vortex/sim/simx/decode.cpp
2022-03-09 02:17:45 -05:00

663 lines
18 KiB
C++

#include <iostream>
#include <string>
#include <stdlib.h>
#include <string.h>
#include <iomanip>
#include <vector>
#include <unordered_map>
#include <util.h>
#include "debug.h"
#include "types.h"
#include "decode.h"
#include "arch.h"
#include "instr.h"
using namespace vortex;
struct InstTableEntry_t {
bool controlFlow;
InstType iType;
};
static const std::unordered_map<Opcode, struct InstTableEntry_t> sc_instTable = {
{Opcode::NOP, {false, InstType::N_TYPE}},
{Opcode::R_INST, {false, InstType::R_TYPE}},
{Opcode::L_INST, {false, InstType::I_TYPE}},
{Opcode::I_INST, {false, InstType::I_TYPE}},
{Opcode::S_INST, {false, InstType::S_TYPE}},
{Opcode::B_INST, {true , InstType::B_TYPE}},
{Opcode::LUI_INST, {false, InstType::U_TYPE}},
{Opcode::AUIPC_INST, {false, InstType::U_TYPE}},
{Opcode::JAL_INST, {true , InstType::J_TYPE}},
{Opcode::JALR_INST, {true , InstType::I_TYPE}},
{Opcode::SYS_INST, {true , InstType::I_TYPE}},
{Opcode::FENCE, {true , InstType::I_TYPE}},
{Opcode::FL, {false, InstType::I_TYPE}},
{Opcode::FS, {false, InstType::S_TYPE}},
{Opcode::FCI, {false, InstType::R_TYPE}},
{Opcode::FMADD, {false, InstType::R4_TYPE}},
{Opcode::FMSUB, {false, InstType::R4_TYPE}},
{Opcode::FMNMADD, {false, InstType::R4_TYPE}},
{Opcode::FMNMSUB, {false, InstType::R4_TYPE}},
{Opcode::VSET, {false, InstType::V_TYPE}},
{Opcode::EXT1, {false, InstType::R_TYPE}},
{Opcode::EXT2, {false, InstType::R4_TYPE}},
{Opcode::R_INST_W, {false, InstType::R_TYPE}},
{Opcode::I_INST_W, {false, InstType::I_TYPE}},
};
enum Constants {
width_opcode= 7,
width_reg = 5,
width_func2 = 2,
width_func3 = 3,
width_func6 = 6,
width_func7 = 7,
width_mop = 3,
width_vmask = 1,
width_i_imm = 12,
width_j_imm = 20,
width_v_imm = 11,
shift_opcode= 0,
shift_rd = width_opcode,
shift_func3 = shift_rd + width_reg,
shift_rs1 = shift_func3 + width_func3,
shift_rs2 = shift_rs1 + width_reg,
shift_func2 = shift_rs2 + width_reg,
shift_func7 = shift_rs2 + width_reg,
shift_rs3 = shift_func7 + width_func2,
shift_vmop = shift_func7 + width_vmask,
shift_vnf = shift_vmop + width_mop,
shift_func6 = shift_func7 + width_vmask,
shift_vset = shift_func7 + width_func6,
mask_opcode = (1<<width_opcode)-1,
mask_reg = (1<<width_reg)-1,
mask_func2 = (1<<width_func2)-1,
mask_func3 = (1<<width_func3)-1,
mask_func6 = (1<<width_func6)-1,
mask_func7 = (1<<width_func7)-1,
mask_i_imm = (1<<width_i_imm)-1,
mask_j_imm = (1<<width_j_imm)-1,
mask_v_imm = (1<<width_v_imm)-1,
};
static const char* op_string(const Instr &instr) {
auto opcode = instr.getOpcode();
auto func2 = instr.getFunc2();
auto func3 = instr.getFunc3();
auto func7 = instr.getFunc7();
auto rs2 = instr.getRSrc(1);
auto imm = instr.getImm();
switch (opcode) {
case Opcode::NOP: return "NOP";
case Opcode::LUI_INST: return "LUI";
case Opcode::AUIPC_INST: return "AUIPC";
case Opcode::R_INST:
if (func7 & 0x1) {
switch (func3) {
case 0: return "MUL";
case 1: return "MULH";
case 2: return "MULHSU";
case 3: return "MULHU";
case 4: return "DIV";
