2
* libmad - MPEG audio decoder library
3
* Copyright (C) 2000-2004 Underbit Technologies, Inc.
5
* This program is free software; you can redistribute it and/or modify
6
* it under the terms of the GNU General Public License as published by
7
* the Free Software Foundation; either version 2 of the License, or
8
* (at your option) any later version.
10
* This program is distributed in the hope that it will be useful,
11
* but WITHOUT ANY WARRANTY; without even the implied warranty of
12
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13
* GNU General Public License for more details.
15
* You should have received a copy of the GNU General Public License
16
* along with this program; if not, write to the Free Software
17
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19
* $Id: fixed.h 1042 2004-05-17 22:42:18Z fbaumgart $
22
# ifndef LIBMAD_FIXED_H
23
# define LIBMAD_FIXED_H
26
typedef signed int mad_fixed_t;
28
typedef signed int mad_fixed64hi_t;
29
typedef unsigned int mad_fixed64lo_t;
31
typedef signed long mad_fixed_t;
33
typedef signed long mad_fixed64hi_t;
34
typedef unsigned long mad_fixed64lo_t;
37
# if defined(_MSC_VER)
38
# define mad_fixed64_t signed __int64
39
# elif 1 || defined(__GNUC__)
40
# define mad_fixed64_t signed long long
43
# if defined(FPM_FLOAT)
44
typedef double mad_sample_t;
46
typedef mad_fixed_t mad_sample_t;
50
* Fixed-point format: 0xABBBBBBB
51
* A == whole part (sign + 3 bits)
52
* B == fractional part (28 bits)
54
* Values are signed two's complement, so the effective range is:
55
* 0x80000000 to 0x7fffffff
56
* -8.0 to +7.9999999962747097015380859375
58
* The smallest representable value is:
59
* 0x00000001 == 0.0000000037252902984619140625 (i.e. about 3.725e-9)
61
* 28 bits of fractional accuracy represent about
62
* 8.6 digits of decimal accuracy.
64
* Fixed-point numbers can be added or subtracted as normal
65
* integers, but multiplication requires shifting the 64-bit result
66
* from 56 fractional bits back to 28 (and rounding.)
68
* Changing the definition of MAD_F_FRACBITS is only partially
69
* supported, and must be done with care.
72
# define MAD_F_FRACBITS 28
74
# if MAD_F_FRACBITS == 28
75
# define MAD_F(x) ((mad_fixed_t) (x##L))
77
# if MAD_F_FRACBITS < 28
78
# warning "MAD_F_FRACBITS < 28"
79
# define MAD_F(x) ((mad_fixed_t) \
81
(1L << (28 - MAD_F_FRACBITS - 1))) >> \
82
(28 - MAD_F_FRACBITS)))
83
# elif MAD_F_FRACBITS > 28
84
# error "MAD_F_FRACBITS > 28 not currently supported"
85
# define MAD_F(x) ((mad_fixed_t) \
86
((x##L) << (MAD_F_FRACBITS - 28)))
90
# define MAD_F_MIN ((mad_fixed_t) -0x80000000L)
91
# define MAD_F_MAX ((mad_fixed_t) +0x7fffffffL)
93
# define MAD_F_ONE MAD_F(0x10000000)
95
# define mad_f_tofixed(x) ((mad_fixed_t) \
96
((x) * (double) (1L << MAD_F_FRACBITS) + 0.5))
97
# define mad_f_todouble(x) ((double) \
98
((x) / (double) (1L << MAD_F_FRACBITS)))
100
# define mad_f_intpart(x) ((x) >> MAD_F_FRACBITS)
101
# define mad_f_fracpart(x) ((x) & ((1L << MAD_F_FRACBITS) - 1))
102
/* (x should be positive) */
104
# define mad_f_fromint(x) ((x) << MAD_F_FRACBITS)
106
# define mad_f_add(x, y) ((x) + (y))
107
# define mad_f_sub(x, y) ((x) - (y))
109
# if defined(FPM_FLOAT)
110
# error "FPM_FLOAT not yet supported"
113
# define MAD_F(x) mad_f_todouble(x)
115
# define mad_f_mul(x, y) ((x) * (y))
116
# define mad_f_scale64
118
# undef ASO_ZEROCHECK
120
# elif defined(FPM_64BIT)
123
* This version should be the most accurate if 64-bit types are supported by
124
* the compiler, although it may not be the most efficient.
