xref: /llvm-project-15.0.7/libcxx/include/ratio (revision a462f5cc)
1// -*- C++ -*-
2//===---------------------------- ratio -----------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_RATIO
12#define _LIBCPP_RATIO
13
14/*
15    ratio synopsis
16
17namespace std
18{
19
20template <intmax_t N, intmax_t D = 1>
21class ratio
22{
23public:
24    static const intmax_t num;
25    static const intmax_t den;
26    typedef ratio<num, den> type;
27};
28
29// ratio arithmetic
30template <class R1, class R2> using ratio_add = ...;
31template <class R1, class R2> using ratio_subtract = ...;
32template <class R1, class R2> using ratio_multiply = ...;
33template <class R1, class R2> using ratio_divide = ...;
34
35// ratio comparison
36template <class R1, class R2> struct ratio_equal;
37template <class R1, class R2> struct ratio_not_equal;
38template <class R1, class R2> struct ratio_less;
39template <class R1, class R2> struct ratio_less_equal;
40template <class R1, class R2> struct ratio_greater;
41template <class R1, class R2> struct ratio_greater_equal;
42
43// convenience SI typedefs
44typedef ratio<1, 1000000000000000000000000> yocto;  // not supported
45typedef ratio<1,    1000000000000000000000> zepto;  // not supported
46typedef ratio<1,       1000000000000000000> atto;
47typedef ratio<1,          1000000000000000> femto;
48typedef ratio<1,             1000000000000> pico;
49typedef ratio<1,                1000000000> nano;
50typedef ratio<1,                   1000000> micro;
51typedef ratio<1,                      1000> milli;
52typedef ratio<1,                       100> centi;
53typedef ratio<1,                        10> deci;
54typedef ratio<                       10, 1> deca;
55typedef ratio<                      100, 1> hecto;
56typedef ratio<                     1000, 1> kilo;
57typedef ratio<                  1000000, 1> mega;
58typedef ratio<               1000000000, 1> giga;
59typedef ratio<            1000000000000, 1> tera;
60typedef ratio<         1000000000000000, 1> peta;
61typedef ratio<      1000000000000000000, 1> exa;
62typedef ratio<   1000000000000000000000, 1> zetta;  // not supported
63typedef ratio<1000000000000000000000000, 1> yotta;  // not supported
64
65}
66*/
67
68#include <__config>
69#include <cstdint>
70#include <climits>
71#include <type_traits>
72
73#pragma GCC system_header
74
75_LIBCPP_BEGIN_NAMESPACE_STD
76
77// __static_gcd
78
79template <intmax_t _Xp, intmax_t _Yp>
80struct __static_gcd
81{
82    static const intmax_t value = __static_gcd<_Yp, _Xp % _Yp>::value;
83};
84
85template <intmax_t _Xp>
86struct __static_gcd<_Xp, 0>
87{
88    static const intmax_t value = _Xp;
89};
90
91// __static_lcm
92
93template <intmax_t _Xp, intmax_t _Yp>
94struct __static_lcm
95{
96    static const intmax_t value = _Xp / __static_gcd<_Xp, _Yp>::value * _Yp;
97};
98
99template <intmax_t _Xp>
100struct __static_abs
101{
102    static const intmax_t value = _Xp < 0 ? -_Xp : _Xp;
103};
104
105template <intmax_t _Xp>
106struct __static_sign
107{
108    static const intmax_t value = _Xp == 0 ? 0 : (_Xp < 0 ? -1 : 1);
109};
110
111template <intmax_t _Xp, intmax_t _Yp, intmax_t = __static_sign<_Yp>::value>
112class __ll_add;
113
114template <intmax_t _Xp, intmax_t _Yp>
115class __ll_add<_Xp, _Yp, 1>
116{
117    static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
118    static const intmax_t max = -min;
119
120    static_assert(_Xp <= max - _Yp, "overflow in __ll_add");
121public:
122    static const intmax_t value = _Xp + _Yp;
123};
124
