qzdoom/libraries/game-music-emu/gme/Spc_Cpu.cpp

549 lines
16 KiB
C++

// Core SPC emulation: CPU, timers, SMP registers, memory
// Game_Music_Emu https://bitbucket.org/mpyne/game-music-emu/
#include "Snes_Spc.h"
#include <string.h>
/* 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 */
#include "blargg_source.h"
#define RAM (m.ram.ram)
#define REGS (m.smp_regs [0])
#define REGS_IN (m.smp_regs [1])
// (n ? n : 256)
#define IF_0_THEN_256( n ) ((uint8_t) ((n) - 1) + 1)
// Note: SPC_MORE_ACCURACY exists mainly so I can run my validation tests, which
// do crazy echo buffer accesses.
#ifndef SPC_MORE_ACCURACY
#define SPC_MORE_ACCURACY 0
#endif
#ifdef BLARGG_ENABLE_OPTIMIZER
#include BLARGG_ENABLE_OPTIMIZER
#endif
//// Timers
#if SPC_DISABLE_TEMPO
#define TIMER_DIV( t, n ) ((n) >> t->prescaler)
#define TIMER_MUL( t, n ) ((n) << t->prescaler)
#else
#define TIMER_DIV( t, n ) ((n) / t->prescaler)
#define TIMER_MUL( t, n ) ((n) * t->prescaler)
#endif
Snes_Spc::Timer* Snes_Spc::run_timer_( Timer* t, rel_time_t time )
{
int elapsed = TIMER_DIV( t, time - t->next_time ) + 1;
t->next_time += TIMER_MUL( t, elapsed );
if ( t->enabled )
{
int remain = IF_0_THEN_256( t->period - t->divider );
int divider = t->divider + elapsed;
int over = elapsed - remain;
if ( over >= 0 )
{
int n = over / t->period;
t->counter = (t->counter + 1 + n) & 0x0F;
divider = over - n * t->period;
}
t->divider = (uint8_t) divider;
}
return t;
}
inline Snes_Spc::Timer* Snes_Spc::run_timer( Timer* t, rel_time_t time )
{
if ( time >= t->next_time )
t = run_timer_( t, time );
return t;
}
//// ROM
void Snes_Spc::enable_rom( int enable )
{
if ( m.rom_enabled != enable )
{
m.rom_enabled = enable;
if ( enable )
memcpy( m.hi_ram, &RAM [rom_addr], sizeof m.hi_ram );
memcpy( &RAM [rom_addr], (enable ? m.rom : m.hi_ram), rom_size );
// TODO: ROM can still get overwritten when DSP writes to echo buffer
}
}
//// DSP
#if SPC_LESS_ACCURATE
int const max_reg_time = 29;
signed char const Snes_Spc::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,
};
#define RUN_DSP( time, offset ) \
int count = (time) - (offset) - m.dsp_time;\
if ( count >= 0 )\
{\
int clock_count = (count & ~(clocks_per_sample - 1)) + clocks_per_sample;\
m.dsp_time += clock_count;\
dsp.run( clock_count );\
}
#else
#define RUN_DSP( time, offset ) \
{\
int count = (time) - m.dsp_time;\
if ( !SPC_MORE_ACCURACY || count )\
{\
assert( count > 0 );\
m.dsp_time = (time);\
dsp.run( count );\
}\
}
#endif
int Snes_Spc::dsp_read( rel_time_t time )
{
RUN_DSP( time, reg_times [REGS [r_dspaddr] & 0x7F] );
int result = dsp.read( REGS [r_dspaddr] & 0x7F );
#ifdef SPC_DSP_READ_HOOK
SPC_DSP_READ_HOOK( spc_time + time, (REGS [r_dspaddr] & 0x7F), result );
#endif
return result;
}
inline void Snes_Spc::dsp_write( int data, rel_time_t time )
{
RUN_DSP( time, reg_times [REGS [r_dspaddr]] )
#if SPC_LESS_ACCURATE
else if ( m.dsp_time == skipping_time )
{
int r = REGS [r_dspaddr];
if ( r == Spc_Dsp::r_kon )
m.skipped_kon |= data & ~dsp.read( Spc_Dsp::r_koff );
if ( r == Spc_Dsp::r_koff )
{
m.skipped_koff |= data;
m.skipped_kon &= ~data;
}
}
#endif
#ifdef SPC_DSP_WRITE_HOOK
SPC_DSP_WRITE_HOOK( m.spc_time + time, REGS [r_dspaddr], (uint8_t) data );
#endif
if ( REGS [r_dspaddr] <= 0x7F )
dsp.write( REGS [r_dspaddr], data );
else if ( !SPC_MORE_ACCURACY )
debug_printf( "SPC wrote to DSP register > $7F\n" );
}
//// Memory access extras
#if SPC_MORE_ACCURACY
#define MEM_ACCESS( time, addr ) \
{\
if ( time >= m.dsp_time )\
{\
RUN_DSP( time, max_reg_time );\
}\
}
#elif !defined (NDEBUG)
// Debug-only check for read/write within echo buffer, since this might result in
// inaccurate emulation due to the DSP not being caught up to the present.
