DC instruction—Floating-point special values

For special values, the syntax of the DC statement is:


>>-DC--+------------+--+-+-E-+--+-B-+-+--+--------------+------->
       '-dup_factor-'  | +-D-+  +-H-+ |  '-program_type-'   
                       | '-L-'  '-D-' |                     
                       '-LQ-----------'                     

                       .-,-----------------.   
                       V                   |   
>--+-----------------+---| nominal_value |-+-------------------><
   '-length_modifier-'                         

nominal_value (type extension B and D)

      .- + -.                  
|--'--+-----+--+-(SNAN)-+--'------------------------------------|
      '- - -'  +-(QNAN)-+      
               +-(NAN)--+      
               +-(INF)--+      
               +-(MAX)--+      
               +-(MIN)--+      
               '-(DMIN)-'      

nominal_value (type extension H)

      .- + -.                  
|--'--+-----+--+-(MAX)--+--'------------------------------------|
      '- - -'  +-(MIN)--+      
               '-(DMIN)-'

dup_factor

Causes the constant to be generated the number of times indicated by the factor.

type

Indicates that the constant is short, long, or extended floating point.

type extension

The type of conversion required to assemble the constant.

program_type

Assign a programmer determined 32 bit value to the symbol naming the DC instruction, if a symbol was present.

length_modifier

Describes the length in bytes or bits into which the constant is to be assembled. For binary floating-point constants (type extension B), the minimum length in bits for INF and NAN is:

11: Short floating-point constant
14: Long floating-point constant
18: Extended floating-point constant

This minimum length allows for the sign, exponent and two fraction bits.

No length modifiers other than 4, 8, and 16 are allowed for decimal (type extension D) floating-point constants.

nominal_value

Defines the special value to be generated.

Notes:

The nominal value can be in mixed case.
SNAN assembles with an exponent of ones and 01 in the high-order fraction bits with the remainder of the fraction containing zeros.
QNAN assembles with an exponent of ones and 11 in the high-order fraction bits with the remainder of the fraction containing zeros.
NAN assembles with an exponent of one and 10 in the high-order fraction bits with the remainder of the fraction containing zeros.
MIN assembles as a normalized minimum value, that is an exponent of one and a fraction of zeros for binary constants, and a fraction with a leading hexadecimal digit 1 followed by zeros for hexadecimal constants.
DMIN assembles as a denormalized minimum value with an exponent of zeros and a fraction of all zeros except for a low-order bit of one.
INF assembles with an exponent of ones and a fraction of zeros.
MAX assembles with a fraction of all ones and an exponent of all ones for hexadecimal constants, and an exponent of all ones except for the low bit for binary constants.