valentina/src/libs/qmuparser/qmuparserbytecode.cpp

/***************************************************************************************************
 **
 **  Original work Copyright (C) 2013 Ingo Berg
 **  Modified work Copyright 2014 Roman Telezhynskyi <dismine(at)gmail.com>
 **
 **  Permission is hereby granted, free of charge, to any person obtaining a copy of this
 **  software and associated documentation files (the "Software"), to deal in the Software
 **  without restriction, including without limitation the rights to use, copy, modify,
 **  merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 **  permit persons to whom the Software is furnished to do so, subject to the following conditions:
 **
 **  The above copyright notice and this permission notice shall be included in all copies or
 **  substantial portions of the Software.
 **
 **  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
 **  NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 **  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
 **  DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 **  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 **
 ******************************************************************************************************/

#include "qmuparserbytecode.h"

#include <cassert>
#include <string>
#include <stack>
#include <iostream>
#include <QString>

#include "qmuparserdef.h"
#include "qmuparsererror.h"
#include "qmuparsertoken.h"


namespace qmu
{
//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Bytecode default constructor.
 */
QmuParserByteCode::QmuParserByteCode()
	:m_iStackPos(0), m_iMaxStackSize(0), m_vRPN(), m_bEnableOptimizer(true)
{
	m_vRPN.reserve(50);
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Copy constructor.
 *
 * Implemented in Terms of Assign(const QParserByteCode &a_ByteCode)
 */
QmuParserByteCode::QmuParserByteCode(const QmuParserByteCode &a_ByteCode)
{
	Assign(a_ByteCode);
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Assignment operator.
 *
 * Implemented in Terms of Assign(const QParserByteCode &a_ByteCode)
 */
QmuParserByteCode& QmuParserByteCode::operator=(const QmuParserByteCode &a_ByteCode)
{
	Assign(a_ByteCode);
	return *this;
}

//----------------------------------------------------------------------------------------------------------------------
void QmuParserByteCode::EnableOptimizer(bool bStat)
{
	m_bEnableOptimizer = bStat;
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Copy state of another object to this.
 *
 * @throw nowthrow
 */
void QmuParserByteCode::Assign(const QmuParserByteCode &a_ByteCode)
{
	if (this==&a_ByteCode)
	{
		return;
	}

	m_iStackPos = a_ByteCode.m_iStackPos;
	m_vRPN = a_ByteCode.m_vRPN;
	m_iMaxStackSize = a_ByteCode.m_iMaxStackSize;
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Add a Variable pointer to bytecode.
 * @param a_pVar Pointer to be added.
 * @throw nothrow
 */
void QmuParserByteCode::AddVar(qreal *a_pVar)
{
	++m_iStackPos;
	m_iMaxStackSize = std::max(m_iMaxStackSize, (size_t)m_iStackPos);

	// optimization does not apply
	SToken tok;
	tok.Cmd       = cmVAR;
	tok.Val.ptr   = a_pVar;
	tok.Val.data  = 1;
	tok.Val.data2 = 0;
	m_vRPN.push_back(tok);
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Add a Variable pointer to bytecode.
 *
 * Value entries in byte code consist of:
 * <ul>
 * <li>value array position of the value</li>
 * <li>the operator code according to ParserToken::cmVAL</li>
 * <li>the value stored in #mc_iSizeVal number of bytecode entries.</li>
 * </ul>
 *
 * @param a_pVal Value to be added.
 * @throw nothrow
 */
void QmuParserByteCode::AddVal(qreal a_fVal)
{
	++m_iStackPos;
	m_iMaxStackSize = std::max(m_iMaxStackSize, (size_t)m_iStackPos);

	// If optimization does not apply
	SToken tok;
	tok.Cmd = cmVAL;
	tok.Val.ptr   = NULL;
	tok.Val.data  = 0;
	tok.Val.data2 = a_fVal;
	m_vRPN.push_back(tok);
}