126
# if defined(OPT_ACCURACY)
127
# define mad_f_mul(x, y) \
129
((((mad_fixed64_t) (x) * (y)) + \
130
(1L << (MAD_F_SCALEBITS - 1))) >> MAD_F_SCALEBITS))
132
# define mad_f_mul(x, y) \
133
((mad_fixed_t) (((mad_fixed64_t) (x) * (y)) >> MAD_F_SCALEBITS))
136
# define MAD_F_SCALEBITS MAD_F_FRACBITS
138
/* --- Intel --------------------------------------------------------------- */
140
# elif defined(FPM_INTEL)
142
# if defined(_MSC_VER)
143
# pragma warning(push)
144
# pragma warning(disable: 4035) /* no return value */
146
mad_fixed_t mad_f_mul_inline(mad_fixed_t x, mad_fixed_t y)
149
fracbits = MAD_F_FRACBITS
155
shrd eax, edx, fracbits
158
/* implicit return of eax */
160
# pragma warning(pop)
162
# define mad_f_mul mad_f_mul_inline
163
# define mad_f_scale64
166
* This Intel version is fast and accurate; the disposition of the least
167
* significant bit depends on OPT_ACCURACY via mad_f_scale64().
169
# define MAD_F_MLX(hi, lo, x, y) \
171
: "=a" (lo), "=d" (hi) \
172
: "%a" (x), "rm" (y) \
175
# if defined(OPT_ACCURACY)
177
* This gives best accuracy but is not very fast.
179
# define MAD_F_MLA(hi, lo, x, y) \
180
({ mad_fixed64hi_t __hi; \
181
mad_fixed64lo_t __lo; \
182
MAD_F_MLX(__hi, __lo, (x), (y)); \
183
asm ("addl %2,%0\n\t" \
185
: "=rm" (lo), "=rm" (hi) \
186
: "r" (__lo), "r" (__hi), "0" (lo), "1" (hi) \
189
# endif /* OPT_ACCURACY */
191
# if defined(OPT_ACCURACY)
193
* Surprisingly, this is faster than SHRD followed by ADC.
195
# define mad_f_scale64(hi, lo) \
196
({ mad_fixed64hi_t __hi_; \
197
mad_fixed64lo_t __lo_; \
198
mad_fixed_t __result; \
199
asm ("addl %4,%2\n\t" \
201
: "=rm" (__lo_), "=rm" (__hi_) \
202
: "0" (lo), "1" (hi), \
203
"ir" (1L << (MAD_F_SCALEBITS - 1)), "ir" (0) \
205
asm ("shrdl %3,%2,%1" \
207
: "0" (__lo_), "r" (__hi_), "I" (MAD_F_SCALEBITS) \
211
# elif defined(OPT_INTEL)
213
* Alternate Intel scaling that may or may not perform better.
215
# define mad_f_scale64(hi, lo) \
216
({ mad_fixed_t __result; \
217
asm ("shrl %3,%1\n\t" \
221
: "0" (lo), "r" (hi), \
222
"I" (MAD_F_SCALEBITS), "I" (32 - MAD_F_SCALEBITS) \
227
# define mad_f_scale64(hi, lo) \
228
({ mad_fixed_t __result; \
229
asm ("shrdl %3,%2,%1" \
231
: "0" (lo), "r" (hi), "I" (MAD_F_SCALEBITS) \
235
# endif /* OPT_ACCURACY */
237
# define MAD_F_SCALEBITS MAD_F_FRACBITS
240
/* --- ARM ----------------------------------------------------------------- */
242
# elif defined(FPM_ARM)
245
* This ARM V4 version is as accurate as FPM_64BIT but much faster. The
246
* least significant bit is properly rounded at no CPU cycle cost!