125template <intmax_t _Xp, intmax_t _Yp>
126class __ll_add<_Xp, _Yp, 0>
127{
128public:
129    static const intmax_t value = _Xp;
130};
131
132template <intmax_t _Xp, intmax_t _Yp>
133class __ll_add<_Xp, _Yp, -1>
134{
135    static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
136    static const intmax_t max = -min;
137
138    static_assert(min - _Yp <= _Xp, "overflow in __ll_add");
139public:
140    static const intmax_t value = _Xp + _Yp;
141};
142
143template <intmax_t _Xp, intmax_t _Yp, intmax_t = __static_sign<_Yp>::value>
144class __ll_sub;
145
146template <intmax_t _Xp, intmax_t _Yp>
147class __ll_sub<_Xp, _Yp, 1>
148{
149    static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
150    static const intmax_t max = -min;
151
152    static_assert(min + _Yp <= _Xp, "overflow in __ll_sub");
153public:
154    static const intmax_t value = _Xp - _Yp;
155};
156
157template <intmax_t _Xp, intmax_t _Yp>
158class __ll_sub<_Xp, _Yp, 0>
159{
160public:
161    static const intmax_t value = _Xp;
162};
163
164template <intmax_t _Xp, intmax_t _Yp>
165class __ll_sub<_Xp, _Yp, -1>
166{
167    static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
168    static const intmax_t max = -min;
169
170    static_assert(_Xp <= max + _Yp, "overflow in __ll_sub");
171public:
172    static const intmax_t value = _Xp - _Yp;
173};
174
175template <intmax_t _Xp, intmax_t _Yp>
176class __ll_mul
177{
178    static const intmax_t nan = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1));
179    static const intmax_t min = nan + 1;
180    static const intmax_t max = -min;
181    static const intmax_t __a_x = __static_abs<_Xp>::value;
182    static const intmax_t __a_y = __static_abs<_Yp>::value;
183
184    static_assert(_Xp != nan && _Yp != nan && __a_x <= max / __a_y, "overflow in __ll_mul");
185public:
186    static const intmax_t value = _Xp * _Yp;
187};
188
189template <intmax_t _Yp>
190class __ll_mul<0, _Yp>
191{
192public:
193    static const intmax_t value = 0;
194};
195
196template <intmax_t _Xp>
197class __ll_mul<_Xp, 0>
198{
199public:
200    static const intmax_t value = 0;
201};
202
203template <>
204class __ll_mul<0, 0>
205{
206public:
207    static const intmax_t value = 0;
208};
209
210// Not actually used but left here in case needed in future maintenance
211template <intmax_t _Xp, intmax_t _Yp>
212class __ll_div
213{
214    static const intmax_t nan = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1));
215    static const intmax_t min = nan + 1;
216    static const intmax_t max = -min;
217
218    static_assert(_Xp != nan && _Yp != nan && _Yp != 0, "overflow in __ll_div");
219public:
220    static const intmax_t value = _Xp / _Yp;
221};
222
223template <intmax_t _Num, intmax_t _Den = 1>
224class _LIBCPP_VISIBLE ratio
225{
226    static_assert(__static_abs<_Num>::value >= 0, "ratio numerator is out of range");
227    static_assert(_Den != 0, "ratio divide by 0");
228    static_assert(__static_abs<_Den>::value >  0, "ratio denominator is out of range");
229    static const intmax_t __na = __static_abs<_Num>::value;
230    static const intmax_t __da = __static_abs<_Den>::value;
231    static const intmax_t __s = __static_sign<_Num>::value * __static_sign<_Den>::value;
232    static const intmax_t __gcd = __static_gcd<__na, __da>::value;
233public:
234    static const intmax_t num = __s * __na / __gcd;
235    static const intmax_t den = __da / __gcd;
236
237    typedef ratio<num, den> type;
238};
239
240template <intmax_t _Num, intmax_t _Den> const intmax_t ratio<_Num, _Den>::num;
