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Diffstat (limited to 'plugins/gme/game-music-emu-0.5.5/gme/Nes_Cpu.cpp')
-rw-r--r--plugins/gme/game-music-emu-0.5.5/gme/Nes_Cpu.cpp1084
1 files changed, 0 insertions, 1084 deletions
diff --git a/plugins/gme/game-music-emu-0.5.5/gme/Nes_Cpu.cpp b/plugins/gme/game-music-emu-0.5.5/gme/Nes_Cpu.cpp
deleted file mode 100644
index 864e0dde..00000000
--- a/plugins/gme/game-music-emu-0.5.5/gme/Nes_Cpu.cpp
+++ /dev/null
@@ -1,1084 +0,0 @@
-// Game_Music_Emu 0.5.5. http://www.slack.net/~ant/
-
-#include "Nes_Cpu.h"
-
-#include "blargg_endian.h"
-#include <limits.h>
-
-#define BLARGG_CPU_X86 1
-
-/* 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 */
-
-#ifdef BLARGG_ENABLE_OPTIMIZER
- #include BLARGG_ENABLE_OPTIMIZER
-#endif
-
-#define FLUSH_TIME() (void) (s.time = s_time)
-#define CACHE_TIME() (void) (s_time = s.time)
-
-#include "nes_cpu_io.h"
-
-#include "blargg_source.h"
-
-#ifndef CPU_DONE
- #define CPU_DONE( cpu, time, result_out ) { result_out = -1; }
-#endif
-
-#ifndef CPU_READ_PPU
- #define CPU_READ_PPU( cpu, addr, out, time )\
- {\
- FLUSH_TIME();\
- out = CPU_READ( cpu, addr, time );\
- CACHE_TIME();\
- }
-#endif
-
-#if BLARGG_NONPORTABLE
- #define PAGE_OFFSET( addr ) (addr)
-#else
- #define PAGE_OFFSET( addr ) ((addr) & (page_size - 1))
-#endif
-
-inline void Nes_Cpu::set_code_page( int i, void const* p )
-{
- state->code_map [i] = (uint8_t const*) p - PAGE_OFFSET( i * page_size );
-}
-
-int const st_n = 0x80;
-int const st_v = 0x40;
-int const st_r = 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 Nes_Cpu::reset( void const* unmapped_page )
-{
- check( state == &state_ );
- state = &state_;
- r.status = st_i;
- r.sp = 0xFF;
- r.pc = 0;
- r.a = 0;
- r.x = 0;
- r.y = 0;
- state_.time = 0;
- state_.base = 0;
- irq_time_ = future_nes_time;
- end_time_ = future_nes_time;
- error_count_ = 0;
-
- assert( page_size == 0x800 ); // assumes this
- set_code_page( page_count, unmapped_page );
- map_code( 0x2000, 0xE000, unmapped_page, true );
- map_code( 0x0000, 0x2000, low_mem, true );
-
- blargg_verify_byte_order();
-}
-
-void Nes_Cpu::map_code( nes_addr_t start, unsigned size, void const* data, bool mirror )
-{
- // address range must begin and end on page boundaries
- require( start % page_size == 0 );
- require( size % page_size == 0 );
- require( start + size <= 0x10000 );
-
- unsigned page = start / page_size;
- for ( unsigned n = size / page_size; n; --n )
- {
- set_code_page( page++, data );
- if ( !mirror )
- data = (char const*) data + page_size;
- }
-}
-
-#define TIME (s_time + s.base)
-#define READ_LIKELY_PPU( addr, out ) {CPU_READ_PPU( this, (addr), out, TIME );}
-#define READ( addr ) CPU_READ( this, (addr), TIME )
-#define WRITE( addr, data ) {CPU_WRITE( this, (addr), (data), TIME );}
-#define READ_LOW( addr ) (low_mem [int (addr)])
-#define WRITE_LOW( addr, data ) (void) (READ_LOW( addr ) = (data))
