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9.4.3 Division ofpoly_ints ¶

Division ofpoly_ints is possible for certain inputs. The functionsfor division return true if the operation is possible and in most casesreturn the results by pointer. The routines are:

‘multiple_p (a,b)’

‘multiple_p (a,b, &quotient)’

Return true ifa is an exact multiple ofb, storing the resultinquotient if so. There are overloads for various combinationsof polynomial and constanta,b andquotient.

‘constant_multiple_p (a,b)’

‘constant_multiple_p (a,b, &quotient)’

Likemultiple_p, but also test whether the multiple is acompile-time constant.

‘can_div_trunc_p (a,b, &quotient)’

‘can_div_trunc_p (a,b, &quotient, &remainder)’

Return true if we can calculate ‘trunc (a /b)’ at compiletime, storing the result inquotient andremainder if so.

‘can_div_away_from_zero_p (a,b, &quotient)’

Return true if we can calculate ‘a /b’ at compile time,rounding away from zero. Store the result inquotient if so.

Note that this is true if and only ifcan_div_trunc_p is true.The only difference is in the rounding of the result.

There is also an asserting form of division:

‘exact_div (a,b)’

Assert thata is a multiple ofb and return‘a /b’. The result is apoly_int ifais apoly_int.

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