intro_conversion - Introduction to conversion routines


Cray Linux Environment (CLE)


These Fortran-callable subroutines perform conversion of data residing in systems memory. Conversion subprograms are listed under the following types of routines:

  • Cray variants (CRY, CRI, MPP)

  • IEEE variants (IEU, MIPS, IA)

  • Other (IBM, VAX)

For more information regarding foreign data conversion, see the Application Programmer’s I/O Guide.


The foreign data conversion routines translate data in both directions between Cray internal representations and that of other vendors, including IBM, IEEE, and DEC (VAX systems). The following tables list these conversion routines by the data type on which they operate. Generally, routines that are inverses of each other (that is, converted from Cray data types to IBM and IBM to Cray ) are listed under a single entry. Routine descriptions follow later in this section, listed alphabetically by entry name.

The following routines are used for data conversion:

Name                  Foreign->Native  Native->Foreign
IBM                   IBM2IEG          IEG2IBM
VAX/VMS               VAX2IEG          IEG2VAX
MIPS                  MIPS2IEG         IEG2MIPS
Cray MPP              MPP2IEG          IEG2MPP
Cray floating-point   CRY2IEG          IEG2CRY
IEEE little-endian    IEU2IEG          IEG2IEU
Cray IEEE (64-bit)    CRI2IEG          IEG2CRI
User conversion*      USR2IEG          IEG2USR
Intel                 IA2IEG           IEG2IA

Note that the user conversion routines USR2IEG and IEG2USR are provided as examples of user-defined interfaces.