//----------------------------------------------------------------------------------------------------------------------
void QmuParserByteCode::ConstantFolding(ECmdCode a_Oprt)
{
	std::size_t sz = m_vRPN.size();
	qreal &x = m_vRPN[sz-2].Val.data2,
	&y = m_vRPN[sz-1].Val.data2;
	switch (a_Oprt)
	{
		case cmLAND:
			x = (int)x && (int)y;
			m_vRPN.pop_back();
			break;
		case cmLOR:
			x = (int)x || (int)y;
			m_vRPN.pop_back();
			break;
		case cmLT:
			x = x < y;
			m_vRPN.pop_back();
			break;
		case cmGT:
			x = x > y;
			m_vRPN.pop_back();
			break;
		case cmLE:
			x = x <= y;
			m_vRPN.pop_back();
			break;
		case cmGE:
			x = x >= y;
			m_vRPN.pop_back();
			break;
		case cmNEQ:
			x = x != y;
			m_vRPN.pop_back();
			break;
		case cmEQ:
			x = x == y;
			m_vRPN.pop_back();
			break;
		case cmADD:
			x = x + y;
			m_vRPN.pop_back();
			break;
		case cmSUB:
			x = x - y;
			m_vRPN.pop_back();
			break;
		case cmMUL:
			x = x * y;
			m_vRPN.pop_back();
			break;
		case cmDIV:
		#if defined(MUP_MATH_EXCEPTIONS)
			if (y==0)
			{
				throw ParserError(ecDIV_BY_ZERO, "0");
			}
		#endif
			x = x / y;
			m_vRPN.pop_back();
			break;
			case cmPOW:
				x = qPow(x, y);
				m_vRPN.pop_back();
				break;
		default:
			break;
	} // switch opcode
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Add an operator identifier to bytecode.
 *
 * Operator entries in byte code consist of:
 * <ul>
 * <li>value array position of the result</li>
 * <li>the operator code according to ParserToken::ECmdCode</li>
 * </ul>
 *
 * @sa  ParserToken::ECmdCode
 */
void QmuParserByteCode::AddOp(ECmdCode a_Oprt)
{
	bool bOptimized = false;

	if (m_bEnableOptimizer)
	{
		std::size_t sz = m_vRPN.size();

		// Check for foldable constants like:
		//   cmVAL cmVAL cmADD
		// where cmADD can stand fopr any binary operator applied to
		// two constant values.
		if (sz>=2 && m_vRPN[sz-2].Cmd == cmVAL && m_vRPN[sz-1].Cmd == cmVAL)
		{
			ConstantFolding(a_Oprt);
			bOptimized = true;
		}
		else
		{
			switch(a_Oprt)
			{
				case  cmPOW:
					// Optimization for ploynomials of low order
					if (m_vRPN[sz-2].Cmd == cmVAR && m_vRPN[sz-1].Cmd == cmVAL)
					{
						if (m_vRPN[sz-1].Val.data2==2)
						{
							m_vRPN[sz-2].Cmd = cmVARPOW2;
						}
						else if (m_vRPN[sz-1].Val.data2==3)
						{
							m_vRPN[sz-2].Cmd = cmVARPOW3;
						}
						else if (m_vRPN[sz-1].Val.data2==4)
						{
							m_vRPN[sz-2].Cmd = cmVARPOW4;
						}
						else
						{
							break;
						}
						m_vRPN.pop_back();
						bOptimized = true;
					}
					break;

				case  cmSUB:
				case  cmADD:
					// Simple optimization based on pattern recognition for a shitload of different
					// bytecode combinations of addition/subtraction
					if ( (m_vRPN[sz-1].Cmd == cmVAR    && m_vRPN[sz-2].Cmd == cmVAL)    ||
						 (m_vRPN[sz-1].Cmd == cmVAL    && m_vRPN[sz-2].Cmd == cmVAR)    ||
						 (m_vRPN[sz-1].Cmd == cmVAL    && m_vRPN[sz-2].Cmd == cmVARMUL) ||
						 (m_vRPN[sz-1].Cmd == cmVARMUL && m_vRPN[sz-2].Cmd == cmVAL)    ||
						 (m_vRPN[sz-1].Cmd == cmVAR    && m_vRPN[sz-2].Cmd == cmVAR &&
						  m_vRPN[sz-2].Val.ptr == m_vRPN[sz-1].Val.ptr) ||
						 (m_vRPN[sz-1].Cmd == cmVAR && m_vRPN[sz-2].Cmd == cmVARMUL
						  && m_vRPN[sz-2].Val.ptr == m_vRPN[sz-1].Val.ptr) ||
						 (m_vRPN[sz-1].Cmd == cmVARMUL && m_vRPN[sz-2].Cmd == cmVAR &&
						  m_vRPN[sz-2].Val.ptr == m_vRPN[sz-1].Val.ptr) ||
						 (m_vRPN[sz-1].Cmd == cmVARMUL && m_vRPN[sz-2].Cmd == cmVARMUL &&
						  m_vRPN[sz-2].Val.ptr == m_vRPN[sz-1].Val.ptr) )
					{
						assert( (m_vRPN[sz-2].Val.ptr==NULL && m_vRPN[sz-1].Val.ptr!=NULL) ||
						(m_vRPN[sz-2].Val.ptr!=NULL && m_vRPN[sz-1].Val.ptr==NULL) ||
						(m_vRPN[sz-2].Val.ptr == m_vRPN[sz-1].Val.ptr) );

