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gzdoom-gles/game-music-emu/gme/Hes_Cpu.cpp
Randy Heit a8de4fc2da - Fixed compilation of i_keyboard.cpp with MinGW, because w32api still doesn't have
everything that was new for XP.
- Swapped snes_spc out for the full Game Music Emu library.

SVN r1631 (trunk)
2009-06-03 03:05:02 +00:00

1303 lines
24 KiB
C++

// Game_Music_Emu 0.5.2. http://www.slack.net/~ant/
#include "Hes_Cpu.h"
#include "blargg_endian.h"
//#include "hes_cpu_log.h"
/* Copyright (C) 2003-2006 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 */
// TODO: support T flag, including clearing it at appropriate times?
// all zero-page should really use whatever is at page 1, but that would
// reduce efficiency quite a bit
int const ram_addr = 0x2000;
#define FLUSH_TIME() (void) (s.time = s_time)
#define CACHE_TIME() (void) (s_time = s.time)
#include "hes_cpu_io.h"
#include "blargg_source.h"
#if BLARGG_NONPORTABLE
#define PAGE_OFFSET( addr ) (addr)
#else
#define PAGE_OFFSET( addr ) ((addr) & (page_size - 1))
#endif
// status flags
int const st_n = 0x80;
int const st_v = 0x40;
int const st_t = 0x20;
int const st_b = 0x10;
int const st_d = 0x08;
int const st_i = 0x04;
int const st_z = 0x02;
int const st_c = 0x01;
void Hes_Cpu::reset()
{
check( state == &state_ );
state = &state_;
state_.time = 0;
state_.base = 0;
irq_time_ = future_hes_time;
end_time_ = future_hes_time;
r.status = st_i;
r.sp = 0;
r.pc = 0;
r.a = 0;
r.x = 0;
r.y = 0;
blargg_verify_byte_order();
}
void Hes_Cpu::set_mmr( int reg, int bank )
{
assert( (unsigned) reg <= page_count ); // allow page past end to be set
assert( (unsigned) bank < 0x100 );
mmr [reg] = bank;
uint8_t const* code = CPU_SET_MMR( this, reg, bank );
state->code_map [reg] = code - PAGE_OFFSET( reg << page_shift );
}
#define TIME (s_time + s.base)
#define READ( addr ) CPU_READ( this, (addr), TIME )
#define WRITE( addr, data ) {CPU_WRITE( this, (addr), (data), TIME );}
#define READ_LOW( addr ) (ram [int (addr)])
#define WRITE_LOW( addr, data ) (void) (READ_LOW( addr ) = (data))
#define READ_PROG( addr ) (s.code_map [(addr) >> page_shift] [PAGE_OFFSET( addr )])
#define SET_SP( v ) (sp = ((v) + 1) | 0x100)
#define GET_SP() ((sp - 1) & 0xFF)
#define PUSH( v ) ((sp = (sp - 1) | 0x100), WRITE_LOW( sp, v ))
// even on x86, using short and unsigned char was slower
typedef int fint16;
typedef unsigned fuint16;
typedef unsigned fuint8;
typedef blargg_long fint32;
bool Hes_Cpu::run( hes_time_t end_time )
{
bool illegal_encountered = false;
set_end_time( end_time );
state_t s = this->state_;
this->state = &s;
// even on x86, using s.time in place of s_time was slower
fint16 s_time = s.time;
// registers
fuint16 pc = r.pc;
fuint8 a = r.a;
fuint8 x = r.x;
fuint8 y = r.y;
fuint16 sp;
