risc-v-tlm/src/M_extension.cpp

288 lines
6.3 KiB
C++

/*!
\file M_extension.h
\brief Implement M extensions part of the RISC-V
\author Màrius Montón
\date November 2018
*/
// SPDX-License-Identifier: GPL-3.0-or-later
#include "M_extension.h"
op_M_Codes M_extension::decode() const {
switch (opcode()) {
case M_MUL:
return OP_M_MUL;
break;
case M_MULH:
return OP_M_MULH;
break;
case M_MULHSU:
return OP_M_MULHSU;
break;
case M_MULHU:
return OP_M_MULHU;
break;
case M_DIV:
return OP_M_DIV;
break;
case M_DIVU:
return OP_M_DIVU;
break;
case M_REM:
return OP_M_REM;
break;
case M_REMU:
return OP_M_REMU;
break;
[[unlikely]] default:
return OP_M_ERROR;
break;
}
return OP_M_ERROR;
}
bool M_extension::Exec_M_MUL() const {
int rd, rs1, rs2;
std::int32_t multiplier, multiplicand;
std::int64_t result;
rd = get_rd();
rs1 = get_rs1();
rs2 = get_rs2();
multiplier = static_cast<std::int32_t>(regs->getValue(rs1));
multiplicand = static_cast<std::int32_t>(regs->getValue(rs2));
result = static_cast<std::int64_t>(multiplier * multiplicand);
result = result & 0x00000000FFFFFFFF;
regs->setValue(rd, static_cast<std::int32_t>(result));
log->SC_log(Log::INFO) << std::dec << "MUL: x" << rs1 << " * x" << rs2
<< " -> x" << rd << "(" << result << ")" << "\n";
return true;
}
bool M_extension::Exec_M_MULH() const {
int rd, rs1, rs2;
std::int32_t multiplier, multiplicand;
std::int64_t result;
std::int32_t ret_value;
rd = get_rd();
rs1 = get_rs1();
rs2 = get_rs2();
multiplier = static_cast<std::int32_t>(regs->getValue(rs1));
multiplicand = static_cast<std::int32_t>(regs->getValue(rs2));
result = static_cast<std::int64_t>(multiplier) * static_cast<std::int64_t>(multiplicand);
ret_value = static_cast<std::int32_t>((result >> 32) & 0x00000000FFFFFFFF);
regs->setValue(rd, ret_value);
log->SC_log(Log::INFO) << std::dec << "MULH: x" << rs1 << " * x" << rs2
<< " -> x" << rd << "(" << result << ")" << "\n";
return true;
}
bool M_extension::Exec_M_MULHSU() const {
int rd, rs1, rs2;
std::int32_t multiplier;
std::uint32_t multiplicand;
std::int64_t result;
rd = get_rd();
rs1 = get_rs1();
rs2 = get_rs2();
multiplier = static_cast<std::int32_t>(regs->getValue(rs1));
multiplicand = regs->getValue(rs2);
result = static_cast<std::int64_t>(multiplier * static_cast<std::uint64_t>(multiplicand));
result = (result >> 32) & 0x00000000FFFFFFFF;
regs->setValue(rd, static_cast<std::int32_t>(result));
log->SC_log(Log::INFO) << std::dec << "MULHSU: x" << rs1 << " * x" << rs2
<< " -> x" << rd << "(" << result << ")" << "\n";
return true;
}
bool M_extension::Exec_M_MULHU() const {
int rd, rs1, rs2;
std::uint32_t multiplier, multiplicand;
std::uint64_t result;
std::int32_t ret_value;
rd = get_rd();
rs1 = get_rs1();
rs2 = get_rs2();
multiplier = static_cast<std::int32_t>(regs->getValue(rs1));
multiplicand = static_cast<std::int32_t>(regs->getValue(rs2));
result = static_cast<std::uint64_t>(multiplier) * static_cast<std::uint64_t>(multiplicand);
ret_value = static_cast<std::int32_t>((result >> 32) & 0x00000000FFFFFFFF);
regs->setValue(rd, ret_value);
log->SC_log(Log::INFO) << std::dec << "MULHU: x" << rs1 << " * x" << rs2
