/** Z80: portable Z80 emulator *******************************/
/**                                                         **/
/**                           Z80.c                         **/
/**                                                         **/
/** This file contains implementation for Z80 CPU. Don't    **/
/** forget to provide RdZ80(), WrZ80(), InZ80(), OutZ80(),  **/
/** LoopZ80(), and PatchZ80() functions to accomodate the   **/
/** emulated machine's architecture.                        **/
/**                                                         **/
/** Copyright (C) Marat Fayzullin 1994-2005                 **/
/**     You are not allowed to distribute this software     **/
/**     commercially. Please, notify me, if you make any    **/   
/**     changes to this file.                               **/
/*************************************************************/

#include "Z80.h"
#include "Tables.h"
#include <stdio.h>

/** INLINE ***************************************************/
/** Different compilers inline C functions differently.     **/
/*************************************************************/
#ifdef __GNUC__
#define INLINE inline
#else
#define INLINE static
#endif

/** System-Dependent Stuff ***********************************/
/** This is system-dependent code put here to speed things  **/
/** up. It has to stay inlined to be fast.                  **/
/*************************************************************/
#ifdef COLEM
extern byte *Page[];
INLINE byte RdZ80(word A) { return(Page[A>>15][A&0x7FFF]); }
#endif
#ifdef MG
extern byte *Page[];
INLINE byte RdZ80(word A) { return(Page[A>>13][A&0x1FFF]); }
#endif
#ifdef FMSX
extern byte *RAM[],PSL[],SSLReg;
INLINE byte RdZ80(word A)
{
  if(A!=0xFFFF) return(RAM[A>>13][A&0x1FFF]);
  else return((PSL[3]==3)? ~SSLReg:RAM[7][0x1FFF]);
}
#endif

#define S(Fl)        R->AF.B.l|=Fl
#define R(Fl)        R->AF.B.l&=~(Fl)
#define FLAGS(Rg,Fl) R->AF.B.l=Fl|ZSTable[Rg]

#define M_RLC(Rg)      \
  R->AF.B.l=Rg>>7;Rg=(Rg<<1)|R->AF.B.l;R->AF.B.l|=PZSTable[Rg]
#define M_RRC(Rg)      \
  R->AF.B.l=Rg&0x01;Rg=(Rg>>1)|(R->AF.B.l<<7);R->AF.B.l|=PZSTable[Rg]
#define M_RL(Rg)       \
  if(Rg&0x80)          \
  {                    \
    Rg=(Rg<<1)|(R->AF.B.l&C_FLAG); \
    R->AF.B.l=PZSTable[Rg]|C_FLAG; \
  }                    \
  else                 \
  {                    \
    Rg=(Rg<<1)|(R->AF.B.l&C_FLAG); \
    R->AF.B.l=PZSTable[Rg];        \
  }
#define M_RR(Rg)       \
  if(Rg&0x01)          \
  {                    \
    Rg=(Rg>>1)|(R->AF.B.l<<7);     \
    R->AF.B.l=PZSTable[Rg]|C_FLAG; \
  }                    \
  else                 \
  {                    \
    Rg=(Rg>>1)|(R->AF.B.l<<7);     \
    R->AF.B.l=PZSTable[Rg];        \
  }
  
#define M_SLA(Rg)      \
  R->AF.B.l=Rg>>7;Rg<<=1;R->AF.B.l|=PZSTable[Rg]
#define M_SRA(Rg)      \
  R->AF.B.l=Rg&C_FLAG;Rg=(Rg>>1)|(Rg&0x80);R->AF.B.l|=PZSTable[Rg]

#define M_SLL(Rg)      \
  R->AF.B.l=Rg>>7;Rg=(Rg<<1)|0x01;R->AF.B.l|=PZSTable[Rg]
#define M_SRL(Rg)      \
  R->AF.B.l=Rg&0x01;Rg>>=1;R->AF.B.l|=PZSTable[Rg]

#define M_BIT(Bit,Rg)  \
  R->AF.B.l=(R->AF.B.l&C_FLAG)|H_FLAG|PZSTable[Rg&(1<<Bit)]

#define M_SET(Bit,Rg) Rg|=1<<Bit
#define M_RES(Bit,Rg) Rg&=~(1<<Bit)