SET_SP( r.sp );
#define IS_NEG (nz & 0x8080)
#define CALC_STATUS( out ) do {\
out = status & (st_v | st_d | st_i);\
out |= ((nz >> 8) | nz) & st_n;\
out |= c >> 8 & st_c;\
if ( !(nz & 0xFF) ) out |= st_z;\
} while ( 0 )
#define SET_STATUS( in ) do {\
status = in & (st_v | st_d | st_i);\
nz = in << 8;\
c = nz;\
nz |= ~in & st_z;\
} while ( 0 )
fuint8 status;
fuint16 c; // carry set if (c & 0x100) != 0
fuint16 nz; // Z set if (nz & 0xFF) == 0, N set if (nz & 0x8080) != 0
{
fuint8 temp = r.status;
SET_STATUS( temp );
}
goto loop;
branch_not_taken:
s_time -= 2;
loop:
#ifndef NDEBUG
{
hes_time_t correct = end_time_;
if ( !(status & st_i) && correct > irq_time_ )
correct = irq_time_;
check( s.base == correct );
/*
static long count;
if ( count == 1844 ) Debugger();
if ( s.base != correct ) dprintf( "%ld\n", count );
count++;
*/
}
#endif
check( (unsigned) GET_SP() < 0x100 );
check( (unsigned) a < 0x100 );
check( (unsigned) x < 0x100 );
uint8_t const* instr = s.code_map [pc >> page_shift];
fuint8 opcode;
// TODO: eliminate this special case
#if BLARGG_NONPORTABLE
opcode = instr [pc];
pc++;
instr += pc;
#else
instr += PAGE_OFFSET( pc );
opcode = *instr++;
pc++;
#endif
// TODO: each reference lists slightly different timing values, ugh
static uint8_t const clock_table [256] =
{// 0 1 2 3 4 5 6 7 8 9 A B C D E F
1,7,3, 4,6,4,6,7,3,2,2,2,7,5,7,6,// 0
4,7,7, 4,6,4,6,7,2,5,2,2,7,5,7,6,// 1
7,7,3, 4,4,4,6,7,4,2,2,2,5,5,7,6,// 2
4,7,7, 2,4,4,6,7,2,5,2,2,5,5,7,6,// 3
7,7,3, 4,8,4,6,7,3,2,2,2,4,5,7,6,// 4
4,7,7, 5,2,4,6,7,2,5,3,2,2,5,7,6,// 5
7,7,2, 2,4,4,6,7,4,2,2,2,7,5,7,6,// 6
4,7,7,17,4,4,6,7,2,5,4,2,7,5,7,6,// 7
4,7,2, 7,4,4,4,7,2,2,2,2,5,5,5,6,// 8
4,7,7, 8,4,4,4,7,2,5,2,2,5,5,5,6,// 9
2,7,2, 7,4,4,4,7,2,2,2,2,5,5,5,6,// A
4,7,7, 8,4,4,4,7,2,5,2,2,5,5,5,6,// B
2,7,2,17,4,4,6,7,2,2,2,2,5,5,7,6,// C
4,7,7,17,2,4,6,7,2,5,3,2,2,5,7,6,// D
2,7,2,17,4,4,6,7,2,2,2,2,5,5,7,6,// E
4,7,7,17,2,4,6,7,2,5,4,2,2,5,7,6 // F
}; // 0x00 was 8
fuint16 data;
data = clock_table [opcode];
if ( (s_time += data) >= 0 )
goto possibly_out_of_time;
almost_out_of_time:
data = *instr;
#ifdef HES_CPU_LOG_H
log_cpu( "new", pc - 1, opcode, instr [0], instr [1], instr [2],
instr [3], instr [4], instr [5] );
//log_opcode( opcode );
#endif
switch ( opcode )
{
possibly_out_of_time:
if ( s_time < (int) data )
goto almost_out_of_time;
s_time -= data;
goto out_of_time;
// Macros
#define GET_MSB() (instr [1])
#define ADD_PAGE( out ) (pc++, out = data + 0x100 * GET_MSB());
#define GET_ADDR() GET_LE16( instr )
// TODO: is the penalty really always added? the original 6502 was much better
//#define PAGE_CROSS_PENALTY( lsb ) (void) (s_time += (lsb) >> 8)
#define PAGE_CROSS_PENALTY( lsb )
// Branch
// TODO: more efficient way to handle negative branch that wraps PC around
