Q34408: Far Pointer Comparisons Assume Same Segment

Article: Q34408
Product(s): See article
Version(s): 5.10   | 5.10
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | | mspl13_c
Last Modified: 12-OCT-1988

When comparing Far pointers with the <, >, <=, or >= operators, the
two pointers must be in the same segment. The equality operator (==)
tests both segment and offset to prevent two pointers that have the
same offset but different segments from being considered equal.

The <, >, <=, and >= operators assume that the pointer share the same
segment because according to the Draft proposed ANSI C standard,
pointers can only be compared for precedence if they point to the same
object. In a segmented architecture such as Intel's, two pointers to
the same object must share the same segment value (unless the
pointers are declared to point to a huge object, in which case
the pointers are handled using 32-bit arithmetic).

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