path: root/source/apu_blargg.c

/***********************************************************************************
  Snes9x - Portable Super Nintendo Entertainment System (TM) emulator.

  (c) Copyright 1996 - 2002  Gary Henderson (gary.henderson@ntlworld.com),
                             Jerremy Koot (jkoot@snes9x.com)

  (c) Copyright 2002 - 2004  Matthew Kendora

  (c) Copyright 2002 - 2005  Peter Bortas (peter@bortas.org)

  (c) Copyright 2004 - 2005  Joel Yliluoma (http://iki.fi/bisqwit/)

  (c) Copyright 2001 - 2006  John Weidman (jweidman@slip.net)

  (c) Copyright 2002 - 2006  funkyass (funkyass@spam.shaw.ca),
                             Kris Bleakley (codeviolation@hotmail.com)

  (c) Copyright 2002 - 2010  Brad Jorsch (anomie@users.sourceforge.net),
                             Nach (n-a-c-h@users.sourceforge.net),
                             zones (kasumitokoduck@yahoo.com)

  (c) Copyright 2006 - 2007  nitsuja

  (c) Copyright 2009 - 2010  BearOso,
                             OV2


  BS-X C emulator code
  (c) Copyright 2005 - 2006  Dreamer Nom,
                             zones

  C4 x86 assembler and some C emulation code
  (c) Copyright 2000 - 2003  _Demo_ (_demo_@zsnes.com),
                             Nach,
                             zsKnight (zsknight@zsnes.com)

  C4 C++ code
  (c) Copyright 2003 - 2006  Brad Jorsch,
                             Nach

  DSP-1 emulator code
  (c) Copyright 1998 - 2006  _Demo_,
                             Andreas Naive (andreasnaive@gmail.com),
                             Gary Henderson,
                             Ivar (ivar@snes9x.com),
                             John Weidman,
                             Kris Bleakley,
                             Matthew Kendora,
                             Nach,
                             neviksti (neviksti@hotmail.com)

  DSP-2 emulator code
  (c) Copyright 2003         John Weidman,
                             Kris Bleakley,
                             Lord Nightmare (lord_nightmare@users.sourceforge.net),
                             Matthew Kendora,
                             neviksti

  DSP-3 emulator code
  (c) Copyright 2003 - 2006  John Weidman,
                             Kris Bleakley,
                             Lancer,
                             z80 gaiden

  DSP-4 emulator code
  (c) Copyright 2004 - 2006  Dreamer Nom,
                             John Weidman,
                             Kris Bleakley,
                             Nach,
                             z80 gaiden

  OBC1 emulator code
  (c) Copyright 2001 - 2004  zsKnight,
                             pagefault (pagefault@zsnes.com),
                             Kris Bleakley
                             Ported from x86 assembler to C by sanmaiwashi

  SPC7110 and RTC C++ emulator code used in 1.39-1.51
  (c) Copyright 2002         Matthew Kendora with research by
                             zsKnight,
                             John Weidman,
                             Dark Force

  SPC7110 and RTC C++ emulator code used in 1.52+
  (c) Copyright 2009         byuu,
                             neviksti

  S-DD1 C emulator code
  (c) Copyright 2003         Brad Jorsch with research by
                             Andreas Naive,
                             John Weidman

  S-RTC C emulator code
  (c) Copyright 2001 - 2006  byuu,
                             John Weidman

  ST010 C++ emulator code
  (c) Copyright 2003         Feather,
                             John Weidman,
                             Kris Bleakley,
                             Matthew Kendora

  Super FX x86 assembler emulator code
  (c) Copyright 1998 - 2003  _Demo_,
                             pagefault,
                             zsKnight

  Super FX C emulator code
  (c) Copyright 1997 - 1999  Ivar,
                             Gary Henderson,
                             John Weidman

  Sound emulator code used in 1.5-1.51
  (c) Copyright 1998 - 2003  Brad Martin
  (c) Copyright 1998 - 2006  Charles Bilyue'

  Sound emulator code used in 1.52+
  (c) Copyright 2004 - 2007  Shay Green (gblargg@gmail.com)

  SH assembler code partly based on x86 assembler code
  (c) Copyright 2002 - 2004  Marcus Comstedt (marcus@mc.pp.se)

  2xSaI filter
  (c) Copyright 1999 - 2001  Derek Liauw Kie Fa

  HQ2x, HQ3x, HQ4x filters
  (c) Copyright 2003         Maxim Stepin (maxim@hiend3d.com)

  NTSC filter
  (c) Copyright 2006 - 2007  Shay Green

  GTK+ GUI code
  (c) Copyright 2004 - 2010  BearOso

  Win32 GUI code
  (c) Copyright 2003 - 2006  blip,
                             funkyass,
                             Matthew Kendora,
                             Nach,
                             nitsuja
  (c) Copyright 2009 - 2010  OV2

  Mac OS GUI code
  (c) Copyright 1998 - 2001  John Stiles
  (c) Copyright 2001 - 2010  zones


  Specific ports contains the works of other authors. See headers in
  individual files.


  Snes9x homepage: http://www.snes9x.com/

  Permission to use, copy, modify and/or distribute Snes9x in both binary
  and source form, for non-commercial purposes, is hereby granted without
  fee, providing that this license information and copyright notice appear
  with all copies and any derived work.

  This software is provided 'as-is', without any express or implied
  warranty. In no event shall the authors be held liable for any damages
  arising from the use of this software or it's derivatives.

  Snes9x is freeware for PERSONAL USE only. Commercial users should
  seek permission of the copyright holders first. Commercial use includes,
  but is not limited to, charging money for Snes9x or software derived from
  Snes9x, including Snes9x or derivatives in commercial game bundles, and/or
  using Snes9x as a promotion for your commercial product.

  The copyright holders request that bug fixes and improvements to the code
  should be forwarded to them so everyone can benefit from the modifications
  in future versions.

  Super NES and Super Nintendo Entertainment System are trademarks of
  Nintendo Co., Limited and its subsidiary companies.
 ***********************************************************************************/
#ifdef USE_BLARGG_APU

#include <math.h>
#include <string.h>
#include <stddef.h>
#include <stdlib.h>
#include <limits.h>

#ifndef INLINE
#ifdef PSP
#define INLINE __attribute((force_inline))
#else
#define INLINE inline
#endif
#endif

#include "blargg_endian.h"
#include "apu_blargg.h"

#include "snes9x.h"
//#include "snapshot.h"
#include "display.h"


/***********************************************************************************
   SPC DSP
***********************************************************************************/

static dsp_state_t dsp_m;

/* Copyright (C) 2007 Shay Green. This module is free software; you
can redistribute it and/or modify it under the terms of the GNU Lesser
General Public License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version. This
module 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 Lesser General Public License for more
details. You should have received a copy of the GNU Lesser General Public
License along with this module; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */

#if INT_MAX < 0x7FFFFFFF
   #error "Requires that int type have at least 32 bits"
#endif

/* if ( io < -32768 ) io = -32768; */
/* if ( io >  32767 ) io =  32767; */
#define CLAMP16( io )\
{\
   if ( (int16_t) io != io )\
      io = (io >> 31) ^ 0x7FFF;\
}

/* Access global DSP register */
#define REG(n)      dsp_m.regs [R_##n]

/* Access voice DSP register */
#define VREG(r,n)   r [V_##n]

#define WRITE_SAMPLES( l, r, out ) \
{\
   out [0] = l;\
   out [1] = r;\
   out += 2;\
   if ( out >= dsp_m.out_end )\
   {\
      out       = dsp_m.extra;\
      dsp_m.out_end = &dsp_m.extra [EXTRA_SIZE];\
   }\
}\


/* Volume registers and efb are signed! Easy to forget int8_t cast. */
/* Prefixes are to avoid accidental use of locals with same names. */

/* Gaussian interpolation */

static short gauss [512] =
{
   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
   1,   1,   1,   1,   1,   1,   1,   1,   1,   1,   1,   2,   2,   2,   2,   2,
   2,   2,   3,   3,   3,   3,   3,   4,   4,   4,   4,   4,   5,   5,   5,   5,
   6,   6,   6,   6,   7,   7,   7,   8,   8,   8,   9,   9,   9,  10,  10,  10,
  11,  11,  11,  12,  12,  13,  13,  14,  14,  15,  15,  15,  16,  16,  17,  17,
  18,  19,  19,  20,  20,  21,  21,  22,  23,  23,  24,  24,  25,  26,  27,  27,
  28,  29,  29,  30,  31,  32,  32,  33,  34,  35,  36,  36,  37,  38,  39,  40,
  41,  42,  43,  44,  45,  46,  47,  48,  49,  50,  51,  52,  53,  54,  55,  56,
  58,  59,  60,  61,  62,  64,  65,  66,  67,  69,  70,  71,  73,  74,  76,  77,
  78,  80,  81,  83,  84,  86,  87,  89,  90,  92,  94,  95,  97,  99, 100, 102,
 104, 106, 107, 109, 111, 113, 115, 117, 118, 120, 122, 124, 126, 128, 130, 132,
 134, 137, 139, 141, 143, 145, 147, 150, 152, 154, 156, 159, 161, 163, 166, 168,
 171, 173, 175, 178, 180, 183, 186, 188, 191, 193, 196, 199, 201, 204, 207, 210,
 212, 215, 218, 221, 224, 227, 230, 233, 236, 239, 242, 245, 248, 251, 254, 257,
 260, 263, 267, 270, 273, 276, 280, 283, 286, 290, 293, 297, 300, 304, 307, 311,
 314, 318, 321, 325, 328, 332, 336, 339, 343, 347, 351, 354, 358, 362, 366, 370,
 374, 378, 381, 385, 389, 393, 397, 401, 405, 410, 414, 418, 422, 426, 430, 434,
 439, 443, 447, 451, 456, 460, 464, 469, 473, 477, 482, 486, 491, 495, 499, 504,
 508, 513, 517, 522, 527, 531, 536, 540, 545, 550, 554, 559, 563, 568, 573, 577,
 582, 587, 592, 596, 601, 606, 611, 615, 620, 625, 630, 635, 640, 644, 649, 654,
 659, 664, 669, 674, 678, 683, 688, 693, 698, 703, 708, 713, 718, 723, 728, 732,
 737, 742, 747, 752, 757, 762, 767, 772, 777, 782, 787, 792, 797, 802, 806, 811,
 816, 821, 826, 831, 836, 841, 846, 851, 855, 860, 865, 870, 875, 880, 884, 889,
 894, 899, 904, 908, 913, 918, 923, 927, 932, 937, 941, 946, 951, 955, 960, 965,
 969, 974, 978, 983, 988, 992, 997,1001,1005,1010,1014,1019,1023,1027,1032,1036,
1040,1045,1049,1053,1057,1061,1066,1070,1074,1078,1082,1086,1090,1094,1098,1102,
1106,1109,1113,1117,1121,1125,1128,1132,1136,1139,1143,1146,1150,1153,1157,1160,
1164,1167,1170,1174,1177,1180,1183,1186,1190,1193,1196,1199,1202,1205,1207,1210,
1213,1216,1219,1221,1224,1227,1229,1232,1234,1237,1239,1241,1244,1246,1248,1251,
1253,1255,1257,1259,1261,1263,1265,1267,1269,1270,1272,1274,1275,1277,1279,1280,
1282,1283,1284,1286,1287,1288,1290,1291,1292,1293,1294,1295,1296,1297,1297,1298,
1299,1300,1300,1301,1302,1302,1303,1303,1303,1304,1304,1304,1304,1304,1305,1305,
};

/* Gaussian interpolation */

static INLINE int dsp_interpolate( dsp_voice_t *v )
{
   int offset, out, *in;
   short *fwd, *rev;

   /* Make pointers into gaussian based on fractional position between samples */
   offset = v->interp_pos >> 4 & 0xFF;
   fwd = gauss + 255 - offset;
   rev = gauss       + offset; /* mirror left half of gaussian */

   in = &v->buf [(v->interp_pos >> 12) + v->buf_pos];
   out  = (fwd [  0] * in [0]) >> 11;
   out += (fwd [256] * in [1]) >> 11;
   out += (rev [256] * in [2]) >> 11;
   out = (int16_t) out;
   out += (rev [  0] * in [3]) >> 11;

   CLAMP16( out );
   out &= ~1;
   return out;
}

/* Counters */

/* 30720 =  2048 * 5 * 3 */
#define SIMPLE_COUNTER_RANGE 30720

static unsigned const counter_rates [32] =
{
   SIMPLE_COUNTER_RANGE + 1, /* never fires */
          2048, 1536,
   1280, 1024,  768,
    640,  512,  384,
    320,  256,  192,
    160,  128,   96,
     80,   64,   48,
     40,   32,   24,
     20,   16,   12,
     10,    8,    6,
      5,    4,    3,
            2,
            1
};

static unsigned const counter_offsets [32] =
{
     1, 0, 1040,
   536, 0, 1040,
   536, 0, 1040,
   536, 0, 1040,
   536, 0, 1040,
   536, 0, 1040,
   536, 0, 1040,
   536, 0, 1040,
   536, 0, 1040,
   536, 0, 1040,
        0,
        0
};

#define RUN_COUNTERS() \
   if ( --dsp_m.counter < 0 ) \
      dsp_m.counter = SIMPLE_COUNTER_RANGE - 1;

#define READ_COUNTER(rate) (((unsigned) dsp_m.counter + counter_offsets [rate]) % counter_rates [rate])

/* Envelope */

static INLINE void dsp_run_envelope( dsp_voice_t* const v )
{
   int env, rate, env_data;

   env = v->env;
   env_data = v->regs[V_ADSR1];

   if ( dsp_m.t_adsr0 & 0x80 ) /* 99% ADSR */
   {
      if ( v->env_mode >= ENV_DECAY ) /* 99% */
      {
         env--;
         env -= env >> 8;
         rate = env_data & 0x1F;
         if ( v->env_mode == ENV_DECAY ) /* 1% */
            rate = (dsp_m.t_adsr0 >> 3 & 0x0E) + 0x10;
      }
      else /* ENV_ATTACK */
      {
         rate = (dsp_m.t_adsr0 & 0x0F) * 2 + 1;
         env += rate < 31 ? 0x20 : 0x400;
      }
   }
   else /* GAIN */
   {
      int mode;
      env_data = v->regs[V_GAIN];
      mode = env_data >> 5;
      if ( mode < 4 ) /* direct */
      {
         env = env_data * 0x10;
         rate = 31;
      }
      else
      {
         rate = env_data & 0x1F;
         if ( mode == 4 ) /* 4: linear decrease */
         {
            env -= 0x20;
         }
         else if ( mode < 6 ) /* 5: exponential decrease */
         {
            env--;
            env -= env >> 8;
         }
         else /* 6,7: linear increase */
         {
            env += 0x20;
            if ( mode > 6 && (unsigned) v->hidden_env >= 0x600 )
               env += 0x8 - 0x20; /* 7: two-slope linear increase */
         }
      }
   }

   /* Sustain level */
   if ( (env >> 8) == (env_data >> 5) && v->env_mode == ENV_DECAY )
      v->env_mode = ENV_SUSTAIN;

   v->hidden_env = env;