-#define READ_PROG( addr ) (s.code_map [(addr) >> page_bits] [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;
-
-bool Nes_Cpu::run( nes_time_t end_time )
-{
- 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 );
-
- // status flags
- #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;
-dec_clock_loop:
- s_time--;
-loop:
-
- check( (unsigned) GET_SP() < 0x100 );
- check( (unsigned) pc < 0x10000 );
- check( (unsigned) a < 0x100 );
- check( (unsigned) x < 0x100 );
- check( (unsigned) y < 0x100 );
- check( -32768 <= s_time && s_time < 32767 );
-
- uint8_t const* instr = s.code_map [pc >> page_bits];
- 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
-
- static uint8_t const clock_table [256] =
- {// 0 1 2 3 4 5 6 7 8 9 A B C D E F
- 0,6,2,8,3,3,5,5,3,2,2,2,4,4,6,6,// 0
- 3,5,2,8,4,4,6,6,2,4,2,7,4,4,7,7,// 1
- 6,6,2,8,3,3,5,5,4,2,2,2,4,4,6,6,// 2
- 3,5,2,8,4,4,6,6,2,4,2,7,4,4,7,7,// 3
- 6,6,2,8,3,3,5,5,3,2,2,2,3,4,6,6,// 4
- 3,5,2,8,4,4,6,6,2,4,2,7,4,4,7,7,// 5
- 6,6,2,8,3,3,5,5,4,2,2,2,5,4,6,6,// 6
- 3,5,2,8,4,4,6,6,2,4,2,7,4,4,7,7,// 7
- 2,6,2,6,3,3,3,3,2,2,2,2,4,4,4,4,// 8
- 3,6,2,6,4,4,4,4,2,5,2,5,5,5,5,5,// 9
- 2,6,2,6,3,3,3,3,2,2,2,2,4,4,4,4,// A
- 3,5,2,5,4,4,4,4,2,4,2,4,4,4,4,4,// B
- 2,6,2,8,3,3,5,5,2,2,2,2,4,4,6,6,// C
- 3,5,2,8,4,4,6,6,2,4,2,7,4,4,7,7,// D
- 2,6,2,8,3,3,5,5,2,2,2,2,4,4,6,6,// E
- 3,5,0,8,4,4,6,6,2,4,2,7,4,4,7,7 // F
- }; // 0x00 was 7 and 0xF2 was 2
-
- fuint16 data;
-
-#if !BLARGG_CPU_X86
- if ( s_time >= 0 )
- goto out_of_time;
- s_time += clock_table [opcode];
-
- data = *instr;
-
- switch ( opcode )
- {
-#else
-
- data = clock_table [opcode];
- if ( (s_time += data) >= 0 )
- goto possibly_out_of_time;
-almost_out_of_time:
-
- data = *instr;
-
- switch ( opcode )
- {
-possibly_out_of_time:
- if ( s_time < (int) data )
- goto almost_out_of_time;
- s_time -= data;
- goto out_of_time;
-#endif
-
-// Macros
-
-#define GET_MSB() (instr [1])
-#define ADD_PAGE() (pc++, data += 0x100 * GET_MSB())
-#define GET_ADDR() GET_LE16( instr )
-
-#define NO_PAGE_CROSSING( lsb )
-#define HANDLE_PAGE_CROSSING( lsb ) s_time += (lsb) >> 8;
-
-#define INC_DEC_XY( reg, n ) reg = uint8_t (nz = reg + n); goto loop;
-
-#define IND_Y( cross, out ) {\
- fuint16 temp = READ_LOW( data ) + y;\
- out = temp + 0x100 * READ_LOW( uint8_t (data + 1) );\
- cross( temp );\
- }
-
-#define IND_X( out ) {\
- fuint16 temp = data + x;\
- out = 0x100 * READ_LOW( uint8_t (temp + 1) ) + READ_LOW( uint8_t (temp) );\
- }
-
-#define ARITH_ADDR_MODES( op )\
-case op - 0x04: /* (ind,x) */\
- IND_X( data )\
- goto ptr##op;\
-case op + 0x0C: /* (ind),y */\
- IND_Y( HANDLE_PAGE_CROSSING, data )\
- 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:\
- HANDLE_PAGE_CROSSING( data );\
-case op + 0x08: /* abs */\
- ADD_PAGE();\
-ptr##op:\
- FLUSH_TIME();\
- data = READ( data );\
- CACHE_TIME();\
-case op + 0x04: /* imm */\
-imm##op:
-
-// TODO: more efficient way to handle negative branch that wraps PC around
-#define BRANCH( cond )\
-{\
- fint16 offset = (BOOST::int8_t) data;\