bool Snes_Spc::check_echo_access( int addr )
{
if ( !(dsp.read( Spc_Dsp::r_flg ) & 0x20) )
{
int start = 0x100 * dsp.read( Spc_Dsp::r_esa );
int size = 0x800 * (dsp.read( Spc_Dsp::r_edl ) & 0x0F);
int end = start + (size ? size : 4);
if ( start <= addr && addr < end )
{
if ( !m.echo_accessed )
{
m.echo_accessed = 1;
return true;
}
}
}
return false;
}
#define MEM_ACCESS( time, addr ) check( !check_echo_access( (uint16_t) addr ) );
#else
#define MEM_ACCESS( time, addr )
#endif
//// CPU write
#if SPC_MORE_ACCURACY
static unsigned char const glitch_probs [3] [256] =
{
0xC3,0x92,0x5B,0x1C,0xD1,0x92,0x5B,0x1C,0xDB,0x9C,0x72,0x18,0xCD,0x5C,0x38,0x0B,
0xE1,0x9C,0x74,0x17,0xCF,0x75,0x45,0x0C,0xCF,0x6E,0x4A,0x0D,0xA3,0x3A,0x1D,0x08,
0xDB,0xA0,0x82,0x19,0xD9,0x73,0x3C,0x0E,0xCB,0x76,0x52,0x0B,0xA5,0x46,0x1D,0x09,
0xDA,0x74,0x55,0x0F,0xA2,0x3F,0x21,0x05,0x9A,0x40,0x20,0x07,0x63,0x1E,0x10,0x01,
0xDF,0xA9,0x85,0x1D,0xD3,0x84,0x4B,0x0E,0xCF,0x6F,0x49,0x0F,0xB3,0x48,0x1E,0x05,
0xD8,0x77,0x52,0x12,0xB7,0x49,0x23,0x06,0xAA,0x45,0x28,0x07,0x7D,0x28,0x0F,0x07,
0xCC,0x7B,0x4A,0x0E,0xB2,0x4F,0x24,0x07,0xAD,0x43,0x2C,0x06,0x86,0x29,0x11,0x07,
0xAE,0x48,0x1F,0x0A,0x76,0x21,0x19,0x05,0x76,0x21,0x14,0x05,0x44,0x11,0x0B,0x01,
0xE7,0xAD,0x96,0x23,0xDC,0x86,0x59,0x0E,0xDC,0x7C,0x5F,0x15,0xBB,0x53,0x2E,0x09,
0xD6,0x7C,0x4A,0x16,0xBB,0x4A,0x25,0x08,0xB3,0x4F,0x28,0x0B,0x8E,0x23,0x15,0x08,
0xCF,0x7F,0x57,0x11,0xB5,0x4A,0x23,0x0A,0xAA,0x42,0x28,0x05,0x7D,0x22,0x12,0x03,
0xA6,0x49,0x28,0x09,0x82,0x2B,0x0D,0x04,0x7A,0x20,0x0F,0x04,0x3D,0x0F,0x09,0x03,
0xD1,0x7C,0x4C,0x0F,0xAF,0x4E,0x21,0x09,0xA8,0x46,0x2A,0x07,0x85,0x1F,0x0E,0x07,
0xA6,0x3F,0x26,0x07,0x7C,0x24,0x14,0x07,0x78,0x22,0x16,0x04,0x46,0x12,0x0A,0x02,
0xA6,0x41,0x2C,0x0A,0x7E,0x28,0x11,0x05,0x73,0x1B,0x14,0x05,0x3D,0x11,0x0A,0x02,
0x70,0x22,0x17,0x05,0x48,0x13,0x08,0x03,0x3C,0x07,0x0D,0x07,0x26,0x07,0x06,0x01,
0xE0,0x9F,0xDA,0x7C,0x4F,0x18,0x28,0x0D,0xE9,0x9F,0xDA,0x7C,0x4F,0x18,0x1F,0x07,
0xE6,0x97,0xD8,0x72,0x64,0x13,0x26,0x09,0xDC,0x67,0xA9,0x38,0x21,0x07,0x15,0x06,
0xE9,0x91,0xD2,0x6B,0x63,0x14,0x2B,0x0E,0xD6,0x61,0xB7,0x41,0x2B,0x0E,0x10,0x09,
0xCF,0x59,0xB0,0x2F,0x35,0x08,0x0F,0x07,0xB6,0x30,0x7A,0x21,0x17,0x07,0x09,0x03,
0xE7,0xA3,0xE5,0x6B,0x65,0x1F,0x34,0x09,0xD8,0x6B,0xBE,0x45,0x27,0x07,0x10,0x07,
0xDA,0x54,0xB1,0x39,0x2E,0x0E,0x17,0x08,0xA9,0x3C,0x86,0x22,0x16,0x06,0x07,0x03,
0xD4,0x51,0xBC,0x3D,0x38,0x0A,0x13,0x06,0xB2,0x37,0x79,0x1C,0x17,0x05,0x0E,0x06,