241template <intmax_t _Num, intmax_t _Den> const intmax_t ratio<_Num, _Den>::den;
242
243template <class _Tp>                    struct __is_ratio                     : false_type {};
244template <intmax_t _Num, intmax_t _Den> struct __is_ratio<ratio<_Num, _Den> > : true_type  {};
245
246typedef ratio<1LL, 1000000000000000000LL> atto;
247typedef ratio<1LL,    1000000000000000LL> femto;
248typedef ratio<1LL,       1000000000000LL> pico;
249typedef ratio<1LL,          1000000000LL> nano;
250typedef ratio<1LL,             1000000LL> micro;
251typedef ratio<1LL,                1000LL> milli;
252typedef ratio<1LL,                 100LL> centi;
253typedef ratio<1LL,                  10LL> deci;
254typedef ratio<                 10LL, 1LL> deca;
255typedef ratio<                100LL, 1LL> hecto;
256typedef ratio<               1000LL, 1LL> kilo;
257typedef ratio<            1000000LL, 1LL> mega;
258typedef ratio<         1000000000LL, 1LL> giga;
259typedef ratio<      1000000000000LL, 1LL> tera;
260typedef ratio<   1000000000000000LL, 1LL> peta;
261typedef ratio<1000000000000000000LL, 1LL> exa;
262
263template <class _R1, class _R2>
264struct __ratio_multiply
265{
266private:
267    static const intmax_t __gcd_n1_d2 = __static_gcd<_R1::num, _R2::den>::value;
268    static const intmax_t __gcd_d1_n2 = __static_gcd<_R1::den, _R2::num>::value;
269public:
270    typedef typename ratio
271        <
272            __ll_mul<_R1::num / __gcd_n1_d2, _R2::num / __gcd_d1_n2>::value,
273            __ll_mul<_R2::den / __gcd_n1_d2, _R1::den / __gcd_d1_n2>::value
274        >::type type;
275};
276
277template <class _R1, class _R2>
278struct _LIBCPP_VISIBLE ratio_multiply
279    : public __ratio_multiply<_R1, _R2>::type {};
280
281template <class _R1, class _R2>
282struct __ratio_divide
283{
284private:
285    static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
286    static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
287public:
288    typedef typename ratio
289        <
290            __ll_mul<_R1::num / __gcd_n1_n2, _R2::den / __gcd_d1_d2>::value,
291            __ll_mul<_R2::num / __gcd_n1_n2, _R1::den / __gcd_d1_d2>::value
292        >::type type;
293};
294
295template <class _R1, class _R2>
296struct _LIBCPP_VISIBLE ratio_divide
297    : public __ratio_divide<_R1, _R2>::type {};
298
299template <class _R1, class _R2>
300struct __ratio_add
301{
302private:
303    static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
304    static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
305public:
306    typedef typename ratio_multiply
307        <
308            ratio<__gcd_n1_n2, _R1::den / __gcd_d1_d2>,
309            ratio
310            <
311                __ll_add
312                <
313                    __ll_mul<_R1::num / __gcd_n1_n2, _R2::den / __gcd_d1_d2>::value,
314                    __ll_mul<_R2::num / __gcd_n1_n2, _R1::den / __gcd_d1_d2>::value
315                >::value,
316                _R2::den
317            >
318        >::type type;
319};
320
321template <class _R1, class _R2>
322struct _LIBCPP_VISIBLE ratio_add
323    : public __ratio_add<_R1, _R2>::type {};
324
325template <class _R1, class _R2>
326struct __ratio_subtract
327{
328private:
329    static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
330    static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
331public:
332    typedef typename ratio_multiply
333        <
334            ratio<__gcd_n1_n2, _R1::den / __gcd_d1_d2>,
335            ratio
336            <
337                __ll_sub