   /* unsigned cast because linear decrease going negative also triggers this */
   if ( (unsigned) env > 0x7FF )
   {
      env = (env < 0 ? 0 : 0x7FF);
      if ( v->env_mode == ENV_ATTACK )
         v->env_mode = ENV_DECAY;
   }

   if (!READ_COUNTER( rate ))
      v->env = env; /* nothing else is controlled by the counter */
}

/* BRR Decoding */

static INLINE void dsp_decode_brr( dsp_voice_t* v )
{
   int nybbles, *pos, *end, header;

   /* Arrange the four input nybbles in 0xABCD order for easy decoding */
   nybbles = dsp_m.t_brr_byte * 0x100 + dsp_m.ram [(v->brr_addr + v->brr_offset + 1) & 0xFFFF];

   header = dsp_m.t_brr_header;

   /* Write to next four samples in circular buffer */
   pos = &v->buf [v->buf_pos];

   if ( (v->buf_pos += 4) >= BRR_BUF_SIZE )
      v->buf_pos = 0;

   /* Decode four samples */
   for ( end = pos + 4; pos < end; pos++, nybbles <<= 4 )
   {
      int filter, p1, p2, s, shift;
      /* Extract nybble and sign-extend */
      s = (int16_t) nybbles >> 12;

      /* Shift sample based on header */
      shift = header >> 4;
      s = (s << shift) >> 1;
      if ( shift >= 0xD ) /* handle invalid range */
         s = (s >> 25) << 11; /* same as: s = (s < 0 ? -0x800 : 0) */

      /* Apply IIR filter (8 is the most commonly used) */
      filter = header & 0x0C;
      p1 = pos [BRR_BUF_SIZE - 1];
      p2 = pos [BRR_BUF_SIZE - 2] >> 1;
      if ( filter >= 8 )
      {
         s += p1;
         s -= p2;
         if ( filter == 8 ) /* s += p1 * 0.953125 - p2 * 0.46875 */
         {
            s += p2 >> 4;
            s += (p1 * -3) >> 6;
         }
         else /* s += p1 * 0.8984375 - p2 * 0.40625 */
         {
            s += (p1 * -13) >> 7;
            s += (p2 * 3) >> 4;
         }
      }
      else if ( filter ) /* s += p1 * 0.46875 */
      {
         s += p1 >> 1;
         s += (-p1) >> 5;
      }

      /* Adjust and write sample */
      CLAMP16( s );
      s = (int16_t) (s * 2);
      pos [BRR_BUF_SIZE] = pos [0] = s; /* second copy simplifies wrap-around */
   }
}

/* Misc */

/* voice 0 doesn't support PMON */

#define MISC_27() dsp_m.t_pmon = dsp_m.regs[R_PMON] & 0xFE;

#define MISC_28() \
   dsp_m.t_non = dsp_m.regs[R_NON]; \
   dsp_m.t_eon = dsp_m.regs[R_EON]; \
   dsp_m.t_dir = dsp_m.regs[R_DIR];

#define MISC_29() \
   if ( (dsp_m.every_other_sample ^= 1) != 0 ) \
      dsp_m.new_kon &= ~dsp_m.kon; /* clears KON 63 clocks after it was last read */

static INLINE void dsp_misc_30 (void)
{
   if ( dsp_m.every_other_sample )
   {
      dsp_m.kon    = dsp_m.new_kon;
      dsp_m.t_koff = dsp_m.regs[R_KOFF];
   }

   RUN_COUNTERS();

   /* Noise */
   if ( !READ_COUNTER( dsp_m.regs[R_FLG] & 0x1F ) )
   {
      int feedback = (dsp_m.noise << 13) ^ (dsp_m.noise << 14);
      dsp_m.noise = (feedback & 0x4000) ^ (dsp_m.noise >> 1);
   }
}

/* Voices */

static INLINE void dsp_voice_V1( dsp_voice_t* const v )
{
   dsp_m.t_dir_addr = dsp_m.t_dir * 0x100 + dsp_m.t_srcn * 4;
   dsp_m.t_srcn = v->regs[V_SRCN];
}

static INLINE void dsp_voice_V2( dsp_voice_t* const v )
{
   uint8_t *entry;

   entry = &dsp_m.ram [dsp_m.t_dir_addr];
   if ( !v->kon_delay )
      entry += 2;

   dsp_m.t_brr_next_addr = GET_LE16( entry );

   dsp_m.t_adsr0 = v->regs [V_ADSR0];


   dsp_m.t_pitch = v->regs [V_PITCHL];
}

static INLINE void dsp_voice_V3a( dsp_voice_t* const v )
{
   dsp_m.t_pitch += (v->regs [V_PITCHH] & 0x3F) << 8;
}

static INLINE void dsp_voice_V3b( dsp_voice_t* const v )
{
   dsp_m.t_brr_byte = dsp_m.ram [(v->brr_addr + v->brr_offset) & 0xffff];
   dsp_m.t_brr_header = dsp_m.ram [v->brr_addr];
}

static void dsp_voice_V3c( dsp_voice_t* const v )
{
   int output;

   /* Pitch modulation using previous voice's output */
   if ( dsp_m.t_pmon & v->vbit )
      dsp_m.t_pitch += ((dsp_m.t_output >> 5) * dsp_m.t_pitch) >> 10;

   if ( v->kon_delay )
   {
      /* Get ready to start BRR decoding on next sample */
      if ( v->kon_delay == 5 )
      {
         v->brr_addr    = dsp_m.t_brr_next_addr;
         v->brr_offset  = 1;
         v->buf_pos     = 0;
         dsp_m.t_brr_header = 0; /* header is ignored on this sample */
      }

      /* Envelope is never run during KON */
      v->env        = 0;
      v->hidden_env = 0;

      /* Disable BRR decoding until last three samples */
      v->interp_pos = 0;
      if ( --v->kon_delay & 3 )
         v->interp_pos = 0x4000;

      /* Pitch is never added during KON */
      dsp_m.t_pitch = 0;
   }

   output = dsp_interpolate( v );

   /* Noise */
   if ( dsp_m.t_non & v->vbit )
      output = (int16_t) (dsp_m.noise * 2);

   /* Apply envelope */
   dsp_m.t_output = (output * v->env) >> 11 & ~1;
   v->t_envx_out = (uint8_t) (v->env >> 4);

   /* Immediate silence due to end of sample or soft reset */
   if ( dsp_m.regs[R_FLG] & 0x80 || (dsp_m.t_brr_header & 3) == 1 )
   {
      v->env_mode = ENV_RELEASE;
      v->env      = 0;
   }

   if ( dsp_m.every_other_sample )
   {
      /* KOFF */
      if ( dsp_m.t_koff & v->vbit )
         v->env_mode = ENV_RELEASE;

      /* KON */
      if ( dsp_m.kon & v->vbit )
      {
         v->kon_delay = 5;
         v->env_mode  = ENV_ATTACK;
      }
   }

   /* Run envelope for next sample */
   if ( !v->kon_delay )
   {
      int env = v->env;
      if ( v->env_mode == ENV_RELEASE ) /* 60% */
      {
         if ( (env -= 0x8) < 0 )
            env = 0;
         v->env = env;
      }
      else
      {
         dsp_run_envelope( v );
      }
   }
}

static INLINE void dsp_voice_output( dsp_voice_t const* v, int ch )
{
   int amp;

   /* Apply left/right volume */
   amp = (dsp_m.t_output * (int8_t) VREG(v->regs,VOLL + ch)) >> 7;

   /* Add to output total */
   dsp_m.t_main_out [ch] += amp;
   CLAMP16( dsp_m.t_main_out [ch] );

   /* Optionally add to echo total */
   if ( dsp_m.t_eon & v->vbit )
   {
      dsp_m.t_echo_out [ch] += amp;
      CLAMP16( dsp_m.t_echo_out [ch] );
   }
}

static INLINE void dsp_voice_V4( dsp_voice_t* const v )
{
   /* Decode BRR */
   dsp_m.t_looped = 0;
   if ( v->interp_pos >= 0x4000 )
   {
      dsp_decode_brr( v );

      if ( (v->brr_offset += 2) >= BRR_BLOCK_SIZE )
      {
         /* Start decoding next BRR block */
         v->brr_addr = (v->brr_addr + BRR_BLOCK_SIZE) & 0xFFFF;
         if ( dsp_m.t_brr_header & 1 )
         {
            v->brr_addr = dsp_m.t_brr_next_addr;
            dsp_m.t_looped = v->vbit;
         }
         v->brr_offset = 1;
      }
   }

   /* Apply pitch */
   v->interp_pos = (v->interp_pos & 0x3FFF) + dsp_m.t_pitch;

   /* Keep from getting too far ahead (when using pitch modulation) */
   if ( v->interp_pos > 0x7FFF )
      v->interp_pos = 0x7FFF;

   /* Output left */
   dsp_voice_output( v, 0 );
}

static INLINE void dsp_voice_V5( dsp_voice_t* const v )
{
   int endx_buf;
   /* Output right */
   dsp_voice_output( v, 1 );

   /* ENDX, OUTX, and ENVX won't update if you wrote to them 1-2 clocks earlier */
   endx_buf = dsp_m.regs[R_ENDX] | dsp_m.t_looped;

   /* Clear bit in ENDX if KON just began */
   if ( v->kon_delay == 5 )
      endx_buf &= ~v->vbit;
   dsp_m.endx_buf = (uint8_t) endx_buf;
}

static INLINE void dsp_voice_V6( dsp_voice_t* const v )
{
   (void) v; /* avoid compiler warning about unused v */
   dsp_m.outx_buf = (uint8_t) (dsp_m.t_output >> 8);
}

static INLINE void dsp_voice_V7( dsp_voice_t* const v )
{
   /* Update ENDX */
   dsp_m.regs[R_ENDX] = dsp_m.endx_buf;

   dsp_m.envx_buf = v->t_envx_out;
}

static INLINE void dsp_voice_V8( dsp_voice_t* const v )
{
   /* Update OUTX */
   v->regs [V_OUTX] = dsp_m.outx_buf;
}

static INLINE void dsp_voice_V9( dsp_voice_t* const v )
{
   v->regs [V_ENVX] = dsp_m.envx_buf;
}

/* Most voices do all these in one clock, so make a handy composite */

static INLINE void dsp_voice_V3( dsp_voice_t* const v )
{
   dsp_voice_V3a( v );
   dsp_voice_V3b( v );
   dsp_voice_V3c( v );
}

/* Common combinations of voice steps on different voices. This greatly reduces
   code size and allows everything to be inlined in these functions. */

static void dsp_voice_V7_V4_V1( dsp_voice_t* const v )
{
   dsp_voice_V7(v);
   dsp_voice_V1(v+3);
   dsp_voice_V4(v+1);
}

static void dsp_voice_V8_V5_V2( dsp_voice_t* const v )
{
   dsp_voice_V8(v);
   dsp_voice_V5(v+1);
   dsp_voice_V2(v+2);
}

static void dsp_voice_V9_V6_V3( dsp_voice_t* const v )
{
   dsp_voice_V9(v);
   dsp_voice_V6(v+1);
   dsp_voice_V3(v+2);
}

/* Echo */

/* Current echo buffer pointer for left/right channel */
#define ECHO_PTR( ch )      (&dsp_m.ram [dsp_m.t_echo_ptr + ch * 2])

/* Sample in echo history buffer, where 0 is the oldest */
#define ECHO_FIR( i )       (dsp_m.echo_hist_pos [i])

/* Calculate FIR point for left/right channel */
#define CALC_FIR( i, ch )   ((ECHO_FIR( i + 1 ) [ch] * (int8_t) REG(FIR + i * 0x10)) >> 6)

#define ECHO_READ(ch) \
{ \
   int s; \
   if ( dsp_m.t_echo_ptr >= 0xffc0 && dsp_m.rom_enabled ) \
      s = GET_LE16SA( &dsp_m.hi_ram [dsp_m.t_echo_ptr + ch * 2 - 0xffc0] ); \
   else \
      s = GET_LE16SA( ECHO_PTR( ch ) ); \
   /* second copy simplifies wrap-around handling */ \
   ECHO_FIR( 0 ) [ch] = ECHO_FIR( 8 ) [ch] = s >> 1; \
}

static INLINE void dsp_echo_22 (void)
{
   int l, r;

   if ( ++dsp_m.echo_hist_pos >= &dsp_m.echo_hist [ECHO_HIST_SIZE] )
      dsp_m.echo_hist_pos = dsp_m.echo_hist;

   dsp_m.t_echo_ptr = (dsp_m.t_esa * 0x100 + dsp_m.echo_offset) & 0xFFFF;

   ECHO_READ(0);

   l = (((dsp_m.echo_hist_pos [0 + 1]) [0] * (int8_t) dsp_m.regs [R_FIR + 0 * 0x10]) >> 6);
   r = (((dsp_m.echo_hist_pos [0 + 1]) [1] * (int8_t) dsp_m.regs [R_FIR + 0 * 0x10]) >> 6);

   dsp_m.t_echo_in [0] = l;
   dsp_m.t_echo_in [1] = r;
}

static INLINE void dsp_echo_23 (void)
{
   int l, r;

   l = (((dsp_m.echo_hist_pos [1 + 1]) [0] * (int8_t) dsp_m.regs [R_FIR + 1 * 0x10]) >> 6) + (((dsp_m.echo_hist_pos [2 + 1]) [0] * (int8_t) dsp_m.regs [R_FIR + 2 * 0x10]) >> 6);
   r = (((dsp_m.echo_hist_pos [1 + 1]) [1] * (int8_t) dsp_m.regs [R_FIR + 1 * 0x10]) >> 6) + (((dsp_m.echo_hist_pos [2 + 1]) [1] * (int8_t) dsp_m.regs [R_FIR + 2 * 0x10]) >> 6);

   dsp_m.t_echo_in [0] += l;
   dsp_m.t_echo_in [1] += r;

   ECHO_READ(1);
}

static INLINE void dsp_echo_24 (void)
{
   int l, r;

   l = (((dsp_m.echo_hist_pos [3 + 1]) [0] * (int8_t) dsp_m.regs [R_FIR + 3 * 0x10]) >> 6) + (((dsp_m.echo_hist_pos [4 + 1]) [0] * (int8_t) dsp_m.regs [R_FIR + 4 * 0x10]) >> 6) + (((dsp_m.echo_hist_pos [5 + 1]) [0] * (int8_t) dsp_m.regs [R_FIR + 5 * 0x10]) >> 6);
   r = (((dsp_m.echo_hist_pos [3 + 1]) [1] * (int8_t) dsp_m.regs [R_FIR + 3 * 0x10]) >> 6) + (((dsp_m.echo_hist_pos [4 + 1]) [1] * (int8_t) dsp_m.regs [R_FIR + 4 * 0x10]) >> 6) + (((dsp_m.echo_hist_pos [5 + 1]) [1] * (int8_t) dsp_m.regs [R_FIR + 5 * 0x10]) >> 6);

   dsp_m.t_echo_in [0] += l;
   dsp_m.t_echo_in [1] += r;
}

static INLINE void dsp_echo_25 (void)
{
   int l = dsp_m.t_echo_in [0] + (((dsp_m.echo_hist_pos [6 + 1]) [0] * (int8_t) dsp_m.regs [R_FIR + 6 * 0x10]) >> 6);
   int r = dsp_m.t_echo_in [1] + (((dsp_m.echo_hist_pos [6 + 1]) [1] * (int8_t) dsp_m.regs [R_FIR + 6 * 0x10]) >> 6);

   l = (int16_t) l;
   r = (int16_t) r;

   l += (int16_t) (((dsp_m.echo_hist_pos [7 + 1]) [0] * (int8_t) dsp_m.regs [R_FIR + 7 * 0x10]) >> 6);
   r += (int16_t) (((dsp_m.echo_hist_pos [7 + 1]) [1] * (int8_t) dsp_m.regs [R_FIR + 7 * 0x10]) >> 6);

   if ( (int16_t) l != l )
      l = (l >> 31) ^ 0x7FFF;
   if ( (int16_t) r != r )
      r = (r >> 31) ^ 0x7FFF;

   dsp_m.t_echo_in [0] = l & ~1;
   dsp_m.t_echo_in [1] = r & ~1;
}

#define ECHO_OUTPUT(var, ch) \
{ \
   var = (int16_t) ((dsp_m.t_main_out [ch] * (int8_t) REG(MVOLL + ch * 0x10)) >> 7) + (int16_t) ((dsp_m.t_echo_in [ch] * (int8_t) REG(EVOLL + ch * 0x10)) >> 7); \
   CLAMP16( var ); \
}

static INLINE void dsp_echo_26 (void)
{
   int l, r;