						m_vRPN[sz-2].Cmd = cmVARMUL;
						m_vRPN[sz-2].Val.ptr    = (qreal*)((long long)(m_vRPN[sz-2].Val.ptr) |
								(long long)(m_vRPN[sz-1].Val.ptr));    // variable
						m_vRPN[sz-2].Val.data2 += ((a_Oprt==cmSUB) ? -1 : 1) * m_vRPN[sz-1].Val.data2; // offset
						m_vRPN[sz-2].Val.data  += ((a_Oprt==cmSUB) ? -1 : 1) * m_vRPN[sz-1].Val.data;  // multiplikatior
						m_vRPN.pop_back();
						bOptimized = true;
					}
					break;
				case  cmMUL:
					if ( (m_vRPN[sz-1].Cmd == cmVAR && m_vRPN[sz-2].Cmd == cmVAL) ||
					(m_vRPN[sz-1].Cmd == cmVAL && m_vRPN[sz-2].Cmd == cmVAR) )
					{
						m_vRPN[sz-2].Cmd        = cmVARMUL;
						m_vRPN[sz-2].Val.ptr    = (qreal*)((long long)(m_vRPN[sz-2].Val.ptr) |
								(long long)(m_vRPN[sz-1].Val.ptr));
						m_vRPN[sz-2].Val.data   = m_vRPN[sz-2].Val.data2 + m_vRPN[sz-1].Val.data2;
						m_vRPN[sz-2].Val.data2  = 0;
						m_vRPN.pop_back();
						bOptimized = true;
					}
					else if ( (m_vRPN[sz-1].Cmd == cmVAL    && m_vRPN[sz-2].Cmd == cmVARMUL) ||
					(m_vRPN[sz-1].Cmd == cmVARMUL && m_vRPN[sz-2].Cmd == cmVAL) )
					{
						// Optimization: 2*(3*b+1) or (3*b+1)*2 -> 6*b+2
						m_vRPN[sz-2].Cmd     = cmVARMUL;
						m_vRPN[sz-2].Val.ptr = (qreal*)((long long)(m_vRPN[sz-2].Val.ptr) |
								(long long)(m_vRPN[sz-1].Val.ptr));
						if (m_vRPN[sz-1].Cmd == cmVAL)
						{
							m_vRPN[sz-2].Val.data  *= m_vRPN[sz-1].Val.data2;
							m_vRPN[sz-2].Val.data2 *= m_vRPN[sz-1].Val.data2;
						}
						else
						{
							m_vRPN[sz-2].Val.data  = m_vRPN[sz-1].Val.data  * m_vRPN[sz-2].Val.data2;
							m_vRPN[sz-2].Val.data2 = m_vRPN[sz-1].Val.data2 * m_vRPN[sz-2].Val.data2;
						}
						m_vRPN.pop_back();
						bOptimized = true;
					}
					else if (m_vRPN[sz-1].Cmd == cmVAR && m_vRPN[sz-2].Cmd == cmVAR &&
					m_vRPN[sz-1].Val.ptr == m_vRPN[sz-2].Val.ptr)
					{
						// Optimization: a*a -> a^2
						m_vRPN[sz-2].Cmd = cmVARPOW2;
						m_vRPN.pop_back();
						bOptimized = true;
					}
					break;
				case cmDIV:
				if (m_vRPN[sz-1].Cmd == cmVAL && m_vRPN[sz-2].Cmd == cmVARMUL && m_vRPN[sz-1].Val.data2!=0)
				{
					// Optimization: 4*a/2 -> 2*a
					m_vRPN[sz-2].Val.data  /= m_vRPN[sz-1].Val.data2;
					m_vRPN[sz-2].Val.data2 /= m_vRPN[sz-1].Val.data2;
					m_vRPN.pop_back();
					bOptimized = true;
				}
				break;

				} // switch a_Oprt
		}
	}

	// If optimization can't be applied just write the value
	if (!bOptimized)
	{
		--m_iStackPos;
		SToken tok;
		tok.Cmd = a_Oprt;
		m_vRPN.push_back(tok);
	}
}

