func ltos

Syntax

   ltos (virtaddr)

The LTOS function converts a virtual address to a short pointer.

If the parameter virtaddr is already a short pointer, it is simply returned.

If the parameter virtaddr is a long pointer, or a full logical code address, a special additional test is performed to ensure that the offset portion can be returned as the short pointer value. The SID (space) portion must match the current value of the associated space register. This ensures that the returned short pointer value can be successfully converted back into the long pointer argument.

Formal Declaration

   ltos:sptr (virtaddr:ptr) 

Examples

   $nmdebug > wl pc
   PROG $3c.12004
   $nmdebug > wl ltos(pc)
   $12004
 
   $nmdebug > var save 42.40151025
   $nmdebug > wl ltos(save)
   $40151025
 
 
   $nmdat > dr sr4
   SR4=$a
   $nmdat > wl ltos(22.200)
   SID in LPTR for LTOS conversion does not match corresponding space reg.
   Error evaluating a predefined function.  (error #4240)
     function is"ltos"

In this example SR4 contains $a. The function LTOS detects that the SID portion of the long pointer ($22) does not match the value of the associated space register (SR4=$a), and the conversion fails.

Limitations, Restrictions

none