case 5: return "DIVU";
case 6: return "REM";
case 7: return "REMU";
default:
std::abort();
}
} else {
switch (func3) {
case 0: return func7 ? "SUB" : "ADD";
case 1: return "SLL";
case 2: return "SLT";
case 3: return "SLTU";
case 4: return "XOR";
case 5: return func7 ? "SRA" : "SRL";
case 6: return "OR";
case 7: return "AND";
default:
std::abort();
}
}
case Opcode::I_INST:
switch (func3) {
case 0: return "ADDI";
case 1: return "SLLI";
case 2: return "SLTI";
case 3: return "SLTIU";
case 4: return "XORI";
case 5: return func7 ? "SRAI" : "SRLI";
case 6: return "ORI";
case 7: return "ANDI";
default:
std::abort();
}
case Opcode::B_INST:
switch (func3) {
case 0: return "BEQ";
case 1: return "BNE";
case 4: return "BLT";
case 5: return "BGE";
case 6: return "BLTU";
case 7: return "BGEU";
default:
std::abort();
}
case Opcode::JAL_INST: return "JAL";
case Opcode::JALR_INST: return "JALR";
case Opcode::L_INST:
switch (func3) {
case 0: return "LBI";
case 1: return "LHI";
case 2: return "LW";
case 3: return "LD";
case 4: return "LBU";
case 5: return "LHU";
case 6: return "LWU";
default:
std::abort();
}
case Opcode::S_INST:
switch (func3) {
case 0: return "SB";
case 1: return "SH";
case 2: return "SW";
case 3: return "SD";
default:
std::abort();
}
case Opcode::R_INST_W:
if (func7 & 0x1){
switch (func3) {
case 0: return "MULW";
case 4: return "DIVW";
case 5: return "DIVUW";
case 6: return "REMW";
case 7: return "REMUW";
default:
std::abort();
}
} else {
switch (func3) {
case 0: return func7 ? "SUBW" : "ADDW";
case 1: return "SLLW";
case 5: return func7 ? "SRAW" : "SRLW";
default:
std::abort();
}
}
case Opcode::I_INST_W:
switch (func3) {
case 0: return "ADDIW";
case 1: return "SLLIW";
case 5: return func7 ? "SRAIW" : "SRLIW";
default:
std::abort();
}
case Opcode::SYS_INST:
switch (func3) {
case 0:
switch (imm) {
case 0x000: return "ECALL";
case 0x001: return "EBREAK";
case 0x002: return "URET";
case 0x102: return "SRET";
case 0x302: return "MRET";
default:
std::abort();
}
case 1: return "CSRRW";
case 2: return "CSRRS";
case 3: return "CSRRC";
case 5: return "CSRRWI";
case 6: return "CSRRSI";
case 7: return "CSRRCI";
default:
std::abort();
}
case Opcode::FENCE: return "FENCE";
case Opcode::FL:
switch (func3) {
case 0x1: return "VL";
case 0x2: return "FLW";
case 0x3: return "FLD";
default:
std::abort();
}
case Opcode::FS:
switch (func3) {
case 0x1: return "VS";
case 0x2: return "FSW";
case 0x3: return "FSD";
default:
std::abort();
}
case Opcode::FCI:
switch (func7) {
case 0x00: return "FADD.S";
case 0x01: return "FADD.D";
case 0x04: return "FSUB.S";
case 0x05: return "FSUB.D";
case 0x08: return "FMUL.S";
case 0x09: return "FMUL.D";
case 0x0c: return "FDIV.S";
case 0x0d: return "FDIV.D";
case 0x2c: return "FSQRT.S";
case 0x2d: return "FSQRT.D";
case 0x10:
switch (func3) {
case 0: return "FSGNJ.S";
case 1: return "FSGNJN.S";
case 2: return "FSGNJX.S";
default:
std::abort();
}
case 0x11:
switch (func3) {
case 0: return "FSGNJ.D";
case 1: return "FSGNJN.D";
case 2: return "FSGNJX.D";
default:
std::abort();
}
case 0x14:
switch (func3) {
case 0: return "FMIN.S";
case 1: return "FMAX.S";
default:
std::abort();
}
case 0x15:
switch (func3) {
case 0: return "FMIN.D";
case 1: return "FMAX.D";
default:
std::abort();
}
case 0x20: return "FCVT.S.D";
case 0x21: return "FCVT.D.S";
case 0x50:
switch (func3) {
case 0: return "FLE.S";
case 1: return "FLT.S";
case 2: return "FEQ.S";
default:
std::abort();
}
case 0x51:
switch (func3) {
case 0: return "FLE.D";
case 1: return "FLT.D";
case 2: return "FEQ.D";
default:
std::abort();
}
case 0x60:
switch (rs2) {
case 0: return "FCVT.W.S";
case 1: return "FCVT.WU.S";
case 2: return "FCVT.L.S";
case 3: return "FCVT.LU.S";
default:
std::abort();
}
case 0x61:
switch (rs2) {
case 0: return "FCVT.W.D";
case 1: return "FCVT.WU.D";
case 2: return "FCVT.L.D";
case 3: return "FCVT.LU.D";
default:
std::abort();
}
case 0x68:
switch (rs2) {
case 0: return "FCVT.S.W";
case 1: return "FCVT.S.WU";
case 2: return "FCVT.S.L";
case 3: return "FCVT.S.LU";
default:
std::abort();
}
case 0x69:
switch (rs2) {
case 0: return "FCVT.D.W";
case 1: return "FCVT.D.WU";
case 2: return "FCVT.D.L";
case 3: return "FCVT.D.LU";
default:
std::abort();
}
case 0x70: return func3 ? "FCLASS.S" : "FMV.X.W";
case 0x71: return func3 ? "FCLASS.D" : "FMV.X.D";
case 0x78: return "FMV.W.X";
case 0x79: return "FMV.D.X";
default:
std::abort();
}
case Opcode::FMADD: return func2 ? "FMADD.D" : "FMADD.S";
case Opcode::FMSUB: return func2 ? "FMSUB.D" : "FMSUB.S";
case Opcode::FMNMADD: return func2 ? "FNMADD.D" : "FNMADD.S";
case Opcode::FMNMSUB: return func2 ? "FNMSUB.D" : "FNMSUB.S";
case Opcode::VSET: return "VSET";
case Opcode::EXT1:
switch (func7) {
case 0:
switch (func3) {
case 0: return rs2 ? "PRED" : "TMC";
case 1: return "WSPAWN";
case 2: return "SPLIT";
case 3: return "JOIN";
case 4: return "BAR";
case 5: return "PREFETCH";
default:
std::abort();
}
case 1:
switch (func3) {
case 0: return "RASTER";
case 1: return "ROP";
default:
std::abort();
}
default:
std::abort();
}
case Opcode::EXT2:
switch (func3) {
case 0: return "TEX";
case 1: {
switch (func2) {
case 0: return "CMOV";
case 1: return "INTERP";
case 2: return "IMADD";
default:
std::abort();
}
}
default:
std::abort();
}
default:
std::abort();
}
}
namespace vortex {
std::ostream &operator<<(std::ostream &os, const Instr &instr) {
auto opcode = instr.getOpcode();
auto func2 = instr.getFunc2();
auto func3 = instr.getFunc3();
os << op_string(instr) << ": ";
if (opcode == S_INST
|| opcode == FS) {
os << "M[x" << std::dec << instr.getRSrc(0) << " + 0x" << std::hex << instr.getImm() << "] <- ";
os << instr.getRSType(1) << std::dec << instr.getRSrc(1);
} else
if (opcode == L_INST
|| opcode == FL) {
os << instr.getRDType() << std::dec << instr.getRDest() << " <- ";
os << "M[x" << std::dec << instr.getRSrc(0) << " + 0x" << std::hex << instr.getImm() << "]";
} else {
if (instr.getRDType() != RegType::None) {
os << instr.getRDType() << std::dec << instr.getRDest() << " <- ";
}
uint32_t i = 0;
for (; i < instr.getNRSrc(); ++i) {
if (i) os << ", ";
os << instr.getRSType(i) << std::dec << instr.getRSrc(i);
