/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program 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.

 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

#include "common/endian.h"

#include "gob/gob.h"
#include "gob/parse.h"
#include "gob/global.h"
#include "gob/inter.h"

namespace Gob {

Parse_v1::Parse_v1(GobEngine *vm) : Parse(vm) {
}

int16 Parse_v1::parseVarIndex(uint16 *arg_0, uint16 *arg_4) {
	int16 temp2;
	byte *arrDesc;
	int16 dim;
	int16 dimCount;
	int16 operation;
	int16 temp;
	int16 offset;
	int16 val;

	operation = *_vm->_global->_inter_execPtr++;
	debugC(5, kDebugParser, "var parse = %d", operation);
	switch (operation) {
	case 23:
	case OP_LOAD_VAR_STR:
		temp = _vm->_inter->load16() * 4;
		debugC(5, kDebugParser, "oper = %d",
				(int16) *_vm->_global->_inter_execPtr);

		if ((operation == OP_LOAD_VAR_STR) && (*_vm->_global->_inter_execPtr == 13)) {
			_vm->_global->_inter_execPtr++;
			val = parseValExpr(OP_END_MARKER);
			temp += val;
			debugC(5, kDebugParser, "parse subscript = %d", val);
		}
		return temp;

	case OP_ARRAY_UINT32:
	case OP_ARRAY_STR:
		temp = _vm->_inter->load16() * 4;
		dimCount = *_vm->_global->_inter_execPtr++;
		arrDesc = _vm->_global->_inter_execPtr;
		_vm->_global->_inter_execPtr += dimCount;
		offset = 0;
		for (dim = 0; dim < dimCount; dim++) {
			temp2 = parseValExpr(OP_END_MARKER);
			offset = arrDesc[dim] * offset + temp2;
		}
		offset *= 4;
		if (operation != OP_ARRAY_STR)
			return temp + offset;

		if (*_vm->_global->_inter_execPtr == 13) {
			_vm->_global->_inter_execPtr++;
			temp += parseValExpr(OP_END_MARKER);
		}
		return offset * _vm->_global->_inter_animDataSize + temp;

	default:
		return 0;
	}
}

int16 Parse_v1::parseValExpr(byte stopToken) {
	int16 values[20];
	byte operStack[20];
	int16 *valPtr;
	byte *operPtr;
	byte *arrDesc;
	byte operation;
	int16 temp2;
	int16 dim;
	int16 dimCount;
	int16 temp;
	int16 offset;
	int16 stkPos;
	int16 brackPos;
	static int16 flag = 0;
	int16 oldflag;

	oldflag = flag;
	if (flag == 0) {
		flag = 1;
		printExpr(stopToken);
	}

	stkPos = -1;
	operPtr = operStack - 1;
	valPtr = values - 1;

	while (true) {
		stkPos++;
		operPtr++;
		valPtr++;

		operation = *_vm->_global->_inter_execPtr++;
		if ((operation >= OP_LOAD_IMM_INT32) && (operation <= OP_FUNC)) {
			*operPtr = OP_LOAD_IMM_INT16;
			switch (operation) {
			case OP_LOAD_IMM_INT32:
				*valPtr = READ_LE_UINT32(_vm->_global->_inter_execPtr);
				_vm->_global->_inter_execPtr += 4;
				break;

			case OP_LOAD_IMM_INT16:
				*valPtr = _vm->_inter->load16();
				break;

			case 23:
				*valPtr = (uint16) VAR(_vm->_inter->load16());
				break;

			case OP_LOAD_VAR_STR:
				temp = _vm->_inter->load16() * 4;
				_vm->_global->_inter_execPtr++;
				temp += parseValExpr(OP_END_MARKER);
				*valPtr = READ_VARO_UINT8(temp);
				break;