#define BRANCH( cond )\
{\
fint16 offset = (BOOST::int8_t) data;\
pc++;\
if ( !(cond) ) goto branch_not_taken;\
pc = BOOST::uint16_t (pc + offset);\
goto loop;\
}
case 0xF0: // BEQ
BRANCH( !((uint8_t) nz) );
case 0xD0: // BNE
BRANCH( (uint8_t) nz );
case 0x10: // BPL
BRANCH( !IS_NEG );
case 0x90: // BCC
BRANCH( !(c & 0x100) )
case 0x30: // BMI
BRANCH( IS_NEG )
case 0x50: // BVC
BRANCH( !(status & st_v) )
case 0x70: // BVS
BRANCH( status & st_v )
case 0xB0: // BCS
BRANCH( c & 0x100 )
case 0x80: // BRA
branch_taken:
BRANCH( true );
case 0xFF:
if ( pc == idle_addr + 1 )
goto idle_done;
case 0x0F: // BBRn
case 0x1F:
case 0x2F:
case 0x3F:
case 0x4F:
case 0x5F:
case 0x6F:
case 0x7F:
case 0x8F: // BBSn
case 0x9F:
case 0xAF:
case 0xBF:
case 0xCF:
case 0xDF:
case 0xEF: {
fuint16 t = 0x101 * READ_LOW( data );
t ^= 0xFF;
pc++;
data = GET_MSB();
BRANCH( t & (1 << (opcode >> 4)) )
}
case 0x4C: // JMP abs
pc = GET_ADDR();
goto loop;
case 0x7C: // JMP (ind+X)
data += x;
case 0x6C:{// JMP (ind)
data += 0x100 * GET_MSB();
pc = GET_LE16( &READ_PROG( data ) );
goto loop;
}
// Subroutine
case 0x44: // BSR
WRITE_LOW( 0x100 | (sp - 1), pc >> 8 );
sp = (sp - 2) | 0x100;
WRITE_LOW( sp, pc );
goto branch_taken;
case 0x20: { // JSR
fuint16 temp = pc + 1;
pc = GET_ADDR();
WRITE_LOW( 0x100 | (sp - 1), temp >> 8 );
sp = (sp - 2) | 0x100;
WRITE_LOW( sp, temp );
goto loop;
}
case 0x60: // RTS
pc = 0x100 * READ_LOW( 0x100 | (sp - 0xFF) );
pc += 1 + READ_LOW( sp );
sp = (sp - 0xFE) | 0x100;
goto loop;
case 0x00: // BRK
goto handle_brk;
// Common
case 0xBD:{// LDA abs,X
PAGE_CROSS_PENALTY( data + x );
fuint16 addr = GET_ADDR() + x;
pc += 2;
CPU_READ_FAST( this, addr, TIME, nz );
a = nz;
goto loop;
}
case 0x9D:{// STA abs,X
fuint16 addr = GET_ADDR() + x;
pc += 2;
CPU_WRITE_FAST( this, addr, a, TIME );
goto loop;
}
case 0x95: // STA zp,x
data = uint8_t (data + x);
case 0x85: // STA zp
pc++;
WRITE_LOW( data, a );
goto loop;
case 0xAE:{// LDX abs
fuint16 addr = GET_ADDR();
pc += 2;
CPU_READ_FAST( this, addr, TIME, nz );
x = nz;
goto loop;
}
case 0xA5: // LDA zp
a = nz = READ_LOW( data );
pc++;
goto loop;
// Load/store
{
fuint16 addr;
case 0x91: // STA (ind),Y
addr = 0x100 * READ_LOW( uint8_t (data + 1) );
addr += READ_LOW( data ) + y;
pc++;
goto sta_ptr;
case 0x81: // STA (ind,X)
data = uint8_t (data + x);
case 0x92: // STA (ind)
addr = 0x100 * READ_LOW( uint8_t (data + 1) );
addr += READ_LOW( data );
pc++;
goto sta_ptr;
case 0x99: // STA abs,Y
data += y;
case 0x8D: // STA abs
addr = data + 0x100 * GET_MSB();
pc += 2;
sta_ptr:
CPU_WRITE_FAST( this, addr, a, TIME );
goto loop;
}
{
fuint16 addr;
case 0xA1: // LDA (ind,X)
data = uint8_t (data + x);
case 0xB2: // LDA (ind)
addr = 0x100 * READ_LOW( uint8_t (data + 1) );
addr += READ_LOW( data );
pc++;