   ECHO_OUTPUT(dsp_m.t_main_out[0], 0 );

   l = dsp_m.t_echo_out [0] + (int16_t) ((dsp_m.t_echo_in [0] * (int8_t) dsp_m.regs [R_EFB]) >> 7);
   r = dsp_m.t_echo_out [1] + (int16_t) ((dsp_m.t_echo_in [1] * (int8_t) dsp_m.regs [R_EFB]) >> 7);

   if ( (int16_t) l != l ) l = (l >> 31) ^ 0x7FFF;
   if ( (int16_t) r != r ) r = (r >> 31) ^ 0x7FFF;

   dsp_m.t_echo_out [0] = l & ~1;
   dsp_m.t_echo_out [1] = r & ~1;
}

static INLINE void dsp_echo_27 (void)
{
   int l, r;
   short *out;

   l = dsp_m.t_main_out [0];
   ECHO_OUTPUT(r, 1);
   dsp_m.t_main_out [0] = 0;
   dsp_m.t_main_out [1] = 0;

   if ( dsp_m.regs [R_FLG] & 0x40 )
   {
      l = 0;
      r = 0;
   }

   out = dsp_m.out;
   out [0] = l;
   out [1] = r;
   out += 2;
   if ( out >= dsp_m.out_end )
   {
      out = dsp_m.extra;
      dsp_m.out_end = &dsp_m.extra [EXTRA_SIZE];
   }
   dsp_m.out = out;
}

#define ECHO_28() dsp_m.t_echo_enabled = dsp_m.regs [R_FLG];

#define ECHO_WRITE(ch) \
   if ( !(dsp_m.t_echo_enabled & 0x20) ) \
   { \
      SET_LE16A( ECHO_PTR( ch ), dsp_m.t_echo_out [ch] ); \
      if ( dsp_m.t_echo_ptr >= 0xffc0 ) \
      { \
         SET_LE16A( &dsp_m.hi_ram [dsp_m.t_echo_ptr + ch * 2 - 0xffc0], dsp_m.t_echo_out [ch] ); \
         if ( dsp_m.rom_enabled ) \
            SET_LE16A( ECHO_PTR( ch ), GET_LE16A( &dsp_m.rom [dsp_m.t_echo_ptr + ch * 2 - 0xffc0] ) ); \
      } \
   } \
   dsp_m.t_echo_out [ch] = 0;

static INLINE void dsp_echo_29 (void)
{
   dsp_m.t_esa = dsp_m.regs [R_ESA];

   if ( !dsp_m.echo_offset )
      dsp_m.echo_length = (dsp_m.regs [R_EDL] & 0x0F) * 0x800;

   dsp_m.echo_offset += 4;
   if ( dsp_m.echo_offset >= dsp_m.echo_length )
      dsp_m.echo_offset = 0;


   ECHO_WRITE(0);

   dsp_m.t_echo_enabled = dsp_m.regs [R_FLG];
}

/* Timing */

/* Execute clock for a particular voice */

/* The most common sequence of clocks uses composite operations
for efficiency. For example, the following are equivalent to the
individual steps on the right:

V(V7_V4_V1,2) -> V(V7,2) V(V4,3) V(V1,5)
V(V8_V5_V2,2) -> V(V8,2) V(V5,3) V(V2,4)
V(V9_V6_V3,2) -> V(V9,2) V(V6,3) V(V3,4) */

/* Voice      0      1      2      3      4      5      6      7 */

/* Runs DSP for specified number of clocks (~1024000 per second). Every 32 clocks
   a pair of samples is be generated. */

static void dsp_run( int clocks_remain )
{
   int phase;

   phase = dsp_m.phase;
   dsp_m.phase = (phase + clocks_remain) & 31;

   switch ( phase )
   {
loop:
      if ( 0 && !--clocks_remain )
         break;
      case 0:
      dsp_voice_V5( &dsp_m.voices [0] );
      dsp_voice_V2( &dsp_m.voices [1] );
      if ( 1 && !--clocks_remain )
         break;
      case 1:
      dsp_voice_V6( &dsp_m.voices [0] );
      dsp_voice_V3( &dsp_m.voices [1] );
      if ( 2 && !--clocks_remain )
         break;
      case 2:
      dsp_voice_V7_V4_V1( &dsp_m.voices [0] );
      if ( 3 && !--clocks_remain )
         break;
      case 3:
      dsp_voice_V8_V5_V2( &dsp_m.voices [0] );
      if ( 4 && !--clocks_remain )
         break;
      case 4:
      dsp_voice_V9_V6_V3( &dsp_m.voices [0] );
      if ( 5 && !--clocks_remain )
         break;
      case 5:
      dsp_voice_V7_V4_V1( &dsp_m.voices [1] );
      if ( 6 && !--clocks_remain )
         break;
      case 6:
      dsp_voice_V8_V5_V2( &dsp_m.voices [1] );
      if ( 7 && !--clocks_remain )
         break;
      case 7:
      dsp_voice_V9_V6_V3( &dsp_m.voices [1] );
      if ( 8 && !--clocks_remain )
         break;
      case 8:
      dsp_voice_V7_V4_V1( &dsp_m.voices [2] );
      if ( 9 && !--clocks_remain )
         break;
      case 9:
      dsp_voice_V8_V5_V2( &dsp_m.voices [2] );
      if ( 10 && !--clocks_remain )
         break;
      case 10:
      dsp_voice_V9_V6_V3( &dsp_m.voices [2] );
      if ( 11 && !--clocks_remain )
         break;
      case 11:
      dsp_voice_V7_V4_V1( &dsp_m.voices [3] );
      if ( 12 && !--clocks_remain )
         break;
      case 12:
      dsp_voice_V8_V5_V2( &dsp_m.voices [3] );
      if ( 13 && !--clocks_remain )
         break;
      case 13:
      dsp_voice_V9_V6_V3( &dsp_m.voices [3] );
      if ( 14 && !--clocks_remain )
         break;
      case 14:
      dsp_voice_V7_V4_V1( &dsp_m.voices [4] );
      if ( 15 && !--clocks_remain )
         break;
      case 15:
      dsp_voice_V8_V5_V2( &dsp_m.voices [4] );
      if ( 16 && !--clocks_remain )
         break;
      case 16:
      dsp_voice_V9_V6_V3( &dsp_m.voices [4] );
      if ( 17 && !--clocks_remain )
         break;
      case 17:
      dsp_voice_V1( &dsp_m.voices [0] );
      dsp_voice_V7( &dsp_m.voices [5] );
      dsp_voice_V4( &dsp_m.voices [6] );
      if ( 18 && !--clocks_remain )
         break;
      case 18:
      dsp_voice_V8_V5_V2( &dsp_m.voices [5] );
      if ( 19 && !--clocks_remain )
         break;
      case 19:
      dsp_voice_V9_V6_V3( &dsp_m.voices [5] );
      if ( 20 && !--clocks_remain )
         break;
      case 20:
      dsp_voice_V1( &dsp_m.voices [1] );
      dsp_voice_V7( &dsp_m.voices [6] );
      dsp_voice_V4( &dsp_m.voices [7] );
      if ( 21 && !--clocks_remain )
         break;
      case 21:
      dsp_voice_V8( &dsp_m.voices [6] );
      dsp_voice_V5( &dsp_m.voices [7] );
      dsp_voice_V2( &dsp_m.voices [0] );
      if ( 22 && !--clocks_remain )
         break;
      case 22:
      dsp_voice_V3a( &dsp_m.voices [0] );
      dsp_voice_V9( &dsp_m.voices [6] );
      dsp_voice_V6( &dsp_m.voices [7] );
      dsp_echo_22();
      if ( 23 && !--clocks_remain )
         break;
      case 23:
      dsp_voice_V7( &dsp_m.voices [7] );
      dsp_echo_23();
      if ( 24 && !--clocks_remain )
         break;
      case 24:
      dsp_voice_V8( &dsp_m.voices [7] );
      dsp_echo_24();
      if ( 25 && !--clocks_remain )
         break;
      case 25:
      dsp_voice_V3b( &dsp_m.voices [0] );
      dsp_voice_V9( &dsp_m.voices [7] );
      dsp_echo_25();
      if ( 26 && !--clocks_remain )
         break;
      case 26:
      dsp_echo_26();
      if ( 27 && !--clocks_remain )
         break;
      case 27:
      MISC_27();
      dsp_echo_27();
      if ( 28 && !--clocks_remain )
         break;
      case 28:
      MISC_28();
      ECHO_28();
      if ( 29 && !--clocks_remain )
         break;
      case 29:
      MISC_29();
      dsp_echo_29();
      if ( 30 && !--clocks_remain )
         break;
      case 30:
      dsp_misc_30();
      dsp_voice_V3c( &dsp_m.voices [0] );
      ECHO_WRITE(1);
      if ( 31 && !--clocks_remain )
         break;
      case 31:
      dsp_voice_V4( &dsp_m.voices [0] );
      dsp_voice_V1( &dsp_m.voices [2] );

      if ( --clocks_remain )
         goto loop;
   }
}

/* Sets destination for output samples. If out is NULL or out_size is 0,
   doesn't generate any. */

static void dsp_set_output( short * out, int size )
{
   if ( !out )
   {
      out  = dsp_m.extra;
      size = EXTRA_SIZE;
   }
   dsp_m.out_begin = out;
   dsp_m.out       = out;
   dsp_m.out_end   = out + size;
}

/* Setup */

static void dsp_soft_reset_common (void)
{
   dsp_m.noise              = 0x4000;
   dsp_m.echo_hist_pos      = dsp_m.echo_hist;
   dsp_m.every_other_sample = 1;
   dsp_m.echo_offset        = 0;
   dsp_m.phase              = 0;

   dsp_m.counter = 0;
}

/* Resets DSP to power-on state */

static void dsp_reset (void)
{
   int i;

   uint8_t const initial_regs [REGISTER_COUNT] =
   {
      0x45,0x8B,0x5A,0x9A,0xE4,0x82,0x1B,0x78,0x00,0x00,0xAA,0x96,0x89,0x0E,0xE0,0x80,
      0x2A,0x49,0x3D,0xBA,0x14,0xA0,0xAC,0xC5,0x00,0x00,0x51,0xBB,0x9C,0x4E,0x7B,0xFF,
      0xF4,0xFD,0x57,0x32,0x37,0xD9,0x42,0x22,0x00,0x00,0x5B,0x3C,0x9F,0x1B,0x87,0x9A,
      0x6F,0x27,0xAF,0x7B,0xE5,0x68,0x0A,0xD9,0x00,0x00,0x9A,0xC5,0x9C,0x4E,0x7B,0xFF,
      0xEA,0x21,0x78,0x4F,0xDD,0xED,0x24,0x14,0x00,0x00,0x77,0xB1,0xD1,0x36,0xC1,0x67,
      0x52,0x57,0x46,0x3D,0x59,0xF4,0x87,0xA4,0x00,0x00,0x7E,0x44,0x00,0x4E,0x7B,0xFF,
      0x75,0xF5,0x06,0x97,0x10,0xC3,0x24,0xBB,0x00,0x00,0x7B,0x7A,0xE0,0x60,0x12,0x0F,
      0xF7,0x74,0x1C,0xE5,0x39,0x3D,0x73,0xC1,0x00,0x00,0x7A,0xB3,0xFF,0x4E,0x7B,0xFF
   };

   /* Resets DSP and uses supplied values to initialize registers */

   for (i = 0; i < REGISTER_COUNT; i++)
      dsp_m.regs[i] = initial_regs[i];

   /* Internal state */
   for ( i = VOICE_COUNT; --i >= 0; )
   {
      dsp_voice_t* v = &dsp_m.voices [i];
      v->brr_offset = 1;
      v->vbit       = 1 << i;
      v->regs       = &dsp_m.regs [i * 0x10];
   }
   dsp_m.new_kon = dsp_m.regs[R_KON];
   dsp_m.t_dir   = dsp_m.regs[R_DIR];
   dsp_m.t_esa   = dsp_m.regs[R_ESA];

   dsp_soft_reset_common();
}

/* Initializes DSP and has it use the 64K RAM provided */

static void dsp_init( void* ram_64k )
{
   dsp_m.ram = (uint8_t*) ram_64k;
   dsp_set_output( 0, 0 );
   dsp_reset();
}

/* Emulates pressing reset switch on SNES */

static void dsp_soft_reset (void)
{
   dsp_m.regs[R_FLG] = 0xE0;
   dsp_soft_reset_common();
}


/* State save/load */

#if !SPC_NO_COPY_STATE_FUNCS

static void spc_copier_copy(spc_state_copy_t * copier, void* state, size_t size )
{
   copier->func(copier->buf, state, size );
}

static int spc_copier_copy_int(spc_state_copy_t * copier, int state, int size )
{
   uint8_t s [2];
   SET_LE16( s, state );
   copier->func(copier->buf, &s, size );
   return GET_LE16( s );
}

static void spc_copier_extra(spc_state_copy_t * copier)
{
   int n = 0;
   n = (uint8_t) spc_copier_copy_int(copier, n, sizeof (uint8_t) );

   if ( n > 0 )
   {
      char temp [64];
      memset( temp, 0, sizeof(temp));
      do
      {
         int size_n = sizeof(temp);
         if ( size_n > n )
            size_n = n;
         n -= size_n;
         copier->func(copier->buf, temp, size_n );
      }
      while ( n );
   }
}

/* Saves/loads exact emulator state */

static void dsp_copy_state( unsigned char** io, dsp_copy_func_t copy )
{
   int i, j;

   spc_state_copy_t copier;
   copier.func = copy;
   copier.buf = io;

   /* DSP registers */
   spc_copier_copy(&copier, dsp_m.regs, REGISTER_COUNT );

   /* Internal state */

   /* Voices */
   for ( i = 0; i < VOICE_COUNT; i++ )
   {
      dsp_voice_t* v;

      v = &dsp_m.voices [i];

      /* BRR buffer */
      for ( j = 0; j < BRR_BUF_SIZE; j++ )
      {
         int s;

         s = v->buf [j];
         SPC_COPY(  int16_t, s );
         v->buf [j] = v->buf [j + BRR_BUF_SIZE] = s;
      }

