summaryrefslogtreecommitdiffstats
path: root/libk3b/plugin/libsamplerate/float_cast.h
blob: af362e3c377f7c95d7a5b051b3349d361cd6e087 (plain)
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
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
/*
** Copyright (C) 2001-2003 Erik de Castro Lopo <erikd@mega-nerd.com>
**  
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 51 Franklin Steet, Fifth Floor, Boston, MA 02110-1301, USA.
*/

/* Version 1.3 */


/*============================================================================
**	On Intel Pentium processors (especially PIII and probably P4), converting
**	from float to int is very slow. To meet the C specs, the code produced by
**	most C compilers targeting Pentium needs to change the FPU rounding mode
**	before the float to int conversion is performed.
**
**	Changing the FPU rounding mode causes the FPU pipeline to be flushed. It
**	is this flushing of the pipeline which is so slow.
**
**	Fortunately the ISO C99 specifications define the functions lrint, lrintf,
**	llrint and llrintf which fix this problem as a side effect.
**
**	On Unix-like systems, the configure process should have detected the
**	presence of these functions. If they weren't found we have to replace them
**	here with a standard C cast.
*/

/*
**	The C99 prototypes for lrint and lrintf are as follows:
**
**		long int lrintf (float x) ;
**		long int lrint  (double x) ;
*/

#include "config.h"

/*
**	The presence of the required functions are detected during the configure
**	process and the values HAVE_LRINT and HAVE_LRINTF are set accordingly in
**	the config.h file.
*/

#define  HAVE_LRINT_REPLACEMENT 0

#if (HAVE_LRINT && HAVE_LRINTF)

	/*
	**	These defines enable functionality introduced with the 1999 ISO C
	**	standard. They must be defined before the inclusion of math.h to
	**	engage them. If optimization is enabled, these functions will be
	**	inlined. With optimization switched off, you have to link in the
	**	maths library using -lm.
	*/

	#define	_ISOC9X_SOURCE	1
	#define _ISOC99_SOURCE	1

	#define	__USE_ISOC9X	1
	#define	__USE_ISOC99	1

	#include	<math.h>

#elif (defined (WIN32) || defined (_WIN32))

	#undef   HAVE_LRINT_REPLACEMENT
	#define  HAVE_LRINT_REPLACEMENT 1
	#include	<math.h>

	/*
	**	Win32 doesn't seem to have these functions.
	**	Therefore implement inline versions of these functions here.
	*/

	__inline long int
	lrint (double flt)
	{	int intgr;

		_asm
		{	fld flt
			fistp intgr
			} ;

		return intgr ;
	}

	__inline long int
	lrintf (float flt)
	{	int intgr;

		_asm
		{	fld flt
			fistp intgr
			} ;

		return intgr ;
	}

#elif (defined (__MWERKS__) && defined (macintosh))

	/* This MacOS 9 solution was provided by Stephane Letz */

	#undef   HAVE_LRINT_REPLACEMENT
	#define  HAVE_LRINT_REPLACEMENT 1
	#include   <math.h>

	#undef	lrint
	#undef	lrintf

	#define	lrint   double2int
	#define	lrintf  float2int

	inline int
	float2int (register float in)
	{	long res [2] ;

		asm
		{	fctiw	in,in
		  	stfd	 in,res
	  	}
		return res [1] ;
	} /* float2int */

	inline int
	double2int (register double in)
	{	long res [2] ;

		asm
		{	fctiw	in,in
			stfd	 in,res
	  	}
		return res [1] ;
	} /* double2int */

#elif (defined (__MACH__) && defined (__APPLE__))

	/* For Apple MacOSX. */

	#undef   HAVE_LRINT_REPLACEMENT
	#define  HAVE_LRINT_REPLACEMENT 1
	#include   <math.h>

	#undef lrint
	#undef lrintf

	#define lrint	double2int
	#define lrintf	float2int

	inline static long int
	float2int (register float in)
	{	int res [2] ;

		__asm__ __volatile__
		(	"fctiw	%1, %1\n\t"
		  	"stfd	%1, %0"
			: "=m" (res)	/* Output */
			: "f" (in)		/* Input */
			: "memory"
			) ;

		return res [1] ;
	} /* lrintf */

	inline static long int
	double2int (register double in)
	{	int res [2] ;

		__asm__ __volatile__
		(	"fctiw	%1, %1\n\t"
		  	"stfd	%1, %0"
			: "=m" (res)	/* Output */
			: "f" (in)		/* Input */
			: "memory"
			) ;

		return res [1] ;
	} /* lrint */

#else
	#ifndef __sgi
	#warning "Don't have the functions lrint() and lrintf()."
	#warning "Replacing these functions with a standard C cast."
	#endif

	#include	<math.h>

	#define	lrint(dbl)		((int) (dbl))
	#define	lrintf(flt)		((int) (flt))

#endif