			case OP_ARRAY_UINT32:
			case OP_ARRAY_STR:
				temp = _vm->_inter->load16();
				dimCount = *_vm->_global->_inter_execPtr++;
				arrDesc = _vm->_global->_inter_execPtr;
				_vm->_global->_inter_execPtr += dimCount;
				offset = 0;
				for (dim = 0; dim < dimCount; dim++) {
					temp2 = parseValExpr(OP_END_MARKER);
					offset = arrDesc[dim] * offset + temp2;
				}
				if (operation == OP_ARRAY_UINT32) {
					*valPtr = (uint16) VAR(temp + offset);
				} else {
					_vm->_global->_inter_execPtr++;
					temp2 = parseValExpr(OP_END_MARKER);
					*valPtr = READ_VARO_UINT8(temp * 4 + offset * 4 *
							_vm->_global->_inter_animDataSize + temp2);
				}
				break;

			case OP_FUNC:
				operation = *_vm->_global->_inter_execPtr++;
				parseExpr(OP_END_EXPR, 0);

				if (operation == FUNC_SQR) {
					_vm->_global->_inter_resVal =
						_vm->_global->_inter_resVal * _vm->_global->_inter_resVal;
				} else if (operation == FUNC_ABS) {
					if (_vm->_global->_inter_resVal < 0)
						_vm->_global->_inter_resVal = -_vm->_global->_inter_resVal;
				} else if (operation == FUNC_RAND) {
					_vm->_global->_inter_resVal =
						_vm->_util->getRandom(_vm->_global->_inter_resVal);
				}
				*valPtr = _vm->_global->_inter_resVal;
				break;

			}	// switch
			if ((stkPos > 0) && (operPtr[-1] == OP_NEG)) {
				stkPos--;
				operPtr--;
				valPtr--;
				operPtr[0] = OP_LOAD_IMM_INT16;
				valPtr[0] = -valPtr[1];
			}

			if ((stkPos > 0) && (operPtr[-1] >= OP_MUL) && (operPtr[-1] <= OP_BITAND)) {
				stkPos -= 2;
				operPtr -= 2;
				valPtr -= 2;

				switch (operPtr[1]) {
				case OP_MUL:
					valPtr[0] *= valPtr[2];
					break;

				case OP_DIV:
					valPtr[0] /= valPtr[2];
					break;

				case OP_MOD:
					valPtr[0] %= valPtr[2];
					break;

				case OP_BITAND:
					valPtr[0] &= valPtr[2];
					break;
				}
			}	// if ((stkPos > 0) && (cmdPtr[-1] >= OP_MUL) && (cmdPtr[-1] <= OP_BITAND))
			continue;
		}

		if ((operation >= OP_NEG) && (operation <= OP_BEGIN_EXPR)) {
			*operPtr = operation;
			continue;
		}

		while (stkPos >= 2) {
			if (operPtr[-2] == OP_BEGIN_EXPR) {
				stkPos--;
				operPtr--;
				valPtr--;

				operPtr[-1] = operPtr[0];
				valPtr[-1] = valPtr[0];
				if ((stkPos > 1) && (operPtr[-2] == OP_NEG)) {
					valPtr[-2] = OP_LOAD_IMM_INT16;
					valPtr[-2] = -valPtr[-1];

					stkPos--;
					operPtr--;
					valPtr--;
				}

				if ((stkPos > 2) && (operPtr[-2] >= OP_MUL) && (operPtr[-2] <= OP_BITAND)) {
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					switch (operPtr[0]) {
					case OP_MUL:
						operPtr[-1] *= operPtr[1];
						break;

					case OP_DIV:
						operPtr[-1] /= operPtr[1];
						break;

					case OP_MOD:
						operPtr[-1] %= operPtr[1];
						break;

					case OP_BITAND:
						operPtr[-1] &= operPtr[1];
						break;
					}
				}
				if (operation == OP_END_EXPR)
					break;
			}	// operPtr[-2] == OP_BEGIN_EXPR

			for (brackPos = (stkPos - 2); (brackPos > 0) &&
			    (operStack[brackPos] < OP_OR) && (operStack[brackPos] != OP_BEGIN_EXPR);
					brackPos--)
				;

			if ((operStack[brackPos] >= OP_OR) || (operStack[brackPos] == OP_BEGIN_EXPR))
				brackPos++;

			if ((operPtr[-2] < 2) || (operPtr[-2] > 8))
				break;