<< " -> x" << rd << "(" << ret_value << ")" << "\n";
return true;
}
bool M_extension::Exec_M_DIV() const {
int rd, rs1, rs2;
std::int32_t divisor, dividend;
std::int64_t result;
rd = get_rd();
rs1 = get_rs1();
rs2 = get_rs2();
dividend = static_cast<std::int32_t>(regs->getValue(rs1));
divisor = static_cast<std::int32_t>(regs->getValue(rs2));
if (divisor == 0) {
result = -1;
} else if ((divisor == -1) && (dividend == static_cast<std::int32_t>(0x80000000)) ) {
result = 0x0000000080000000;
} else {
result = dividend / divisor;
result = result & 0x00000000FFFFFFFF;
}
regs->setValue(rd, static_cast<std::int32_t>(result));
log->SC_log(Log::INFO) << std::dec << "DIV: x" << rs1 << " / x" << rs2
<< " -> x" << rd << "(" << result << ")" << "\n";
return true;
}
bool M_extension::Exec_M_DIVU() const {
int rd, rs1, rs2;
std::uint32_t divisor, dividend;
std::uint64_t result;
rd = get_rd();
rs1 = get_rs1();
rs2 = get_rs2();
dividend = regs->getValue(rs1);
divisor = regs->getValue(rs2);
if (divisor == 0) {
result = -1;
} else {
result = dividend / divisor;
result = result & 0x00000000FFFFFFFF;
}
regs->setValue(rd, static_cast<std::int32_t>(result));
log->SC_log(Log::INFO) << std::dec << "DIVU: x" << rs1 << " / x" << rs2
<< " -> x" << rd << "(" << result << ")" << "\n";
return true;
}
bool M_extension::Exec_M_REM() const {
int rd, rs1, rs2;
std::int32_t divisor, dividend;
std::int32_t result;
rd = get_rd();
rs1 = get_rs1();
rs2 = get_rs2();
dividend = static_cast<std::int32_t>(regs->getValue(rs1));
divisor = static_cast<std::int32_t>(regs->getValue(rs2));
if (divisor == 0) {
result = dividend;
} else if ((divisor == -1) && (dividend == static_cast<std::int32_t>(0x80000000)) ) {
result = 0;
} else {
result = dividend % divisor;
}
regs->setValue(rd, result);
log->SC_log(Log::INFO) << std::dec << "REM: x" << rs1 << " / x" << rs2
<< " -> x" << rd << "(" << result << ")" << "\n";
return true;
}
bool M_extension::Exec_M_REMU() const {
int rd, rs1, rs2;
std::uint32_t divisor, dividend;
std::uint32_t result;
rd = get_rd();
rs1 = get_rs1();
rs2 = get_rs2();
dividend = static_cast<std::int32_t>(regs->getValue(rs1));
divisor = static_cast<std::int32_t>(regs->getValue(rs2));
if (divisor == 0) {
result = dividend;
} else {
result = dividend % divisor;
}
regs->setValue(rd, static_cast<std::int32_t>(result));
log->SC_log(Log::INFO) << std::dec << "REMU: x" << rs1 << " / x" << rs2
<< " -> x" << rd << "(" << result << ")" << "\n";
return true;
}
bool M_extension::process_instruction(Instruction &inst) {
bool PC_not_affected = true;
setInstr(inst.getInstr());
switch (decode()) {
case OP_M_MUL:
Exec_M_MUL();
break;
case OP_M_MULH:
Exec_M_MULH();
break;
case OP_M_MULHSU:
Exec_M_MULHSU();
break;
case OP_M_MULHU:
Exec_M_MULHU();
break;
case OP_M_DIV:
Exec_M_DIV();
break;
case OP_M_DIVU:
Exec_M_DIVU();
break;
case OP_M_REM:
Exec_M_REM();
break;
case OP_M_REMU:
Exec_M_REMU();
break;
[[unlikely]] default:
std::cout << "M instruction not implemented yet" << "\n";
inst.dump();
//NOP(inst);
sc_core::sc_stop();
break;
}
return PC_not_affected;
}