1 /* `Deep Thought', a softcore CPU implemented on a FPGA
3 Copyright (C) 2010 Markus Hofstaetter <markus.manrow@gmx.at>
4 Copyright (C) 2010 Martin Perner <e0725782@student.tuwien.ac.at>
5 Copyright (C) 2010 Stefan Rebernig <stefan.rebernig@gmail.com>
6 Copyright (C) 2010 Manfred Schwarz <e0725898@student.tuwien.ac.at>
7 Copyright (C) 2010 Bernhard Urban <lewurm@gmail.com>
9 This program is free software: you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation, either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "../Iinstr.hpp"
24 class Cbranch : public Iinstr {
32 std::string toString();
37 * Name: create_instruction
38 * Purpose: if compiled as shared library, this functions creates the
41 * Returns: pointer to instruction object
43 extern "C" Iinstr* create_instruction() {
47 Iinstr* Cbranch::getNew()
52 * Name: destroy_instruction
53 * Purpose: if compiled as shared library, this functions destoys the
56 * Parameter: IInstruction - the instruction object to delete
58 extern "C" void destroy_instruction(Iinstr* p) {
62 Cbranch::Cbranch() : m_taken(1), m_typ(0)
68 void Cbranch::evalInstr()
70 this->m_s = argbits[0];
71 this->m_taken = argbits[1];
75 dynamic_bitset<> type = argbits;
77 this->m_typ = type.to_ulong();
95 cerr << "What have you done? 2 bits that have more than 4 values?!" << endl;
100 dynamic_bitset<> immb = argbits;
102 this->m_imm = this->generate16ImmSign(immb.to_ulong())*4;
106 void Cbranch::execInstr()
108 //cout << "should exec " << this->toString() << endl;
109 CDat pc = this->m_cpu->getCurPC();
110 switch(this->m_typ) {
113 CDat sp = this->m_cpu->getStack();
115 this->m_cpu->setRAM(sp, this->m_cpu->getNextPC());
116 this->m_cpu->setStack(sp);
120 this->m_cpu->setNextPC(pc+(this->m_imm));
124 this->m_cpu->setNextPC(this->m_cpu->getRAM(this->m_cpu->getStack()));
125 this->m_cpu->setStack(this->m_cpu->getStack()+4);
129 this->m_cpu->setNextPC(400);
133 std::string Cbranch::toString()
136 op << this->getName();
140 op << this->getConditionFlag() << (m_taken ? '+' : '-');
142 op << " 0x" << std::hex << m_imm << "(" << std::dec << m_imm << ", " << (int) m_imm << ")";