as: VAX-float
9.49.2 VAX Floating Point
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Conversion of flonums to floating point is correct, and compatible with
previous assemblers. Rounding is towards zero if the remainder is
exactly half the least significant bit.
'D', 'F', 'G' and 'H' floating point formats are understood.
Immediate floating literals (_e.g._ 'S`$6.9') are rendered
correctly. Again, rounding is towards zero in the boundary case.
The '.float' directive produces 'f' format numbers. The '.double'
directive produces 'd' format numbers.