}
if (instr.hasImm()) {
if (i) os << ", ";
os << "imm=0x" << std::hex << instr.getImm();
}
if (opcode == EXT2 && func3 == 0) {
os << ", stage=" << std::dec << func2;
}
}
return os;
}
}
Decoder::Decoder(const Arch&) {}
std::shared_ptr<Instr> Decoder::decode(uint32_t code) const {
auto instr = std::make_shared<Instr>();
auto op = Opcode((code >> shift_opcode) & mask_opcode);
instr->setOpcode(op);
auto func2 = (code >> shift_func2) & mask_func2;
auto func3 = (code >> shift_func3) & mask_func3;
auto func6 = (code >> shift_func6) & mask_func6;
auto func7 = (code >> shift_func7) & mask_func7;
auto rd = (code >> shift_rd) & mask_reg;
auto rs1 = (code >> shift_rs1) & mask_reg;
auto rs2 = (code >> shift_rs2) & mask_reg;
auto rs3 = (code >> shift_rs3) & mask_reg;
auto op_it = sc_instTable.find(op);
if (op_it == sc_instTable.end()) {
std::cout << std::hex << "Error: invalid opcode: 0x" << op << std::endl;
return nullptr;
}
auto iType = op_it->second.iType;
if (op == Opcode::FL || op == Opcode::FS) {
if (func3 != 0x2 && func3 != 0x3) {
iType = InstType::V_TYPE;
}
}
switch (iType) {
case InstType::N_TYPE:
break;
case InstType::R_TYPE:
if (op == Opcode::FCI) {
switch (func7) {
case 0x50: // FLE.S, FLT.S, FEQ.S
case 0x51: // FLE.D, FLT.D, FEQ.D
instr->setDestReg(rd, RegType::Integer);
instr->setSrcReg(rs1, RegType::Float);
instr->setSrcReg(rs2, RegType::Float);
break;
case 0x60: // FCVT.W.D, FCVT.WU.D, FCVT.L.D, FCVT.LU.D
case 0x61: // FCVT.WU.S, FCVT.W.S, FCVT.L.S, FCVT.LU.S
instr->setDestReg(rd, RegType::Integer);
instr->setSrcReg(rs1, RegType::Float);
instr->setSrcReg(rs2, RegType::Integer);
break;
case 0x68: // FCVT.S.W, FCVT.S.WU, FCVT.S.L, FCVT.S.LU
case 0x69: // FCVT.D.W, FCVT.D.WU, FCVT.D.L, FCVT.D.LU
instr->setDestReg(rd, RegType::Float);
instr->setSrcReg(rs1, RegType::Integer);
instr->setSrcReg(rs2, RegType::Integer);
break;
case 0x70: // FCLASS.S, FMV.X.W
case 0x71: // FCLASS.D, FMV.X.D
instr->setDestReg(rd, RegType::Integer);
instr->setSrcReg(rs1, RegType::Float);
break;
case 0x78: // FMV.W.X
case 0x79: // FMV.D.X
instr->setDestReg(rd, RegType::Float);
instr->setSrcReg(rs1, RegType::Integer);
break;
default:
instr->setDestReg(rd, RegType::Float);
instr->setSrcReg(rs1, RegType::Float);
instr->setSrcReg(rs2, RegType::Float);
break;
}
} else {
instr->setDestReg(rd, RegType::Integer);
instr->setSrcReg(rs1, RegType::Integer);
instr->setSrcReg(rs2, RegType::Integer);
}
instr->setFunc3(func3);
instr->setFunc7(func7);
break;
case InstType::I_TYPE: {
instr->setSrcReg(rs1, RegType::Integer);
if (op == Opcode::FL) {
instr->setDestReg(rd, RegType::Float);
} else {
instr->setDestReg(rd, RegType::Integer);
}
instr->setFunc3(func3);
instr->setFunc7(func7);
switch (op) {
case Opcode::SYS_INST:
if (func3 != 0) {
// RV32I: CSR*
instr->setDestReg(rd, RegType::Integer);
}
// uint12
instr->setImm(code >> shift_rs2);
break;
case Opcode::FENCE:
// uint12
instr->setImm(code >> shift_rs2);
break;
case Opcode::I_INST:
case Opcode::I_INST_W:
if (func3 == 0x1 || func3 == 0x5) {
auto shamt = rs2; // uint5
#if (XLEN == 64)