#define M_POP(Rg)      \
  R->Rg.B.l=RdZ80(R->SP.W++);R->Rg.B.h=RdZ80(R->SP.W++)
#define M_PUSH(Rg)     \
  WrZ80(--R->SP.W,R->Rg.B.h);WrZ80(--R->SP.W,R->Rg.B.l)

#define M_CALL         \
  J.B.l=RdZ80(R->PC.W++);J.B.h=RdZ80(R->PC.W++);         \
  WrZ80(--R->SP.W,R->PC.B.h);WrZ80(--R->SP.W,R->PC.B.l); \
  R->PC.W=J.W

#define M_JP  J.B.l=RdZ80(R->PC.W++);J.B.h=RdZ80(R->PC.W);R->PC.W=J.W
#define M_JR  R->PC.W+=(offset)RdZ80(R->PC.W)+1
#define M_RET R->PC.B.l=RdZ80(R->SP.W++);R->PC.B.h=RdZ80(R->SP.W++)

#define M_RST(Ad)      \
  WrZ80(--R->SP.W,R->PC.B.h);WrZ80(--R->SP.W,R->PC.B.l);R->PC.W=Ad

#define M_LDWORD(Rg)   \
  R->Rg.B.l=RdZ80(R->PC.W++);R->Rg.B.h=RdZ80(R->PC.W++)

#define M_ADD(Rg)      \
  J.W=R->AF.B.h+Rg;     \
  R->AF.B.l=            \
    (~(R->AF.B.h^Rg)&(Rg^J.B.l)&0x80? V_FLAG:0)| \
    J.B.h|ZSTable[J.B.l]|                        \
    ((R->AF.B.h^Rg^J.B.l)&H_FLAG);               \
  R->AF.B.h=J.B.l       

#define M_SUB(Rg)      \
  J.W=R->AF.B.h-Rg;    \
  R->AF.B.l=           \
    ((R->AF.B.h^Rg)&(R->AF.B.h^J.B.l)&0x80? V_FLAG:0)| \
    N_FLAG|-J.B.h|ZSTable[J.B.l]|                      \
    ((R->AF.B.h^Rg^J.B.l)&H_FLAG);                     \
  R->AF.B.h=J.B.l

#define M_ADC(Rg)      \
  J.W=R->AF.B.h+Rg+(R->AF.B.l&C_FLAG); \
  R->AF.B.l=                           \
    (~(R->AF.B.h^Rg)&(Rg^J.B.l)&0x80? V_FLAG:0)| \
    J.B.h|ZSTable[J.B.l]|              \
    ((R->AF.B.h^Rg^J.B.l)&H_FLAG);     \
  R->AF.B.h=J.B.l

#define M_SBC(Rg)      \
  J.W=R->AF.B.h-Rg-(R->AF.B.l&C_FLAG); \
  R->AF.B.l=                           \
    ((R->AF.B.h^Rg)&(R->AF.B.h^J.B.l)&0x80? V_FLAG:0)| \
    N_FLAG|-J.B.h|ZSTable[J.B.l]|      \
    ((R->AF.B.h^Rg^J.B.l)&H_FLAG);     \
  R->AF.B.h=J.B.l

#define M_CP(Rg)       \
  J.W=R->AF.B.h-Rg;    \
  R->AF.B.l=           \
    ((R->AF.B.h^Rg)&(R->AF.B.h^J.B.l)&0x80? V_FLAG:0)| \
    N_FLAG|-J.B.h|ZSTable[J.B.l]|                      \
    ((R->AF.B.h^Rg^J.B.l)&H_FLAG)

#define M_AND(Rg) R->AF.B.h&=Rg;R->AF.B.l=H_FLAG|PZSTable[R->AF.B.h]
#define M_OR(Rg)  R->AF.B.h|=Rg;R->AF.B.l=PZSTable[R->AF.B.h]
#define M_XOR(Rg) R->AF.B.h^=Rg;R->AF.B.l=PZSTable[R->AF.B.h]

#define M_IN(Rg)        \
  Rg=InZ80(R->BC.B.l);  \
  R->AF.B.l=PZSTable[Rg]|(R->AF.B.l&C_FLAG)

