/[svn]/linuxsampler/trunk/src/common/RTMath.cpp
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Contents of /linuxsampler/trunk/src/common/RTMath.cpp

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Revision 328 - (show annotations) (download)
Sat Dec 25 21:58:58 2004 UTC (19 years, 5 months ago) by schoenebeck
File size: 3482 byte(s)
* architecture independence fixes, should now compile again for non x86
  systems
* tiny fix of command line switch --version

1 /***************************************************************************
2 * *
3 * LinuxSampler - modular, streaming capable sampler *
4 * *
5 * Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6 * *
7 * This program is free software; you can redistribute it and/or modify *
8 * it under the terms of the GNU General Public License as published by *
9 * the Free Software Foundation; either version 2 of the License, or *
10 * (at your option) any later version. *
11 * *
12 * This program is distributed in the hope that it will be useful, *
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
15 * GNU General Public License for more details. *
16 * *
17 * You should have received a copy of the GNU General Public License *
18 * along with this program; if not, write to the Free Software *
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
20 * MA 02111-1307 USA *
21 ***************************************************************************/
22
23 #include "RTMath.h"
24
25 float RTMathBase::CentsToFreqTable[MAX_PITCH * 1200 * 2 + 1]; // +-1200 cents per octave
26 float* RTMathBase::pCentsToFreqTable(InitCentsToFreqTable());
27
28 /*
29 * Creates a real time stamp for the current moment. Out of efficiency this
30 * is implemented in inline assembly for each CPU independently; we currently
31 * don't use a generic solution for CPUs that are not yet covered by the
32 * assembly code, instead an error message is prompted on compile time, forcing
33 * the user to contact us.
34 */
35 RTMathBase::time_stamp_t RTMathBase::CreateTimeStamp() {
36 #if defined(__i386__) || defined(__x86_64__)
37 uint64_t t;
38 __asm__ __volatile__ ("rdtsc" : "=A" (t));
39 return t >> 8;
40 #elif defined(__ia64__)
41 time_stamp_t t;
42 __asm__ __volatile__ ("mov %0=ar.itc" : "=r"(t));
43 return t;
44 #elif defined(__powerpc__)
45 time_stamp_t t;
46 __asm__ __volatile__ (
47 "98: mftb %0\n"
48 "99:\n"
49 ".section __ftr_fixup,\"a\"\n"
50 " .long %1\n"
51 " .long 0\n"
52 " .long 98b\n"
53 " .long 99b\n"
54 ".previous"
55 : "=r" (t) : "i" (0x00000100)
56 );
57 return t;
58 #elif defined(__alpha__)
59 time_stamp_t t;
60 __asm__ __volatile__ ("rpcc %0" : "=r"(t));
61 return t;
62 #else // we don't want to use a slow generic solution
63 # error "Sorry, LinuxSampler lacks time stamp code for your system."
64 # error "Please report this error and the CPU you are using to the LinuxSampler developers mailing list!"
65 #endif
66 }
67
68 /**
69 * Will automatically be called once to initialize the 'Cents to frequency
70 * ratio' table.
71 */
72 float* RTMathBase::InitCentsToFreqTable() {
73 float* pMiddleOfTable = &CentsToFreqTable[MAX_PITCH * 1200];
74 for (int i = -1200; i <= 1200; i++) {
75 pMiddleOfTable[i] = pow(TWELVEHUNDREDTH_ROOT_OF_TWO, i);
76 }
77 return pMiddleOfTable;
78 }

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