      SPC_COPY( uint16_t, v->interp_pos );
      SPC_COPY( uint16_t, v->brr_addr );
      SPC_COPY( uint16_t, v->env );
      SPC_COPY(  int16_t, v->hidden_env );
      SPC_COPY(  uint8_t, v->buf_pos );
      SPC_COPY(  uint8_t, v->brr_offset );
      SPC_COPY(  uint8_t, v->kon_delay );
      {
         int m;

         m = v->env_mode;
         SPC_COPY(  uint8_t, m );
         v->env_mode = m;
      }
      SPC_COPY(  uint8_t, v->t_envx_out );

      spc_copier_extra(&copier);
   }

   /* Echo history */
   for ( i = 0; i < ECHO_HIST_SIZE; i++ )
   {
      int s, s2;

      s = dsp_m.echo_hist_pos [i] [0];
      s2 = dsp_m.echo_hist_pos [i] [1];

      SPC_COPY( int16_t, s );
      dsp_m.echo_hist [i] [0] = s; /* write back at offset 0 */

      SPC_COPY( int16_t, s2 );
      dsp_m.echo_hist [i] [1] = s2; /* write back at offset 0 */
   }
   dsp_m.echo_hist_pos = dsp_m.echo_hist;
   memcpy( &dsp_m.echo_hist [ECHO_HIST_SIZE], dsp_m.echo_hist, ECHO_HIST_SIZE * sizeof dsp_m.echo_hist [0] );

   /* Misc */
   SPC_COPY(  uint8_t, dsp_m.every_other_sample );
   SPC_COPY(  uint8_t, dsp_m.kon );

   SPC_COPY( uint16_t, dsp_m.noise );
   SPC_COPY( uint16_t, dsp_m.counter );
   SPC_COPY( uint16_t, dsp_m.echo_offset );
   SPC_COPY( uint16_t, dsp_m.echo_length );
   SPC_COPY(  uint8_t, dsp_m.phase );

   SPC_COPY(  uint8_t, dsp_m.new_kon );
   SPC_COPY(  uint8_t, dsp_m.endx_buf );
   SPC_COPY(  uint8_t, dsp_m.envx_buf );
   SPC_COPY(  uint8_t, dsp_m.outx_buf );

   SPC_COPY(  uint8_t, dsp_m.t_pmon );
   SPC_COPY(  uint8_t, dsp_m.t_non );
   SPC_COPY(  uint8_t, dsp_m.t_eon );
   SPC_COPY(  uint8_t, dsp_m.t_dir );
   SPC_COPY(  uint8_t, dsp_m.t_koff );

   SPC_COPY( uint16_t, dsp_m.t_brr_next_addr );
   SPC_COPY(  uint8_t, dsp_m.t_adsr0 );
   SPC_COPY(  uint8_t, dsp_m.t_brr_header );
   SPC_COPY(  uint8_t, dsp_m.t_brr_byte );
   SPC_COPY(  uint8_t, dsp_m.t_srcn );
   SPC_COPY(  uint8_t, dsp_m.t_esa );
   SPC_COPY(  uint8_t, dsp_m.t_echo_enabled );

   SPC_COPY(  int16_t, dsp_m.t_main_out [0] );
   SPC_COPY(  int16_t, dsp_m.t_main_out [1] );
   SPC_COPY(  int16_t, dsp_m.t_echo_out [0] );
   SPC_COPY(  int16_t, dsp_m.t_echo_out [1] );
   SPC_COPY(  int16_t, dsp_m.t_echo_in  [0] );
   SPC_COPY(  int16_t, dsp_m.t_echo_in  [1] );

   SPC_COPY( uint16_t, dsp_m.t_dir_addr );
   SPC_COPY( uint16_t, dsp_m.t_pitch );
   SPC_COPY(  int16_t, dsp_m.t_output );
   SPC_COPY( uint16_t, dsp_m.t_echo_ptr );
   SPC_COPY(  uint8_t, dsp_m.t_looped );

   spc_copier_extra(&copier);
}
#endif

/* Core SPC emulation: CPU, timers, SMP registers, memory */

/* snes_spc 0.9.0. http://www.slack.net/~ant/ */

/***********************************************************************************
   SNES SPC
***********************************************************************************/

static spc_state_t m;
static signed char reg_times [256];
static bool allow_time_overflow;

/* Copyright (C) 2004-2007 Shay Green. This module is free software; you
can redistribute it and/or modify it under the terms of the GNU Lesser
General Public License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version. This
module 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 Lesser General Public License for more
details. You should have received a copy of the GNU Lesser General Public
License along with this module; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */

/* (n ? n : 256) */
#define IF_0_THEN_256( n ) ((uint8_t) ((n) - 1) + 1)

/* Timers */

#define TIMER_DIV( t, n ) ((n) >> t->prescaler)
#define TIMER_MUL( t, n ) ((n) << t->prescaler)

static Timer* spc_run_timer_( Timer* t, int time )
{
   int elapsed;

   elapsed = TIMER_DIV( t, time - t->next_time ) + 1;
   t->next_time += TIMER_MUL( t, elapsed );

   if ( t->enabled )
   {
      int remain, divider, over, n;

      remain = IF_0_THEN_256( t->period - t->divider );
      divider = t->divider + elapsed;
      over = elapsed - remain;
      if ( over >= 0 )
      {
         n = over / t->period;
         t->counter = (t->counter + 1 + n) & 0x0F;
         divider = over - n * t->period;
      }
      t->divider = (uint8_t) divider;
   }
   return t;
}

/* ROM */

void spc_enable_rom( int enable )
{
   if ( m.rom_enabled != enable )
   {
      m.rom_enabled = dsp_m.rom_enabled = enable;
      if ( enable )
         memcpy( m.hi_ram, &m.ram.ram[ROM_ADDR], sizeof m.hi_ram );
      memcpy( &m.ram.ram[ROM_ADDR], (enable ? m.rom : m.hi_ram), ROM_SIZE );
      /* TODO: ROM can still get overwritten when DSP writes to echo buffer */
   }
}


/* DSP */

#define MAX_REG_TIME 29

#define RUN_DSP( time, offset ) \
   int count = (time) - (offset) - m.dsp_time; \
   if ( count >= 0 ) \
   { \
      int clock_count; \
      clock_count = (count & ~(CLOCKS_PER_SAMPLE - 1)) + CLOCKS_PER_SAMPLE; \
      m.dsp_time += clock_count; \
      dsp_run( clock_count ); \
   }

static INLINE void spc_dsp_write( int data, int time )
{
   int addr;

   /* Writes DSP registers. */
   addr = m.smp_regs[0][R_DSPADDR];
   dsp_m.regs [addr] = (uint8_t) data;
   switch ( addr & 0x0F )
   {
      case V_ENVX:
         dsp_m.envx_buf = (uint8_t) data;
         break;

      case V_OUTX:
         dsp_m.outx_buf = (uint8_t) data;
         break;
      case 0x0C:
         if ( addr == R_KON )
            dsp_m.new_kon = (uint8_t) data;

         if ( addr == R_ENDX ) /* always cleared, regardless of data written */
         {
            dsp_m.endx_buf = 0;
            dsp_m.regs [R_ENDX] = 0;
         }
         break;
   }
   /* dprintf( "SPC wrote to DSP register > $7F\n" ); */
}


/* Memory access extras */

/* CPU write */

/* divided into multiple functions to keep rarely-used functionality separate
   so often-used functionality can be optimized better by compiler */

/* If write isn't preceded by read, data has this added to it
   int const no_read_before_write = 0x2000; */

#define NO_READ_BEFORE_WRITE			8192
#define NO_READ_BEFORE_WRITE_DIVIDED_BY_TWO	4096

static void spc_cpu_write_smp_reg_( int data, int time, int addr )
{
   switch ( addr )
   {
      case R_T0TARGET:
      case R_T1TARGET:
      case R_T2TARGET:
         {
            int period;
            Timer *t;

            t = &m.timers [addr - R_T0TARGET];
            period = IF_0_THEN_256( data );

            if ( t->period != period )
            {
               if ( time >= t->next_time )
                  t = spc_run_timer_( t, time );
               t->period = period;
            }
            break;
         }
      case R_T0OUT:
      case R_T1OUT:
      case R_T2OUT:
             /* dprintf( "SPC wrote to counter %d\n", (int) addr - R_T0OUT ); */

             if ( data < NO_READ_BEFORE_WRITE_DIVIDED_BY_TWO)
             {
                if ( (time - 1) >= m.timers[addr - R_T0OUT].next_time )
                   spc_run_timer_( &m.timers [addr - R_T0OUT], time - 1 )->counter = 0;
               else
                  m.timers[addr - R_T0OUT].counter = 0;
             }
             break;

             /* Registers that act like RAM */
      case 0x8:
      case 0x9:
             m.smp_regs[1][addr] = (uint8_t) data;
             break;

      case R_TEST:
#if 0
             if ( (uint8_t) data != 0x0A )
                dprintf( "SPC wrote to test register\n" );
#endif
             break;

      case R_CONTROL:
             {
               int i;
                /* port clears */
                if ( data & 0x10 )
                {
                   m.smp_regs[1][R_CPUIO0] = 0;
                   m.smp_regs[1][R_CPUIO1] = 0;
                }
                if ( data & 0x20 )
                {
                   m.smp_regs[1][R_CPUIO2] = 0;
                   m.smp_regs[1][R_CPUIO3] = 0;
                }

                /* timers */
                {
                   for ( i = 0; i < TIMER_COUNT; i++ )
                   {
                      Timer* t = &m.timers [i];
                      int enabled = data >> i & 1;
                      if ( t->enabled != enabled )
                      {
                         if ( time >= t->next_time )
                            t = spc_run_timer_( t, time );
                         t->enabled = enabled;
                         if ( enabled )
                         {
                            t->divider = 0;
                            t->counter = 0;
                         }
                      }
                   }
                }
                spc_enable_rom( data & 0x80 );
             }
             break;
   }
}

static int const bits_in_int = CHAR_BIT * sizeof (int);

static void spc_cpu_write( int data, int addr, int time )
{
   int reg;
   /* RAM */
   m.ram.ram[addr] = (uint8_t) data;
   reg = addr - 0xF0;
   if ( reg >= 0 ) /* 64% */
   {
      /* $F0-$FF */
      if ( reg < REG_COUNT ) /* 87% */
      {
         m.smp_regs[0][reg] = (uint8_t) data;

         /* Registers other than $F2 and $F4-$F7
            if ( reg != 2 && reg != 4 && reg != 5 && reg != 6 && reg != 7 )
            TODO: this is a bit on the fragile side */

         if ( ((~0x2F00 << (bits_in_int - 16)) << reg) < 0 ) /* 36% */
         {
            if ( reg == R_DSPDATA ) /* 99% */
            {
               RUN_DSP(time, reg_times [m.smp_regs[0][R_DSPADDR]] );
               if (m.smp_regs[0][R_DSPADDR] <= 0x7F )
                  spc_dsp_write( data, time );
            }
            else
               spc_cpu_write_smp_reg_( data, time, reg);
         }
      }
      /* High mem/address wrap-around */
      else
      {
         reg -= ROM_ADDR - 0xF0;
         if ( reg >= 0 ) /* 1% in IPL ROM area or address wrapped around */
         {
            if ( reg < ROM_SIZE )
            {
               m.hi_ram [reg] = (uint8_t) data;
               if ( m.rom_enabled )
                  m.ram.ram[reg + ROM_ADDR] = m.rom [reg]; /* restore overwritten ROM */
            }
            else
            {
               *(&(m.ram.ram[0]) + reg + ROM_ADDR) = CPU_PAD_FILL; /* restore overwritten padding */
               spc_cpu_write( data, addr & 0xFFFF, time );
            }
         }
      }
   }
}

/* CPU read */

static int spc_cpu_read( int addr, int time )
{
   int result, reg;

   /* RAM */
   result = m.ram.ram[addr];
   reg = addr - 0xF0;

   if ( reg >= 0 ) /* 40% */
   {
      reg -= 0x10;
      if ( (unsigned) reg >= 0xFF00 ) /* 21% */
      {
         reg += 0x10 - R_T0OUT;

         /* Timers */
         if ( (unsigned) reg < TIMER_COUNT ) /* 90% */
         {
            Timer* t = &m.timers [reg];
            if ( time >= t->next_time )
               t = spc_run_timer_( t, time );
            result = t->counter;
            t->counter = 0;
         }
         /* Other registers */
         else if ( reg < 0 ) /* 10% */
         {
            int reg_tmp;

            reg_tmp = reg + R_T0OUT;
            result = m.smp_regs[1][reg_tmp];
            reg_tmp -= R_DSPADDR;
            /* DSP addr and data */
            if ( (unsigned) reg_tmp <= 1 ) /* 4% 0xF2 and 0xF3 */
            {
               result = m.smp_regs[0][R_DSPADDR];
               if ( (unsigned) reg_tmp == 1 )
               {
                  RUN_DSP( time, reg_times [m.smp_regs[0][R_DSPADDR] & 0x7F] );

                  result = dsp_m.regs[m.smp_regs[0][R_DSPADDR] & 0x7F]; /* 0xF3 */
               }
            }
         }
         else /* 1% */
            result = spc_cpu_read( reg + (R_T0OUT + 0xF0 - 0x10000), time );
      }
   }

   return result;
}

/***********************************************************************************
 SPC CPU
***********************************************************************************/

/* Inclusion here allows static memory access functions and better optimization */

/* Timers are by far the most common thing read from dp */

#define CPU_READ_TIMER( time, offset, addr_, out )\
{\
   int adj_time, dp_addr, ti; \
   adj_time = time + offset;\
   dp_addr = addr_;\
   ti = dp_addr - (R_T0OUT + 0xF0);\
   if ( (unsigned) ti < TIMER_COUNT )\
   {\
      Timer* t = &m.timers [ti];\
      if ( adj_time >= t->next_time )\
      t = spc_run_timer_( t, adj_time );\
      out = t->counter;\
      t->counter = 0;\
   }\
   else\
   {\
      int i, reg; \
      out = ram [dp_addr];\
      i = dp_addr - 0xF0;\
      if ( (unsigned) i < 0x10 )\
      { \
         reg = i;  \
         out = m.smp_regs[1][reg]; \
         reg -= R_DSPADDR; \
         /* DSP addr and data */ \
         if ( (unsigned) reg <= 1 ) /* 4% 0xF2 and 0xF3 */ \
         { \
            out = m.smp_regs[0][R_DSPADDR]; \
            if ( (unsigned) reg == 1 ) \
            { \
               RUN_DSP( adj_time, reg_times [m.smp_regs[0][R_DSPADDR] & 0x7F] ); \
               out = dsp_m.regs[m.smp_regs[0][R_DSPADDR] & 0x7F ]; /* 0xF3 */ \
            } \
         } \
      } \
   }\
}

#define READ_TIMER( time, addr, out )	CPU_READ_TIMER( rel_time, time, (addr), out )
#define SPC_CPU_READ( time, addr )		spc_cpu_read((addr), rel_time + time )
#define SPC_CPU_WRITE( time, addr, data )	spc_cpu_write((data), (addr), rel_time + time )

static unsigned spc_CPU_mem_bit( uint8_t const* pc, int rel_time )
{
   unsigned addr, t;

   addr = GET_LE16( pc );
   t = SPC_CPU_READ( 0, addr & 0x1FFF ) >> (addr >> 13);
   return t << 8 & 0x100;
}