#define M_INC(Rg)       \
  Rg++;                 \
  R->AF.B.l=            \
    (R->AF.B.l&C_FLAG)|ZSTable[Rg]|           \
    (Rg==0x80? V_FLAG:0)|(Rg&0x0F? 0:H_FLAG)

#define M_DEC(Rg)       \
  Rg--;                 \
  R->AF.B.l=            \
    N_FLAG|(R->AF.B.l&C_FLAG)|ZSTable[Rg]| \
    (Rg==0x7F? V_FLAG:0)|((Rg&0x0F)==0x0F? H_FLAG:0)

#define M_ADDW(Rg1,Rg2) \
  J.W=(R->Rg1.W+R->Rg2.W)&0xFFFF;                        \
  R->AF.B.l=                                             \
    (R->AF.B.l&~(H_FLAG|N_FLAG|C_FLAG))|                 \
    ((R->Rg1.W^R->Rg2.W^J.W)&0x1000? H_FLAG:0)|          \
    (((long)R->Rg1.W+(long)R->Rg2.W)&0x10000? C_FLAG:0); \
  R->Rg1.W=J.W

#define M_ADCW(Rg)      \
  I=R->AF.B.l&C_FLAG;J.W=(R->HL.W+R->Rg.W+I)&0xFFFF;           \
  R->AF.B.l=                                                   \
    (((long)R->HL.W+(long)R->Rg.W+(long)I)&0x10000? C_FLAG:0)| \
    (~(R->HL.W^R->Rg.W)&(R->Rg.W^J.W)&0x8000? V_FLAG:0)|       \
    ((R->HL.W^R->Rg.W^J.W)&0x1000? H_FLAG:0)|                  \
    (J.W? 0:Z_FLAG)|(J.B.h&S_FLAG);                            \
  R->HL.W=J.W
   
#define M_SBCW(Rg)      \
  I=R->AF.B.l&C_FLAG;J.W=(R->HL.W-R->Rg.W-I)&0xFFFF;           \
  R->AF.B.l=                                                   \
    N_FLAG|                                                    \
    (((long)R->HL.W-(long)R->Rg.W-(long)I)&0x10000? C_FLAG:0)| \
    ((R->HL.W^R->Rg.W)&(R->HL.W^J.W)&0x8000? V_FLAG:0)|        \
    ((R->HL.W^R->Rg.W^J.W)&0x1000? H_FLAG:0)|                  \
    (J.W? 0:Z_FLAG)|(J.B.h&S_FLAG);                            \
  R->HL.W=J.W