if (op == Opcode::I_INST) {
// uint6
shamt |= ((func7 & 0x1) << 5);
}
#endif
instr->setImm(shamt);
} else {
// int12
auto imm = code >> shift_rs2;
instr->setImm(sext(imm, width_i_imm));
}
break;
default:
// int12
auto imm = code >> shift_rs2;
instr->setImm(sext(imm, width_i_imm));
break;
}
} break;
case InstType::S_TYPE: {
instr->setSrcReg(rs1, RegType::Integer);
if (op == Opcode::FS) {
instr->setSrcReg(rs2, RegType::Float);
} else {
instr->setSrcReg(rs2, RegType::Integer);
}
instr->setFunc3(func3);
auto imm = (func7 << width_reg) | rd;
instr->setImm(sext(imm, width_i_imm));
} break;
case InstType::B_TYPE: {
instr->setSrcReg(rs1, RegType::Integer);
instr->setSrcReg(rs2, RegType::Integer);
instr->setFunc3(func3);
auto bit_11 = rd & 0x1;
auto bits_4_1 = rd >> 1;
auto bit_10_5 = func7 & 0x3f;
auto bit_12 = func7 >> 6;
auto imm = (bits_4_1 << 1) | (bit_10_5 << 5) | (bit_11 << 11) | (bit_12 << 12);
instr->setImm(sext(imm, width_i_imm+1));
} break;
case InstType::U_TYPE: {
instr->setDestReg(rd, RegType::Integer);
auto imm = code >> shift_func3;
instr->setImm(sext(imm, width_j_imm));
} break;
case InstType::J_TYPE: {
instr->setDestReg(rd, RegType::Integer);
auto unordered = code >> shift_func3;
auto bits_19_12 = unordered & 0xff;
auto bit_11 = (unordered >> 8) & 0x1;
auto bits_10_1 = (unordered >> 9) & 0x3ff;
auto bit_20 = (unordered >> 19) & 0x1;
auto imm = (bits_10_1 << 1) | (bit_11 << 11) | (bits_19_12 << 12) | (bit_20 << 20);
instr->setImm(sext(imm, width_j_imm+1));
} break;
case InstType::V_TYPE:
switch (op) {
case Opcode::VSET: {
instr->setDestVReg(rd);
instr->setSrcVReg(rs1);
instr->setFunc3(func3);
if (func3 == 7) {
instr->setImm(!(code >> shift_vset));
if (instr->getImm()) {
auto immed = (code >> shift_rs2) & mask_v_imm;
instr->setImm(immed);
instr->setVlmul(immed & 0x3);
instr->setVediv((immed >> 4) & 0x3);
instr->setVsew((immed >> 2) & 0x3);
} else {
instr->setSrcVReg(rs2);
}
} else {
instr->setSrcVReg(rs2);
instr->setVmask((code >> shift_func7) & 0x1);
instr->setFunc6(func6);
}
} break;
case Opcode::FL:
instr->setDestVReg(rd);
instr->setSrcVReg(rs1);
instr->setVlsWidth(func3);
instr->setSrcVReg(rs2);
instr->setVmask(code >> shift_func7);
instr->setVmop((code >> shift_vmop) & mask_func3);
instr->setVnf((code >> shift_vnf) & mask_func3);
break;
case Opcode::FS:
instr->setVs3(rd);
instr->setSrcVReg(rs1);
instr->setVlsWidth(func3);
instr->setSrcVReg(rs2);
instr->setVmask(code >> shift_func7);
instr->setVmop((code >> shift_vmop) & mask_func3);
instr->setVnf((code >> shift_vnf) & mask_func3);
break;
default:
std::abort();
}
break;
case R4_TYPE:
if (op == Opcode::EXT2) {
instr->setDestReg(rd, RegType::Integer);
instr->setSrcReg(rs1, RegType::Integer);
instr->setSrcReg(rs2, RegType::Integer);
instr->setSrcReg(rs3, RegType::Integer);
} else {
instr->setDestReg(rd, RegType::Float);
instr->setSrcReg(rs1, RegType::Float);
instr->setSrcReg(rs2, RegType::Float);
instr->setSrcReg(rs3, RegType::Float);
}
instr->setFunc2(func2);
instr->setFunc3(func3);
break;
default:
std::abort();
}
return instr;
}