/cln-1.3.2/src/rational/division/cl_RA_ceil22.cc

 1// ceiling2().
 2
 3// General includes.
 4#include "base/cl_sysdep.h"
 5
 6// Specification.
 7#include "cln/rational.h"
 8
 9
10// Implementation.
11
12#include "rational/cl_RA.h"
13#include "cln/integer.h"
14
15namespace cln {
16
17const cl_RA_div_t ceiling2 (const cl_RA& x, const cl_RA& y)
18{
19#if 1 // Ist das wirklich schneller??
20// Methode:
21// x = a/b, y = c/d ->
22//   (ceiling (* a d) (* b c)) liefert q und r.
23//   Liefere q und r/(b*d).
24// x Integer -> dito mit b=1.
25// y Integer -> dito mit d=1.
26// x und y Integer -> bekannt.
27	if (integerp(x)) {
28		DeclareType(cl_I,x);
29		if (integerp(y)) {
30			DeclareType(cl_I,y);
31			var cl_I_div_t q_r = ceiling2(x,y);
32			var cl_I& q = q_r.quotient;
33			var cl_I& r = q_r.remainder;
34			return cl_RA_div_t(q,r);
35		} else {
36			DeclareType(cl_RT,y);
37			var const cl_I& c = numerator(y);
38			var const cl_I& d = denominator(y);
39			var cl_I_div_t q_r = ceiling2(x*d,c);
40			var cl_I& q = q_r.quotient;
41			var cl_I& r = q_r.remainder;
42			return cl_RA_div_t(q,I_posI_div_RA(r,d));
43		}
44	} else {
45		DeclareType(cl_RT,x);
46		var const cl_I& a = numerator(x);
47		var const cl_I& b = denominator(x);
48		if (integerp(y)) {
49			DeclareType(cl_I,y);
50			var cl_I_div_t q_r = ceiling2(a,b*y);
51			var cl_I& q = q_r.quotient;
52			var cl_I& r = q_r.remainder;
53			return cl_RA_div_t(q,I_posI_div_RA(r,b));
54		} else {
55			DeclareType(cl_RT,y);
56			var const cl_I& c = numerator(y);
57			var const cl_I& d = denominator(y);
58			var cl_I_div_t q_r = ceiling2(a*d,b*c);
59			var cl_I& q = q_r.quotient;
60			var cl_I& r = q_r.remainder;
61			return cl_RA_div_t(q,I_posI_div_RA(r,b*d));
62		}
63	}
64#else
65// Methode:
66// ceiling2(x/y) -> (q,r). Liefere q und x-y*q=y*r.
67	var cl_RA_div_t q_r = ceiling2(x/y);
68	var cl_I& q = q_r.quotient;
69	var cl_RA& r = q_r.remainder;
70	return cl_RA_div_t(q,y*r);
71#endif
72}
73
74}  // namespace cln