HLASM Language Reference

DC Instruction—Binary Floating-Point Constants
To accommodate the definition of both hexadecimal and binary floating-point
constants the syntax for coding a DC instruction is:
|
►►──DC──┬────────────┬──┬─┬─E─┬──┬───┬─┬──┬──────────────┬──┬──────────┬────►
└─dup_factor─ ┘ │ ├ ─D─ ┤ ├ ─B─┤
│ └─program_type─ ┘ └─modifier─┘
|
│ └ ─L─ ┘ └ ─H─┘
│
└─LQ───────────┘
►──┤ nominal_value ├───────────────────────────────────────────────────────►◄
nominal_value (no type extension):
┌─ + ─┐
├──'──┼─────┼──value──┬──────────┬──'───────────────────────────────────────┤
└─ - ─┘
└─exponent─┘
nominal_value (type extension B):
┌─ + ─┐
┌─R4───────┐
├──'──┼─────┼──value──┬──────────┬──┼──────────┼──'─────────────────────────┤
└─ - ─┘
└─exponent─┘
└─R─┬─1─┬──┘
├─5─┤
├─6─┤
└─7─┘
nominal_value (type extension H):
┌─ + ─┐
┌─R1───────┐
├──'──┼─────┼──value──┬──────────┬──┼──────────┼──'─────────────────────────┤
└─ - ─┘
└─exponent─┘
└─R─┬─4─┬──┘
├─5─┤
├─6─┤
└─7─┘
Figure 53. DC Instruction Syntax
dup_factor
causes the constant to be generated the number of times indicated by the
factor.
type
indicates that the constant is either short, long or extended floating point.
type extension
the type of conversion required to assemble the constant. Valid values are:
null
B
H
Hexadecimal floating-point constant which is converted using the
conversion logic of rounding mode 1 and slightly less precise algorithms
Binary floating-point constant which is converted allowing all rounding
modes
Hexadecimal floating-point constant which is converted allowing all
rounding modes
| program_type
| assign a programmer determined 32-bit value to the symbol naming the DC
| instruction, if a symbol was present.
modifier
describes the length, the scaling and the exponent of the nominal_value. The
minimum length of the 'H' hexadecimal constant is 12 bits. The minimum
length in bits of the binary constant is:
9 Short floating-point constant
168 HLASM V1R5 Language Reference