goto a_nz_read_addr;
case 0xB1:// LDA (ind),Y
addr = READ_LOW( data ) + y;
PAGE_CROSS_PENALTY( addr );
addr += 0x100 * READ_LOW( (uint8_t) (data + 1) );
pc++;
goto a_nz_read_addr;
case 0xB9: // LDA abs,Y
data += y;
PAGE_CROSS_PENALTY( data );
case 0xAD: // LDA abs
addr = data + 0x100 * GET_MSB();
pc += 2;
a_nz_read_addr:
CPU_READ_FAST( this, addr, TIME, nz );
a = nz;
goto loop;
}
case 0xBE:{// LDX abs,y
PAGE_CROSS_PENALTY( data + y );
fuint16 addr = GET_ADDR() + y;
pc += 2;
FLUSH_TIME();
x = nz = READ( addr );
CACHE_TIME();
goto loop;
}
case 0xB5: // LDA zp,x
a = nz = READ_LOW( uint8_t (data + x) );
pc++;
goto loop;
case 0xA9: // LDA #imm
pc++;
a = data;
nz = data;
goto loop;
// Bit operations
case 0x3C: // BIT abs,x
data += x;
case 0x2C:{// BIT abs
fuint16 addr;
ADD_PAGE( addr );
FLUSH_TIME();
nz = READ( addr );
CACHE_TIME();
goto bit_common;
}
case 0x34: // BIT zp,x
data = uint8_t (data + x);
case 0x24: // BIT zp
data = READ_LOW( data );
case 0x89: // BIT imm
nz = data;
bit_common:
pc++;
status &= ~st_v;
status |= nz & st_v;
if ( nz & a )
goto loop; // Z should be clear, and nz must be non-zero if nz & a is
nz <<= 8; // set Z flag without affecting N flag
goto loop;
{
fuint16 addr;
case 0xB3: // TST abs,x
addr = GET_MSB() + x;
goto tst_abs;
case 0x93: // TST abs
addr = GET_MSB();
tst_abs:
addr += 0x100 * instr [2];
pc++;
FLUSH_TIME();
nz = READ( addr );
CACHE_TIME();
goto tst_common;
}
case 0xA3: // TST zp,x
nz = READ_LOW( uint8_t (GET_MSB() + x) );
goto tst_common;
case 0x83: // TST zp
nz = READ_LOW( GET_MSB() );
tst_common:
pc += 2;
status &= ~st_v;
status |= nz & st_v;
if ( nz & data )
goto loop; // Z should be clear, and nz must be non-zero if nz & data is
nz <<= 8; // set Z flag without affecting N flag
goto loop;
{
fuint16 addr;
case 0x0C: // TSB abs
case 0x1C: // TRB abs
addr = GET_ADDR();
pc++;
goto txb_addr;
// TODO: everyone lists different behaviors for the status flags, ugh
case 0x04: // TSB zp
case 0x14: // TRB zp
addr = data + ram_addr;
txb_addr:
FLUSH_TIME();
nz = a | READ( addr );
if ( opcode & 0x10 )
nz ^= a; // bits from a will already be set, so this clears them
status &= ~st_v;
status |= nz & st_v;
pc++;
WRITE( addr, nz );
CACHE_TIME();
goto loop;
}
case 0x07: // RMBn
case 0x17:
case 0x27:
case 0x37:
case 0x47:
case 0x57:
case 0x67:
case 0x77:
pc++;
READ_LOW( data ) &= ~(1 << (opcode >> 4));
goto loop;
case 0x87: // SMBn
case 0x97:
case 0xA7:
case 0xB7:
case 0xC7:
case 0xD7:
case 0xE7:
case 0xF7:
pc++;
READ_LOW( data ) |= 1 << ((opcode >> 4) - 8);
goto loop;
// Load/store
case 0x9E: // STZ abs,x
data += x;
case 0x9C: // STZ abs
ADD_PAGE( data );
pc++;
FLUSH_TIME();
WRITE( data, 0 );
CACHE_TIME();
goto loop;
case 0x74: // STZ zp,x
data = uint8_t (data + x);
case 0x64: // STZ zp
pc++;
WRITE_LOW( data, 0 );
