CodeGen

optimise.cpp

bool CJitter::ConstantFolding2(StatementList& statements)
{
	bool changed = false;
	for(auto statementIterator(statements.rbegin());
		statementIterator != statements.rend(); ++statementIterator)
	{
		STATEMENT& outerStatement(*statementIterator);

		if(outerStatement.op == OP_ADD)
		{
			auto statementIterator0 = std::next(statementIterator);
			if(statementIterator0 == statements.rend())
				break;

			STATEMENT& innerStatement(*statementIterator0);
			if(innerStatement.op == OP_ADD)
			{
				if(outerStatement.dst->Equals(innerStatement.dst.get()))
				{
						CSymbol* src2cst0 = dynamic_symbolref_cast(SYM_CONSTANT, innerStatement.src2);
						CSymbol* src2cst1 = dynamic_symbolref_cast(SYM_CONSTANT, outerStatement.src2);
						if(src2cst0 && src2cst1)
						{
							uint32 result = src2cst0->m_valueLow + src2cst1->m_valueLow;
							fprintf(stderr, "OPTIMSED %d + %d == %d\n", src2cst0->m_valueLow, src2cst1->m_valueLow, result);
							innerStatement.src2 = MakeSymbolRef(MakeSymbol(SYM_CONSTANT, result));
							outerStatement.src2 = MakeSymbolRef(MakeSymbol(SYM_CONSTANT, 0));

							// statements.erase(std::next(statementIterator).base());
							changed = true;
							// break;
						}
				}
			}

		}
	}
	return changed;
}