0xA7,0x31,0x74,0x1C,0x11,0x06,0x0C,0x02,0x6D,0x1A,0x38,0x10,0x0B,0x05,0x06,0x03,
0xEB,0x9A,0xE1,0x7A,0x6F,0x13,0x34,0x0E,0xE6,0x75,0xC5,0x45,0x3E,0x0B,0x1A,0x05,
0xD8,0x63,0xC1,0x40,0x3C,0x1B,0x19,0x06,0xB3,0x42,0x83,0x29,0x18,0x0A,0x08,0x04,
0xD4,0x58,0xBA,0x43,0x3F,0x0A,0x1F,0x09,0xB1,0x33,0x8A,0x1F,0x1F,0x06,0x0D,0x05,
0xAF,0x3C,0x7A,0x1F,0x16,0x08,0x0A,0x01,0x72,0x1B,0x52,0x0D,0x0B,0x09,0x06,0x01,
0xCF,0x63,0xB7,0x47,0x40,0x10,0x14,0x06,0xC0,0x41,0x96,0x20,0x1C,0x09,0x10,0x05,
0xA6,0x35,0x82,0x1A,0x20,0x0C,0x0E,0x04,0x80,0x1F,0x53,0x0F,0x0B,0x02,0x06,0x01,
0xA6,0x31,0x81,0x1B,0x1D,0x01,0x08,0x08,0x7B,0x20,0x4D,0x19,0x0E,0x05,0x07,0x03,
0x6B,0x17,0x49,0x07,0x0E,0x03,0x0A,0x05,0x37,0x0B,0x1F,0x06,0x04,0x02,0x07,0x01,
0xF0,0xD6,0xED,0xAD,0xEC,0xB1,0xEB,0x79,0xAC,0x22,0x47,0x1E,0x6E,0x1B,0x32,0x0A,
0xF0,0xD6,0xEA,0xA4,0xED,0xC4,0xDE,0x82,0x98,0x1F,0x50,0x13,0x52,0x15,0x2A,0x0A,
0xF1,0xD1,0xEB,0xA2,0xEB,0xB7,0xD8,0x69,0xA2,0x1F,0x5B,0x18,0x55,0x18,0x2C,0x0A,
0xED,0xB5,0xDE,0x7E,0xE6,0x85,0xD3,0x59,0x59,0x0F,0x2C,0x09,0x24,0x07,0x15,0x09,
0xF1,0xD6,0xEA,0xA0,0xEC,0xBB,0xDA,0x77,0xA9,0x23,0x58,0x14,0x5D,0x12,0x2F,0x09,
0xF1,0xC1,0xE3,0x86,0xE4,0x87,0xD2,0x4E,0x68,0x15,0x26,0x0B,0x27,0x09,0x15,0x02,
0xEE,0xA6,0xE0,0x5C,0xE0,0x77,0xC3,0x41,0x67,0x1B,0x3C,0x07,0x2A,0x06,0x19,0x07,
0xE4,0x75,0xC6,0x43,0xCC,0x50,0x95,0x23,0x35,0x09,0x14,0x04,0x15,0x05,0x0B,0x04,
0xEE,0xD6,0xED,0xAD,0xEC,0xB1,0xEB,0x79,0xAC,0x22,0x56,0x14,0x5A,0x12,0x26,0x0A,
0xEE,0xBB,0xE7,0x7E,0xE9,0x8D,0xCB,0x49,0x67,0x11,0x34,0x07,0x2B,0x0B,0x14,0x07,
0xED,0xA7,0xE5,0x76,0xE3,0x7E,0xC4,0x4B,0x77,0x14,0x34,0x08,0x27,0x07,0x14,0x04,
0xE7,0x8B,0xD2,0x4C,0xCA,0x56,0x9E,0x31,0x36,0x0C,0x11,0x07,0x14,0x04,0x0A,0x02,
0xF0,0x9B,0xEA,0x6F,0xE5,0x81,0xC4,0x43,0x74,0x10,0x30,0x0B,0x2D,0x08,0x1B,0x06,
0xE6,0x83,0xCA,0x48,0xD9,0x56,0xA7,0x23,0x3B,0x09,0x12,0x09,0x15,0x07,0x0A,0x03,
0xE5,0x5F,0xCB,0x3C,0xCF,0x48,0x91,0x22,0x31,0x0A,0x17,0x08,0x15,0x04,0x0D,0x02,
0xD1,0x43,0x91,0x20,0xA9,0x2D,0x54,0x12,0x17,0x07,0x09,0x02,0x0C,0x04,0x05,0x03,
};
#endif
// Read/write handlers are 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;
void Snes_Spc::cpu_write_smp_reg_( int data, rel_time_t time, uint16_t addr )
{
switch ( addr )
{
case r_t0target:
case r_t1target:
case r_t2target: {
Timer* t = &m.timers [addr - r_t0target];
int period = IF_0_THEN_256( data );
if ( t->period != period )
{
t = run_timer( t, time );
