Message        The register "<register>" cannot be mapped to a
                register on the target platform.

 Description    The pragma linkage directive contains
                architecture-specific information.  The Alpha
                register conventions are different from the IA64
                registers conventions.  The compiler will normally
                try to map the Alpha registers to the corresponding
                registers on IA64.  In this case this register cannot
                be mapped because there is no corresponding IA64
                register.

 User Action    Update the linkage to use a register that can be
                mapped, or specify the linkage to use the
                linkage_ia64 directive.