10.2  ARM Pre-Computation Exceptions

The floating-point pre-computation behavior of the ARM architecture is formalized by the functions arm-binary-pre-comp, arm-sqrt-pre-comp, and arm-fma-pre-comp.

We have noted that in the ARM architecture, a pre-computation exception never prevents the return of a value, and an exception flag is not set unless the corresponding trap enable is clear. The only other departures from SSE pre-computation exception handling are in the returned value in the case of a NaN operand and the setting of the denormal flag.

The conditions that may cause an exception flag to be set, or the operation to be terminated with a QNaN value, or both, prior to an ARM floating-point computation are as follows:

David Russinoff 2017-08-01