//----------------------------------------------------------------------------------------------------------------------
void QmuParserByteCode::AddIfElse(ECmdCode a_Oprt)
{
	SToken tok;
	tok.Cmd = a_Oprt;
	m_vRPN.push_back(tok);
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Add an assignement operator
 *
 * Operator entries in byte code consist of:
 * <ul>
 * <li>cmASSIGN code</li>
 * <li>the pointer of the destination variable</li>
 * </ul>
 *
 * @sa  ParserToken::ECmdCode
 */
void QmuParserByteCode::AddAssignOp(qreal *a_pVar)
{
	--m_iStackPos;

	SToken tok;
	tok.Cmd = cmASSIGN;
	tok.Val.ptr = a_pVar;
	m_vRPN.push_back(tok);
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Add function to bytecode.
 *
 * @param a_iArgc Number of arguments, negative numbers indicate multiarg functions.
 * @param a_pFun Pointer to function callback.
 */
void QmuParserByteCode::AddFun(generic_fun_type a_pFun, int a_iArgc)
{
	if (a_iArgc>=0)
	{
		m_iStackPos = m_iStackPos - a_iArgc + 1;
	}
	else
	{
		// function with unlimited number of arguments
		m_iStackPos = m_iStackPos + a_iArgc + 1;
	}
	m_iMaxStackSize = std::max(m_iMaxStackSize, (size_t)m_iStackPos);

	SToken tok;
	tok.Cmd = cmFUNC;
	tok.Fun.argc = a_iArgc;
	tok.Fun.ptr = a_pFun;
	m_vRPN.push_back(tok);
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Add a bulk function to bytecode.
 *
 * @param a_iArgc Number of arguments, negative numbers indicate multiarg functions.
 * @param a_pFun Pointer to function callback.
 */
void QmuParserByteCode::AddBulkFun(generic_fun_type a_pFun, int a_iArgc)
{
	m_iStackPos = m_iStackPos - a_iArgc + 1;
	m_iMaxStackSize = std::max(m_iMaxStackSize, (size_t)m_iStackPos);

	SToken tok;
	tok.Cmd = cmFUNC_BULK;
	tok.Fun.argc = a_iArgc;
	tok.Fun.ptr = a_pFun;
	m_vRPN.push_back(tok);
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Add Strung function entry to the parser bytecode.
 * @throw nothrow
 *
 * A string function entry consists of the stack position of the return value, followed by a cmSTRFUNC code, the
 * function pointer and an index into the string buffer maintained by the parser.
 */
void QmuParserByteCode::AddStrFun(generic_fun_type a_pFun, int a_iArgc, int a_iIdx)
{
	m_iStackPos = m_iStackPos - a_iArgc + 1;

	SToken tok;
	tok.Cmd = cmFUNC_STR;
	tok.Fun.argc = a_iArgc;
	tok.Fun.idx = a_iIdx;
	tok.Fun.ptr = a_pFun;
	m_vRPN.push_back(tok);

	m_iMaxStackSize = std::max(m_iMaxStackSize, (size_t)m_iStackPos);
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Add end marker to bytecode.
 *
 * @throw nothrow
 */
void QmuParserByteCode::Finalize()
{
	SToken tok;
	tok.Cmd = cmEND;
	m_vRPN.push_back(tok);
	rpn_type(m_vRPN).swap(m_vRPN);     // shrink bytecode vector to fit

	// Determine the if-then-else jump offsets
	QStack<int> stIf, stElse;
	int idx;
	for (int i=0; i<(int)m_vRPN.size(); ++i)
	{
		switch(m_vRPN[i].Cmd)
		{
			case cmIF:
				stIf.push(i);
				break;
			case  cmELSE:
				stElse.push(i);
				idx = stIf.pop();
				m_vRPN[idx].Oprt.offset = i - idx;
				break;
			case cmENDIF:
				idx = stElse.pop();
				m_vRPN[idx].Oprt.offset = i - idx;
				break;
			default:
				break;
		}
	}
}

//----------------------------------------------------------------------------------------------------------------------
const SToken* QmuParserByteCode::GetBase() const
{
	if (m_vRPN.size()==0)
	{
		throw QmuParserError(ecINTERNAL_ERROR);
	}
	else
	{
		return &m_vRPN[0];
	}
}

