/*
 *   fetch.c
 *
 *   This file is part of Emu48
 *
 *   Copyright (C) 1999 Christoph Gießelink
 *
 */
#include "pch.h"
#include "Opcodes.h"

#define F	0xFF							// F = function

typedef const struct
{
	const VOID  *pLnk;
	const DWORD dwTyp;
} JMPTAB, *PJMPTAB;

// jump tables
static JMPTAB oF_[] =
{
	oF0,		F,
	oF1,		F,
	oF2,		F,
	oF3,		F,
	oF4,		F,
	oF5,		F,
	oF6,		F,
	oF7,		F,
	oF8,		F,
	oF9,		F,
	oFA,		F,
	oFB,		F,
	oFC,		F,
	oFD,		F,
	oFE,		F,
	oFF,		F
};

static JMPTAB oE_[] =
{
	oE0,		F,
	oE1,		F,
	oE2,		F,
	oE3,		F,
	oE4,		F,
	oE5,		F,
	oE6,		F,
	oE7,		F,
	oE8,		F,
	oE9,		F,
	oEA,		F,
	oEB,		F,
	oEC,		F,
	oED,		F,
	oEE,		F,
	oEF,		F
};

static JMPTAB oD_[] =
{
	oD0,		F,
	oD1,		F,
	oD2,		F,
	oD3,		F,
	oD4,		F,
	oD5,		F,
	oD6,		F,
	oD7,		F,
	oD8,		F,
	oD9,		F,
	oDA,		F,
	oDB,		F,
	oDC,		F,
	oDD,		F,
	oDE,		F,
	oDF,		F
};

static JMPTAB oC_[] =
{
	oC0,		F,
	oC1,		F,
	oC2,		F,
	oC3,		F,
	oC4,		F,
	oC5,		F,
	oC6,		F,
	oC7,		F,
	oC8,		F,
	oC9,		F,
	oCA,		F,
	oCB,		F,
	oCC,		F,
	oCD,		F,
	oCE,		F,
	oCF,		F
};

static JMPTAB oBb_[] =
{
	oBb0,		F,
	oBb1,		F,
	oBb2,		F,
	oBb3,		F,
	oBb4,		F,
	oBb5,		F,
	oBb6,		F,
	oBb7,		F,
	oBb8,		F,
	oBb9,		F,
	oBbA,		F,
	oBbB,		F,
	oBbC,		F,
	oBbD,		F,
	oBbE,		F,
	oBbF,		F
};

static JMPTAB oBa_[] =
{
	oBa0,		F,
	oBa1,		F,
	oBa2,		F,
	oBa3,		F,
	oBa4,		F,
	oBa5,		F,
	oBa6,		F,
	oBa7,		F,
	oBa8,		F,
	oBa9,		F,
	oBaA,		F,
	oBaB,		F,
	oBaC,		F,
	oBaD,		F,
	oBaE,		F,
	oBaF,		F
};

static JMPTAB oB_[] =
{
	oBa_,		2,
	oBa_,		2,
	oBa_,		2,
	oBa_,		2,
	oBa_,		2,
	oBa_,		2,
	oBa_,		2,
	oBa_,		2,
	oBb_,		2,
	oBb_,		2,
	oBb_,		2,
	oBb_,		2,
	oBb_,		2,
	oBb_,		2,
	oBb_,		2,
	oBb_,		2
};

static JMPTAB oAb_[] =
{
	oAb0,		F,
	oAb1,		F,
	oAb2,		F,
	oAb3,		F,
	oAb4,		F,
	oAb5,		F,
	oAb6,		F,
	oAb7,		F,
	oAb8,		F,
	oAb9,		F,
	oAbA,		F,
	oAbB,		F,
	oAbC,		F,
	oAbD,		F,
	oAbE,		F,
	oAbF,		F
};