enum Codes
{
  NOP,LD_BC_WORD,LD_xBC_A,INC_BC,INC_B,DEC_B,LD_B_BYTE,RLCA,
  EX_AF_AF,ADD_HL_BC,LD_A_xBC,DEC_BC,INC_C,DEC_C,LD_C_BYTE,RRCA,
  DJNZ,LD_DE_WORD,LD_xDE_A,INC_DE,INC_D,DEC_D,LD_D_BYTE,RLA,
  JR,ADD_HL_DE,LD_A_xDE,DEC_DE,INC_E,DEC_E,LD_E_BYTE,RRA,
  JR_NZ,LD_HL_WORD,LD_xWORD_HL,INC_HL,INC_H,DEC_H,LD_H_BYTE,DAA,
  JR_Z,ADD_HL_HL,LD_HL_xWORD,DEC_HL,INC_L,DEC_L,LD_L_BYTE,CPL,
  JR_NC,LD_SP_WORD,LD_xWORD_A,INC_SP,INC_xHL,DEC_xHL,LD_xHL_BYTE,SCF,
  JR_C,ADD_HL_SP,LD_A_xWORD,DEC_SP,INC_A,DEC_A,LD_A_BYTE,CCF,
  LD_B_B,LD_B_C,LD_B_D,LD_B_E,LD_B_H,LD_B_L,LD_B_xHL,LD_B_A,
  LD_C_B,LD_C_C,LD_C_D,LD_C_E,LD_C_H,LD_C_L,LD_C_xHL,LD_C_A,
  LD_D_B,LD_D_C,LD_D_D,LD_D_E,LD_D_H,LD_D_L,LD_D_xHL,LD_D_A,
  LD_E_B,LD_E_C,LD_E_D,LD_E_E,LD_E_H,LD_E_L,LD_E_xHL,LD_E_A,
  LD_H_B,LD_H_C,LD_H_D,LD_H_E,LD_H_H,LD_H_L,LD_H_xHL,LD_H_A,
  LD_L_B,LD_L_C,LD_L_D,LD_L_E,LD_L_H,LD_L_L,LD_L_xHL,LD_L_A,
  LD_xHL_B,LD_xHL_C,LD_xHL_D,LD_xHL_E,LD_xHL_H,LD_xHL_L,HALT,LD_xHL_A,
  LD_A_B,LD_A_C,LD_A_D,LD_A_E,LD_A_H,LD_A_L,LD_A_xHL,LD_A_A,
  ADD_B,ADD_C,ADD_D,ADD_E,ADD_H,ADD_L,ADD_xHL,ADD_A,
  ADC_B,ADC_C,ADC_D,ADC_E,ADC_H,ADC_L,ADC_xHL,ADC_A,
  SUB_B,SUB_C,SUB_D,SUB_E,SUB_H,SUB_L,SUB_xHL,SUB_A,
  SBC_B,SBC_C,SBC_D,SBC_E,SBC_H,SBC_L,SBC_xHL,SBC_A,
  AND_B,AND_C,AND_D,AND_E,AND_H,AND_L,AND_xHL,AND_A,
  XOR_B,XOR_C,XOR_D,XOR_E,XOR_H,XOR_L,XOR_xHL,XOR_A,
  OR_B,OR_C,OR_D,OR_E,OR_H,OR_L,OR_xHL,OR_A,
  CP_B,CP_C,CP_D,CP_E,CP_H,CP_L,CP_xHL,CP_A,
  RET_NZ,POP_BC,JP_NZ,JP,CALL_NZ,PUSH_BC,ADD_BYTE,RST00,
  RET_Z,RET,JP_Z,PFX_CB,CALL_Z,CALL,ADC_BYTE,RST08,
  RET_NC,POP_DE,JP_NC,OUTA,CALL_NC,PUSH_DE,SUB_BYTE,RST10,
  RET_C,EXX,JP_C,INA,CALL_C,PFX_DD,SBC_BYTE,RST18,
  RET_PO,POP_HL,JP_PO,EX_HL_xSP,CALL_PO,PUSH_HL,AND_BYTE,RST20,
  RET_PE,LD_PC_HL,JP_PE,EX_DE_HL,CALL_PE,PFX_ED,XOR_BYTE,RST28,
  RET_P,POP_AF,JP_P,DI,CALL_P,PUSH_AF,OR_BYTE,RST30,
  RET_M,LD_SP_HL,JP_M,EI,CALL_M,PFX_FD,CP_BYTE,RST38
};

