summaryrefslogtreecommitdiffstatshomepage
path: root/src/emu/netlist/nl_util.h
blob: 6aea597977a2fe49634eb8668087e90dec3f5d0f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
// license:???
// copyright-holders:???
/*
 * nl_util.h
 *
 */

#ifndef NL_UTIL_H_
#define NL_UTIL_H_

#include "pstring.h"
#include "plists.h"
#include <cmath>

class nl_util
{
// this is purely static
private:
	nl_util() {};

public:
	typedef plinearlist_t<pstring, 10> pstring_list;

	static pstring_list split(const pstring &str, const pstring &onstr)
	{
		pstring_list temp;

		int p = 0;
		int pn;

		pn = str.find(onstr, p);
		while (pn>=0)
		{
			temp.add(str.substr(p, pn - p));
			p = pn + onstr.len();
			pn = str.find(onstr, p);
		}
		if (p<str.len())
			temp.add(str.substr(p));
		return temp;
	}
};

class nl_math
{
// this is purely static
private:
	nl_math() {};

public:
	ATTR_HOT inline static float exp(const float x) { return std::exp(x); }
	ATTR_HOT inline static double abs(const double x) { return std::abs(x); }
	ATTR_HOT inline static float abs(const float x) { return std::abs(x); }
	ATTR_HOT inline static double log(const double x) { return std::log(x); }
	ATTR_HOT inline static float log(const float x) { return std::log(x); }
#if defined(_MSC_VER) && _MSC_VER < 1800
	ATTR_HOT inline static double log1p(const double x) { return nl_math::log(1.0 + x); }
	ATTR_HOT inline static float log1p(const float x) { return nl_math::log(1.0 + x); }
#else
	ATTR_HOT inline static double e_log1p(const double x) { return log1p(x); }
	ATTR_HOT inline static float e_log1p(const float x) { return log1pf(x); }
#endif
	ATTR_HOT inline static double sqrt(const double x) { return std::sqrt(x); }
	ATTR_HOT inline static float sqrt(const float x) { return std::sqrt(x); }

	// this one has an accuracy of better than 5%. That's enough for our purpose
	// add c3 and it'll be better than 1%

#if 0
	inline static double fastexp_h(const double x)
	{
		static const double ln2r = 1.442695040888963387;
		static const double ln2  = 0.693147180559945286;
		static const double c3   = 0.166666666666666667;

		const double y = x * ln2r;
		const unsigned int t = y;
		const double z = (x - ln2 * (double) t);
		const double zz = z * z;
		const double zzz = zz * z;

		return (double)(1 << t)*(1.0 + z + 0.5 * zz + c3 * zzz);
	}

	ATTR_HOT inline static double exp(const double x)
	{
		if (x<0)
			return 1.0 / fastexp_h(-x);
		else
			return fastexp_h(x);
	}
#else
	ATTR_HOT inline static double exp(const double x)  { return std::exp(x); }
#endif

};

#endif /* NL_UTIL_H_ */