SHA256MSG2 X11, X11      // 450f38cddb
	// Test VPERMQ with both uint8 and int8 immediate args
	VPERMQ $-40, Y8, Y8 // c443fd00c0d8
	VPERMQ $216, Y8, Y8 // c443fd00c0d8
	// Test that VPERMPD that shares ytab list with VPERMQ continues to work too.
	VPERMPD $-40, Y7, Y7 // c4e3fd01ffd8
	VPERMPD $216, Y7, Y7 // c4e3fd01ffd8
	// Check that LEAL is permitted to use overflowing offset.

given element may be less than the index of the same element in the
underlying array.
</p>
<p>
A slice, once initialized, is always associated with an underlying
array that holds its elements.  A slice therefore shares storage
with its array and with other slices of the same array; by contrast,
distinct arrays always represent distinct storage.
</p>
<p>
The array underlying a slice may extend past the end of the slice.

given element may be less than the index of the same element in the
underlying array.
</p>
<p>
A slice, once initialized, is always associated with an underlying
array that holds its elements.  A slice therefore shares storage
with its array and with other slices of the same array; by contrast,
distinct arrays always represent distinct storage.
</p>
<p>
The array underlying a slice may extend past the end of the slice.

	// but be prepared.
	s.base = base
}

func (s *Slice) Line() int {
	return s.line
}

func (s *Slice) Col() int {
	// TODO: Col is only called when defining a macro and all it cares about is increasing
	// position to discover whether there is a blank before the parenthesis.
	// We only get here if defining a macro inside a macro.
	// This imperfect implementation means we cannot tell the difference between