enum CodesCB
{
  RLC_B,RLC_C,RLC_D,RLC_E,RLC_H,RLC_L,RLC_xHL,RLC_A,
  RRC_B,RRC_C,RRC_D,RRC_E,RRC_H,RRC_L,RRC_xHL,RRC_A,
  RL_B,RL_C,RL_D,RL_E,RL_H,RL_L,RL_xHL,RL_A,
  RR_B,RR_C,RR_D,RR_E,RR_H,RR_L,RR_xHL,RR_A,
  SLA_B,SLA_C,SLA_D,SLA_E,SLA_H,SLA_L,SLA_xHL,SLA_A,
  SRA_B,SRA_C,SRA_D,SRA_E,SRA_H,SRA_L,SRA_xHL,SRA_A,
  SLL_B,SLL_C,SLL_D,SLL_E,SLL_H,SLL_L,SLL_xHL,SLL_A,
  SRL_B,SRL_C,SRL_D,SRL_E,SRL_H,SRL_L,SRL_xHL,SRL_A,
  BIT0_B,BIT0_C,BIT0_D,BIT0_E,BIT0_H,BIT0_L,BIT0_xHL,BIT0_A,
  BIT1_B,BIT1_C,BIT1_D,BIT1_E,BIT1_H,BIT1_L,BIT1_xHL,BIT1_A,
  BIT2_B,BIT2_C,BIT2_D,BIT2_E,BIT2_H,BIT2_L,BIT2_xHL,BIT2_A,
  BIT3_B,BIT3_C,BIT3_D,BIT3_E,BIT3_H,BIT3_L,BIT3_xHL,BIT3_A,
  BIT4_B,BIT4_C,BIT4_D,BIT4_E,BIT4_H,BIT4_L,BIT4_xHL,BIT4_A,
  BIT5_B,BIT5_C,BIT5_D,BIT5_E,BIT5_H,BIT5_L,BIT5_xHL,BIT5_A,
  BIT6_B,BIT6_C,BIT6_D,BIT6_E,BIT6_H,BIT6_L,BIT6_xHL,BIT6_A,
  BIT7_B,BIT7_C,BIT7_D,BIT7_E,BIT7_H,BIT7_L,BIT7_xHL,BIT7_A,
  RES0_B,RES0_C,RES0_D,RES0_E,RES0_H,RES0_L,RES0_xHL,RES0_A,
  RES1_B,RES1_C,RES1_D,RES1_E,RES1_H,RES1_L,RES1_xHL,RES1_A,
  RES2_B,RES2_C,RES2_D,RES2_E,RES2_H,RES2_L,RES2_xHL,RES2_A,
  RES3_B,RES3_C,RES3_D,RES3_E,RES3_H,RES3_L,RES3_xHL,RES3_A,
  RES4_B,RES4_C,RES4_D,RES4_E,RES4_H,RES4_L,RES4_xHL,RES4_A,
  RES5_B,RES5_C,RES5_D,RES5_E,RES5_H,RES5_L,RES5_xHL,RES5_A,
  RES6_B,RES6_C,RES6_D,RES6_E,RES6_H,RES6_L,RES6_xHL,RES6_A,
  RES7_B,RES7_C,RES7_D,RES7_E,RES7_H,RES7_L,RES7_xHL,RES7_A,  
  SET0_B,SET0_C,SET0_D,SET0_E,SET0_H,SET0_L,SET0_xHL,SET0_A,
  SET1_B,SET1_C,SET1_D,SET1_E,SET1_H,SET1_L,SET1_xHL,SET1_A,
  SET2_B,SET2_C,SET2_D,SET2_E,SET2_H,SET2_L,SET2_xHL,SET2_A,
  SET3_B,SET3_C,SET3_D,SET3_E,SET3_H,SET3_L,SET3_xHL,SET3_A,
  SET4_B,SET4_C,SET4_D,SET4_E,SET4_H,SET4_L,SET4_xHL,SET4_A,
  SET5_B,SET5_C,SET5_D,SET5_E,SET5_H,SET5_L,SET5_xHL,SET5_A,
  SET6_B,SET6_C,SET6_D,SET6_E,SET6_H,SET6_L,SET6_xHL,SET6_A,
  SET7_B,SET7_C,SET7_D,SET7_E,SET7_H,SET7_L,SET7_xHL,SET7_A
};
  