338                <
339                    __ll_mul<_R1::num / __gcd_n1_n2, _R2::den / __gcd_d1_d2>::value,
340                    __ll_mul<_R2::num / __gcd_n1_n2, _R1::den / __gcd_d1_d2>::value
341                >::value,
342                _R2::den
343            >
344        >::type type;
345};
346
347template <class _R1, class _R2>
348struct _LIBCPP_VISIBLE ratio_subtract
349    : public __ratio_subtract<_R1, _R2>::type {};
350
351// ratio_equal
352
353template <class _R1, class _R2>
354struct _LIBCPP_VISIBLE ratio_equal
355    : public integral_constant<bool, _R1::num == _R2::num && _R1::den == _R2::den> {};
356
357template <class _R1, class _R2>
358struct _LIBCPP_VISIBLE ratio_not_equal
359    : public integral_constant<bool, !ratio_equal<_R1, _R2>::value> {};
360
361// ratio_less
362
363template <class _R1, class _R2, bool _Odd = false,
364          intmax_t _Q1 = _R1::num / _R1::den, intmax_t _M1 = _R1::num % _R1::den,
365          intmax_t _Q2 = _R2::num / _R2::den, intmax_t _M2 = _R2::num % _R2::den>
366struct __ratio_less1
367{
368    static const bool value = _Odd ? _Q2 < _Q1 : _Q1 < _Q2;
369};
370
371template <class _R1, class _R2, bool _Odd, intmax_t _Q>
372struct __ratio_less1<_R1, _R2, _Odd, _Q, 0, _Q, 0>
373{
374    static const bool value = false;
375};
376
377template <class _R1, class _R2, bool _Odd, intmax_t _Q, intmax_t _M2>
378struct __ratio_less1<_R1, _R2, _Odd, _Q, 0, _Q, _M2>
379{
380    static const bool value = !_Odd;
381};
382
383template <class _R1, class _R2, bool _Odd, intmax_t _Q, intmax_t _M1>
384struct __ratio_less1<_R1, _R2, _Odd, _Q, _M1, _Q, 0>
385{
386    static const bool value = _Odd;
387};
388
389template <class _R1, class _R2, bool _Odd, intmax_t _Q, intmax_t _M1,
390                                                        intmax_t _M2>
391struct __ratio_less1<_R1, _R2, _Odd, _Q, _M1, _Q, _M2>
392{
393    static const bool value = __ratio_less1<ratio<_R1::den, _M1>,
394                                            ratio<_R2::den, _M2>, !_Odd>::value;
395};
396
397template <class _R1, class _R2, intmax_t _S1 = __static_sign<_R1::num>::value,
398                                intmax_t _S2 = __static_sign<_R2::num>::value>
399struct __ratio_less
400{
401    static const bool value = _S1 < _S2;
402};
403
404template <class _R1, class _R2>
405struct __ratio_less<_R1, _R2, 1LL, 1LL>
406{
407    static const bool value = __ratio_less1<_R1, _R2>::value;
408};
409
410template <class _R1, class _R2>
411struct __ratio_less<_R1, _R2, -1LL, -1LL>
412{
413    static const bool value = __ratio_less1<ratio<-_R2::num, _R2::den>, ratio<-_R1::num, _R1::den> >::value;
414};
415
416template <class _R1, class _R2>
417struct _LIBCPP_VISIBLE ratio_less
418    : public integral_constant<bool, __ratio_less<_R1, _R2>::value> {};
419
420template <class _R1, class _R2>
421struct _LIBCPP_VISIBLE ratio_less_equal
422    : public integral_constant<bool, !ratio_less<_R2, _R1>::value> {};
423
424template <class _R1, class _R2>
425struct _LIBCPP_VISIBLE ratio_greater
426    : public integral_constant<bool, ratio_less<_R2, _R1>::value> {};
427
428template <class _R1, class _R2>
429struct _LIBCPP_VISIBLE ratio_greater_equal
430    : public integral_constant<bool, !ratio_less<_R1, _R2>::value> {};
431
432template <class _R1, class _R2>
433struct __ratio_gcd
434{
435    typedef ratio<__static_gcd<_R1::num, _R2::num>::value,
436                  __static_lcm<_R1::den, _R2::den>::value> type;
437};
438
439_LIBCPP_END_NAMESPACE_STD
440
441#endif  // _LIBCPP_RATIO
442