as: TILEPro Registers

 
 9.47.2.2 Register Names
 .......................
 
 General-purpose registers are represented by predefined symbols of the
 form 'rN', where N represents a number between '0' and '63'.  However,
 the following registers have canonical names that must be used instead:
 
 'r54'
      sp
 
 'r55'
      lr
 
 'r56'
      sn
 
 'r57'
      idn0
 
 'r58'
      idn1
 
 'r59'
      udn0
 
 'r60'
      udn1
 
 'r61'
      udn2
 
 'r62'
      udn3
 
 'r63'
      zero
 
    The assembler will emit a warning if a numeric name is used instead
 of the canonical name.  The '.no_require_canonical_reg_names' assembler
 pseudo-op turns off this warning.  '.require_canonical_reg_names' turns
 it back on.