[0]
	if c0 < 0x80 { // is ASCII
		return bidiValues[c0]
	}
	i := bidiIndex[c0]
	if c0 < 0xE0 { // 2-byte UTF-8
		return t.lookupValue(uint32(i), s[1])
	}
	i = bidiIndex[uint32(i)<<6+uint32(s[1])]
	if c0 < 0xF0 { // 3-byte UTF-8
		return t.lookupValue(uint32(i), s[2])
	}
	i = bidiIndex[uint32(i)<<6+uint32(s[2])]
	if c0 < 0xF8 { // 4-byte UTF-8
		return t.lookupValue(uint32(i), s[3])
	}

	c0 := s[0]
	if c0 < 0x80 { // is ASCII
		return bidiValues[c0]
	}
	i := bidiIndex[c0]
	if c0 < 0xE0 { // 2-byte UTF-8
		return t.lookupValue(uint32(i), s[1])
	}
	i = bidiIndex[uint32(i)<<6+uint32(s[1])]
	if c0 < 0xF0 { // 3-byte UTF-8
		return t.lookupValue(uint32(i), s[2])
	}
	i = bidiIndex[uint32(i)<<6+uint32(s[2])]
	if c0 < 0xF8 { // 4-byte UTF-8
		return t.lookupValue(uint32(i), s[3])
	}

	Hungarian            Tag = Tag{language: huIndex, locale: huIndex}
	Armenian             Tag = Tag{language: hyIndex, locale: hyIndex}
	Indonesian           Tag = Tag{language: idIndex, locale: idIndex}
	Icelandic            Tag = Tag{language: isIndex, locale: isIndex}
	Italian              Tag = Tag{language: itIndex, locale: itIndex}
	Japanese             Tag = Tag{language: jaIndex, locale: jaIndex}

	// Erroneous cases.
	{"%[d", SE{2, 1}, "%!d(BADINDEX)"},
	{"%]d", SE{2, 1}, "%!](int=2)d%!(EXTRA int=1)"},
	{"%[]d", SE{2, 1}, "%!d(BADINDEX)"},
	{"%[-3]d", SE{2, 1}, "%!d(BADINDEX)"},
	{"%[99]d", SE{2, 1}, "%!d(BADINDEX)"},
	{"%[3]", SE{2, 1}, "%!(NOVERB)"},
	{"%[1].2d", SE{5, 6}, "%!d(BADINDEX)"},
	{"%[1]2d", SE{2, 1}, "%!d(BADINDEX)"},
	{"%3.[2]d", SE{7}, "%!d(BADINDEX)"},
	{"%.[2]d", SE{7}, "%!d(BADINDEX)"},

		Printf("%*s", 4.5, "hi"):  %!(BADWIDTH)hi
		Printf("%.*s", 4.5, "hi"): %!(BADPREC)hi
	Invalid or invalid use of argument index: %!(BADINDEX)
		Printf("%*[2]d", 7):       %!d(BADINDEX)
		Printf("%.[2]d", 7):       %!d(BADINDEX)

All errors begin with the string "%!" followed sometimes
by a single character (the verb) and end with a parenthesized
description.

		s.refillAllocCache(whichByte)
		aCache = s.allocCache
		bitIndex = sys.TrailingZeros64(aCache)
		// nothing available in cached bits
		// grab the next 8 bytes and try again.
	}
	result := sfreeindex + uint16(bitIndex)
	if result >= snelems {
		s.freeindex = snelems
		return snelems
	}

	s.allocCache >>= uint(bitIndex + 1)
	sfreeindex = result + 1