goto loop;
case 0x94: // STY zp,x
data = uint8_t (data + x);
case 0x84: // STY zp
pc++;
WRITE_LOW( data, y );
goto loop;
case 0x96: // STX zp,y
data = uint8_t (data + y);
case 0x86: // STX zp
pc++;
WRITE_LOW( data, x );
goto loop;
case 0xB6: // LDX zp,y
data = uint8_t (data + y);
case 0xA6: // LDX zp
data = READ_LOW( data );
case 0xA2: // LDX #imm
pc++;
x = data;
nz = data;
goto loop;
case 0xB4: // LDY zp,x
data = uint8_t (data + x);
case 0xA4: // LDY zp
data = READ_LOW( data );
case 0xA0: // LDY #imm
pc++;
y = data;
nz = data;
goto loop;
case 0xBC: // LDY abs,X
data += x;
PAGE_CROSS_PENALTY( data );
case 0xAC:{// LDY abs
fuint16 addr = data + 0x100 * GET_MSB();
pc += 2;
FLUSH_TIME();
y = nz = READ( addr );
CACHE_TIME();
goto loop;
}
{
fuint8 temp;
case 0x8C: // STY abs
temp = y;
goto store_abs;
case 0x8E: // STX abs
temp = x;
store_abs:
fuint16 addr = GET_ADDR();
pc += 2;
FLUSH_TIME();
WRITE( addr, temp );
CACHE_TIME();
goto loop;
}
// Compare
case 0xEC:{// CPX abs
fuint16 addr = GET_ADDR();
pc++;
FLUSH_TIME();
data = READ( addr );
CACHE_TIME();
goto cpx_data;
}
case 0xE4: // CPX zp
data = READ_LOW( data );
case 0xE0: // CPX #imm
cpx_data:
nz = x - data;
pc++;
c = ~nz;
nz &= 0xFF;
goto loop;
case 0xCC:{// CPY abs
fuint16 addr = GET_ADDR();
pc++;
FLUSH_TIME();
data = READ( addr );
CACHE_TIME();
goto cpy_data;
}
case 0xC4: // CPY zp
data = READ_LOW( data );
case 0xC0: // CPY #imm
cpy_data:
nz = y - data;
pc++;
c = ~nz;
nz &= 0xFF;
goto loop;
// Logical
#define ARITH_ADDR_MODES( op )\
case op - 0x04: /* (ind,x) */\
data = uint8_t (data + x);\
case op + 0x0D: /* (ind) */\
data = 0x100 * READ_LOW( uint8_t (data + 1) ) + READ_LOW( data );\
goto ptr##op;\
case op + 0x0C:{/* (ind),y */\
fuint16 temp = READ_LOW( data ) + y;\
PAGE_CROSS_PENALTY( temp );\
data = temp + 0x100 * READ_LOW( uint8_t (data + 1) );\
goto ptr##op;\
}\
case op + 0x10: /* zp,X */\
data = uint8_t (data + x);\
case op + 0x00: /* zp */\
data = READ_LOW( data );\
goto imm##op;\
case op + 0x14: /* abs,Y */\
data += y;\
goto ind##op;\
case op + 0x18: /* abs,X */\
data += x;\
ind##op:\
PAGE_CROSS_PENALTY( data );\
case op + 0x08: /* abs */\
ADD_PAGE( data );\
ptr##op:\
FLUSH_TIME();\
data = READ( data );\
CACHE_TIME();\
case op + 0x04: /* imm */\
imm##op:
ARITH_ADDR_MODES( 0xC5 ) // CMP
nz = a - data;
pc++;
c = ~nz;
nz &= 0xFF;
goto loop;
ARITH_ADDR_MODES( 0x25 ) // AND
nz = (a &= data);
pc++;
goto loop;
ARITH_ADDR_MODES( 0x45 ) // EOR
nz = (a ^= data);
pc++;
goto loop;
ARITH_ADDR_MODES( 0x05 ) // ORA
nz = (a |= data);
pc++;
goto loop;
// Add/subtract
ARITH_ADDR_MODES( 0xE5 ) // SBC
data ^= 0xFF;
goto adc_imm;
ARITH_ADDR_MODES( 0x65 ) // ADC
adc_imm: {
if ( status & st_d )
dprintf( "Decimal mode not supported\n" );
fint16 carry = c >> 8 & 1;
