as: Flonums

1 
1 3.6.2.3 Flonums
1 ...............
1 
1 A "flonum" represents a floating point number.  The translation is
1 indirect: a decimal floating point number from the text is converted by
1 'as' to a generic binary floating point number of more than sufficient
1 precision.  This generic floating point number is converted to a
1 particular computer's floating point format (or formats) by a portion of
1 'as' specialized to that computer.
1 
1    A flonum is written by writing (in order)
1    * The digit '0'.  ('0' is optional on the HPPA.)
1 
1    * A letter, to tell 'as' the rest of the number is a flonum.  'e' is
1      recommended.  Case is not important.
1 
1      On the H8/300, Renesas / SuperH SH, and AMD 29K architectures, the
1      letter must be one of the letters 'DFPRSX' (in upper or lower
1      case).
1 
1      On the ARC, the letter must be one of the letters 'DFRS' (in upper
1      or lower case).
1 
1      On the Intel 960 architecture, the letter must be one of the
1      letters 'DFT' (in upper or lower case).
1 
1      On the HPPA architecture, the letter must be 'E' (upper case only).
1 
1    * An optional sign: either '+' or '-'.
1 
1    * An optional "integer part": zero or more decimal digits.
1 
1    * An optional "fractional part": '.' followed by zero or more decimal
1      digits.
1 
1    * An optional exponent, consisting of:
1 
1         * An 'E' or 'e'.
1         * Optional sign: either '+' or '-'.
1         * One or more decimal digits.
1 
1    At least one of the integer part or the fractional part must be
1 present.  The floating point number has the usual base-10 value.
1 
1    'as' does all processing using integers.  Flonums are computed
1 independently of any floating point hardware in the computer running
1 'as'.
1