4.10.20 VAX Floating Multiply
Format:
MULxFa.rx,Fb.rx,Fc.wx!Floating-point Operate format
Operation:
Fc ← Fav * Fbv
Exceptions:
Invalid Operation
Overflow
Underflow
Instruction mnemonics:
MULF | Multiply F_floating |
MULG | Multiply G_floating |
Qualifiers:
Rounding: | Chopped (/C) |
Trapping: | Exception Completion (/S) |
| Underflow Enable (/U) |
Description:
The multiplicand operand in register Fb is multiplied by the multiplier operand in register Fa and the product is written to register Fc.
The product is rounded or chopped to the specified precision and then the corresponding range is checked for overflow/underflow. The
An invalid operation trap is signaled if either operand has exp=0 and is not a true zero (that is, VAX reserved operands and dirty zeros trap). The contents of Fc are UNPREDICTABLE if this occurs.
See Section 4.7.7 for details of the stored result on overflow or underflow.