250
* This is faster than the default implementation via MAD_F_MLX() and
253
# define mad_f_mul(x, y) \
254
({ mad_fixed64hi_t __hi; \
255
mad_fixed64lo_t __lo; \
256
mad_fixed_t __result; \
257
asm ("smull %0, %1, %3, %4\n\t" \
258
"movs %0, %0, lsr %5\n\t" \
259
"adc %2, %0, %1, lsl %6" \
260
: "=&r" (__lo), "=&r" (__hi), "=r" (__result) \
261
: "%r" (x), "r" (y), \
262
"M" (MAD_F_SCALEBITS), "M" (32 - MAD_F_SCALEBITS) \
268
# define MAD_F_MLX(hi, lo, x, y) \
269
asm ("smull %0, %1, %2, %3" \
270
: "=&r" (lo), "=&r" (hi) \
273
# define MAD_F_MLA(hi, lo, x, y) \
274
asm ("smlal %0, %1, %2, %3" \
275
: "+r" (lo), "+r" (hi) \
278
# define MAD_F_MLN(hi, lo) \
279
asm ("rsbs %0, %2, #0\n\t" \
281
: "=r" (lo), "=r" (hi) \
282
: "0" (lo), "1" (hi) \
285
# define mad_f_scale64(hi, lo) \
286
({ mad_fixed_t __result; \
287
asm ("movs %0, %1, lsr %3\n\t" \
288
"adc %0, %0, %2, lsl %4" \
290
: "r" (lo), "r" (hi), \
291
"M" (MAD_F_SCALEBITS), "M" (32 - MAD_F_SCALEBITS) \
296
# define MAD_F_SCALEBITS MAD_F_FRACBITS
298
/* --- MIPS ---------------------------------------------------------------- */
300
# elif defined(FPM_MIPS)
303
* This MIPS version is fast and accurate; the disposition of the least
304
* significant bit depends on OPT_ACCURACY via mad_f_scale64().
306
# define MAD_F_MLX(hi, lo, x, y) \
308
: "=l" (lo), "=h" (hi) \
311
# if defined(HAVE_MADD_ASM)
312
# define MAD_F_MLA(hi, lo, x, y) \
314
: "+l" (lo), "+h" (hi) \
316
# elif defined(HAVE_MADD16_ASM)
318
* This loses significant accuracy due to the 16-bit integer limit in the
319
* multiply/accumulate instruction.
321
# define MAD_F_ML0(hi, lo, x, y) \
323
: "=l" (lo), "=h" (hi) \
324
: "%r" ((x) >> 12), "r" ((y) >> 16))
325
# define MAD_F_MLA(hi, lo, x, y) \
326
asm ("madd16 %2,%3" \
327
: "+l" (lo), "+h" (hi) \
328
: "%r" ((x) >> 12), "r" ((y) >> 16))
329
# define MAD_F_MLZ(hi, lo) ((mad_fixed_t) (lo))
332
# if defined(OPT_SPEED)
333
# define mad_f_scale64(hi, lo) \
334
((mad_fixed_t) ((hi) << (32 - MAD_F_SCALEBITS)))
335
# define MAD_F_SCALEBITS MAD_F_FRACBITS
338
/* --- SPARC --------------------------------------------------------------- */
340
# elif defined(FPM_SPARC)
343
* This SPARC V8 version is fast and accurate; the disposition of the least
344
* significant bit depends on OPT_ACCURACY via mad_f_scale64().
346
# define MAD_F_MLX(hi, lo, x, y) \
347
asm ("smul %2, %3, %0\n\t" \
349
: "=r" (lo), "=r" (hi) \
350
: "%r" (x), "rI" (y))
352
/* --- PowerPC ------------------------------------------------------------- */
354
# elif defined(FPM_PPC)
357
* This PowerPC version is fast and accurate; the disposition of the least
358
* significant bit depends on OPT_ACCURACY via mad_f_scale64().
360
# define MAD_F_MLX(hi, lo, x, y) \
362
asm ("mullw %0,%1,%2" \
364
: "%r" (x), "r" (y)); \
365
asm ("mulhw %0,%1,%2" \
367
: "%r" (x), "r" (y)); \
371
# if defined(OPT_ACCURACY)
373
* This gives best accuracy but is not very fast.
