HP 3000 Manuals

HP Pascal/XL Migration Guide

Data Format Conversion 

The MPE V floating-point routines can access MPE V real numbers that
begin on 16-bit boundaries.  This is not true for IEEE floating-point on
MPE XL based systems.  These floating-point routines are written with the
32-bit boundary as the "natural" boundary for data types such as real
numbers.  Programs using IEEE floating-point require four or eight byte
alignment for floating-point data.  Refer to the HP Pascal Programmer's
Guide for further information on alignment.

The difference in floating-point formats can be handled by the
hpFPCONVERT intrinsic.  This intrinsic converts a floating point number
from one format to another, as needed.  This conversion is illustrated in
the data file migration example in Chapter 4.  Refer to the Programmer's
Skill Migration Guide for a description of hpFPCONVERT.

Strconvert Procedure 

The predefined procedure strconvert converts a string from Pascal/V
packing algorithm (HP3000_16) format to HP Pascal/XL packing algorithm
(HP3000_32) format.  It is enabled by the HP3000_16 compiler option.

Syntax 

     strconvert(string1,string2)

Parameters 

string1          The name of the string variable to be converted.  The
                 string variable must be in Pascal/V packing algorithm
                 (HP3000_16) format.

string2          The name of the string variable into which the converted
                 string is to be stored.  The string variable must be in
                 HP Pascal/XL packing algorithm (HP3000_32) format.

Example 

     $HP3000_16$  {Enables strconvert procedure}
     PROGRAM prog;

     TYPE
        str16_20=string[20];             {Pascal/V packing algorithm (HP3000_16)}
        str32_40=$HP3000_32$ string[40]; {Pascal/XL packing algorithm (HP3000_32)}

     VAR
        sv32_1,
        sv32_2 : str32_40;

        sv16_1,
        sv16_2 : str16_20;

     BEGIN
        strconvert(sv16_1,sv32_"1);
        strconvert(sv32_2,sv32_1);         {Illegal}
        strconvert(sv16_1,sv16_2);         {Illegal}
     END.

Setconvert Procedure 

The predefined procedure setconvert converts a set from HP Pascal/XL
packing algorithm (HP3000_32) format to Pascal/V packing algorithm
(HP3000_16) format, or vice versa.  It is enabled by the HP3000_16
compiler option.

Syntax 

     setconvert(set1,set2)

Parameters 

set1             The name of the set variable to be converted.

set2             The name of the set variable into which the converted
                 set is to be stored.

The sets set1 and set2 can vary only in packing algorithm format.  Their
packing (unpacked, packed, or crunched) and base types must be the same.
It is an error if their packing or base types are different.  It is also
an error if their packing algorithm formats are the same.

Example 

     $HP3000_16$  {Enables setconvert procedure}
     PROGRAM prog;

     TYPE
        hp3000_16_set1 = SET OF char;

        hp3000_32_set1 = $HP3000_32$ SET OF char;
        hp3000_32_set2 = $HP3000_32$ PACKED SET OF char;
        hp3000_32_set3 = $HP3000_32$ SET OF integer;

     VAR
        set16_1,
        set16_2 : hp3000_16_set1;

        set32_1 : hp3000_32_set1;
        set32_2 : hp3000_32_set2;
        set32_3 : hp3000_32_set3;

     BEGIN
        setconvert(set16_1,set32_1);  {convert from Pascal/V to HP Pascal}
        setconvert(set32_1,set16_1);  {convert from HP Pascal/XL to Pascal/V}

        setconvert(set16_1,set32_2);  {Illegal -- different packings}
        setconvert(set16_1,set32_3);  {Illegal -- different base types}
        setconvert(set16_1,set16_2);  {Illegal -- same packing algorithm format}
     END.


NOTE  The data file migration example in Chapter 4 shows the use of
      hpFPCONVERT, setconvert, and strconvert.

MPE/iX 5.0 Documentation