			stkPos -= 2;
			operPtr -= 2;
			valPtr -= 2;
			switch (operPtr[0]) {
			case OP_ADD:
				values[brackPos] += valPtr[1];
				continue;
			case OP_SUB:
				values[brackPos] -= valPtr[1];
				continue;
			case OP_BITOR:
				values[brackPos] |= valPtr[1];
				continue;
			case OP_MUL:
				valPtr[-1] *= valPtr[1];
				continue;
			case OP_DIV:
				valPtr[-1] /= valPtr[1];
				continue;
			case OP_MOD:
				valPtr[-1] %= valPtr[1];
				continue;
			case OP_BITAND:
				valPtr[-1] &= valPtr[1];
				continue;
			}
		}

		if (operation != OP_END_EXPR) {
			if (operation != stopToken)
				debugC(5, kDebugParser, "stoptoken error: %d != %d",
						operation, stopToken);

			flag = oldflag;
			return values[0];
		}

		stkPos--;
		operPtr--;
		valPtr--;
	}
}

int16 Parse_v1::parseExpr(byte stopToken, byte *arg_2) {
	int32 values[20];
	byte operStack[20];
	int32 prevPrevVal;
	int32 prevVal;
	int32 curVal;
	int32 *valPtr;
	byte *operPtr;
	byte *arrDescPtr;
	byte operation;
	int16 dimCount;
	int16 temp;
	int16 temp2;
	uint16 offset;
	int16 dim;
	bool var_1A;
	int16 stkPos;
	int16 brackStart;

	stkPos = -1;
	operPtr = operStack - 1;
	valPtr = values - 1;

	while (true) {
		stkPos++;
		operPtr++;
		valPtr++;
		operation = *_vm->_global->_inter_execPtr++;
		if ((operation >= OP_LOAD_IMM_INT32) && (operation <= OP_FUNC)) {
			switch (operation) {
			case OP_LOAD_IMM_INT32:
				*operPtr = OP_LOAD_IMM_INT16;
				*valPtr = READ_LE_UINT32(_vm->_global->_inter_execPtr);
				_vm->_global->_inter_execPtr += 4;
				break;

			case OP_LOAD_IMM_INT16:
				*operPtr = OP_LOAD_IMM_INT16;
				*valPtr = _vm->_inter->load16();
				break;

			case OP_LOAD_IMM_STR:
				*operPtr = OP_LOAD_IMM_STR;
				*valPtr = encodePtr(_vm->_global->_inter_execPtr, kExecPtr);
				_vm->_global->_inter_execPtr +=
					strlen((char *) _vm->_global->_inter_execPtr) + 1;
				break;

			case 23:
				*operPtr = OP_LOAD_IMM_INT16;
				*valPtr = VAR(_vm->_inter->load16());
				break;

			case OP_LOAD_VAR_STR:
				*operPtr = OP_LOAD_IMM_STR;
				temp = _vm->_inter->load16() * 4;
				*valPtr = encodePtr(_vm->_inter->_variables->getAddressOff8(temp),
						kInterVar);
				if (*_vm->_global->_inter_execPtr == 13) {
					_vm->_global->_inter_execPtr++;
					temp += parseValExpr(OP_END_MARKER);
					*operPtr = OP_LOAD_IMM_INT16;
					*valPtr = READ_VARO_UINT8(temp);
				}
				break;

			case OP_ARRAY_UINT32:
			case OP_ARRAY_STR:
				*operPtr = operation - 6;
				temp = _vm->_inter->load16();
				dimCount = *_vm->_global->_inter_execPtr++;
				arrDescPtr = _vm->_global->_inter_execPtr;
				_vm->_global->_inter_execPtr += dimCount;
				offset = 0;
				dim = 0;
				for (dim = 0; dim < dimCount; dim++) {
					temp2 = parseValExpr(OP_END_MARKER);
					offset = offset * arrDescPtr[dim] + temp2;
				}