fint16 ov = (a ^ 0x80) + carry + (BOOST::int8_t) data; // sign-extend
status &= ~st_v;
status |= ov >> 2 & 0x40;
c = nz = a + data + carry;
pc++;
a = (uint8_t) nz;
goto loop;
}
// Shift/rotate
case 0x4A: // LSR A
c = 0;
case 0x6A: // ROR A
nz = c >> 1 & 0x80;
c = a << 8;
nz |= a >> 1;
a = nz;
goto loop;
case 0x0A: // ASL A
nz = a << 1;
c = nz;
a = (uint8_t) nz;
goto loop;
case 0x2A: { // ROL A
nz = a << 1;
fint16 temp = c >> 8 & 1;
c = nz;
nz |= temp;
a = (uint8_t) nz;
goto loop;
}
case 0x5E: // LSR abs,X
data += x;
case 0x4E: // LSR abs
c = 0;
case 0x6E: // ROR abs
ror_abs: {
ADD_PAGE( data );
FLUSH_TIME();
int temp = READ( data );
nz = (c >> 1 & 0x80) | (temp >> 1);
c = temp << 8;
goto rotate_common;
}
case 0x3E: // ROL abs,X
data += x;
goto rol_abs;
case 0x1E: // ASL abs,X
data += x;
case 0x0E: // ASL abs
c = 0;
case 0x2E: // ROL abs
rol_abs:
ADD_PAGE( data );
nz = c >> 8 & 1;
FLUSH_TIME();
nz |= (c = READ( data ) << 1);
rotate_common:
pc++;
WRITE( data, (uint8_t) nz );
CACHE_TIME();
goto loop;
case 0x7E: // ROR abs,X
data += x;
goto ror_abs;
case 0x76: // ROR zp,x
data = uint8_t (data + x);
goto ror_zp;
case 0x56: // LSR zp,x
data = uint8_t (data + x);
case 0x46: // LSR zp
c = 0;
case 0x66: // ROR zp
ror_zp: {
int temp = READ_LOW( data );
nz = (c >> 1 & 0x80) | (temp >> 1);
c = temp << 8;
goto write_nz_zp;
}
case 0x36: // ROL zp,x
data = uint8_t (data + x);
goto rol_zp;
case 0x16: // ASL zp,x
data = uint8_t (data + x);
case 0x06: // ASL zp
c = 0;
case 0x26: // ROL zp
rol_zp:
nz = c >> 8 & 1;
nz |= (c = READ_LOW( data ) << 1);
goto write_nz_zp;
// Increment/decrement
#define INC_DEC_AXY( reg, n ) reg = uint8_t (nz = reg + n); goto loop;
case 0x1A: // INA
INC_DEC_AXY( a, +1 )
case 0xE8: // INX
INC_DEC_AXY( x, +1 )
case 0xC8: // INY
INC_DEC_AXY( y, +1 )
case 0x3A: // DEA
INC_DEC_AXY( a, -1 )
case 0xCA: // DEX
INC_DEC_AXY( x, -1 )
case 0x88: // DEY
INC_DEC_AXY( y, -1 )
case 0xF6: // INC zp,x
data = uint8_t (data + x);
case 0xE6: // INC zp
nz = 1;
goto add_nz_zp;
case 0xD6: // DEC zp,x
data = uint8_t (data + x);
case 0xC6: // DEC zp
nz = (unsigned) -1;
add_nz_zp:
nz += READ_LOW( data );
write_nz_zp:
pc++;
WRITE_LOW( data, nz );
goto loop;
case 0xFE: // INC abs,x
data = x + GET_ADDR();
goto inc_ptr;
case 0xEE: // INC abs
data = GET_ADDR();
inc_ptr:
nz = 1;
goto inc_common;
case 0xDE: // DEC abs,x
data = x + GET_ADDR();
goto dec_ptr;
case 0xCE: // DEC abs
data = GET_ADDR();
dec_ptr:
nz = (unsigned) -1;
inc_common:
FLUSH_TIME();
nz += READ( data );
pc += 2;
WRITE( data, (uint8_t) nz );
CACHE_TIME();
goto loop;
// Transfer
case 0xA8: // TAY
y = a;
nz = a;
goto loop;
case 0x98: // TYA
a = y;
nz = y;
goto loop;
case 0xAA: // TAX
x = a;
nz = a;
goto loop;
case 0x8A: // TXA
a = x;
nz = x;
goto loop;
case 0x9A: // TXS