enum CodesED
{
  DB_00,DB_01,DB_02,DB_03,DB_04,DB_05,DB_06,DB_07,
  DB_08,DB_09,DB_0A,DB_0B,DB_0C,DB_0D,DB_0E,DB_0F,
  DB_10,DB_11,DB_12,DB_13,DB_14,DB_15,DB_16,DB_17,
  DB_18,DB_19,DB_1A,DB_1B,DB_1C,DB_1D,DB_1E,DB_1F,
  DB_20,DB_21,DB_22,DB_23,DB_24,DB_25,DB_26,DB_27,
  DB_28,DB_29,DB_2A,DB_2B,DB_2C,DB_2D,DB_2E,DB_2F,
  DB_30,DB_31,DB_32,DB_33,DB_34,DB_35,DB_36,DB_37,
  DB_38,DB_39,DB_3A,DB_3B,DB_3C,DB_3D,DB_3E,DB_3F,
  IN_B_xC,OUT_xC_B,SBC_HL_BC,LD_xWORDe_BC,NEG,RETN,IM_0,LD_I_A,
  IN_C_xC,OUT_xC_C,ADC_HL_BC,LD_BC_xWORDe,DB_4C,RETI,DB_,LD_R_A,
  IN_D_xC,OUT_xC_D,SBC_HL_DE,LD_xWORDe_DE,DB_54,DB_55,IM_1,LD_A_I,
  IN_E_xC,OUT_xC_E,ADC_HL_DE,LD_DE_xWORDe,DB_5C,DB_5D,IM_2,LD_A_R,
  IN_H_xC,OUT_xC_H,SBC_HL_HL,LD_xWORDe_HL,DB_64,DB_65,DB_66,RRD,
  IN_L_xC,OUT_xC_L,ADC_HL_HL,LD_HL_xWORDe,DB_6C,DB_6D,DB_6E,RLD,
  IN_F_xC,DB_71,SBC_HL_SP,LD_xWORDe_SP,DB_74,DB_75,DB_76,DB_77,
  IN_A_xC,OUT_xC_A,ADC_HL_SP,LD_SP_xWORDe,DB_7C,DB_7D,DB_7E,DB_7F,
  DB_80,DB_81,DB_82,DB_83,DB_84,DB_85,DB_86,DB_87,
  DB_88,DB_89,DB_8A,DB_8B,DB_8C,DB_8D,DB_8E,DB_8F,
  DB_90,DB_91,DB_92,DB_93,DB_94,DB_95,DB_96,DB_97,
  DB_98,DB_99,DB_9A,DB_9B,DB_9C,DB_9D,DB_9E,DB_9F,
  LDI,CPI,INI,OUTI,DB_A4,DB_A5,DB_A6,DB_A7,
  LDD,CPD,IND,OUTD,DB_AC,DB_AD,DB_AE,DB_AF,
  LDIR,CPIR,INIR,OTIR,DB_B4,DB_B5,DB_B6,DB_B7,
  LDDR,CPDR,INDR,OTDR,DB_BC,DB_BD,DB_BE,DB_BF,
  DB_C0,DB_C1,DB_C2,DB_C3,DB_C4,DB_C5,DB_C6,DB_C7,
  DB_C8,DB_C9,DB_CA,DB_CB,DB_CC,DB_CD,DB_CE,DB_CF,
  DB_D0,DB_D1,DB_D2,DB_D3,DB_D4,DB_D5,DB_D6,DB_D7,
  DB_D8,DB_D9,DB_DA,DB_DB,DB_DC,DB_DD,DB_DE,DB_DF,
  DB_E0,DB_E1,DB_E2,DB_E3,DB_E4,DB_E5,DB_E6,DB_E7,
  DB_E8,DB_E9,DB_EA,DB_EB,DB_EC,DB_ED,DB_EE,DB_EF,
  DB_F0,DB_F1,DB_F2,DB_F3,DB_F4,DB_F5,DB_F6,DB_F7,
  DB_F8,DB_F9,DB_FA,DB_FB,DB_FC,DB_FD,DB_FE,DB_FF
};

static void CodesCB(register Z80 *R)
{
  register byte I;

  I=RdZ80(R->PC.W++);
  R->ICount-=CyclesCB[I];
  switch(I)
  {
#include "CodesCB.h"
    default:
      if(R->TrapBadOps)
        printf
        (   
          "[Z80 %lX] Unrecognized instruction: CB %02X at PC=%04X\n",
          (long)(R->User),RdZ80(R->PC.W-1),R->PC.W-2
        );
  }
}

static void CodesDDCB(register Z80 *R)
{
  register pair J;
  register byte I;

#define XX IX    
  J.W=R->XX.W+(offset)RdZ80(R->PC.W++);
  I=RdZ80(R->PC.W++);
  R->ICount-=CyclesXXCB[I];
  switch(I)
  {
#include "CodesXCB.h"
    default:
      if(R->TrapBadOps)
        printf
        (
          "[Z80 %lX] Unrecognized instruction: DD CB %02X %02X at PC=%04X\n",
          (long)(R->User),RdZ80(R->PC.W-2),RdZ80(R->PC.W-1),R->PC.W-4
        );
  }
#undef XX
}

static void CodesFDCB(register Z80 *R)
{
  register pair J;
  register byte I;

