SPL to HP C/XL Migration Guide (30231-90001)

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representations noted above. Floating-point data stored on disk must be
converted or replaced if the programs are converted to HP C/XL.
The MPE XL intrinsic HPFPCONVERT may be used to convert floating point
data to and from the various representations. See the
MPE XL Intrinsics
Reference Manual
for details.
Data Storage Alignment
On MPE V, a data item whose size is two bytes or greater is aligned on a
two-byte boundary.
On MPE XL, a data item is aligned on a boundary not less than the size of
the data item itself, that is, a multiple of 1, 2, 4, or 8 bytes.
Thus, a character followed by a 64-bit floating-point number would
require 10 bytes in MPE V and 16 bytes in MPE XL.
In MPE V, the character would start at byte 0, there would be one unused
byte, and the floating-point number would start at byte 3. In MPE XL,
the character would start at byte 0, there would be seven unused bytes,
and the floating point number would start at byte 8.
This incompatibility of data storage affects program access to data both
in memory and on disk.