#if SPC_MORE_ACCURACY
// Insane behavior when target is written just after counter is
// clocked and counter matches new period and new period isn't 1, 2, 4, or 8
if ( t->divider == (period & 0xFF) &&
t->next_time == time + TIMER_MUL( t, 1 ) &&
((period - 1) | ~0x0F) & period )
{
//debug_printf( "SPC pathological timer target write\n" );
// If the period is 3, 5, or 9, there's a probability this behavior won't occur,
// based on the previous period
int prob = 0xFF;
int old_period = t->period & 0xFF;
if ( period == 3 ) prob = glitch_probs [0] [old_period];
if ( period == 5 ) prob = glitch_probs [1] [old_period];
if ( period == 9 ) prob = glitch_probs [2] [old_period];
// The glitch suppresses incrementing of one of the counter bits, based on
// the lowest set bit in the new period
int b = 1;
while ( !(period & b) )
b <<= 1;
if ( (rand() >> 4 & 0xFF) <= prob )
t->divider = (t->divider - b) & 0xFF;
}
#endif
t->period = period;
}
break;
}
case r_t0out:
case r_t1out:
case r_t2out:
if ( !SPC_MORE_ACCURACY )
debug_printf( "SPC wrote to counter %d\n", (int) addr - r_t0out );
if ( data < no_read_before_write / 2 )
run_timer( &m.timers [addr - r_t0out], time - 1 )->counter = 0;
break;
// Registers that act like RAM
case 0x8:
case 0x9:
REGS_IN [addr] = (uint8_t) data;
break;
case r_test:
if ( (uint8_t) data != 0x0A )
debug_printf( "SPC wrote to test register\n" );
break;
case r_control:
// port clears
if ( data & 0x10 )
{
REGS_IN [r_cpuio0] = 0;
REGS_IN [r_cpuio1] = 0;
}
if ( data & 0x20 )
{
REGS_IN [r_cpuio2] = 0;
REGS_IN [r_cpuio3] = 0;
}
// timers
{
for ( int i = 0; i < timer_count; i++ )
{
Timer* t = &m.timers [i];
int enabled = data >> i & 1;
if ( t->enabled != enabled )
{
t = run_timer( t, time );
t->enabled = enabled;
if ( enabled )
{
t->divider = 0;
t->counter = 0;
}
}
}
}
enable_rom( data & 0x80 );
break;
}
}
void Snes_Spc::cpu_write_smp_reg( int data, rel_time_t time, uint16_t addr )
{
if ( addr == r_dspdata ) // 99%
dsp_write( data, time );
else
cpu_write_smp_reg_( data, time, addr );
}
void Snes_Spc::cpu_write_high( int data, uint8_t i )
{
assert ( i < rom_size );
m.hi_ram [i] = (uint8_t) data;
if ( m.rom_enabled )
RAM [i + rom_addr] = m.rom [i]; // restore overwritten ROM
}
void Snes_Spc::cpu_write( int data, uint16_t addr, rel_time_t time )
{
MEM_ACCESS( time, addr )
// RAM
RAM [addr] = (uint8_t) data;
if ( addr >= 0xF0 ) // 64%
{
const uint16_t reg = addr - 0xF0;
// $F0-$FF