SET_SP( x ); // verified (no flag change)
goto loop;
case 0xBA: // TSX
x = nz = GET_SP();
goto loop;
#define SWAP_REGS( r1, r2 ) {\
fuint8 t = r1;\
r1 = r2;\
r2 = t;\
goto loop;\
}
case 0x02: // SXY
SWAP_REGS( x, y );
case 0x22: // SAX
SWAP_REGS( a, x );
case 0x42: // SAY
SWAP_REGS( a, y );
case 0x62: // CLA
a = 0;
goto loop;
case 0x82: // CLX
x = 0;
goto loop;
case 0xC2: // CLY
y = 0;
goto loop;
// Stack
case 0x48: // PHA
PUSH( a );
goto loop;
case 0xDA: // PHX
PUSH( x );
goto loop;
case 0x5A: // PHY
PUSH( y );
goto loop;
case 0x40:{// RTI
fuint8 temp = READ_LOW( sp );
pc = READ_LOW( 0x100 | (sp - 0xFF) );
pc |= READ_LOW( 0x100 | (sp - 0xFE) ) * 0x100;
sp = (sp - 0xFD) | 0x100;
data = status;
SET_STATUS( temp );
this->r.status = status; // update externally-visible I flag
if ( (data ^ status) & st_i )
{
hes_time_t new_time = end_time_;
if ( !(status & st_i) && new_time > irq_time_ )
new_time = irq_time_;
blargg_long delta = s.base - new_time;
s.base = new_time;
s_time += delta;
}
goto loop;
}
#define POP() READ_LOW( sp ); sp = (sp - 0xFF) | 0x100
case 0x68: // PLA
a = nz = POP();
goto loop;
case 0xFA: // PLX
x = nz = POP();
goto loop;
case 0x7A: // PLY
y = nz = POP();
goto loop;
case 0x28:{// PLP
fuint8 temp = POP();
fuint8 changed = status ^ temp;
SET_STATUS( temp );
if ( !(changed & st_i) )
goto loop; // I flag didn't change
if ( status & st_i )
goto handle_sei;
goto handle_cli;
}
#undef POP
case 0x08: { // PHP
fuint8 temp;
CALC_STATUS( temp );
PUSH( temp | st_b );
goto loop;
}
// Flags
case 0x38: // SEC
c = (unsigned) ~0;
goto loop;
case 0x18: // CLC
c = 0;
goto loop;
case 0xB8: // CLV
status &= ~st_v;
goto loop;
case 0xD8: // CLD
status &= ~st_d;
goto loop;
case 0xF8: // SED
status |= st_d;
goto loop;
case 0x58: // CLI
if ( !(status & st_i) )
goto loop;
status &= ~st_i;
handle_cli: {
this->r.status = status; // update externally-visible I flag
blargg_long delta = s.base - irq_time_;
if ( delta <= 0 )
{
if ( TIME < irq_time_ )
goto loop;
goto delayed_cli;
}
s.base = irq_time_;
s_time += delta;
if ( s_time < 0 )
goto loop;
if ( delta >= s_time + 1 )
{
// delayed irq until after next instruction
s.base += s_time + 1;
s_time = -1;
irq_time_ = s.base; // TODO: remove, as only to satisfy debug check in loop
goto loop;
}
delayed_cli:
dprintf( "Delayed CLI not supported\n" ); // TODO: implement
goto loop;
}
case 0x78: // SEI
if ( status & st_i )
goto loop;
status |= st_i;
handle_sei: {
this->r.status = status; // update externally-visible I flag
blargg_long delta = s.base - end_time_;
s.base = end_time_;
s_time += delta;
if ( s_time < 0 )
goto loop;
dprintf( "Delayed SEI not supported\n" ); // TODO: implement
goto loop;
}
// Special
case 0x53:{// TAM
fuint8 const bits = data; // avoid using data across function call
pc++;
