Integer overflow: Difference between revisions

Revision as of 00:42, 25 October 2006

Revision as of 10:00, 25 October 2006

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The [[register width]] of the processor determines the the range of values that can be represented. Typical [[Binary numeral system|binary]] register widths include:

: 8 bits (maximum representable value 256255),

: 16 bits (maximum representable value 65,536535),

: 32 bits (the most common width for personal computers [[as of 2005]], maximum representable value 4,294,967,296295),

: 64 bits (maximum representable value 18,446,744,073,709,551,616615),

: 128 bits.

: 128 bits (maximum representable value 340,282,366,920,938,463,463,374,607,431,768,211,456).

Since an arithmetic operation may produce a result larger than the maximum representable value, an potential error condition may result. In the [[C programming language]], for example, signed integer overflow causes [[undefined behavior]], although arithmetic on unsigned integers, however, is reduced [[modular arithmetic|modulo a power of two]], meaning that unsigned integers "wrap around" on overflow.