				if (operation == OP_ARRAY_UINT32) {
					*valPtr = VAR(temp + offset);
					break;
				}
				*valPtr = encodePtr(_vm->_inter->_variables->getAddressOff8(
							temp * 4 + offset * _vm->_global->_inter_animDataSize * 4),
						kInterVar);
				if (*_vm->_global->_inter_execPtr == 13) {
					_vm->_global->_inter_execPtr++;
					temp2 = parseValExpr(OP_END_MARKER);
					*operPtr = OP_LOAD_IMM_INT16;
					*valPtr = READ_VARO_UINT8(temp * 4 +
							offset * 4 * _vm->_global->_inter_animDataSize + temp2);
				}
				break;

			case OP_FUNC:
				operation = *_vm->_global->_inter_execPtr++;
				parseExpr(OP_END_EXPR, 0);

				switch (operation) {
				case FUNC_SQR:
					_vm->_global->_inter_resVal =
						_vm->_global->_inter_resVal * _vm->_global->_inter_resVal;
					break;

				case FUNC_SQRT1:
				case FUNC_SQRT2:
				case FUNC_SQRT3:
					curVal = 1;
					prevVal = 1;

					do {
						prevPrevVal = prevVal;
						prevVal = curVal;
						curVal = (curVal + _vm->_global->_inter_resVal / curVal) / 2;
					} while ((curVal != prevVal) && (curVal != prevPrevVal));
					_vm->_global->_inter_resVal = curVal;
					break;

				case FUNC_RAND:
					_vm->_global->_inter_resVal =
						_vm->_util->getRandom(_vm->_global->_inter_resVal);
					break;

				case FUNC_ABS:
					if (_vm->_global->_inter_resVal < 0)
						_vm->_global->_inter_resVal = -_vm->_global->_inter_resVal;
					break;
				}
				*operPtr = OP_LOAD_IMM_INT16;
				*valPtr = _vm->_global->_inter_resVal;
			}

			if ((stkPos > 0) && ((operPtr[-1] == OP_NEG) || (operPtr[-1] == OP_NOT))) {
				stkPos--;
				operPtr--;
				valPtr--;

				if (*operPtr == OP_NEG) {
					*operPtr = OP_LOAD_IMM_INT16;
					valPtr[0] = -valPtr[1];
				} else if (*operPtr == OP_NOT) {
					if (operPtr[1] == GOB_FALSE)
						*operPtr = GOB_TRUE;
					else
						*operPtr = GOB_FALSE;
				}
			}

			if (stkPos <= 0)
				continue;

			switch (operPtr[-1]) {
			case OP_ADD:
				if (operPtr[-2] == OP_LOAD_IMM_STR) {
					if ((char *) decodePtr(valPtr[-2]) != _vm->_global->_inter_resStr) {
						strcpy(_vm->_global->_inter_resStr, (char *) decodePtr(valPtr[-2]));
						valPtr[-2] = encodePtr((byte *) _vm->_global->_inter_resStr, kResStr);
					}
					strcat(_vm->_global->_inter_resStr, (char *) decodePtr(valPtr[0]));
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
				}
				break;

			case OP_MUL:
				valPtr[-2] *= valPtr[0];
				stkPos -= 2;
				operPtr -= 2;
				valPtr -= 2;
				break;

			case OP_DIV:
				valPtr[-2] /= valPtr[0];
				stkPos -= 2;
				operPtr -= 2;
				valPtr -= 2;
				break;

			case OP_MOD:
				valPtr[-2] %= valPtr[0];
				stkPos -= 2;
				operPtr -= 2;
				valPtr -= 2;
				break;

			case OP_BITAND:
				valPtr[-2] &= valPtr[0];
				stkPos -= 2;
				operPtr -= 2;
				valPtr -= 2;
				break;
			}
			continue;
		} // (op >= OP_LOAD_IMM_INT32) && (op <= OP_FUNC)

		if ((operation == stopToken) || (operation == OP_OR) ||
		    (operation == OP_AND) || (operation == OP_END_EXPR)) {
			while (stkPos >= 2) {
				var_1A = false;
				if ((operPtr[-2] == OP_BEGIN_EXPR) &&
						((operation == OP_END_EXPR) || (operation == stopToken))) {
					operPtr[-2] = operPtr[-1];
					if ((operPtr[-2] == OP_LOAD_IMM_INT16) || (operPtr[-2] == OP_LOAD_IMM_STR))
						valPtr[-2] = valPtr[-1];