- fuint16 extra_clock = (++pc & 0xFF) + offset;\
- if ( !(cond) ) goto dec_clock_loop;\
- pc = BOOST::uint16_t (pc + offset);\
- s_time += extra_clock >> 8 & 1;\
- goto loop;\
-}
-
-// Often-Used
-
- case 0xB5: // LDA zp,x
- a = nz = READ_LOW( uint8_t (data + x) );
- pc++;
- goto loop;
-
- case 0xA5: // LDA zp
- a = nz = READ_LOW( data );
- pc++;
- goto loop;
-
- case 0xD0: // BNE
- BRANCH( (uint8_t) nz );
-
- 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 0x4C: // JMP abs
- pc = GET_ADDR();
- goto loop;
-
- case 0xE8: // INX
- INC_DEC_XY( x, 1 )
-
- case 0x10: // BPL
- BRANCH( !IS_NEG )
-
- ARITH_ADDR_MODES( 0xC5 ) // CMP
- nz = a - data;
- pc++;
- c = ~nz;
- nz &= 0xFF;
- goto loop;
-
- case 0x30: // BMI
- BRANCH( IS_NEG )
-
- case 0xF0: // BEQ
- BRANCH( !(uint8_t) nz );
-
- case 0x95: // STA zp,x
- data = uint8_t (data + x);
- case 0x85: // STA zp
- pc++;
- WRITE_LOW( data, a );
- goto loop;
-
- case 0xC8: // INY
- INC_DEC_XY( y, 1 )
-
- case 0xA8: // TAY
- y = a;
- nz = a;
- goto loop;
-
- case 0x98: // TYA
- a = y;
- nz = y;
- goto loop;
-
- case 0xAD:{// LDA abs
- unsigned addr = GET_ADDR();
- pc += 2;
- READ_LIKELY_PPU( addr, nz );
- a = nz;
- goto loop;
- }
-
- case 0x60: // RTS
- pc = 1 + READ_LOW( sp );
- pc += 0x100 * READ_LOW( 0x100 | (sp - 0xFF) );
- sp = (sp - 0xFE) | 0x100;
- goto loop;
-
- {
- fuint16 addr;
-
- case 0x99: // STA abs,Y
- addr = y + GET_ADDR();
- pc += 2;
- if ( addr <= 0x7FF )
- {
- WRITE_LOW( addr, a );
- goto loop;
- }
- goto sta_ptr;
-
- case 0x8D: // STA abs
- addr = GET_ADDR();
- pc += 2;
- if ( addr <= 0x7FF )
- {
- WRITE_LOW( addr, a );
- goto loop;
- }
- goto sta_ptr;
-
- case 0x9D: // STA abs,X (slightly more common than STA abs)
- addr = x + GET_ADDR();
- pc += 2;
- if ( addr <= 0x7FF )
- {
- WRITE_LOW( addr, a );
- goto loop;
- }
- sta_ptr:
- FLUSH_TIME();
- WRITE( addr, a );
- CACHE_TIME();
- goto loop;
-
- case 0x91: // STA (ind),Y
- IND_Y( NO_PAGE_CROSSING, addr )
- pc++;
- goto sta_ptr;
-
- case 0x81: // STA (ind,X)
- IND_X( addr )
- pc++;
- goto sta_ptr;
-
- }
-
- case 0xA9: // LDA #imm
- pc++;
- a = data;
- nz = data;
- goto loop;
-
- // common read instructions
- {
- fuint16 addr;
-
- case 0xA1: // LDA (ind,X)
- IND_X( addr )
- pc++;
- goto a_nz_read_addr;
-
- case 0xB1:// LDA (ind),Y
- addr = READ_LOW( data ) + y;
- HANDLE_PAGE_CROSSING( addr );
- addr += 0x100 * READ_LOW( (uint8_t) (data + 1) );
- pc++;
- a = nz = READ_PROG( addr );
- if ( (addr ^ 0x8000) <= 0x9FFF )
- goto loop;
- goto a_nz_read_addr;
-
- case 0xB9: // LDA abs,Y
- HANDLE_PAGE_CROSSING( data + y );
- addr = GET_ADDR() + y;
- pc += 2;
- a = nz = READ_PROG( addr );
- if ( (addr ^ 0x8000) <= 0x9FFF )
- goto loop;
- goto a_nz_read_addr;
-
- case 0xBD: // LDA abs,X
- HANDLE_PAGE_CROSSING( data + x );
- addr = GET_ADDR() + x;
- pc += 2;
- a = nz = READ_PROG( addr );
- if ( (addr ^ 0x8000) <= 0x9FFF )
- goto loop;
- a_nz_read_addr:
- FLUSH_TIME();
- a = nz = READ( addr );
- CACHE_TIME();
- goto loop;
-
- }
