DAportable and older architecture - what is the cost of using this

[Steve Miller_3]

We have a C110 we would like to use as a development box. We notice that binaries copied from the N4000 to the C110 give an "incompatible hardware" error message unless linked with +DAportable.

In the scenario that we use the C110 to compile/link our objects for the N4000, will we pay a severe performance price if we use the DAportable option. It would seem that we won't be able to optimize the object code for the N4000 architecture. Is this backward compatibility safe or will we see our programs behaving strangely on the N4000 because of the portable option.

Steve

[A. Clay Stephenson · Accepted solution]

Hi Steve,

The +DAportable compiler directive does work well (of course, you are generating PA-RISC 1.1 code rather than 2.0 so that some of the enhanced instructions of the newer processors are not used. For the vast majority of program the slight loss in performance in insignificant. If you are doing some intense numerical ananlysis you might see a small performance degradation.

Regards, Clay