apps/codecs/lib/fixedpoint.h

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id: fixedpoint.h -1   $
   9  *
  10  * Copyright (C) 2006 Jens Arnold
  11  *
  12  * Fixed point library for plugins
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
  16  * as published by the Free Software Foundation; either version 2
  17  * of the License, or (at your option) any later version.
  18  *
  19  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  20  * KIND, either express or implied.
  21  *
  22  ****************************************************************************/
  23
  24 #ifndef _FIXEDPOINT_H
  25 #define _FIXEDPOINT_H
  26
  27 #include <inttypes.h>
  28
  29 /** TAKEN FROM apps/dsp.h */
  30 /* A bunch of fixed point assembler helper macros */
  31 #if defined(CPU_COLDFIRE)
  32 /* These macros use the Coldfire EMAC extension and need the MACSR flags set
  33  * to fractional mode with no rounding.
  34  */
  35
  36 /* Multiply two S.31 fractional integers and return the sign bit and the
  37  * 31 most significant bits of the result.
  38  */
  39 #define FRACMUL(x, y) \
  40 ({ \
  41     long t; \
  42     asm ("mac.l    %[a], %[b], %%acc0\n\t" \
  43          "movclr.l %%acc0, %[t]\n\t" \
  44          : [t] "=r" (t) : [a] "r" (x), [b] "r" (y)); \
  45     t; \
  46 })
  47
  48 /* Multiply two S.31 fractional integers, and return the 32 most significant
  49  * bits after a shift left by the constant z. NOTE: Only works for shifts of
  50  * 1 to 8 on Coldfire!
  51  */
  52 #define FRACMUL_SHL(x, y, z) \
  53 ({ \
  54     long t, t2; \
  55     asm ("mac.l    %[a], %[b], %%acc0\n\t" \
  56          "moveq.l  %[d], %[t]\n\t" \
  57          "move.l   %%accext01, %[t2]\n\t" \
  58          "and.l    %[mask], %[t2]\n\t" \
  59          "lsr.l    %[t], %[t2]\n\t" \
  60          "movclr.l %%acc0, %[t]\n\t" \
  61          "asl.l    %[c], %[t]\n\t" \
  62          "or.l     %[t2], %[t]\n\t" \
  63          : [t] "=&d" (t), [t2] "=&d" (t2) \
  64          : [a] "r" (x), [b] "r" (y), [mask] "d" (0xff), \
  65            [c] "i" ((z)), [d] "i" (8 - (z))); \
  66     t; \
  67 })
  68
  69 #elif defined(CPU_ARM)
  70
  71 /* Multiply two S.31 fractional integers and return the sign bit and the
  72  * 31 most significant bits of the result.
  73  */
  74 #define FRACMUL(x, y) \
  75 ({ \
  76     long t, t2; \
  77     asm ("smull    %[t], %[t2], %[a], %[b]\n\t" \
  78          "mov      %[t2], %[t2], asl #1\n\t" \
  79          "orr      %[t], %[t2], %[t], lsr #31\n\t" \
  80          : [t] "=&r" (t), [t2] "=&r" (t2) \
  81          : [a] "r" (x), [b] "r" (y)); \
  82     t; \
  83 })
  84
  85 /* Multiply two S.31 fractional integers, and return the 32 most significant
  86  * bits after a shift left by the constant z.
  87  */
  88 #define FRACMUL_SHL(x, y, z) \
  89 ({ \
  90     long t, t2; \
  91     asm ("smull    %[t], %[t2], %[a], %[b]\n\t" \
  92          "mov      %[t2], %[t2], asl %[c]\n\t" \
  93          "orr      %[t], %[t2], %[t], lsr %[d]\n\t" \
  94          : [t] "=&r" (t), [t2] "=&r" (t2) \
  95          : [a] "r" (x), [b] "r" (y), \
  96            [c] "M" ((z) + 1), [d] "M" (31 - (z))); \
  97     t; \
  98 })
  99
 100 #else
 101
 102 #define FRACMUL(x, y) (long) (((((long long) (x)) * ((long long) (y))) >> 31))
 103 #define FRACMUL_SHL(x, y, z) \
 104 ((long)(((((long long) (x)) * ((long long) (y))) >> (31 - (z)))))
 105
 106 #endif
 107
 108 #define DIV64(x, y, z) (long)(((long long)(x) << (z))/(y))
 109
 110
 111 /** TAKEN FROM ORIGINAL fixedpoint.h */
 112 /* fast unsigned multiplication (16x16bit->32bit or 32x32bit->32bit,
 113  * whichever is faster for the architecture) */
 114 #ifdef CPU_ARM
 115 #define FMULU(a, b) ((uint32_t) (((uint32_t) (a)) * ((uint32_t) (b))))
 116 #else /* SH1, coldfire */
 117 #define FMULU(a, b) ((uint32_t) (((uint16_t) (a)) * ((uint16_t) (b))))
 118 #endif
 119
 120 long fsincos(unsigned long phase, long *cos);
 121 long fsqrt(long a, unsigned int fracbits);
 122 long cos_int(int val);
 123 long sin_int(int val);
 124 long flog(int x);
 125
 126 #endif