-
-// Branch
-
- case 0x50: // BVC
- BRANCH( !(status & st_v) )
-
- case 0x70: // BVS
- BRANCH( status & st_v )
-
- case 0xB0: // BCS
- BRANCH( c & 0x100 )
-
- case 0x90: // BCC
- BRANCH( !(c & 0x100) )
-
-// Load/store
-
- 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;
- HANDLE_PAGE_CROSSING( data );
- case 0xAC:{// LDY abs
- unsigned addr = data + 0x100 * GET_MSB();
- pc += 2;
- FLUSH_TIME();
- y = nz = READ( addr );
- CACHE_TIME();
- goto loop;
- }
-
- case 0xBE: // LDX abs,y
- data += y;
- HANDLE_PAGE_CROSSING( data );
- case 0xAE:{// LDX abs
- unsigned addr = data + 0x100 * GET_MSB();
- pc += 2;
- FLUSH_TIME();
- x = 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:
- unsigned addr = GET_ADDR();
- pc += 2;
- if ( addr <= 0x7FF )
- {
- WRITE_LOW( addr, temp );
- goto loop;
- }
- FLUSH_TIME();
- WRITE( addr, temp );
- CACHE_TIME();
- goto loop;
- }
-
-// Compare
-
- case 0xEC:{// CPX abs
- unsigned 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
- unsigned 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
-
- 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;
-
- case 0x2C:{// BIT abs
- unsigned addr = GET_ADDR();
- pc += 2;
- status &= ~st_v;
- READ_LIKELY_PPU( addr, nz );
- status |= nz & st_v;
- if ( a & nz )
- goto loop;
- nz <<= 8; // result must be zero, even if N bit is set
- goto loop;
- }
-
- case 0x24: // BIT zp
- nz = READ_LOW( data );
- pc++;
- status &= ~st_v;
- status |= nz & st_v;
- if ( a & nz )
- goto loop;
- nz <<= 8; // result must be zero, even if N bit is set
- goto loop;
-
-// Add/subtract
-
- ARITH_ADDR_MODES( 0xE5 ) // SBC
- case 0xEB: // unofficial equivalent
- data ^= 0xFF;
- goto adc_imm;
-
- ARITH_ADDR_MODES( 0x65 ) // ADC
- adc_imm: {
- 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();
- 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();
- 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
-
- case 0xCA: // DEX
- INC_DEC_XY( x, -1 )
-
- case 0x88: // DEY
- INC_DEC_XY( 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 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;
-
-// Stack
-
- case 0x48: // PHA
- PUSH( a ); // verified
- goto loop;
-
- case 0x68: // PLA
- a = nz = READ_LOW( sp );
- sp = (sp - 0xFF) | 0x100;
- 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 );
- if ( !((data ^ status) & st_i) ) goto loop; // I flag didn't change
- this->r.status = status; // update externally-visible I flag
- blargg_long delta = s.base - irq_time_;
- if ( delta <= 0 ) goto loop;
- if ( status & st_i ) goto loop;
- s_time += delta;
- s.base = irq_time_;
- goto loop;
- }
-
- case 0x28:{// PLP
- fuint8 temp = READ_LOW( sp );
- sp = (sp - 0xFF) | 0x100;
- 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;
- }
-
- case 0x08: { // PHP
- fuint8 temp;
- CALC_STATUS( temp );
- PUSH( temp | (st_b | st_r) );
- goto loop;
- }
-
- case 0x6C:{// JMP (ind)
- data = GET_ADDR();
- check( unsigned (data - 0x2000) >= 0x4000 ); // ensure it's outside I/O space
