COBHAM GR740 User Manual

GR740-UM-DS, Nov 2017, Version 1.7 85 www.cobham.com/gaisler
GR740
8.2.6 Non-standard Mode
GRFPU can operate in a non-standard mode where all denormalized operands to arithmetic and con-
version operations are treated as (correctly signed) zeroes. Calculations are performed on zero oper-
ands instead of the denormalized numbers obeying all rules of the floating-point arithmetics including
rounding of the results and detecting exceptions.
8.2.7 NaNs
GRFPU supports handling of Not-a-Numbers (NaNs) as defined in the IEEE-754 standard. Opera-
tions on signaling NaNs (SNaNs) and invalid operations (e.g. inf/inf) generate the Invalid exception
and deliver QNaN_GEN as result. Operations on Quiet NaNs (QNaNs), except for FCMPES and
FCMPED, do not raise any exceptions and propagate QNaNs through the FP operations by delivering
NaN-results according to table 64. QNaN_GEN is 0x7fffe00000000000 for double precision results
and 0x7fff0000 for single precision results.
Table 64. : Operations on NaNs
Operand 2



Operand 1
FP QNaN2 SNaN2
none FP QNaN2 QNaN_GEN
FP FP QNaN2 QNaN_GEN
QNaN1 QNaN1 QNaN2 QNaN_GEN
SNaN1 QNaN_GEN QNaN_GEN QNaN_GEN

COBHAM GR740 Specifications

General

Brand	COBHAM
Model	GR740
Category	Computer Hardware
Language	English