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From: Jacob Sparre Andersen <sparre@nbi.dk>
Newsgroups: comp.lang.ada
Subject: Re: Wraparound on multiply overflow
Date: Thu, 09 Aug 2001 18:23:40 +0200
Organization: Centre for Chaos and Turbulence Studies, Niels Bohr Institute
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Date: 2001-08-09T18:23:40+02:00
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Paul:

> In C it is defined that the result of multiplying two unsigned integers
> is the mathematical result modulo the value (int_max + 1), where int_max
> is the maximum unsigned integer.

That kind of integers are called modular types in Ada. Have
a look at 3.5.4(4) and 3.5.4(36) in the Ada Reference Manual
(1995 edition).

> I know that Ada has modular types, but these don't work with multiply,
> do they?

You might want to RTFM. 4.5.5(1):

   "The multiplying operators [...] are predefined for EVERY
    specific integer type T:"

(my emphasis) and modular types are together with signed
integer types classified as integer types.

Jacob
-- 
"You've got to build bypasses!"