if ( reg < reg_count ) // 87%
{
REGS [reg] = (uint8_t) data;
// Ports
#ifdef SPC_PORT_WRITE_HOOK
if ( (unsigned) (reg - r_cpuio0) < port_count )
SPC_PORT_WRITE_HOOK( m.spc_time + time, (reg - r_cpuio0),
(uint8_t) data, &REGS [r_cpuio0] );
#endif
// Registers other than $F2 and $F4-$F7
if ( reg != 2 && (reg < 4 || reg > 7) ) // 36%
cpu_write_smp_reg( data, time, reg );
}
// High mem/address wrap-around
else if ( addr >= rom_addr ) // 1% in IPL ROM area or address wrapped around
cpu_write_high( data, addr - rom_addr );
}
}
//// CPU read
inline int Snes_Spc::cpu_read_smp_reg( int reg, rel_time_t time )
{
int result = REGS_IN [reg];
reg -= r_dspaddr;
// DSP addr and data
if ( (unsigned) reg <= 1 ) // 4% 0xF2 and 0xF3
{
result = REGS [r_dspaddr];
if ( (unsigned) reg == 1 )
result = dsp_read( time ); // 0xF3
}
return result;
}
int Snes_Spc::cpu_read( uint16_t addr, rel_time_t time )
{
MEM_ACCESS( time, addr )
// RAM
int result = RAM [addr];
int 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 = run_timer_( t, time );
result = t->counter;
t->counter = 0;
}
// Other registers
else if ( reg < 0 ) // 10%
{
result = cpu_read_smp_reg( reg + r_t0out, time );
}
else // 1%
{
assert( reg + (r_t0out + 0xF0 - 0x10000) < 0x100 );
result = cpu_read( reg + (r_t0out + 0xF0 - 0x10000), time );
}
}
}
return result;
}
//// Run
// Prefix and suffix for CPU emulator function
#define SPC_CPU_RUN_FUNC \
uint8_t* Snes_Spc::run_until_( time_t end_time )\
{\
rel_time_t rel_time = m.spc_time - end_time;\
assert( rel_time <= 0 );\
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;
#define SPC_CPU_RUN_FUNC_END \
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;\
assert( m.spc_time <= end_time );\
return &REGS [r_cpuio0];\
}
int const cpu_lag_max = 12 - 1; // DIV YA,X takes 12 clocks
void Snes_Spc::end_frame( time_t end_time )
{
// 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 )
run_until_( end_time );
m.spc_time -= end_time;
m.extra_clocks += end_time;
// Greatest number of clocks early that emulation can stop early due to
// not being able to execute current instruction without going over
// allowed time.
assert( -cpu_lag_max <= m.spc_time && m.spc_time <= 0 );
// Catch timers up to CPU
for ( int i = 0; i < timer_count; i++ )
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 )
save_extra();
}
// Inclusion here allows static memory access functions and better optimization
#include "Spc_Cpu.h"