firmware/asm/arm/pcm-mixer-armv6.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2011 by Michael Sevakis
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #define MIXER_OPTIMIZED_MIX_SAMPLES
  22 #define MIXER_OPTIMIZED_WRITE_SAMPLES
  23
  24 /* Mix channels' samples and apply gain factors */
  25 static FORCE_INLINE void mix_samples(void *out,
  26                                      const void *src0,
  27                                      int32_t src0_amp,
  28                                      const void *src1,
  29                                      int32_t src1_amp,
  30                                      size_t size)
  31 {
  32     uint32_t s0, s1;
  33
  34     if (src0_amp == MIX_AMP_UNITY && src1_amp == MIX_AMP_UNITY)
  35     {
  36         /* Both are unity amplitude */
  37         asm volatile (
  38         "1:                      \n"
  39             "ldr    %4, [%1], #4 \n"
  40             "ldr    %5, [%2], #4 \n"
  41             "subs   %3, %3, #4   \n"
  42             "qadd16 %5, %5, %4   \n"
  43             "str    %5, [%0], #4 \n"
  44             "bhi    1b           \n"
  45             : "+r"(out), "+r"(src0), "+r"(src1), "+r"(size),
  46               "=&r"(s0), "=&r"(s1));
  47     }
  48     else
  49     {
  50         /* One or neither are unity amplitude */
  51         uint32_t tmp;
  52         asm volatile (
  53         "1:                             \n"
  54             "ldr    %4, [%1], #4        \n"
  55             "ldr    %5, [%2], #4        \n"
  56             "subs   %3, %3, #4          \n"
  57             "smulwb %6, %7, %4          \n"
  58             "smulwt %4, %7, %4          \n"
  59             "smlawb %6, %8, %5, %6      \n"
  60             "smlawt %4, %8, %5, %4      \n"
  61             "ssat   %6, #16, %6         \n"
  62             "ssat   %4, #16, %4         \n"
  63             "pkhbt  %6, %6, %4, asl #16 \n"
  64             "str    %6, [%0], #4        \n"
  65             "bhi    1b                  \n"
  66             : "+r"(out), "+r"(src0), "+r"(src1), "+r"(size),
  67               "=&r"(s0), "=&r"(s1), "=&r"(tmp)
  68             : "r"(src0_amp), "r"(src1_amp));
  69     }
  70 }
  71
  72 /* Write channel's samples and apply gain factor */
  73 static FORCE_INLINE void write_samples(void *out,
  74                                        const void *src,
  75                                        int32_t amp,
  76                                        size_t size)
  77 {
  78     if (LIKELY(amp == MIX_AMP_UNITY))
  79     {
  80         /* Channel is unity amplitude */
  81         asm volatile (
  82             "ands       r1, %2, #0x1f  \n"
  83             "beq        2f             \n"
  84         "1:                            \n"
  85             "ldr        r0, [%1], #4   \n"
  86             "subs       r1, r1, #4     \n"
  87             "str        r0, [%0], #4   \n"
  88             "bne        1b             \n"
  89             "bics       %2, %2, #0x1f  \n"
  90             "beq        3f             \n"
  91         "2:                            \n"
  92             "ldmia      %1!, { r0-r7 } \n"
  93             "subs       %2, %2, #32    \n"
  94             "stmia      %0!, { r0-r7 } \n"
  95             "bhi        2b             \n"
  96         "3:                            \n"
  97             : "+r"(out), "+r"(src), "+r"(size)
  98             :
  99             : "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7");
 100     }
 101     else
 102     {
 103         /* Channel needs amplitude cut */
 104         uint32_t s, tmp;
 105         asm volatile(
 106         "1:                             \n"
 107             "ldr    %3, [%1], #4        \n"
 108             "subs   %2, %2, #4          \n"
 109             "smulwt %4, %5, %3          \n"
 110             "smulwb %3, %5, %3          \n"
 111             "pkhbt  %4, %3, %4, asl #16 \n"
 112             "str    %4, [%0], #4        \n"
 113             "bhi    1b                  \n"
 114             : "+r"(out), "+r"(src), "+r"(size),
 115               "=&r"(s), "=&r"(tmp)
 116             : "r"(amp));
 117     }
 118 }