#define DP_ADDR( addr )                     (dp + (addr))

#define READ_DP_TIMER(  time, addr, out )   CPU_READ_TIMER( rel_time, time, DP_ADDR( addr ), out )
#define READ_DP(  time, addr )              SPC_CPU_READ( time, DP_ADDR( addr ) )
#define WRITE_DP( time, addr, data )        SPC_CPU_WRITE( time, DP_ADDR( addr ), data )

#define READ_PROG16( addr )                 GET_LE16( ram + (addr) )

#define SET_PC( n )     (pc = ram + (n))
#define GET_PC()        (pc - ram)
#define READ_PC( pc )   (*(pc))

#define SET_SP( v )     (sp = ram + 0x101 + (v))
#define GET_SP()        (sp - 0x101 - ram)

#define PUSH16( v )     (sp -= 2, SET_LE16( sp, v ))
#define PUSH( v )       (void) (*--sp = (uint8_t) (v))
#define POP( out )      (void) ((out) = *sp++)

#define MEM_BIT( rel ) spc_CPU_mem_bit( pc, rel_time + rel )

#define GET_PSW( out )\
{\
   out = psw & ~(N80 | P20 | Z02 | C01);\
   out |= c  >> 8 & C01;\
   out |= dp >> 3 & P20;\
   out |= ((nz >> 4) | nz) & N80;\
   if ( !(uint8_t) nz ) out |= Z02;\
}

#define SET_PSW( in )\
{\
   psw = in;\
   c   = in << 8;\
   dp  = in << 3 & 0x100;\
   nz  = (in << 4 & 0x800) | (~in & Z02);\
}

static uint8_t* spc_run_until_( int end_time )
{
   int dp, nz, c, psw, a, x, y;
   uint8_t *ram, *pc, *sp;
   int rel_time = m.spc_time - end_time;
   m.spc_time = end_time;
   m.dsp_time += rel_time;
   m.timers [0].next_time += rel_time;
   m.timers [1].next_time += rel_time;
   m.timers [2].next_time += rel_time;
   ram = m.ram.ram;
   a = m.cpu_regs.a;
   x = m.cpu_regs.x;
   y = m.cpu_regs.y;

   SET_PC( m.cpu_regs.pc );
   SET_SP( m.cpu_regs.sp );
   SET_PSW( m.cpu_regs.psw );

   goto loop;


   /* Main loop */

cbranch_taken_loop:
   pc += *(int8_t const*) pc;
inc_pc_loop:
   pc++;
loop:
   {
      unsigned opcode, data;

      opcode = *pc;

      if (allow_time_overflow && rel_time >= 0 )
         goto stop;
      if ( (rel_time += m.cycle_table [opcode]) > 0 && !allow_time_overflow)
         goto out_of_time;

      /* TODO: if PC is at end of memory, this will get wrong operand (very obscure) */
      data = *++pc;
      switch ( opcode )
      {

         /* Common instructions */

#define BRANCH( cond )\
         {\
            pc++;\
            pc += (int8_t) data;\
            if ( cond )\
            goto loop;\
            pc -= (int8_t) data;\
            rel_time -= 2;\
            goto loop;\
         }

         case 0xF0: /* BEQ */
            BRANCH( !(uint8_t) nz ) /* 89% taken */

         case 0xD0: /* BNE */
               BRANCH( (uint8_t) nz )

         case 0x3F:
               { /* CALL */
                  int old_addr;
                  old_addr = GET_PC() + 2;
                  SET_PC( GET_LE16( pc ) );
                  PUSH16( old_addr );
                  goto loop;
               }
         case 0x6F: /* RET */
               SET_PC( GET_LE16( sp ) );
               sp += 2;
               goto loop;

         case 0xE4: /* MOV a,dp */
               ++pc;
               /* 80% from timer */
               READ_DP_TIMER( 0, data, a = nz );
               goto loop;

         case 0xFA:{ /* MOV dp,dp */
                 int temp;
                 READ_DP_TIMER( -2, data, temp );
                 data = temp + NO_READ_BEFORE_WRITE ;
              }
              /* fall through */
         case 0x8F:
              { /* MOV dp,#imm */
                 int i, temp;
                 temp = READ_PC( pc + 1 );
                 pc += 2;

                 i = dp + temp;
                 ram [i] = (uint8_t) data;
                 i -= 0xF0;
                 if ( (unsigned) i < 0x10 ) /* 76% */
                 {
                    m.smp_regs[0][i] = (uint8_t) data;

                    /* Registers other than $F2 and $F4-$F7 */
                    /* if ( i != 2 && i != 4 && i != 5 && i != 6 && i != 7 ) */
                    if ( ((~0x2F00 << (bits_in_int - 16)) << i) < 0 ) /* 12% */
                    {
                       if ( i == R_DSPDATA ) /* 99% */
                       {
                          RUN_DSP(rel_time, reg_times [m.smp_regs[0][R_DSPADDR]] );
                          if (m.smp_regs[0][R_DSPADDR] <= 0x7F )
                             spc_dsp_write( data, rel_time );
                       }
                       else
                          spc_cpu_write_smp_reg_( data, rel_time, i);
                    }
                 }
                 goto loop;
              }

         case 0xC4: /* MOV dp,a */
              ++pc;
              {
                 int i;
                 i = dp + data;
                 ram [i] = (uint8_t) a;
                 i -= 0xF0;
                 if ( (unsigned) i < 0x10 ) /* 39% */
                 {
                    unsigned sel;
                    sel = i - 2;
                    m.smp_regs[0][i] = (uint8_t) a;

                    if ( sel == 1 ) /* 51% $F3 */
                    {
                       RUN_DSP(rel_time, reg_times [m.smp_regs[0][R_DSPADDR]] );
                       if (m.smp_regs[0][R_DSPADDR] <= 0x7F )
                          spc_dsp_write( a, rel_time );
                    }
                    else if ( sel > 1 ) /* 1% not $F2 or $F3 */
                       spc_cpu_write_smp_reg_( a, rel_time, i );
                 }
              }
              goto loop;

#define CASE( n )   case n:

              /* Define common address modes based on opcode for immediate mode. Execution
                 ends with data set to the address of the operand. */
#define ADDR_MODES_( op )\
              CASE( op - 0x02 ) /* (X) */\
              data = x + dp;\
              pc--;\
              goto end_##op;\
              CASE( op + 0x0F ) /* (dp)+Y */\
              data = READ_PROG16( data + dp ) + y;\
              goto end_##op;\
              CASE( op - 0x01 ) /* (dp+X) */\
              data = READ_PROG16( ((uint8_t) (data + x)) + dp );\
              goto end_##op;\
              CASE( op + 0x0E ) /* abs+Y */\
              data += y;\
              goto abs_##op;\
              CASE( op + 0x0D ) /* abs+X */\
              data += x;\
              CASE( op - 0x03 ) /* abs */\
              abs_##op:\
              data += 0x100 * READ_PC( ++pc );\
              goto end_##op;\
              CASE( op + 0x0C ) /* dp+X */\
              data = (uint8_t) (data + x);

#define ADDR_MODES_NO_DP( op )\
              ADDR_MODES_( op )\
              data += dp;\
              end_##op:

#define ADDR_MODES( op )\
              ADDR_MODES_( op )\
              CASE( op - 0x04 ) /* dp */\
              data += dp;\
              end_##op:

              /* 1. 8-bit Data Transmission Commands. Group I */

              ADDR_MODES_NO_DP( 0xE8 ) /* MOV A,addr */
                 a = nz = SPC_CPU_READ( 0, data );
              goto inc_pc_loop;

         case 0xBF:
              {
                 /* MOV A,(X)+ */
                 int temp;
                 temp = x + dp;
                 x = (uint8_t) (x + 1);
                 a = nz = SPC_CPU_READ( -1, temp );
                 goto loop;
              }

         case 0xE8: /* MOV A,imm */
              a  = data;
              nz = data;
              goto inc_pc_loop;

         case 0xF9: /* MOV X,dp+Y */
              data = (uint8_t) (data + y);
         case 0xF8: /* MOV X,dp */
              READ_DP_TIMER( 0, data, x = nz );
              goto inc_pc_loop;

         case 0xE9: /* MOV X,abs */
              data = GET_LE16( pc );
              ++pc;
              data = SPC_CPU_READ( 0, data );
         case 0xCD: /* MOV X,imm */
              x  = data;
              nz = data;
              goto inc_pc_loop;

         case 0xFB: /* MOV Y,dp+X */
              data = (uint8_t) (data + x);
         case 0xEB: /* MOV Y,dp */
              /* 70% from timer */
              pc++;
              READ_DP_TIMER( 0, data, y = nz );
              goto loop;

         case 0xEC:
              { /* MOV Y,abs */
                 int temp;
                 temp = GET_LE16( pc );
                 pc += 2;
                 READ_TIMER( 0, temp, y = nz );
                 /* y = nz = SPC_CPU_READ( 0, temp ); */
                 goto loop;
              }

         case 0x8D: /* MOV Y,imm */
              y  = data;
              nz = data;
              goto inc_pc_loop;

              /* 2. 8-BIT DATA TRANSMISSION COMMANDS, GROUP 2 */

              ADDR_MODES_NO_DP( 0xC8 ) /* MOV addr,A */
                 SPC_CPU_WRITE( 0, data, a );
              goto inc_pc_loop;

              {
                 int temp;
                 case 0xCC: /* MOV abs,Y */
                 temp = y;
                 goto mov_abs_temp;
                 case 0xC9: /* MOV abs,X */
                 temp = x;
mov_abs_temp:
                 SPC_CPU_WRITE( 0, GET_LE16( pc ), temp );
                 pc += 2;
                 goto loop;
              }

         case 0xD9: /* MOV dp+Y,X */
              data = (uint8_t) (data + y);
         case 0xD8: /* MOV dp,X */
              SPC_CPU_WRITE( 0, data + dp, x );
              goto inc_pc_loop;

         case 0xDB: /* MOV dp+X,Y */
              data = (uint8_t) (data + x);
         case 0xCB: /* MOV dp,Y */
              SPC_CPU_WRITE( 0, data + dp, y );
              goto inc_pc_loop;

              /* 3. 8-BIT DATA TRANSMISSION COMMANDS, GROUP 3. */

         case 0x7D: /* MOV A,X */
              a  = x;
              nz = x;
              goto loop;

         case 0xDD: /* MOV A,Y */
              a  = y;
              nz = y;
              goto loop;

         case 0x5D: /* MOV X,A */
              x  = a;
              nz = a;
              goto loop;

         case 0xFD: /* MOV Y,A */
              y  = a;
              nz = a;
              goto loop;

         case 0x9D: /* MOV X,SP */
              x = nz = GET_SP();
              goto loop;

         case 0xBD: /* MOV SP,X */
              SET_SP( x );
              goto loop;

              /* case 0xC6: // MOV (X),A (handled by MOV addr,A in group 2) */

         case 0xAF: /* MOV (X)+,A */
              WRITE_DP( 0, x, a + NO_READ_BEFORE_WRITE  );
              x++;
              goto loop;

              /* 5. 8-BIT LOGIC OPERATION COMMANDS */

#define LOGICAL_OP( op, func )\
              ADDR_MODES( op ) /* addr */\
              data = SPC_CPU_READ( 0, data );\
         case op: /* imm */\
                 nz = a func##= data;\
              goto inc_pc_loop;\
              {   unsigned addr;\
                 case op + 0x11: /* X,Y */\
                           data = READ_DP( -2, y );\
                 addr = x + dp;\
                 goto addr_##op;\
                 case op + 0x01: /* dp,dp */\
                             data = READ_DP( -3, data );\
                 case op + 0x10:{/*dp,imm*/\
                         uint8_t const* addr2 = pc + 1;\
                         pc += 2;\
                         addr = READ_PC( addr2 ) + dp;\
                      }\
                 addr_##op:\
                 nz = data func SPC_CPU_READ( -1, addr );\
                 SPC_CPU_WRITE( 0, addr, nz );\
                 goto loop;\
              }

              LOGICAL_OP( 0x28, & ); /* AND */

              LOGICAL_OP( 0x08, | ); /* OR */

              LOGICAL_OP( 0x48, ^ ); /* EOR */

              /* 4. 8-BIT ARITHMETIC OPERATION COMMANDS */

              ADDR_MODES( 0x68 ) /* CMP addr */
                 data = SPC_CPU_READ( 0, data );
         case 0x68: /* CMP imm */
              nz = a - data;
              c = ~nz;
              nz &= 0xFF;
              goto inc_pc_loop;

         case 0x79: /* CMP (X),(Y) */
              data = READ_DP( -2, y );
              nz = READ_DP( -1, x ) - data;
              c = ~nz;
              nz &= 0xFF;
              goto loop;

         case 0x69: /* CMP dp,dp */
              data = READ_DP( -3, data );
         case 0x78: /* CMP dp,imm */
              nz = READ_DP( -1, READ_PC( ++pc ) ) - data;
              c = ~nz;
              nz &= 0xFF;
              goto inc_pc_loop;

         case 0x3E: /* CMP X,dp */
              data += dp;
              goto cmp_x_addr;
         case 0x1E: /* CMP X,abs */
              data = GET_LE16( pc );
              pc++;
cmp_x_addr:
              data = SPC_CPU_READ( 0, data );
         case 0xC8: /* CMP X,imm */
              nz = x - data;
              c = ~nz;
              nz &= 0xFF;
              goto inc_pc_loop;

         case 0x7E: /* CMP Y,dp */
              data += dp;
              goto cmp_y_addr;
         case 0x5E: /* CMP Y,abs */
              data = GET_LE16( pc );
              pc++;
cmp_y_addr:
              data = SPC_CPU_READ( 0, data );
         case 0xAD: /* CMP Y,imm */
              nz = y - data;
              c = ~nz;
              nz &= 0xFF;
              goto inc_pc_loop;

              {
                 int addr;
                 case 0xB9: /* SBC (x),(y) */
                 case 0x99: /* ADC (x),(y) */
                 pc--; /* compensate for inc later */
                 data = READ_DP( -2, y );
                 addr = x + dp;
                 goto adc_addr;
                 case 0xA9: /* SBC dp,dp */
                 case 0x89: /* ADC dp,dp */
                 data = READ_DP( -3, data );
                 case 0xB8: /* SBC dp,imm */
                 case 0x98: /* ADC dp,imm */
                 addr = READ_PC( ++pc ) + dp;
adc_addr:
                 nz = SPC_CPU_READ( -1, addr );
                 goto adc_data;

                 /* catch ADC and SBC together, then decode later based on operand */
#undef CASE
#define CASE( n ) case n: case (n) + 0x20:
                 ADDR_MODES( 0x88 ) /* ADC/SBC addr */
                    data = SPC_CPU_READ( 0, data );
                 case 0xA8: /* SBC imm */
                 case 0x88: /* ADC imm */
                 addr = -1; /* A */
                 nz = a;
adc_data: {
        int flags;
        if ( opcode >= 0xA0 ) /* SBC */
           data ^= 0xFF;

        flags = data ^ nz;
        nz += data + (c >> 8 & 1);
        flags ^= nz;

        psw = (psw & ~(V40 | H08)) |
           (flags >> 1 & H08) |
           ((flags + 0x80) >> 2 & V40);
        c = nz;
        if ( addr < 0 )
        {
           a = (uint8_t) nz;
           goto inc_pc_loop;
        }
        SPC_CPU_WRITE( 0, addr, /*(uint8_t)*/ nz );
        goto inc_pc_loop;
     }