#define XX IY
  J.W=R->XX.W+(offset)RdZ80(R->PC.W++);
  I=RdZ80(R->PC.W++);
  R->ICount-=CyclesXXCB[I];
  switch(I)
  {
#include "CodesXCB.h"
    default:
      if(R->TrapBadOps)
        printf
        (
          "[Z80 %lX] Unrecognized instruction: FD CB %02X %02X at PC=%04X\n",
          (long)R->User,RdZ80(R->PC.W-2),RdZ80(R->PC.W-1),R->PC.W-4
        );
  }
#undef XX
}

static void CodesED(register Z80 *R)
{
  register byte I;
  register pair J;

  I=RdZ80(R->PC.W++);
  R->ICount-=CyclesED[I];
  switch(I)
  {
#include "CodesED.h"
    case PFX_ED:
      R->PC.W--;break;
    default:
      if(R->TrapBadOps)
        printf
        (
          "[Z80 %lX] Unrecognized instruction: ED %02X at PC=%04X\n",
          (long)R->User,RdZ80(R->PC.W-1),R->PC.W-2
        );
  }
}

static void CodesDD(register Z80 *R)
{
  register byte I;
  register pair J;

#define XX IX
  I=RdZ80(R->PC.W++);
  R->ICount-=CyclesXX[I];
  switch(I)
  {
#include "CodesXX.h"
    case PFX_FD:
    case PFX_DD:
      R->PC.W--;break;
    case PFX_CB:
      CodesDDCB(R);break;
    default:
      if(R->TrapBadOps)
        printf
        (
          "[Z80 %lX] Unrecognized instruction: DD %02X at PC=%04X\n",
          (long)R->User,RdZ80(R->PC.W-1),R->PC.W-2
        );
  }
#undef XX
}

static void CodesFD(register Z80 *R)
{
  register byte I;
  register pair J;

#define XX IY
  I=RdZ80(R->PC.W++);
  R->ICount-=CyclesXX[I];
  switch(I)
  {
#include "CodesXX.h"
    case PFX_FD:
    case PFX_DD:
      R->PC.W--;break;
    case PFX_CB:
      CodesFDCB(R);break;
    default:
        printf
        (
          "Unrecognized instruction: FD %02X at PC=%04X\n",
          RdZ80(R->PC.W-1),R->PC.W-2
        );
  }
#undef XX
}

/** ResetZ80() ***********************************************/
/** This function can be used to reset the register struct  **/
/** before starting execution with Z80(). It sets the       **/
/** registers to their supposed initial values.             **/
/*************************************************************/
void ResetZ80(Z80 *R)
{
  R->PC.W     = 0x0000;
  R->SP.W     = 0xF000;
  R->AF.W     = 0x0000;
  R->BC.W     = 0x0000;
  R->DE.W     = 0x0000;
  R->HL.W     = 0x0000;
  R->AF1.W    = 0x0000;
  R->BC1.W    = 0x0000;
  R->DE1.W    = 0x0000;
  R->HL1.W    = 0x0000;
  R->IX.W     = 0x0000;
  R->IY.W     = 0x0000;
  R->I        = 0x00;
  R->IFF      = 0x00;
  R->ICount   = R->IPeriod;
  R->IRequest = INT_NONE;
}

/** ExecZ80() ************************************************/
/** This function will execute a single Z80 opcode. It will **/
/** then return next PC, and current register values in R.  **/
/*************************************************************/
word ExecZ80(Z80 *R)
{
  register byte I;
  register pair J;

  I=RdZ80(R->PC.W++);
  R->ICount-=Cycles[I];
  switch(I)
  {
#include "Codes.h"
    case PFX_CB: CodesCB(R);break;
    case PFX_ED: CodesED(R);break;
    case PFX_FD: CodesFD(R);break;
    case PFX_DD: CodesDD(R);break;
  }

  /* We are done */
  return(R->PC.W);
}

/** IntZ80() *************************************************/
/** This function will generate interrupt of given vector.  **/
/*************************************************************/
void IntZ80(Z80 *R,word Vector)
{
  if((R->IFF&IFF_1)||(Vector==INT_NMI))
  {
    /* If HALTed, take CPU off HALT instruction */
    if(R->IFF&IFF_HALT) { R->PC.W++;R->IFF&=~IFF_HALT; }