//----------------------------------------------------------------------------------------------------------------------
std::size_t QmuParserByteCode::GetMaxStackSize() const
{
	return m_iMaxStackSize+1;
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Returns the number of entries in the bytecode.
 */
std::size_t QmuParserByteCode::GetSize() const
{
	return m_vRPN.size();
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Delete the bytecode.
 *
 * @throw nothrow
 *
 * The name of this function is a violation of my own coding guidelines but this way it's more in line with the STL
 * functions thus more intuitive.
 */
void QmuParserByteCode::clear()
{
	m_vRPN.clear();
	m_iStackPos = 0;
	m_iMaxStackSize = 0;
}

//----------------------------------------------------------------------------------------------------------------------
/**
 * @brief Dump bytecode (for debugging only!).
 */
void QmuParserByteCode::AsciiDump()
{
	if (!m_vRPN.size())
	{
		qDebug() << "No bytecode available\n";
		return;
	}

	qDebug() << "Number of RPN tokens:" << m_vRPN.size() << "\n";
	for (std::size_t i=0; i<m_vRPN.size() && m_vRPN[i].Cmd!=cmEND; ++i)
	{
		qDebug() << i << " : \t";
		switch (m_vRPN[i].Cmd)
		{
			case cmVAL:
				qDebug() << "VAL \t" << "[" << m_vRPN[i].Val.data2 << "]\n";
				break;
			case cmVAR:
				qDebug() << "VAR \t" << "[ADDR: 0x" << QString::number(*m_vRPN[i].Val.ptr, 'f', 16) << "]\n";
				break;
			case cmVARPOW2:
				qDebug() << "VARPOW2 \t" << "[ADDR: 0x" << QString::number(*m_vRPN[i].Val.ptr, 'f', 16) << "]\n";
				break;
			case cmVARPOW3:
				qDebug() << "VARPOW3 \t" << "[ADDR: 0x" << QString::number(*m_vRPN[i].Val.ptr, 'f', 16) << "]\n";
				break;
			case cmVARPOW4:
				qDebug() << "VARPOW4 \t" << "[ADDR: 0x" << QString::number(*m_vRPN[i].Val.ptr, 'f', 16) << "]\n";
				break;
			case cmVARMUL:
				qDebug() << "VARMUL \t" << "[ADDR: 0x" << QString::number(*m_vRPN[i].Val.ptr, 'f', 16) << "]" << " * ["
						 << m_vRPN[i].Val.data << "]" << " + [" << m_vRPN[i].Val.data2 << "]\n";
				break;
			case cmFUNC:
				qDebug() << "CALL\t" << "[ARG:" << m_vRPN[i].Fun.argc << "]" << "[ADDR: 0x" << m_vRPN[i].Fun.ptr << "]"
						 << "\n";
				break;
			case cmFUNC_STR:
				qDebug() << "CALL STRFUNC\t" << "[ARG:" << m_vRPN[i].Fun.argc << "]" << "[IDX:" << m_vRPN[i].Fun.idx
						 << "]" << "[ADDR: 0x" << m_vRPN[i].Fun.ptr << "]\n";
				break;
			case cmLT:
				qDebug() << "LT\n";
				break;
			case cmGT:
				qDebug() << "GT\n";
				break;
			case cmLE:
				qDebug() << "LE\n";
				break;
			case cmGE:
				qDebug() << "GE\n";
				break;
			case cmEQ:
				qDebug() << "EQ\n";
				break;
			case cmNEQ:
				qDebug() << "NEQ\n";
				break;
			case cmADD:
				qDebug() << "ADD\n";
				break;
			case cmLAND:
				qDebug() << "&&\n";
				break;
			case cmLOR:
				qDebug() << "||\n";
				break;
			case cmSUB:
				qDebug() << "SUB\n";
				break;
			case cmMUL:
				qDebug() << "MUL\n";
				break;
			case cmDIV:
				qDebug() << "DIV\n";
				break;
			case cmPOW:
				qDebug() << "POW\n";
				break;
			case cmIF:
				qDebug() << "IF\t" << "[OFFSET:" << m_vRPN[i].Oprt.offset << "]\n";
				break;
			case cmELSE:
				qDebug() << "ELSE\t" << "[OFFSET:" << m_vRPN[i].Oprt.offset << "]\n";
				break;
			case cmENDIF:
				qDebug() << "ENDIF\n"; break;
			case cmASSIGN:
				qDebug() << "ASSIGN\t" << "[ADDR: 0x" << QString::number(*m_vRPN[i].Oprt.ptr, 'f', 16) << "]\n";
				break;
			default:
				qDebug() << "(unknown code: " << m_vRPN[i].Cmd << ")\n";
				break;
		} // switch cmdCode
	} // while bytecode

	qDebug() << "END";
}
} // namespace qmu