              }

              /* 6. ADDITION & SUBTRACTION COMMANDS */

#define INC_DEC_REG( reg, op )\
              nz  = reg op;\
              reg = (uint8_t) nz;\
              goto loop;

         case 0xBC: INC_DEC_REG( a, + 1 ) /* INC A */
         case 0x3D: INC_DEC_REG( x, + 1 ) /* INC X */
         case 0xFC: INC_DEC_REG( y, + 1 ) /* INC Y */

         case 0x9C: INC_DEC_REG( a, - 1 ) /* DEC A */
         case 0x1D: INC_DEC_REG( x, - 1 ) /* DEC X */
         case 0xDC: INC_DEC_REG( y, - 1 ) /* DEC Y */

         case 0x9B: /* DEC dp+X */
         case 0xBB: /* INC dp+X */
               data = (uint8_t) (data + x);
         case 0x8B: /* DEC dp */
         case 0xAB: /* INC dp */
               data += dp;
               goto inc_abs;
         case 0x8C: /* DEC abs */
         case 0xAC: /* INC abs */
               data = GET_LE16( pc );
               pc++;
inc_abs:
               nz = (opcode >> 4 & 2) - 1;
               nz += SPC_CPU_READ( -1, data );
               SPC_CPU_WRITE( 0, data, /*(uint8_t)*/ nz );
               goto inc_pc_loop;

               /* 7. SHIFT, ROTATION COMMANDS */

         case 0x5C: /* LSR A */
               c = 0;
         case 0x7C:{ /* ROR A */
                 nz = (c >> 1 & 0x80) | (a >> 1);
                 c = a << 8;
                 a = nz;
                 goto loop;
              }

         case 0x1C: /* ASL A */
              c = 0;
         case 0x3C:
              {/* ROL A */
                 int temp;
                 temp = c >> 8 & 1;
                 c = a << 1;
                 nz = c | temp;
                 a = (uint8_t) nz;
                 goto loop;
              }

         case 0x0B: /* ASL dp */
              c = 0;
              data += dp;
              goto rol_mem;
         case 0x1B: /* ASL dp+X */
              c = 0;
         case 0x3B: /* ROL dp+X */
              data = (uint8_t) (data + x);
         case 0x2B: /* ROL dp */
              data += dp;
              goto rol_mem;
         case 0x0C: /* ASL abs */
              c = 0;
         case 0x2C: /* ROL abs */
              data = GET_LE16( pc );
              pc++;
rol_mem:
              nz = c >> 8 & 1;
              nz |= (c = SPC_CPU_READ( -1, data ) << 1);
              SPC_CPU_WRITE( 0, data, /*(uint8_t)*/ nz );
              goto inc_pc_loop;

         case 0x4B: /* LSR dp */
              c = 0;
              data += dp;
              goto ror_mem;
         case 0x5B: /* LSR dp+X */
              c = 0;
         case 0x7B: /* ROR dp+X */
              data = (uint8_t) (data + x);
         case 0x6B: /* ROR dp */
              data += dp;
              goto ror_mem;
         case 0x4C: /* LSR abs */
              c = 0;
         case 0x6C: /* ROR abs */
              data = GET_LE16( pc );
              pc++;
ror_mem: {
       int temp = SPC_CPU_READ( -1, data );
       nz = (c >> 1 & 0x80) | (temp >> 1);
       c = temp << 8;
       SPC_CPU_WRITE( 0, data, nz );
       goto inc_pc_loop;
    }

         case 0x9F: /* XCN */
    nz = a = (a >> 4) | (uint8_t) (a << 4);
    goto loop;

    /* 8. 16-BIT TRANSMISION COMMANDS */

         case 0xBA: /* MOVW YA,dp */
    a = READ_DP( -2, data );
    nz = (a & 0x7F) | (a >> 1);
    y = READ_DP( 0, (uint8_t) (data + 1) );
    nz |= y;
    goto inc_pc_loop;

         case 0xDA: /* MOVW dp,YA */
    WRITE_DP( -1, data, a );
    WRITE_DP( 0, (uint8_t) (data + 1), y + NO_READ_BEFORE_WRITE  );
    goto inc_pc_loop;

    /* 9. 16-BIT OPERATION COMMANDS */

         case 0x3A: /* INCW dp */
         case 0x1A:{/* DECW dp */
                 int temp;
                 /* low byte */
                 data += dp;
                 temp = SPC_CPU_READ( -3, data );
                 temp += (opcode >> 4 & 2) - 1; /* +1 for INCW, -1 for DECW */
                 nz = ((temp >> 1) | temp) & 0x7F;
                 SPC_CPU_WRITE( -2, data, /*(uint8_t)*/ temp );

                 /* high byte */
                 data = (uint8_t) (data + 1) + dp;
                 temp = (uint8_t) ((temp >> 8) + SPC_CPU_READ( -1, data ));
                 nz |= temp;
                 SPC_CPU_WRITE( 0, data, temp );

                 goto inc_pc_loop;
              }

         case 0x7A: /* ADDW YA,dp */
         case 0x9A:
              {/* SUBW YA,dp */
                 int lo, hi, result, flags;
                 lo = READ_DP( -2, data );
                 hi = READ_DP( 0, (uint8_t) (data + 1) );

                 if ( opcode == 0x9A ) /* SUBW */
                 {
                    lo = (lo ^ 0xFF) + 1;
                    hi ^= 0xFF;
                 }

                 lo += a;
                 result = y + hi + (lo >> 8);
                 flags = hi ^ y ^ result;

                 psw = (psw & ~(V40 | H08)) |
                    (flags >> 1 & H08) |
                    ((flags + 0x80) >> 2 & V40);
                 c = result;
                 a = (uint8_t) lo;
                 result = (uint8_t) result;
                 y = result;
                 nz = (((lo >> 1) | lo) & 0x7F) | result;

                 goto inc_pc_loop;
              }

         case 0x5A:
              { /* CMPW YA,dp */
                 int temp;
                 temp = a - READ_DP( -1, data );
                 nz = ((temp >> 1) | temp) & 0x7F;
                 temp = y + (temp >> 8);
                 temp -= READ_DP( 0, (uint8_t) (data + 1) );
                 nz |= temp;
                 c  = ~temp;
                 nz &= 0xFF;
                 goto inc_pc_loop;
              }

               /* 10. MULTIPLICATION & DIVISON COMMANDS */

         case 0xCF: { /* MUL YA */
                  unsigned temp = y * a;
                  a = (uint8_t) temp;
                  nz = ((temp >> 1) | temp) & 0x7F;
                  y = temp >> 8;
                  nz |= y;
                  goto loop;
               }

         case 0x9E: /* DIV YA,X */
               {
                  unsigned ya = y * 0x100 + a;

                  psw &= ~(H08 | V40);

                  if ( y >= x )
                     psw |= V40;

                  if ( (y & 15) >= (x & 15) )
                     psw |= H08;

                  if ( y < x * 2 )
                  {
                     a = ya / x;
                     y = ya - a * x;
                  }
                  else
                  {
                     a = 255 - (ya - x * 0x200) / (256 - x);
                     y = x   + (ya - x * 0x200) % (256 - x);
                  }

                  nz = (uint8_t) a;
                  a = (uint8_t) a;

                  goto loop;
               }

               /* 11. DECIMAL COMPENSATION COMMANDS */

         case 0xDF: /* DAA */
               if ( a > 0x99 || c & 0x100 )
               {
                  a += 0x60;
                  c = 0x100;
               }

               if ( (a & 0x0F) > 9 || psw & H08 )
                  a += 0x06;

               nz = a;
               a = (uint8_t) a;
               goto loop;

         case 0xBE: /* DAS */
               if ( a > 0x99 || !(c & 0x100) )
               {
                  a -= 0x60;
                  c = 0;
               }

               if ( (a & 0x0F) > 9 || !(psw & H08) )
                  a -= 0x06;

               nz = a;
               a = (uint8_t) a;
               goto loop;

               /* 12. BRANCHING COMMANDS */

         case 0x2F: /* BRA rel */
               pc += (int8_t) data;
               goto inc_pc_loop;

         case 0x30: /* BMI */
               BRANCH( (nz & NZ_NEG_MASK) )

         case 0x10: /* BPL */
                  BRANCH( !(nz & NZ_NEG_MASK) )

         case 0xB0: /* BCS */
                  BRANCH( c & 0x100 )

         case 0x90: /* BCC */
                  BRANCH( !(c & 0x100) )

         case 0x70: /* BVS */
                  BRANCH( psw & V40 )

         case 0x50: /* BVC */
                  BRANCH( !(psw & V40) )

#define CBRANCH( cond )\
                  {\
                     pc++;\
                     if ( cond )\
                        goto cbranch_taken_loop;\
                     rel_time -= 2;\
                     goto inc_pc_loop;\
                  }

         case 0x03: /* BBS dp.bit,rel */
         case 0x23:
         case 0x43:
         case 0x63:
         case 0x83:
         case 0xA3:
         case 0xC3:
         case 0xE3:
                  CBRANCH( READ_DP( -4, data ) >> (opcode >> 5) & 1 )

         case 0x13: /* BBC dp.bit,rel */
         case 0x33:
         case 0x53:
         case 0x73:
         case 0x93:
         case 0xB3:
         case 0xD3:
         case 0xF3:
               CBRANCH( !(READ_DP( -4, data ) >> (opcode >> 5) & 1) )

         case 0xDE: /* CBNE dp+X,rel */
                                       data = (uint8_t) (data + x);
                                       /* fall through */
         case 0x2E:{ /* CBNE dp,rel */
                 int temp;
                 /* 61% from timer */
                 READ_DP_TIMER( -4, data, temp );
                 CBRANCH( temp != a )
              }

         case 0x6E: { /* DBNZ dp,rel */
                  unsigned temp = READ_DP( -4, data ) - 1;
                  WRITE_DP( -3, (uint8_t) data, /*(uint8_t)*/ temp + NO_READ_BEFORE_WRITE  );
                  CBRANCH( temp )
               }

         case 0xFE: /* DBNZ Y,rel */
               y = (uint8_t) (y - 1);
               BRANCH( y )

         case 0x1F: /* JMP [abs+X] */
                  SET_PC( GET_LE16( pc ) + x );
                  /* fall through */
         case 0x5F: /* JMP abs */
                  SET_PC( GET_LE16( pc ) );
                  goto loop;

                  /* 13. SUB-ROUTINE CALL RETURN COMMANDS */

         case 0x0F:{/* BRK */
                 int temp;
                 int ret_addr = GET_PC();
                 SET_PC( READ_PROG16( 0xFFDE ) ); /* vector address verified */
                 PUSH16( ret_addr );
                 GET_PSW( temp );
                 psw = (psw | B10) & ~I04;
                 PUSH( temp );
                 goto loop;
              }

         case 0x4F:{/* PCALL offset */
                 int ret_addr = GET_PC() + 1;
                 SET_PC( 0xFF00 | data );
                 PUSH16( ret_addr );
                 goto loop;
              }

         case 0x01: /* TCALL n */
         case 0x11:
         case 0x21:
         case 0x31:
         case 0x41:
         case 0x51:
         case 0x61:
         case 0x71:
         case 0x81:
         case 0x91:
         case 0xA1:
         case 0xB1:
         case 0xC1:
         case 0xD1:
         case 0xE1:
         case 0xF1: {
                  int ret_addr = GET_PC();
                  SET_PC( READ_PROG16( 0xFFDE - (opcode >> 3) ) );
                  PUSH16( ret_addr );
                  goto loop;
               }

               /* 14. STACK OPERATION COMMANDS */

               {
                  int temp;
                  case 0x7F: /* RET1 */
                  temp = *sp;
                  SET_PC( GET_LE16( sp + 1 ) );
                  sp += 3;
                  goto set_psw;
                  case 0x8E: /* POP PSW */
                  POP( temp );
set_psw:
                  SET_PSW( temp );
                  goto loop;
               }

         case 0x0D: { /* PUSH PSW */
                  int temp;
                  GET_PSW( temp );
                  PUSH( temp );
                  goto loop;
               }

         case 0x2D: /* PUSH A */
               PUSH( a );
               goto loop;

         case 0x4D: /* PUSH X */
               PUSH( x );
               goto loop;

         case 0x6D: /* PUSH Y */
               PUSH( y );
               goto loop;

         case 0xAE: /* POP A */
               POP( a );
               goto loop;

         case 0xCE: /* POP X */
               POP( x );
               goto loop;

         case 0xEE: /* POP Y */
               POP( y );
               goto loop;

               /* 15. BIT OPERATION COMMANDS */

         case 0x02: /* SET1 */
         case 0x22:
         case 0x42:
         case 0x62:
         case 0x82:
         case 0xA2:
         case 0xC2:
         case 0xE2:
         case 0x12: /* CLR1 */
         case 0x32:
         case 0x52:
         case 0x72:
         case 0x92:
         case 0xB2:
         case 0xD2:
         case 0xF2:
               {
                  int bit, mask;
                  bit = 1 << (opcode >> 5);
                  mask = ~bit;
                  if ( opcode & 0x10 )
                     bit = 0;
                  data += dp;
                  SPC_CPU_WRITE( 0, data, (SPC_CPU_READ( -1, data ) & mask) | bit );
                  goto inc_pc_loop;
               }

         case 0x0E: /* TSET1 abs */
         case 0x4E: /* TCLR1 abs */
               data = GET_LE16( pc );
               pc += 2;
               {
                  unsigned temp = SPC_CPU_READ( -2, data );
                  nz = (uint8_t) (a - temp);
                  temp &= ~a;
                  if ( opcode == 0x0E )
                     temp |= a;
                  SPC_CPU_WRITE( 0, data, temp );
               }
               goto loop;

         case 0x4A: /* AND1 C,mem.bit */
               c &= MEM_BIT( 0 );
               pc += 2;
               goto loop;

         case 0x6A: /* AND1 C,/mem.bit */
               c &= ~MEM_BIT( 0 );
               pc += 2;
               goto loop;

         case 0x0A: /* OR1 C,mem.bit */
               c |= MEM_BIT( -1 );
               pc += 2;
               goto loop;

         case 0x2A: /* OR1 C,/mem.bit */
               c |= ~MEM_BIT( -1 );
               pc += 2;
               goto loop;

         case 0x8A: /* EOR1 C,mem.bit */
               c ^= MEM_BIT( -1 );
               pc += 2;
               goto loop;

         case 0xEA: /* NOT1 mem.bit */
               data = GET_LE16( pc );
               pc += 2;
               {
                  unsigned temp = SPC_CPU_READ( -1, data & 0x1FFF );
                  temp ^= 1 << (data >> 13);
                  SPC_CPU_WRITE( 0, data & 0x1FFF, temp );
               }
               goto loop;

         case 0xCA: /* MOV1 mem.bit,C */
               data = GET_LE16( pc );
               pc += 2;
               {
                  unsigned temp, bit;
                  temp = SPC_CPU_READ( -2, data & 0x1FFF );
                  bit = data >> 13;
                  temp = (temp & ~(1 << bit)) | ((c >> 8 & 1) << bit);
                  SPC_CPU_WRITE( 0, data & 0x1FFF, temp + NO_READ_BEFORE_WRITE  );
               }
               goto loop;

         case 0xAA: /* MOV1 C,mem.bit */
               c = MEM_BIT( 0 );
               pc += 2;
               goto loop;