- uint8_t const* page = s.code_map [data >> page_bits];
- pc = page [PAGE_OFFSET( data )];
- data = (data & 0xFF00) | ((data + 1) & 0xFF);
- pc |= page [PAGE_OFFSET( data )] << 8;
- goto loop;
- }
-
- case 0x00: // BRK
- goto handle_brk;
-
-// 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: {
- //debug_printf( "CLI at %d\n", TIME );
- 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 )
- {
- s.base += s_time + 1;
- s_time = -1;
- goto loop;
- }
-
- // TODO: implement
- delayed_cli:
- debug_printf( "Delayed CLI not emulated\n" );
- 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;
-
- debug_printf( "Delayed SEI not emulated\n" );
- goto loop;
- }
-
-// Unofficial
-
- // SKW - Skip word
- case 0x1C: case 0x3C: case 0x5C: case 0x7C: case 0xDC: case 0xFC:
- HANDLE_PAGE_CROSSING( data + x );
- case 0x0C:
- pc++;
- // SKB - Skip byte
- case 0x74: case 0x04: case 0x14: case 0x34: case 0x44: case 0x54: case 0x64:
- case 0x80: case 0x82: case 0x89: case 0xC2: case 0xD4: case 0xE2: case 0xF4:
- pc++;
- goto loop;
-
- // NOP
- case 0xEA: case 0x1A: case 0x3A: case 0x5A: case 0x7A: case 0xDA: case 0xFA:
- goto loop;
-
- case bad_opcode: // HLT
- pc--;
- if ( pc > 0xFFFF )
- {
- // handle wrap-around (assumes caller has put page of HLT at 0x10000)
- pc &= 0xFFFF;
- goto loop;
- }
- case 0x02: case 0x12: case 0x22: case 0x32: case 0x42: case 0x52:
- case 0x62: case 0x72: case 0x92: case 0xB2: case 0xD2:
- goto stop;
-
-// Unimplemented
-
- case 0xFF: // force 256-entry jump table for optimization purposes
- c |= 1;
- default:
- check( (unsigned) opcode <= 0xFF );
- // skip over proper number of bytes
- static unsigned char const illop_lens [8] = {
- 0x40, 0x40, 0x40, 0x80, 0x40, 0x40, 0x80, 0xA0
- };
- fuint8 opcode = instr [-1];
- fint16 len = illop_lens [opcode >> 2 & 7] >> (opcode << 1 & 6) & 3;
- if ( opcode == 0x9C )
- len = 2;
- pc += len;
- error_count_++;
-
- if ( (opcode >> 4) == 0x0B )
- {
- if ( opcode == 0xB3 )
- data = READ_LOW( data );
- if ( opcode != 0xB7 )
- HANDLE_PAGE_CROSSING( data + y );
- }
- goto loop;
- }
- assert( false );
-
- int result_;
-handle_brk:
- pc++;
- result_ = 4;
-
-interrupt:
- {
- s_time += 7;
-
- WRITE_LOW( 0x100 | (sp - 1), pc >> 8 );
- WRITE_LOW( 0x100 | (sp - 2), pc );
- pc = GET_LE16( &READ_PROG( 0xFFFA ) + result_ );
-
- sp = (sp - 3) | 0x100;
- fuint8 temp;
- CALC_STATUS( temp );
- temp |= st_r;
- if ( result_ )
- temp |= st_b; // TODO: incorrectly sets B flag for IRQ
- WRITE_LOW( sp, temp );
-
- this->r.status = status |= st_i;
- blargg_long delta = s.base - end_time_;
- if ( delta >= 0 ) goto loop;
- s_time += delta;
- s.base = end_time_;
- goto loop;
- }
-
-out_of_time:
- pc--;
- FLUSH_TIME();
- CPU_DONE( this, TIME, result_ );
- CACHE_TIME();
- if ( result_ >= 0 )
- goto interrupt;
- if ( s_time < 0 )
- goto loop;
-
-stop:
-
- 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 s_time < 0;
-}
-
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-02 03:26:52 +0000