Infix Operators
---------------

   "Infix operators" take two arguments, one on either side.  Operators
have precedence, but operations with equal precedence are performed left
to right.  Apart from `+' or `-', both arguments must be absolute, and
the result is absolute.

  1. Highest Precedence

    `*'
          "Multiplication".

    `/'
          "Division".  Truncation is the same as the C operator `/'

    `%'
          "Remainder".

    `<'
    `<<'
          "Shift Left".  Same as the C operator `<<'

    `>'
    `>>'
          "Shift Right".  Same as the C operator `>>'

  2. Intermediate precedence

    `|'
          "Bitwise Inclusive Or".

    `&'
          "Bitwise And".

    `^'
          "Bitwise Exclusive Or".

    `!'
          "Bitwise Or Not".

  3. Lowest Precedence

    `+'
          "Addition".  If either argument is absolute, the result has
          the section of the other argument.  If either argument is
          pass1 or undefined, the result is pass1.  Otherwise `+' is
          illegal.

    `-'
          "Subtraction".  If the right argument is absolute, the result
          has the section of the left argument.  If either argument is
          pass1 the result is pass1.  If either argument is undefined
          the result is difference section.  If both arguments are in
          the same section, the result is absolute--provided that
          section is one of text, data or bss.  Otherwise subtraction
          is illegal.

   The sense of the rule for addition is that it's only meaningful to
add the *offsets* in an address; you can only have a defined section in
one of the two arguments.

   Similarly, you can't subtract quantities from two different sections.