               /* 16. PROGRAM PSW FLAG OPERATION COMMANDS */

         case 0x60: /* CLRC */
               c = 0;
               goto loop;

         case 0x80: /* SETC */
               c = ~0;
               goto loop;

         case 0xED: /* NOTC */
               c ^= 0x100;
               goto loop;

         case 0xE0: /* CLRV */
               psw &= ~(V40 | H08);
               goto loop;

         case 0x20: /* CLRP */
               dp = 0;
               goto loop;

         case 0x40: /* SETP */
               dp = 0x100;
               goto loop;

         case 0xA0: /* EI */
               psw |= I04;
               goto loop;

         case 0xC0: /* DI */
               psw &= ~I04;
               goto loop;

               /* 17. OTHER COMMANDS */

         case 0x00: /* NOP */
               goto loop;

         case 0xFF:
               { /* STOP */
                  /* handle PC wrap-around */
                  unsigned addr = GET_PC() - 1;
                  if ( addr >= 0x10000 )
                  {
                     addr &= 0xFFFF;
                     SET_PC( addr );
                     /* dprintf( "SPC: PC wrapped around\n" ); */
                     goto loop;
                  }
               }
              /* fall through */
         case 0xEF: /* SLEEP */
              --pc;
              rel_time = 0;
              goto stop;
      } /* switch */
   }
out_of_time:
   rel_time -= m.cycle_table [*pc]; /* undo partial execution of opcode */
stop:

   /* Uncache registers */
#if 0
   if ( GET_PC() >= 0x10000 )
      dprintf( "SPC: PC wrapped around\n" );
#endif
   m.cpu_regs.pc = (uint16_t) GET_PC();
   m.cpu_regs.sp = ( uint8_t) GET_SP();
   m.cpu_regs.a  = ( uint8_t) a;
   m.cpu_regs.x  = ( uint8_t) x;
   m.cpu_regs.y  = ( uint8_t) y;
   {
      int temp;
      GET_PSW( temp );
      m.cpu_regs.psw = (uint8_t) temp;
   }
   m.spc_time += rel_time;
   m.dsp_time -= rel_time;
   m.timers [0].next_time -= rel_time;
   m.timers [1].next_time -= rel_time;
   m.timers [2].next_time -= rel_time;
   return &m.smp_regs[0][R_CPUIO0];
}

/* Runs SPC to end_time and starts a new time frame at 0 */

static void spc_end_frame( int end_time )
{
   int i;
   /* Catch CPU up to as close to end as possible. If final instruction
      would exceed end, does NOT execute it and leaves m.spc_time < end. */

   if ( end_time > m.spc_time )
      spc_run_until_( end_time );

   m.spc_time     -= end_time;
   m.extra_clocks += end_time;

   /* Catch timers up to CPU */
   for ( i = 0; i < TIMER_COUNT; i++ )
   {
      if ( 0 >= m.timers[i].next_time )
         spc_run_timer_( &m.timers [i], 0 );
   }

   /* Catch DSP up to CPU */
   if ( m.dsp_time < 0 )
   {
      RUN_DSP( 0, MAX_REG_TIME );
   }

   /* Save any extra samples beyond what should be generated */
   if ( m.buf_begin )
   {
      short *main_end, *dsp_end, *out, *in;
      /* Get end pointers */
      main_end = m.buf_end;	/* end of data written to buf */
      dsp_end  = dsp_m.out;	/* end of data written to dsp.extra() */
      if ( m.buf_begin <= dsp_end && dsp_end <= main_end )
      {
         main_end = dsp_end;
         dsp_end  = dsp_m.extra; /* nothing in DSP's extra */
      }

      /* Copy any extra samples at these ends into extra_buf */
      out = m.extra_buf;
      for ( in = m.buf_begin + SPC_SAMPLE_COUNT(); in < main_end; in++ )
         *out++ = *in;
      for ( in = dsp_m.extra; in < dsp_end ; in++ )
         *out++ = *in;

      m.extra_pos = out;
   }
}

/* Support SNES_MEMORY_APURAM */

uint8_t * spc_apuram()
{
   return m.ram.ram;
}

/* Init */

static void spc_reset_buffer(void)
{
   short *out;
   /* Start with half extra buffer of silence */
   out = m.extra_buf;
   while ( out < &m.extra_buf [EXTRA_SIZE_DIV_2] )
      *out++ = 0;
   m.extra_pos = out;
   m.buf_begin = 0;
   dsp_set_output( 0, 0 );
}

/* Sets tempo, where tempo_unit = normal, tempo_unit / 2 = half speed, etc. */

static void spc_set_tempo( int t )
{
   int timer2_shift, other_shift;
   m.tempo = t;
   timer2_shift = 4; /* 64 kHz */
   other_shift  = 3; /*  8 kHz */

   m.timers [2].prescaler = timer2_shift;
   m.timers [1].prescaler = timer2_shift + other_shift;
   m.timers [0].prescaler = timer2_shift + other_shift;
}

static void spc_reset_common( int timer_counter_init )
{
   int i;
   for ( i = 0; i < TIMER_COUNT; i++ )
      m.smp_regs[1][R_T0OUT + i] = timer_counter_init;

   /* Run IPL ROM */
   memset( &m.cpu_regs, 0, sizeof(m.cpu_regs));
   m.cpu_regs.pc = ROM_ADDR;

   m.smp_regs[0][R_TEST   ] = 0x0A;
   m.smp_regs[0][R_CONTROL] = 0xB0; /* ROM enabled, clear ports */
   for ( i = 0; i < PORT_COUNT; i++ )
      m.smp_regs[1][R_CPUIO0 + i] = 0;

   /* reset time registers */
   m.spc_time      = 0;
   m.dsp_time      = 0;
   m.dsp_time = CLOCKS_PER_SAMPLE + 1;

   for ( i = 0; i < TIMER_COUNT; i++ )
   {
      Timer* t = &m.timers [i];
      t->next_time = 1;
      t->divider   = 0;
   }

   /* Registers were just loaded. Applies these new values. */
   spc_enable_rom( m.smp_regs[0][R_CONTROL] & 0x80 );

   /*	Timer registers have been loaded. Applies these to the timers. Does not
      reset timer prescalers or dividers. */
   for ( i = 0; i < TIMER_COUNT; i++ )
   {
      Timer* t = &m.timers [i];
      t->period  = IF_0_THEN_256( m.smp_regs[0][R_T0TARGET + i] );
      t->enabled = m.smp_regs[0][R_CONTROL] >> i & 1;
      t->counter = m.smp_regs[1][R_T0OUT + i] & 0x0F;
   }

   spc_set_tempo( m.tempo );

   m.extra_clocks = 0;
   spc_reset_buffer();
}

/*	Resets SPC to power-on state. This resets your output buffer, so you must
   call set_output() after this. */

static void spc_reset (void)
{
   m.cpu_regs.pc  = 0xFFC0;
   m.cpu_regs.a   = 0x00;
   m.cpu_regs.x   = 0x00;
   m.cpu_regs.y   = 0x00;
   m.cpu_regs.psw = 0x02;
   m.cpu_regs.sp  = 0xEF;
   memset( m.ram.ram, 0x00, 0x10000 );

   /*	RAM was just loaded from SPC, with $F0-$FF containing SMP registers
      and timer counts. Copies these to proper registers. */
   m.rom_enabled = dsp_m.rom_enabled = 0;

   /* Loads registers from unified 16-byte format */
   memcpy( m.smp_regs[0], &m.ram.ram[0xF0], REG_COUNT );
   memcpy( m.smp_regs[1], m.smp_regs[0], REG_COUNT );

   /* These always read back as 0 */
   m.smp_regs[1][R_TEST    ] = 0;
   m.smp_regs[1][R_CONTROL ] = 0;
   m.smp_regs[1][R_T0TARGET] = 0;
   m.smp_regs[1][R_T1TARGET] = 0;
   m.smp_regs[1][R_T2TARGET] = 0;

   /* Put STOP instruction around memory to catch PC underflow/overflow */
   memset( m.ram.padding1, CPU_PAD_FILL, sizeof m.ram.padding1 );
   memset( m.ram.padding2, CPU_PAD_FILL, sizeof m.ram.padding2 );

   spc_reset_common( 0x0F );
   dsp_reset();
}


/*	Emulates pressing reset switch on SNES. This resets your output buffer, so
   you must call set_output() after this. */

static void spc_soft_reset (void)
{
   spc_reset_common( 0 );
   dsp_soft_reset();
}

#if !SPC_NO_COPY_STATE_FUNCS
void spc_copy_state( unsigned char** io, dsp_copy_func_t copy )
{
   int i;
   spc_state_copy_t copier;
   copier.func = copy;
   copier.buf = io;

   /*	Make state data more readable by putting 64K RAM, 16 SMP registers,
      then DSP (with its 128 registers) first */

   /* RAM */
   spc_enable_rom( 0 ); /* will get re-enabled if necessary in regs_loaded() below */
   spc_copier_copy(&copier, m.ram.ram, 0x10000 );

   {
      /* SMP registers */
      uint8_t regs [REG_COUNT], regs_in [REG_COUNT];

      memcpy( regs, m.smp_regs[0], REG_COUNT );
      memcpy( regs_in, m.smp_regs[1], REG_COUNT );

      spc_copier_copy(&copier, regs, sizeof(regs));
      spc_copier_copy(&copier, regs_in, sizeof(regs_in));

      memcpy( m.smp_regs[0], regs, REG_COUNT);
      memcpy( m.smp_regs[1], regs_in, REG_COUNT );

      spc_enable_rom( m.smp_regs[0][R_CONTROL] & 0x80 );
   }

   /* CPU registers */
   SPC_COPY( uint16_t, m.cpu_regs.pc );
   SPC_COPY(  uint8_t, m.cpu_regs.a );
   SPC_COPY(  uint8_t, m.cpu_regs.x );
   SPC_COPY(  uint8_t, m.cpu_regs.y );
   SPC_COPY(  uint8_t, m.cpu_regs.psw );
   SPC_COPY(  uint8_t, m.cpu_regs.sp );
   spc_copier_extra(&copier);

   SPC_COPY( int16_t, m.spc_time );
   SPC_COPY( int16_t, m.dsp_time );

   /* DSP */
   dsp_copy_state( io, copy );

   /* Timers */
   for ( i = 0; i < TIMER_COUNT; i++ )
   {
      Timer *t;

      t = &m.timers [i];
      t->period  = IF_0_THEN_256( m.smp_regs[0][R_T0TARGET + i] );
      t->enabled = m.smp_regs[0][R_CONTROL] >> i & 1;
      SPC_COPY( int16_t, t->next_time );
      SPC_COPY( uint8_t, t->divider );
      SPC_COPY( uint8_t, t->counter );
      spc_copier_extra(&copier);
   }

   spc_set_tempo( m.tempo );

   spc_copier_extra(&copier);
}
#endif


/***********************************************************************************
 APU
***********************************************************************************/

#define APU_DEFAULT_INPUT_RATE		32000
#define APU_MINIMUM_SAMPLE_COUNT	(512*8)
#define APU_MINIMUM_SAMPLE_BLOCK	(128*8)
#define APU_NUMERATOR_NTSC		15664
#define APU_DENOMINATOR_NTSC		328125
#define APU_NUMERATOR_PAL		34176
#define APU_DENOMINATOR_PAL		709379

static apu_callback	sa_callback     = NULL;

static bool		sound_in_sync   = true;

static int		buffer_size;
static int		lag_master      = 0;
static int		lag             = 0;

static short		*landing_buffer = NULL;

static bool		resampler      = false;

static int32_t		reference_time;
static uint32_t		spc_remainder;

static int		timing_hack_denominator = TEMPO_UNIT;
/* Set these to NTSC for now. Will change to PAL in S9xAPUTimingSetSpeedup
   if necessary on game load. */
static uint32_t		ratio_numerator = APU_NUMERATOR_NTSC;
static uint32_t		ratio_denominator = APU_DENOMINATOR_NTSC;

/***********************************************************************************
   RESAMPLER
************************************************************************************/
static int rb_size;
static int rb_buffer_size;
static int rb_start;
static unsigned char *rb_buffer;
static uint32_t r_step;
static uint32_t r_frac;
static int    r_left[4], r_right[4];

#define SPACE_EMPTY() (rb_buffer_size - rb_size)
#define SPACE_FILLED() (rb_size)
#define MAX_WRITE() (SPACE_EMPTY() >> 1)
#define AVAIL() (((((uint32_t) rb_size) << 14) - r_frac) / r_step * 2)

#define RESAMPLER_MIN(a, b) ((a) < (b) ? (a) : (b))
#define CLAMP(x, low, high) (((x) > (high)) ? (high) : (((x) < (low)) ? (low) : (x)))
#define SHORT_CLAMP(n) ((short) CLAMP((n), -32768, 32767))

static INLINE int32_t hermite (int32_t mu1, int32_t a, int32_t b, int32_t c, int32_t d)
{
   int32_t mu2, mu3, m0, m1, a0, a1, a2, a3;

   mu2 = ((mu1 * mu1) >> 15);
   mu3 = ((mu2 * mu1) >> 15);

   m0 = (c - a) << 14;
   m1 = (d - b) << 14;

   a0 = (((mu3 << 1) - (3 * mu2) + 32768) * b);
   a1 = ((mu3 - (mu2 << 1) + mu1) * m0) >> 15;
   a2 = ((mu3 -     mu2) * m1) >> 15;
   a3 = ((3 * mu2 - (mu3 << 1)) * c);

   return ((a0) + (a1) + (a2) + (a3)) >> 15;
}

static void resampler_clear(void)
{
   rb_start = 0;
   rb_size = 0;
   memset (rb_buffer,  0, rb_buffer_size);

   r_frac = 65536;
   r_left [0] = r_left [1] = r_left [2] = r_left [3] = 0;
   r_right[0] = r_right[1] = r_right[2] = r_right[3] = 0;
}

static void resampler_time_ratio(double ratio)
{
   r_step = 65536 * ratio;
   resampler_clear();
}

static void resampler_read(short *data, int num_samples)
{
   int i_position, o_position, consumed;
   short *internal_buffer;

   i_position = rb_start >> 1;
   internal_buffer = (short *)rb_buffer;
   o_position = 0;
   consumed = 0;

   while (o_position < num_samples && consumed < rb_buffer_size)
   {
      int s_left, s_right, max_samples;
      int hermite_val;

      s_left = internal_buffer[i_position];
      s_right = internal_buffer[i_position + 1];
      max_samples = rb_buffer_size >> 1;

      while (r_frac <= 65536 && o_position < num_samples)
      {
         hermite_val	= hermite(r_frac >> 1, r_left [0], r_left [1], r_left [2], r_left [3]);
         data[o_position]     = SHORT_CLAMP (hermite_val);
         hermite_val = hermite(r_frac >> 1, r_right[0], r_right[1], r_right[2], r_right[3]);
         data[o_position + 1] = SHORT_CLAMP (hermite_val);

         o_position += 2;

         r_frac += r_step;
      }

      if (r_frac > 65536)
      {
         r_left [0] = r_left [1];
         r_left [1] = r_left [2];
         r_left [2] = r_left [3];
         r_left [3] = s_left;

         r_right[0] = r_right[1];
         r_right[1] = r_right[2];
         r_right[2] = r_right[3];
         r_right[3] = s_right;

         r_frac -= 65536;

         i_position += 2;
         if (i_position >= max_samples)
            i_position -= max_samples;
         consumed += 2;
      }
   }

   rb_size -= consumed << 1;
   rb_start += consumed << 1;
   if (rb_start >= rb_buffer_size)
      rb_start -= rb_buffer_size;
}

static void resampler_new(int num_samples)
{
   int new_size = num_samples << 1;

   rb_buffer_size = new_size;
   rb_buffer = (unsigned char*)malloc(rb_buffer_size);
   memset (rb_buffer, 0, rb_buffer_size);

   rb_size = 0;
   rb_start = 0;
   resampler_clear();
}

static INLINE bool resampler_push(short *src, int num_samples)
{
   int bytes, end, first_write_size;
   unsigned char *src_ring;

   bytes = num_samples << 1;
   if (MAX_WRITE() < num_samples || SPACE_EMPTY() < bytes)
      return false;

