| Geant4 Cross Reference |
1 // -*- C++ -*-
2 // -----------------------------------------------------------------------
3 // HEP Random
4 // --- DoubConv ---
5 // class implementation file
6 // -----------------------------------------------------------------------
7
8 #include "CLHEP/Random/DoubConv.h"
9
10 #include <sstream>
11 #include <iomanip>
12 #include <vector>
13
14 namespace CLHEP {
15
16 CLHEP_THREAD_LOCAL bool DoubConv::byte_order_known = false;
17 CLHEP_THREAD_LOCAL int DoubConv::byte_order[8];
18
19 void DoubConv::fill_byte_order () {
20 double x = 1.0;
21 int t30 = 1 << 30;
22 int t22 = 1 << 22;
23 x *= t30;
24 x *= t22;
25 double y = 1;
26 double z = 1;
27 x *= z;
28 for (int k=0; k<6; k++) {
29 x += y*z;
30 y += 1;
31 z *= 256;
32 }
33 // x, in IEEE format, would now be 0x4330060504030201
34 DB8 xb;
35 xb.d = x;
36 int n;
37 static const int UNSET = -1;
38 for (n=0; n<8; n++) {
39 byte_order[n] = UNSET;
40 }
41 int order;
42 for (n=0; n<8; n++) {
43 switch ( xb.b[n] ) {
44 case 0x43:
45 order = 0;
46 break;
47 case 0x30:
48 order = 1;
49 break;
50 case 0x06:
51 order = 2;
52 break;
53 case 0x05:
54 order = 3;
55 break;
56 case 0x04:
57 order = 4;
58 break;
59 case 0x03:
60 order = 5;
61 break;
62 case 0x02:
63 order = 6;
64 break;
65 case 0x01:
66 order = 7;
67 break;
68 default:
69 throw DoubConvException(
70 "Cannot determine byte-ordering of doubles on this system");
71 }
72 if (byte_order[n] != UNSET) {
73 throw DoubConvException(
74 "Confusion in byte-ordering of doubles on this system");
75 }
76 byte_order[n] = order;
77 byte_order_known = true;
78 }
79 return;
80 }
81
82 std::string DoubConv::d2x(double d) {
83 if ( !byte_order_known ) fill_byte_order ();
84 DB8 db;
85 db.d = d;
86 std::ostringstream ss;
87 for (int i=0; i<8; ++i) {
88 int k = byte_order[i];
89 ss << std::hex << std::setw(2) << std::setfill('0') << (int)db.b[k];
90 }
91 return ss.str();
92 }
93
94 std::vector<unsigned long> DoubConv::dto2longs(double d) {
95 std::vector<unsigned long> v(2);
96 if ( !byte_order_known ) fill_byte_order ();
97 DB8 db;
98 db.d = d;
99 v[0] = ((static_cast<unsigned long>(db.b[byte_order[0]])) << 24)
100 | ((static_cast<unsigned long>(db.b[byte_order[1]])) << 16)
101 | ((static_cast<unsigned long>(db.b[byte_order[2]])) << 8)
102 | ((static_cast<unsigned long>(db.b[byte_order[3]])) );
103 v[1] = ((static_cast<unsigned long>(db.b[byte_order[4]])) << 24)
104 | ((static_cast<unsigned long>(db.b[byte_order[5]])) << 16)
105 | ((static_cast<unsigned long>(db.b[byte_order[6]])) << 8)
106 | ((static_cast<unsigned long>(db.b[byte_order[7]])) );
107 return v;
108 }
109
110 double DoubConv::longs2double (const std::vector<unsigned long> & v) {
111 DB8 db;
112 unsigned char bytes[8];
113 if ( !byte_order_known ) fill_byte_order ();
114 bytes[0] = static_cast<unsigned char>((v[0] >> 24) & 0xFF);
115 bytes[1] = static_cast<unsigned char>((v[0] >> 16) & 0xFF);
116 bytes[2] = static_cast<unsigned char>((v[0] >> 8) & 0xFF);
117 bytes[3] = static_cast<unsigned char>((v[0] ) & 0xFF);
118 bytes[4] = static_cast<unsigned char>((v[1] >> 24) & 0xFF);
119 bytes[5] = static_cast<unsigned char>((v[1] >> 16) & 0xFF);
120 bytes[6] = static_cast<unsigned char>((v[1] >> 8) & 0xFF);
121 bytes[7] = static_cast<unsigned char>((v[1] ) & 0xFF);
122 for (int i=0; i<8; ++i) {
123 db.b[byte_order[i]] = bytes[i];
124 }
125 return db.d;
126 }
127
128 } // end namespace CLHEP
129