static JMPTAB oAa_[] =
{
	oAa0,		F,
	oAa1,		F,
	oAa2,		F,
	oAa3,		F,
	oAa4,		F,
	oAa5,		F,
	oAa6,		F,
	oAa7,		F,
	oAa8,		F,
	oAa9,		F,
	oAaA,		F,
	oAaB,		F,
	oAaC,		F,
	oAaD,		F,
	oAaE,		F,
	oAaF,		F
};

static JMPTAB oA_[] =
{
	oAa_,		2,
	oAa_,		2,
	oAa_,		2,
	oAa_,		2,
	oAa_,		2,
	oAa_,		2,
	oAa_,		2,
	oAa_,		2,
	oAb_,		2,
	oAb_,		2,
	oAb_,		2,
	oAb_,		2,
	oAb_,		2,
	oAb_,		2,
	oAb_,		2,
	oAb_,		2
};

static JMPTAB o9b_[] =
{
	o9b0,		F,
	o9b1,		F,
	o9b2,		F,
	o9b3,		F,
	o9b4,		F,
	o9b5,		F,
	o9b6,		F,
	o9b7,		F,
	o9b8,		F,
	o9b9,		F,
	o9bA,		F,
	o9bB,		F,
	o9bC,		F,
	o9bD,		F,
	o9bE,		F,
	o9bF,		F
};

static JMPTAB o9a_[] =
{
	o9a0,		F,
	o9a1,		F,
	o9a2,		F,
	o9a3,		F,
	o9a4,		F,
	o9a5,		F,
	o9a6,		F,
	o9a7,		F,
	o9a8,		F,
	o9a9,		F,
	o9aA,		F,
	o9aB,		F,
	o9aC,		F,
	o9aD,		F,
	o9aE,		F,
	o9aF,		F
};

static JMPTAB o9_[] =
{
	o9a_,		2,
	o9a_,		2,
	o9a_,		2,
	o9a_,		2,
	o9a_,		2,
	o9a_,		2,
	o9a_,		2,
	o9a_,		2,
	o9b_,		2,
	o9b_,		2,
	o9b_,		2,
	o9b_,		2,
	o9b_,		2,
	o9b_,		2,
	o9b_,		2,
	o9b_,		2
};

static JMPTAB o8B_[] =
{
	o8B0,		F,
	o8B1,		F,
	o8B2,		F,
	o8B3,		F,
	o8B4,		F,
	o8B5,		F,
	o8B6,		F,
	o8B7,		F,
	o8B8,		F,
	o8B9,		F,
	o8BA,		F,
	o8BB,		F,
	o8BC,		F,
	o8BD,		F,
	o8BE,		F,
	o8BF,		F
};

static JMPTAB o8A_[] =
{
	o8A0,		F,
	o8A1,		F,
	o8A2,		F,
	o8A3,		F,
	o8A4,		F,
	o8A5,		F,
	o8A6,		F,
	o8A7,		F,
	o8A8,		F,
	o8A9,		F,
	o8AA,		F,
	o8AB,		F,
	o8AC,		F,
	o8AD,		F,
	o8AE,		F,
	o8AF,		F
};

static JMPTAB o81B_[] =
{
	o_invalid4,	F,
	o81B1,		F,							// normally o_invalid4, beep patch
	o81B2,		F,
	o81B3,		F,
	o81B4,		F,
	o81B5,		F,
	o81B6,		F,
	o81B7,		F,
	o_invalid4,	F,
	o_invalid4,	F,
	o_invalid4,	F,
	o_invalid4,	F,
	o_invalid4,	F,
	o_invalid4,	F,
	o_invalid4,	F,
	o_invalid4,	F
};

static JMPTAB o81Af2_[] =
{
	o81Af20,	F,
	o81Af21,	F,
	o81Af22,	F,
	o81Af23,	F,
	o81Af24,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o81Af28,	F,
	o81Af29,	F,
	o81Af2A,	F,
	o81Af2B,	F,
	o81Af2C,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F
};

