Filter
Top Products
4–126 Alpha Architecture Handbook
4.10.20 VAX Floating Multiply
Format:
Operation:
Fc ← Fav * Fbv
Exceptions:
Instruction mnemonics:
Qualifiers:
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 single-precision operation on canonical single-preci-
sion values produces a canonical single-precision result.
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.
MULx Fa.rx,Fb.rx,Fc.wx
!Floating-point Operate format
Invalid Operation
Overflow
Underflow
MULF Multiply F_floating
MULG Multiply G_floating
Rounding: Chopped (/C)
Trapping: Exception Completion (/S)
Underflow Enable (/U)