					stkPos--;
					operPtr--;
					valPtr--;

					if (stkPos > 1) {
						if (operPtr[-2] == OP_NEG) {
							operPtr[-2] = OP_LOAD_IMM_INT16;
							valPtr[-2] = -valPtr[-1];
							stkPos--;
							operPtr--;
							valPtr--;
						} else if (operPtr[-2] == OP_NOT) {
							if (operPtr[-1] == GOB_FALSE)
								operPtr[-2] = GOB_TRUE;
							else
								operPtr[-2] = GOB_FALSE;

							stkPos--;
							operPtr--;
							valPtr--;
						}
					}	// stkPos > 1

					if (stkPos > 2) {
						switch (operPtr[-2]) {
						case OP_MUL:
							valPtr[-3] *= valPtr[-1];
							stkPos -= 2;
							operPtr -= 2;
							valPtr -= 2;
							break;
						case OP_DIV:
							valPtr[-3] /= valPtr[-1];
							stkPos -= 2;
							operPtr -= 2;
							valPtr -= 2;
							break;

						case OP_MOD:
							valPtr[-3] %= valPtr[-1];
							stkPos -= 2;
							operPtr -= 2;
							valPtr -= 2;
							break;

						case OP_BITAND:
							valPtr[-3] &= valPtr[-1];
							stkPos -= 2;
							operPtr -= 2;
							valPtr -= 2;
							break;
						}	// switch
					}	// stkPos > 2

					if (operation != stopToken)
						break;
				}	// if ((operPtr[-2] == OP_BEGIN_EXPR) && ...)

				for (brackStart = (stkPos - 2); (brackStart > 0) &&
				    (operStack[brackStart] < OP_OR) && (operStack[brackStart] != OP_BEGIN_EXPR);
						brackStart--)
					;

				if ((operStack[brackStart] >= OP_OR) || (operStack[brackStart] == OP_BEGIN_EXPR))
					brackStart++;

				switch (operPtr[-2]) {
				case OP_ADD:
					if (operStack[brackStart] == OP_LOAD_IMM_INT16) {
						values[brackStart] += valPtr[-1];
					} else if (operStack[brackStart] == OP_LOAD_IMM_STR) {
						if ((char *) decodePtr(values[brackStart]) != _vm->_global->_inter_resStr) {
							strcpy(_vm->_global->_inter_resStr, (char *) decodePtr(values[brackStart]));
							values[brackStart] =
								encodePtr((byte *) _vm->_global->_inter_resStr, kResStr);
						}
						strcat(_vm->_global->_inter_resStr, (char *) decodePtr(valPtr[-1]));
					}
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					continue;

				case OP_SUB:
					values[brackStart] -= valPtr[-1];
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					continue;

				case OP_BITOR:
					values[brackStart] |= valPtr[-1];
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					continue;

				case OP_MUL:
					valPtr[-3] *= valPtr[-1];
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					break;

				case OP_DIV:
					valPtr[-3] /= valPtr[-1];
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					break;

				case OP_MOD:
					valPtr[-3] %= valPtr[-1];
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					break;

				case OP_BITAND:
					valPtr[-3] &= valPtr[-1];
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					break;

				case OP_OR:
					// (x OR false) == x
					// (x OR true) == true
					if (operPtr[-3] == GOB_FALSE)
						operPtr[-3] = operPtr[-1];
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					break;

				case OP_AND:
					// (x AND false) == false
					// (x AND true) == x
					if (operPtr[-3] == GOB_TRUE)
						operPtr[-3] = operPtr[-1];
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					break;

				case OP_LESS:
					operPtr[-3] = (cmpHelper(operPtr, valPtr) < 0) ? GOB_TRUE : GOB_FALSE;
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					break;

				case OP_LEQ:
					operPtr[-3] = (cmpHelper(operPtr, valPtr) <= 0) ? GOB_TRUE : GOB_FALSE;
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					break;

				case OP_GREATER:
					operPtr[-3] = (cmpHelper(operPtr, valPtr) > 0) ? GOB_TRUE : GOB_FALSE;
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					break;