static JMPTAB o81Af1_[] =
{
	o81Af10,	F,
	o81Af11,	F,
	o81Af12,	F,
	o81Af13,	F,
	o81Af14,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o81Af18,	F,
	o81Af19,	F,
	o81Af1A,	F,
	o81Af1B,	F,
	o81Af1C,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F
};

static JMPTAB o81Af0_[] =
{
	o81Af00,	F,
	o81Af01,	F,
	o81Af02,	F,
	o81Af03,	F,
	o81Af04,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o81Af08,	F,
	o81Af09,	F,
	o81Af0A,	F,
	o81Af0B,	F,
	o81Af0C,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F
};

static JMPTAB o81A_[] =
{
	o81Af0_,	5,
	o81Af1_,	5,
	o81Af2_,	5,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F
};

static JMPTAB o819_[] =
{
	o819f0,		F,
	o819f1,		F,
	o819f2,		F,
	o819f3,		F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F
};

static JMPTAB o818_[] =
{
	o818f0x,	F,
	o818f1x,	F,
	o818f2x,	F,
	o818f3x,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o818f8x,	F,
	o818f9x,	F,
	o818fAx,	F,
	o818fBx,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F,
	o_invalid6,	F
};

static JMPTAB o81_[] =
{
	o810,		F,
	o811,		F,
	o812,		F,
	o813,		F,
	o814,		F,
	o815,		F,
	o816,		F,
	o817,		F,
	o818_,		4,
	o819_,		4,
	o81A_,		4,
	o81B_,		3,
	o81C,		F,
	o81D,		F,
	o81E,		F,
	o81F,		F
};

static JMPTAB o8081_[] =
{
	o80810,		F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F,
	o_invalid5,	F
};

static JMPTAB o808_[] =
{
	o8080,		F,
	o8081_,		4,
	o8082X,		F,
	o8083,		F,
	o8084n,		F,
	o8085n,		F,
	o8086n,		F,
	o8087n,		F,
	o8088n,		F,
	o8089n,		F,
	o808An,		F,
	o808Bn,		F,
	o808C,		F,
	o808D,		F,
	o808E,		F,
	o808F,		F
};

static JMPTAB o80_[] =
{
	o800,		F,
	o801,		F,
	o802,		F,
	o803,		F,
	o804,		F,
	o805,		F,
	o806,		F,
	o807,		F,
	o808_,		3,
	o809,		F,
	o80A,		F,
	o80B,		F,
	o80Cn,		F,
	o80Dn,		F,
	o80E,		F,
	o80Fn,		F
};

static JMPTAB o8_[] =
{
	o80_,		2,
	o81_,		2,
	o82n,		F,
	o83n,		F,
	o84n,		F,
	o85n,		F,
	o86n,		F,
	o87n,		F,
	o88n,		F,
	o89n,		F,
	o8A_,		2,
	o8B_,		2,
	o8Cd4,		F,
	o8Dd5,		F,
	o8Ed4,		F,
	o8Fd5,		F
};

static JMPTAB o15_[] =
{
	o150a,		F,
	o151a,		F,
	o152a,		F,
	o153a,		F,
	o154a,		F,
	o155a,		F,
	o156a,		F,
	o157a,		F,
	o158x,		F,
	o159x,		F,
	o15Ax,		F,
	o15Bx,		F,
	o15Cx,		F,
	o15Dx,		F,
	o15Ex,		F,
	o15Fx,		F
};

static JMPTAB o14_[] =
{
	o140,		F,
	o141,		F,
	o142,		F,
	o143,		F,
	o144,		F,
	o145,		F,
	o146,		F,
	o147,		F,
	o148,		F,
	o149,		F,
	o14A,		F,
	o14B,		F,
	o14C,		F,
	o14D,		F,
	o14E,		F,
	o14F,		F
};

