Apple-2-Tools/AppleWin
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AppleWin/source/CPU/cpu_general.inl

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/*
AppleWin : An Apple //e emulator for Windows
Copyright (C) 1994-1996, Michael O'Brien
Copyright (C) 1999-2001, Oliver Schmidt
Copyright (C) 2002-2005, Tom Charlesworth
Copyright (C) 2006-2010, Tom Charlesworth, Michael Pohoreski
AppleWin is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
AppleWin 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with AppleWin; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* Description: 6502/65C02 emulation
*
* Author: Various
*/
/****************************************************************************
*
* GENERAL PURPOSE MACROS
*
***/
#undef AF_TO_EF
#undef EF_TO_AF
#define AF_TO_EF flagc = (regs.ps & AF_CARRY); \
flagn = (regs.ps & AF_SIGN); \
flagv = (regs.ps & AF_OVERFLOW); \
flagz = (regs.ps & AF_ZERO);
#define EF_TO_AF regs.ps = (regs.ps & ~(AF_CARRY | AF_SIGN | \
AF_OVERFLOW | AF_ZERO)) \
| flagc \
| flagn \
| (flagv ? AF_OVERFLOW : 0) \
| (flagz ? AF_ZERO : 0) \
| AF_RESERVED | AF_BREAK;
// CYC(a): This can be optimised, as only certain opcodes will affect uExtraCycles
#define CYC(a) uExecutedCycles += (a)+uExtraCycles; g_nIrqCheckTimeout -= (a)+uExtraCycles;
#define POP (*(mem+((regs.sp >= 0x1FF) ? (regs.sp = 0x100) : ++regs.sp)))
#define PUSH(a) *(mem+regs.sp--) = (a); \
if (regs.sp < 0x100) \
regs.sp = 0x1FF;
#define READ ( \
((addr & 0xF000) == 0xC000) \
? IORead[(addr>>4) & 0xFF](regs.pc,addr,0,0,uExecutedCycles) \
: *(mem+addr) \
)
#define SETNZ(a) { \
flagn = ((a) & 0x80); \
flagz = !((a) & 0xFF); \
}
#define SETZ(a) flagz = !((a) & 0xFF);
#define WRITE(a) { \
memdirty[addr >> 8] = 0xFF; \
LPBYTE page = memwrite[addr >> 8]; \
if (page) \
*(page+(addr & 0xFF)) = (BYTE)(a); \
else if ((addr & 0xF000) == 0xC000) \
IOWrite[(addr>>4) & 0xFF](regs.pc,addr,1,(BYTE)(a),uExecutedCycles); \
}
#define ON_PAGECROSS_REPLACE_HI_ADDR if ((base ^ addr) >> 8) {addr = (val<<8) | (addr&0xff);} /* GH#282 */
//
// ExtraCycles:
// +1 if branch taken
// +1 if page boundary crossed
#define BRANCH_TAKEN { \
base = regs.pc; \
regs.pc += addr; \
if ((base ^ regs.pc) & 0xFF00) \
uExtraCycles=2; \
else \
uExtraCycles=1; \
}
//
// TODO Optimization Note: uExtraCycles = ((base ^ addr) >> 8) & 1;
#define CHECK_PAGE_CHANGE if ((base ^ addr) & 0xFF00) \
uExtraCycles=1;
/****************************************************************************
*
* ADDRESSING MODE MACROS
*
***/
#define ABS addr = *(LPWORD)(mem+regs.pc); regs.pc += 2;
#define IABSX addr = *(LPWORD)(mem+(*(LPWORD)(mem+regs.pc))+(WORD)regs.x); regs.pc += 2;
// Optimised for page-cross
#define ABSX_OPT base = *(LPWORD)(mem+regs.pc); addr = base+(WORD)regs.x; regs.pc += 2; CHECK_PAGE_CHANGE;
// Not optimised for page-cross
#define ABSX_CONST base = *(LPWORD)(mem+regs.pc); addr = base+(WORD)regs.x; regs.pc += 2;
// Optimised for page-cross
#define ABSY_OPT base = *(LPWORD)(mem+regs.pc); addr = base+(WORD)regs.y; regs.pc += 2; CHECK_PAGE_CHANGE;
// Not optimised for page-cross
#define ABSY_CONST base = *(LPWORD)(mem+regs.pc); addr = base+(WORD)regs.y; regs.pc += 2;
// TODO Optimization Note (just for IABSCMOS): uExtraCycles = ((base & 0xFF) + 1) >> 8;
#define IABS_CMOS base = *(LPWORD)(mem+regs.pc); \
addr = *(LPWORD)(mem+base); \
if ((base & 0xFF) == 0xFF) uExtraCycles=1; \
regs.pc += 2;
#define IABS_NMOS base = *(LPWORD)(mem+regs.pc); \
if ((base & 0xFF) == 0xFF) \
addr = *(mem+base)+((WORD)*(mem+(base&0xFF00))<<8);\
else \
addr = *(LPWORD)(mem+base); \
regs.pc += 2;
#define IMM addr = regs.pc++;
#define INDX base = ((*(mem+regs.pc++))+regs.x) & 0xFF; \
if (base == 0xFF) \
addr = *(mem+0xFF)+(((WORD)*mem)<<8); \
else \
addr = *(LPWORD)(mem+base);
// Optimised for page-cross
#define INDY_OPT if (*(mem+regs.pc) == 0xFF) /*incurs an extra cycle for page-crossing*/ \
base = *(mem+0xFF)+(((WORD)*mem)<<8); \
else \
base = *(LPWORD)(mem+*(mem+regs.pc)); \
regs.pc++; \
addr = base+(WORD)regs.y; \
CHECK_PAGE_CHANGE;
// Not optimised for page-cross
#define INDY_CONST if (*(mem+regs.pc) == 0xFF) /*no extra cycle for page-crossing*/ \
base = *(mem+0xFF)+(((WORD)*mem)<<8); \
else \
base = *(LPWORD)(mem+*(mem+regs.pc)); \
regs.pc++; \
addr = base+(WORD)regs.y;
#define IZPG base = *(mem+regs.pc++); \
if (base == 0xFF) \
addr = *(mem+0xFF)+(((WORD)*mem)<<8); \
else \
addr = *(LPWORD)(mem+base);
#define REL addr = (signed char)*(mem+regs.pc++);
// TODO Optimization Note:
// . Opcodes that generate zero-page addresses can't be accessing $C000..$CFFF
// so they could be paired with special READZP/WRITEZP macros (instead of READ/WRITE)
#define ZPG addr = *(mem+regs.pc++);
#define ZPGX addr = ((*(mem+regs.pc++))+regs.x) & 0xFF;
#define ZPGY addr = ((*(mem+regs.pc++))+regs.y) & 0xFF;
// Tidy 3 char addressing modes to keep the opcode table visually aligned, clean, and readable.
#undef asl
#undef idx
#undef imm
#undef izp
#undef lsr
#undef rel
#undef rol
#undef ror
#undef zpx
#undef zpy
#define asl ASLA // Arithmetic Shift Left
#define idx INDX
#define imm IMM
#define izp IZPG
#define lsr LSRA // Logical Shift Right
#define rel REL
#define rol ROLA // Rotate Left
#define ror RORA // Rotate Right
#define zpx ZPGX
#define zpy ZPGY
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