				case OP_GEQ:
					operPtr[-3] = (cmpHelper(operPtr, valPtr) >= 0) ? GOB_TRUE : GOB_FALSE;
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					break;

				case OP_EQ:
					operPtr[-3] = (cmpHelper(operPtr, valPtr) == 0) ? GOB_TRUE : GOB_FALSE;
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					break;

				case OP_NEQ:
					operPtr[-3] = (cmpHelper(operPtr, valPtr) != 0) ? GOB_TRUE : GOB_FALSE;
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
					break;

				default:
					var_1A = true;
					break;
				}	// switch

				if (var_1A)
					break;
			}	// while (stkPos >= 2)

			if ((operation == OP_OR) || (operation == OP_AND)) {
				if (operPtr[-1] == OP_LOAD_IMM_INT16) {
					if (valPtr[-1] != 0)
						operPtr[-1] = GOB_TRUE;
					else
						operPtr[-1] = GOB_FALSE;
				}

				if (((operation == OP_OR) && (operPtr[-1] == GOB_TRUE)) ||
				    ((operation == OP_AND) && (operPtr[-1] == GOB_FALSE))) {
					if ((stkPos > 1) && (operPtr[-2] == OP_BEGIN_EXPR)) {
						skipExpr(OP_END_EXPR);
						operPtr[-2] = operPtr[-1];
						stkPos -= 2;
						operPtr -= 2;
						valPtr -= 2;
					} else
						skipExpr(stopToken);

					operation = _vm->_global->_inter_execPtr[-1];
					if ((stkPos > 0) && (operPtr[-1] == OP_NOT)) {
						if (operPtr[0] == GOB_FALSE)
							operPtr[-1] = GOB_TRUE;
						else
							operPtr[-1] = GOB_FALSE;

						stkPos--;
						operPtr--;
						valPtr--;
					}
				} else
					operPtr[0] = operation;
			} else {
				stkPos--;
				operPtr--;
				valPtr--;
			}

			if (operation != stopToken)
				continue;

			if (arg_2 != 0)
				*arg_2 = operStack[0];

			switch (operStack[0]) {
			case OP_LOAD_IMM_INT16:
				_vm->_global->_inter_resVal = values[0];
				break;

			case OP_LOAD_IMM_STR:
				if ((char *) decodePtr(values[0]) != _vm->_global->_inter_resStr)
					strcpy(_vm->_global->_inter_resStr, (char *) decodePtr(values[0]));
				break;

			case OP_NOT:
				if (arg_2 != 0)
					*arg_2 ^= 1;
				break;

			case 23:
			case 24:
				break;

			default:
				_vm->_global->_inter_resVal = 0;
				if (arg_2 != 0)
					*arg_2 = OP_LOAD_IMM_INT16;
				break;
			}
			return 0;
		}		// (operation == stopToken) || (operation == OP_OR) || (operation == OP_AND) || (operation == OP_END_EXPR)

		if (operation < OP_NEG || operation > OP_NOT) {
			if (operation < OP_LESS || operation > OP_NEQ)
				continue;

			if (stkPos > 2) {
				if (operPtr[-2] == OP_ADD) {
					if (operPtr[-3] == OP_LOAD_IMM_INT16) {
						valPtr[-3] += valPtr[-1];
					} else if (operPtr[-3] == OP_LOAD_IMM_STR) {
						if ((char *) decodePtr(valPtr[-3]) != _vm->_global->_inter_resStr) {
							strcpy(_vm->_global->_inter_resStr, (char *) decodePtr(valPtr[-3]));
							valPtr[-3] = encodePtr((byte *) _vm->_global->_inter_resStr, kResStr);
						}
						strcat(_vm->_global->_inter_resStr, (char *) decodePtr(valPtr[-1]));
					}
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;

				} else if (operPtr[-2] == OP_SUB) {
					valPtr[-3] -= valPtr[-1];
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
				} else if (operPtr[-2] == OP_BITOR) {
					valPtr[-3] |= valPtr[-1];
					stkPos -= 2;
					operPtr -= 2;
					valPtr -= 2;
				}
			}
		}
		*operPtr = operation;
	}
}

} // End of namespace Gob