   /* Ring buffer push */
   src_ring = (unsigned char*)src;
   end = (rb_start + rb_size) % rb_buffer_size;
   first_write_size = RESAMPLER_MIN(bytes, rb_buffer_size - end);

   memcpy (rb_buffer + end, src_ring, first_write_size);

   if (bytes > first_write_size)
      memcpy (rb_buffer, src_ring + first_write_size, bytes - first_write_size);

   rb_size += bytes;

   return true;
}

static INLINE void resampler_resize (int num_samples)
{
   /* int size; */
   /* size = num_samples << 1; */
   free(rb_buffer);
   rb_buffer_size = rb_size;
   rb_buffer = (unsigned char*)malloc(rb_buffer_size);
   memset (rb_buffer, 0, rb_buffer_size);

   rb_size = 0;
   rb_start = 0;
}

/***********************************************************************************
   APU
 ***********************************************************************************/

bool S9xMixSamples (short *buffer, unsigned sample_count)
{
   if (AVAIL() >= (sample_count + lag))
   {
      resampler_read(buffer, sample_count);
      if (lag == lag_master)
         lag = 0;
   }
   else
   {
      memset(buffer, 0, sample_count << 1);
      if (lag == 0)
         lag = lag_master;

      return (false);
   }

   return (true);
}

int S9xGetSampleCount (void)
{
   return AVAIL();
}

/* Sets destination for output samples */

static void spc_set_output( short* out, int size )
{
   short *out_end, *in;

   out_end = out + size;
   m.buf_begin = out;
   m.buf_end   = out_end;

   /* Copy extra to output */
   in = m.extra_buf;
   while ( in < m.extra_pos && out < out_end )
      *out++ = *in++;

   /* Handle output being full already */
   if ( out >= out_end )
   {
      /* Have DSP write to remaining extra space */
      out     = dsp_m.extra;
      out_end = &dsp_m.extra[EXTRA_SIZE];

      /* Copy any remaining extra samples as if DSP wrote them */
      while ( in < m.extra_pos )
         *out++ = *in++;
   }

   dsp_set_output( out, out_end - out );
}

void S9xFinalizeSamples (void)
{
   bool ret;

   ret = resampler_push(landing_buffer, SPC_SAMPLE_COUNT());
   sound_in_sync = false;

   /* We weren't able to process the entire buffer. Potential overrun. */
   if (!ret && Settings.SoundSync)
      return;

   if (!Settings.SoundSync || (SPACE_EMPTY() >= SPACE_FILLED()))
      sound_in_sync = true;

   m.extra_clocks &= CLOCKS_PER_SAMPLE - 1;
   spc_set_output(landing_buffer, buffer_size);
}

void S9xClearSamples (void)
{
   resampler_clear();
   lag = lag_master;
}

bool S9xSyncSound (void)
{
   if (!Settings.SoundSync || sound_in_sync)
      return true;

   sa_callback();

   return sound_in_sync;
}

void S9xSetSamplesAvailableCallback (apu_callback callback)
{
   sa_callback = callback;
}

static void UpdatePlaybackRate (void)
{
   double time_ratio;
   if (Settings.SoundInputRate == 0)
      Settings.SoundInputRate = APU_DEFAULT_INPUT_RATE;

   time_ratio = (double) Settings.SoundInputRate * TEMPO_UNIT / (Settings.SoundPlaybackRate * timing_hack_denominator);
   resampler_time_ratio(time_ratio);
}

bool S9xInitSound (int buffer_ms, int lag_ms)
{
   /*	buffer_ms : buffer size given in millisecond
      lag_ms    : allowable time-lag given in millisecond */
   int sample_count, lag_sample_count;

   sample_count     = buffer_ms * 32000 / 1000;
   lag_sample_count = lag_ms    * 32000 / 1000;

   lag_master = lag_sample_count;

   lag_master <<= 1;

   lag = lag_master;

   if (sample_count < APU_MINIMUM_SAMPLE_COUNT)
      sample_count = APU_MINIMUM_SAMPLE_COUNT;

   buffer_size = sample_count;
   buffer_size <<= 1;
   buffer_size <<= 1;

   printf("Sound buffer size: %d (%d samples)\n", buffer_size, sample_count);

   if (landing_buffer)
      free(landing_buffer);
   landing_buffer = (short*)malloc(buffer_size * 2);
   if (!landing_buffer)
      return (false);

   /* The resampler and spc unit use samples (16-bit short) as
      arguments. Use 2x in the resampler for buffer leveling with SoundSync */

   if (!resampler)
   {
      resampler_new(buffer_size >> (Settings.SoundSync ? 0 : 1));
      resampler = true;
   }
   else
      resampler_resize(buffer_size >> (Settings.SoundSync ? 0 : 1));

   m.extra_clocks &= CLOCKS_PER_SAMPLE - 1;
   spc_set_output(landing_buffer, buffer_size >> 1);

   UpdatePlaybackRate();

   return true;
}

/* Must be called once before using */
static unsigned char cycle_table [128] =
{/*   01   23   45   67   89   AB   CD   EF */
   0x28,0x47,0x34,0x36,0x26,0x54,0x54,0x68, /* 0 */
   0x48,0x47,0x45,0x56,0x55,0x65,0x22,0x46, /* 1 */
   0x28,0x47,0x34,0x36,0x26,0x54,0x54,0x74, /* 2 */
   0x48,0x47,0x45,0x56,0x55,0x65,0x22,0x38, /* 3 */
   0x28,0x47,0x34,0x36,0x26,0x44,0x54,0x66, /* 4 */
   0x48,0x47,0x45,0x56,0x55,0x45,0x22,0x43, /* 5 */
   0x28,0x47,0x34,0x36,0x26,0x44,0x54,0x75, /* 6 */
   0x48,0x47,0x45,0x56,0x55,0x55,0x22,0x36, /* 7 */
   0x28,0x47,0x34,0x36,0x26,0x54,0x52,0x45, /* 8 */
   0x48,0x47,0x45,0x56,0x55,0x55,0x22,0xC5, /* 9 */
   0x38,0x47,0x34,0x36,0x26,0x44,0x52,0x44, /* A */
   0x48,0x47,0x45,0x56,0x55,0x55,0x22,0x34, /* B */
   0x38,0x47,0x45,0x47,0x25,0x64,0x52,0x49, /* C */
   0x48,0x47,0x56,0x67,0x45,0x55,0x22,0x83, /* D */
   0x28,0x47,0x34,0x36,0x24,0x53,0x43,0x40, /* E */
   0x48,0x47,0x45,0x56,0x34,0x54,0x22,0x60, /* F */
};

static signed char const reg_times_ [256] =
{
   -1,  0,-11,-10,-15,-11, -2, -2,  4,  3, 14, 14, 26, 26, 14, 22,
   2,  3,  0,  1,-12,  0,  1,  1,  7,  6, 14, 14, 27, 14, 14, 23,
   5,  6,  3,  4, -1,  3,  4,  4, 10,  9, 14, 14, 26, -5, 14, 23,
   8,  9,  6,  7,  2,  6,  7,  7, 13, 12, 14, 14, 27, -4, 14, 24,
   11, 12,  9, 10,  5,  9, 10, 10, 16, 15, 14, 14, -2, -4, 14, 24,
   14, 15, 12, 13,  8, 12, 13, 13, 19, 18, 14, 14, -2,-36, 14, 24,
   17, 18, 15, 16, 11, 15, 16, 16, 22, 21, 14, 14, 28, -3, 14, 25,
   20, 21, 18, 19, 14, 18, 19, 19, 25, 24, 14, 14, 14, 29, 14, 25,

   29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
   29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
   29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
   29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
   29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
   29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
   29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
   29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
};

bool S9xInitAPU (void)
{
   int i;

   uint8_t APUROM[64] =
   {
      0xCD, 0xEF, 0xBD, 0xE8, 0x00, 0xC6, 0x1D, 0xD0,
      0xFC, 0x8F, 0xAA, 0xF4, 0x8F, 0xBB, 0xF5, 0x78,
      0xCC, 0xF4, 0xD0, 0xFB, 0x2F, 0x19, 0xEB, 0xF4,
      0xD0, 0xFC, 0x7E, 0xF4, 0xD0, 0x0B, 0xE4, 0xF5,
      0xCB, 0xF4, 0xD7, 0x00, 0xFC, 0xD0, 0xF3, 0xAB,
      0x01, 0x10, 0xEF, 0x7E, 0xF4, 0x10, 0xEB, 0xBA,
      0xF6, 0xDA, 0x00, 0xBA, 0xF4, 0xC4, 0xF4, 0xDD,
      0x5D, 0xD0, 0xDB, 0x1F, 0x00, 0x00, 0xC0, 0xFF
   };

   memset( &m, 0, sizeof m );
   dsp_init( m.ram.ram );

   m.tempo = TEMPO_UNIT;

   /*	Most SPC music doesn't need ROM, and almost all the rest only
      rely on these two bytes */

   m.rom [0x3E] = 0xFF;
   m.rom [0x3F] = 0xC0;


   /* unpack cycle table */
   for ( i = 0; i < 128; i++ )
   {
      int n;
      n = cycle_table [i];
      m.cycle_table [i * 2 + 0] = n >> 4;
      m.cycle_table [i * 2 + 1] = n & 0x0F;
   }

   allow_time_overflow = false;

   dsp_m.rom = m.rom;
   dsp_m.hi_ram = m.hi_ram;


   memcpy( reg_times, reg_times_, sizeof reg_times );

   spc_reset();


   memcpy( m.rom, APUROM, sizeof m.rom );

   landing_buffer = NULL;

   return true;
}

void S9xDeinitAPU (void)
{
   if (resampler)
   {
      free(rb_buffer);
      resampler = false;
   }

   if (landing_buffer)
   {
      free(landing_buffer);
      landing_buffer = NULL;
   }
}

#define S9X_APU_GET_CLOCK(cpucycles)		((ratio_numerator * (cpucycles - reference_time) + spc_remainder) / ratio_denominator)
#define S9X_APU_GET_CLOCK_REMAINDER(cpucycles)	((ratio_numerator * (cpucycles - reference_time) + spc_remainder) % ratio_denominator)

/* Emulated port read at specified time */

uint8_t S9xAPUReadPort (int port)	{ return ((uint8_t) spc_run_until_(S9X_APU_GET_CLOCK(CPU.Cycles))[port]); }

/* Emulated port write at specified time */

void S9xAPUWritePort (int port, uint8_t byte)
{
   spc_run_until_( S9X_APU_GET_CLOCK(CPU.Cycles) ) [0x10 + port] = byte;
   m.ram.ram [0xF4 + port] = byte;
}

void S9xAPUSetReferenceTime (int32_t cpucycles)
{
   reference_time = cpucycles;
}

void S9xAPUExecute (void)
{
   /* Accumulate partial APU cycles */
   spc_end_frame(S9X_APU_GET_CLOCK(CPU.Cycles));

   spc_remainder = S9X_APU_GET_CLOCK_REMAINDER(CPU.Cycles);
   reference_time = CPU.Cycles;

   if (SPC_SAMPLE_COUNT() >= APU_MINIMUM_SAMPLE_BLOCK || !sound_in_sync)
      sa_callback();
}

void S9xAPUTimingSetSpeedup (int ticks)
{
   if (ticks != 0)
      printf("APU speedup hack: %d\n", ticks);

   timing_hack_denominator = TEMPO_UNIT - ticks;
   spc_set_tempo(timing_hack_denominator);

   ratio_numerator = Settings.PAL ? APU_NUMERATOR_PAL : APU_NUMERATOR_NTSC;
   ratio_denominator = Settings.PAL ? APU_DENOMINATOR_PAL : APU_DENOMINATOR_NTSC;
   ratio_denominator = ratio_denominator * timing_hack_denominator / TEMPO_UNIT;

   UpdatePlaybackRate();
}

void S9xAPUAllowTimeOverflow (bool allow)
{
   allow_time_overflow = allow;
}

void S9xResetAPU (void)
{
   reference_time = 0;
   spc_remainder = 0;
   spc_reset();

   m.extra_clocks &= CLOCKS_PER_SAMPLE - 1;

   spc_set_output(landing_buffer, buffer_size >> 1);

   resampler_clear();
}

void S9xSoftResetAPU (void)
{
   reference_time = 0;
   spc_remainder = 0;
   spc_soft_reset();

   m.extra_clocks &= CLOCKS_PER_SAMPLE - 1;
   spc_set_output(landing_buffer, buffer_size >> 1);

   resampler_clear();
}

static void from_apu_to_state (uint8_t **buf, void *var, size_t size)
{
   memcpy(*buf, var, size);
   *buf += size;
}

static void to_apu_from_state (uint8_t **buf, void *var, size_t size)
{
   memcpy(var, *buf, size);
   *buf += size;
}

// work around optimization bug in android GCC
// similar to this: http://jeffq.com/blog/over-aggressive-gcc-optimization-can-cause-sigbus-crash-when-using-memcpy-with-the-android-ndk/
#if defined(ANDROID) || defined(__QNX__)
void __attribute__((optimize(0))) S9xAPUSaveState (uint8_t *block)
#else
void S9xAPUSaveState (uint8_t *block)
#endif
{
   uint8_t *ptr;

   ptr = block;

   spc_copy_state(&ptr, from_apu_to_state);

   SET_LE32(ptr, reference_time);
   ptr += sizeof(int32_t);
   SET_LE32(ptr, spc_remainder);
}

#if defined(ANDROID) || defined(__QNX__)
void __attribute__((optimize(0))) S9xAPULoadState (uint8_t *block)
#else
void S9xAPULoadState (uint8_t *block)
#endif
{
   uint8_t *ptr;

   ptr = block;

   S9xResetAPU();

   spc_copy_state(&ptr, to_apu_from_state);

   reference_time = GET_LE32(ptr);
   ptr += sizeof(int32_t);
   spc_remainder = GET_LE32(ptr);
}

#undef  INLINE
#define INLINE static inline

#endif