static JMPTAB o13_[] =
{
	o130,		F,
	o131,		F,
	o132,		F,
	o133,		F,
	o134,		F,
	o135,		F,
	o136,		F,
	o137,		F,
	o138,		F,
	o139,		F,
	o13A,		F,
	o13B,		F,
	o13C,		F,
	o13D,		F,
	o13E,		F,
	o13F,		F
};

static JMPTAB o12_[] =
{
	o120,		F,
	o121,		F,
	o122,		F,
	o123,		F,
	o124,		F,
	o_invalid3,	F,
	o_invalid3,	F,
	o_invalid3,	F,
	o128,		F,
	o129,		F,
	o12A,		F,
	o12B,		F,
	o12C,		F,
	o_invalid3,	F,
	o_invalid3,	F,
	o_invalid3,	F
};

static JMPTAB o11_[] =
{
	o110,		F,
	o111,		F,
	o112,		F,
	o113,		F,
	o114,		F,
	o_invalid3,	F,
	o_invalid3,	F,
	o_invalid3,	F,
	o118,		F,
	o119,		F,
	o11A,		F,
	o11B,		F,
	o11C,		F,
	o_invalid3,	F,
	o_invalid3,	F,
	o_invalid3,	F
};

static JMPTAB o10_[] =
{
	o100,		F,
	o101,		F,
	o102,		F,
	o103,		F,
	o104,		F,
	o_invalid3,	F,
	o_invalid3,	F,
	o_invalid3,	F,
	o108,		F,
	o109,		F,
	o10A,		F,
	o10B,		F,
	o10C,		F,
	o_invalid3,	F,
	o_invalid3,	F,
	o_invalid3,	F
};

static JMPTAB o1_[] =
{
	o10_,		2,
	o11_,		2,
	o12_,		2,
	o13_,		2,
	o14_,		2,
	o15_,		2,
	o16x,		F,
	o17x,		F,
	o18x,		F,
	o19d2,		F,
	o1Ad4,		F,
	o1Bd5,		F,
	o1Cx,		F,
	o1Dd2,		F,
	o1Ed4,		F,
	o1Fd5,		F
};

static JMPTAB o0E_[] =
{
	o0Ef0,		F,
	o0Ef1,		F,
	o0Ef2,		F,
	o0Ef3,		F,
	o0Ef4,		F,
	o0Ef5,		F,
	o0Ef6,		F,
	o0Ef7,		F,
	o0Ef8,		F,
	o0Ef9,		F,
	o0EfA,		F,
	o0EfB,		F,
	o0EfC,		F,
	o0EfD,		F,
	o0EfE,		F,
	o0EfF,		F
};

static JMPTAB o0_[] =
{
	o00,		F,
	o01,		F,
	o02,		F,
	o03,		F,
	o04,		F,
	o05,		F,
	o06,		F,
	o07,		F,
	o08,		F,
	o09,		F,
	o0A,		F,
	o0B,		F,
	o0C,		F,
	o0D,		F,
	o0E_,		3,
	o0F,		F
};

static JMPTAB o_[] =
{
	o0_,		1,
	o1_,		1,
	o2n,		F,
	o3X,		F,
	o4d2,		F,
	o5d2,		F,
	o6d3,		F,
	o7d3,		F,
	o8_,		1,
	o9_,		1,
	oA_,		1,
	oB_,		1,
	oC_,		1,
	oD_,		1,
	oE_,		1,
	oF_,		1
};

// opcode dispatcher
VOID EvalOpcode(LPBYTE I)
{
	DWORD   dwIndex = 0;
	PJMPTAB pJmpTab = o_;

	do
	{
		_ASSERT(I[dwIndex] <= 0xf);			// found packed data
		pJmpTab = &pJmpTab[I[dwIndex]];		// table entry by opcode
		dwIndex = pJmpTab->dwTyp;			// next pointer type
		pJmpTab = (PJMPTAB) pJmpTab->pLnk;	// next pointer to table/function
	}
	while (dwIndex != F);					// reference to table? -> again

	((VOID (*)(LPBYTE)) pJmpTab)(I);		// call function
	return;
}