for ( int i = 0; i < 8; i++ )
if ( bits & (1 << i) )
set_mmr( i, a );
goto loop;
}
case 0x43:{// TMA
pc++;
byte const* in = mmr;
do
{
if ( data & 1 )
a = *in;
in++;
}
while ( (data >>= 1) != 0 );
goto loop;
}
case 0x03: // ST0
case 0x13: // ST1
case 0x23:{// ST2
fuint16 addr = opcode >> 4;
if ( addr )
addr++;
pc++;
FLUSH_TIME();
CPU_WRITE_VDP( this, addr, data, TIME );
CACHE_TIME();
goto loop;
}
case 0xEA: // NOP
goto loop;
case 0x54: // CSL
dprintf( "CSL not supported\n" );
illegal_encountered = true;
goto loop;
case 0xD4: // CSH
goto loop;
case 0xF4: { // SET
//fuint16 operand = GET_MSB();
dprintf( "SET not handled\n" );
//switch ( data )
//{
//}
illegal_encountered = true;
goto loop;
}
// Block transfer
{
fuint16 in_alt;
fint16 in_inc;
fuint16 out_alt;
fint16 out_inc;
case 0xE3: // TIA
in_alt = 0;
goto bxfer_alt;
case 0xF3: // TAI
in_alt = 1;
bxfer_alt:
in_inc = in_alt ^ 1;
out_alt = in_inc;
out_inc = in_alt;
goto bxfer;
case 0xD3: // TIN
in_inc = 1;
out_inc = 0;
goto bxfer_no_alt;
case 0xC3: // TDD
in_inc = -1;
out_inc = -1;
goto bxfer_no_alt;
case 0x73: // TII
in_inc = 1;
out_inc = 1;
bxfer_no_alt:
in_alt = 0;
out_alt = 0;
bxfer:
fuint16 in = GET_LE16( instr + 0 );
fuint16 out = GET_LE16( instr + 2 );
int count = GET_LE16( instr + 4 );
if ( !count )
count = 0x10000;
pc += 6;
WRITE_LOW( 0x100 | (sp - 1), y );
WRITE_LOW( 0x100 | (sp - 2), a );
WRITE_LOW( 0x100 | (sp - 3), x );
FLUSH_TIME();
do
{
// TODO: reads from $0800-$1400 in I/O page return 0 and don't access I/O
fuint8 t = READ( in );
in += in_inc;
in &= 0xFFFF;
s.time += 6;
if ( in_alt )
in_inc = -in_inc;
WRITE( out, t );
out += out_inc;
out &= 0xFFFF;
if ( out_alt )
out_inc = -out_inc;
}
while ( --count );
CACHE_TIME();
goto loop;
}
// Illegal
default:
assert( (unsigned) opcode <= 0xFF );
dprintf( "Illegal opcode $%02X at $%04X\n", (int) opcode, (int) pc - 1 );
illegal_encountered = true;
goto loop;
}
assert( false );
int result_;
handle_brk:
pc++;
result_ = 6;
interrupt:
{
s_time += 7;
WRITE_LOW( 0x100 | (sp - 1), pc >> 8 );
WRITE_LOW( 0x100 | (sp - 2), pc );
pc = GET_LE16( &READ_PROG( 0xFFF0 ) + result_ );
sp = (sp - 3) | 0x100;
fuint8 temp;
CALC_STATUS( temp );
if ( result_ == 6 )
temp |= st_b;
WRITE_LOW( sp, temp );
status &= ~st_d;
status |= st_i;
this->r.status = status; // update externally-visible I flag
blargg_long delta = s.base - end_time_;
s.base = end_time_;
s_time += delta;
goto loop;
}
idle_done:
s_time = 0;
out_of_time:
pc--;
FLUSH_TIME();
CPU_DONE( this, TIME, result_ );
CACHE_TIME();
if ( result_ > 0 )
goto interrupt;
if ( s_time < 0 )
goto loop;
s.time = s_time;
r.pc = pc;
r.sp = GET_SP();
r.a = a;
r.x = x;
r.y = y;
{
fuint8 temp;
CALC_STATUS( temp );
r.status = temp;
}
this->state_ = s;
this->state = &this->state_;
return illegal_encountered;
}