    /* Save PC on stack */
    M_PUSH(PC);

    /* Automatically reset IRequest if needed */
    if(R->IAutoReset&&(Vector==R->IRequest)) R->IRequest=INT_NONE;

    /* If it is NMI... */
    if(Vector==INT_NMI)
    {
      /* Copy IFF1 to IFF2 */
      if(R->IFF&IFF_1) R->IFF|=IFF_2; else R->IFF&=~IFF_2;
      /* Clear IFF1 */
      R->IFF&=~(IFF_1|IFF_EI);
      /* Jump to hardwired NMI vector */
      R->PC.W=0x0066;
      /* Done */
      return;
    }

    /* Further interrupts off */
    R->IFF&=~(IFF_1|IFF_2|IFF_EI);

    /* If in IM2 mode... */
    if(R->IFF&IFF_IM2)
    {
      /* Make up the vector address */
      Vector=(Vector&0xFF)|((word)(R->I)<<8);
      /* Read the vector */
      R->PC.B.l=RdZ80(Vector++);
      R->PC.B.h=RdZ80(Vector);
      /* Done */
      return;
    }

    /* If in IM1 mode, just jump to hardwired IRQ vector */
    if(R->IFF&IFF_IM1) { R->PC.W=0x0038;return; }

    /* If in IM0 mode... */

    /* Jump to a vector */
    switch(Vector)
    {
      case INT_RST00: R->PC.W=0x0000;break;
      case INT_RST08: R->PC.W=0x0008;break;
      case INT_RST10: R->PC.W=0x0010;break;
      case INT_RST18: R->PC.W=0x0018;break;
      case INT_RST20: R->PC.W=0x0020;break;
      case INT_RST28: R->PC.W=0x0028;break;
      case INT_RST30: R->PC.W=0x0030;break;
      case INT_RST38: R->PC.W=0x0038;break;
    }
  }
}

/** RunZ80() *************************************************/
/** This function will run Z80 code until an LoopZ80() call **/
/** returns INT_QUIT. It will return the PC at which        **/
/** emulation stopped, and current register values in R.    **/
/*************************************************************/
word RunZ80(Z80 *R)
{
  register byte I;
  register pair J;

  for(;;)
  {
#ifdef DEBUG
    /* Turn tracing on when reached trap address */
    if(R->PC.W==R->Trap) R->Trace=1;
    /* Call single-step debugger, exit if requested */
    if(R->Trace)
      if(!DebugZ80(R)) return(R->PC.W);
#endif

    I=RdZ80(R->PC.W++);
    R->ICount-=Cycles[I];
    switch(I)
    {
#include "Codes.h"
      case PFX_CB: CodesCB(R);break;
      case PFX_ED: CodesED(R);break;
      case PFX_FD: CodesFD(R);break;
      case PFX_DD: CodesDD(R);break;
    }
 
    /* If cycle counter expired... */
    if(R->ICount<=0)
    {
      /* If we have come after EI, get address from IRequest */
      /* Otherwise, get it from the loop handler             */
      if(R->IFF&IFF_EI)
      {
        R->IFF=(R->IFF&~IFF_EI)|IFF_1; /* Done with AfterEI state */
        R->ICount+=R->IBackup-1;       /* Restore the ICount      */

        /* Call periodic handler or set pending IRQ */
        if(R->ICount>0) J.W=R->IRequest;
        else
        {
          J.W=LoopZ80(R);        /* Call periodic handler    */
          R->ICount+=R->IPeriod; /* Reset the cycle counter  */
          if(J.W==INT_NONE) J.W=R->IRequest;  /* Pending IRQ */
        }
      }
      else
      {
        J.W=LoopZ80(R);          /* Call periodic handler    */
        R->ICount+=R->IPeriod;   /* Reset the cycle counter  */
        if(J.W==INT_NONE) J.W=R->IRequest;    /* Pending IRQ */
      }

      if(J.W==INT_QUIT) return(R->PC.W); /* Exit if INT_QUIT */
      if(J.W!=INT_NONE) IntZ80(R,J.W);   /* Int-pt if needed */
    }
  }

  /* Execution stopped */
  return(R->PC.W);
}