375
# define MAD_F_MLA(hi, lo, x, y) \
376
({ mad_fixed64hi_t __hi; \
377
mad_fixed64lo_t __lo; \
378
MAD_F_MLX(__hi, __lo, (x), (y)); \
379
asm ("addc %0,%2,%3\n\t" \
381
: "=r" (lo), "=r" (hi) \
382
: "%r" (lo), "r" (__lo), \
383
"%r" (hi), "r" (__hi) \
388
# if defined(OPT_ACCURACY)
390
* This is slower than the truncating version below it.
392
# define mad_f_scale64(hi, lo) \
393
({ mad_fixed_t __result, __round; \
394
asm ("rotrwi %0,%1,%2" \
396
: "r" (lo), "i" (MAD_F_SCALEBITS)); \
397
asm ("extrwi %0,%1,1,0" \
400
asm ("insrwi %0,%1,%2,0" \
402
: "r" (hi), "i" (MAD_F_SCALEBITS)); \
403
asm ("add %0,%1,%2" \
405
: "%r" (__result), "r" (__round)); \
409
# define mad_f_scale64(hi, lo) \
410
({ mad_fixed_t __result; \
411
asm ("rotrwi %0,%1,%2" \
413
: "r" (lo), "i" (MAD_F_SCALEBITS)); \
414
asm ("insrwi %0,%1,%2,0" \
416
: "r" (hi), "i" (MAD_F_SCALEBITS)); \
421
# define MAD_F_SCALEBITS MAD_F_FRACBITS
423
/* --- Default ------------------------------------------------------------- */
425
# elif defined(FPM_DEFAULT)
428
* This version is the most portable but it loses significant accuracy.
429
* Furthermore, accuracy is biased against the second argument, so care
430
* should be taken when ordering operands.
432
* The scale factors are constant as this is not used with SSO.
434
* Pre-rounding is required to stay within the limits of compliance.
436
# if defined(OPT_SPEED)
437
# define mad_f_mul(x, y) (((x) >> 12) * ((y) >> 16))
439
# define mad_f_mul(x, y) ((((x) + (1L << 11)) >> 12) * \
440
(((y) + (1L << 15)) >> 16))
443
/* ------------------------------------------------------------------------- */
446
# error "no FPM selected"
449
/* default implementations */
451
# if !defined(mad_f_mul)
452
# define mad_f_mul(x, y) \
453
({ register mad_fixed64hi_t __hi; \
454
register mad_fixed64lo_t __lo; \
455
MAD_F_MLX(__hi, __lo, (x), (y)); \
456
mad_f_scale64(__hi, __lo); \
460
# if !defined(MAD_F_MLA)
461
# define MAD_F_ML0(hi, lo, x, y) ((lo) = mad_f_mul((x), (y)))
462
# define MAD_F_MLA(hi, lo, x, y) ((lo) += mad_f_mul((x), (y)))
463
# define MAD_F_MLN(hi, lo) ((lo) = -(lo))
464
# define MAD_F_MLZ(hi, lo) ((void) (hi), (mad_fixed_t) (lo))
467
# if !defined(MAD_F_ML0)
468
# define MAD_F_ML0(hi, lo, x, y) MAD_F_MLX((hi), (lo), (x), (y))
471
# if !defined(MAD_F_MLN)
472
# define MAD_F_MLN(hi, lo) ((hi) = ((lo) = -(lo)) ? ~(hi) : -(hi))
475
# if !defined(MAD_F_MLZ)
476
# define MAD_F_MLZ(hi, lo) mad_f_scale64((hi), (lo))
479
# if !defined(mad_f_scale64)
480
# if defined(OPT_ACCURACY)
481
# define mad_f_scale64(hi, lo) \
483
(((hi) << (32 - (MAD_F_SCALEBITS - 1))) | \
484
((lo) >> (MAD_F_SCALEBITS - 1)))) + 1) >> 1)
486
# define mad_f_scale64(hi, lo) \
488
(((hi) << (32 - MAD_F_SCALEBITS)) | \
489
((lo) >> MAD_F_SCALEBITS)))
491
# define MAD_F_SCALEBITS MAD_F_FRACBITS
496
mad_fixed_t mad_f_abs(mad_fixed_t);
497
mad_fixed_t mad_f_div(mad_fixed_t, mad_fixed_t);
added
removed
input/mad/fixed.h
