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[CPU] Many fixes
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@liuk7071
liuk7071 committed Sep 23, 2023
1 parent 2fb4c68 commit c9e13e0
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Showing 2 changed files with 70 additions and 44 deletions.
106 changes: 65 additions & 41 deletions src/cpu/backends/interpreter/interpreter.cpp
View file
Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
#include "interpreter.hpp"


#define DONT_CRASH_ON_BAD_READWRITE
#define DONT_CRASH_ON_BAD_JUMP
//#define DONT_CRASH_ON_BAD_READWRITE
//#define DONT_CRASH_ON_BAD_JUMP

void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
// Handle interrupts
Expand Down Expand Up @@ -61,6 +61,7 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
#ifndef DONT_CRASH_ON_BAD_JUMP
Helpers::panic("Bad JR addr\n");
#else
core->exception(CpuCore::Exception::BadFetchAddr, true);
break;
#endif
}
Expand All @@ -70,14 +71,15 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
}
case CpuOpcodes::SPECIALOpcode::JALR: {
const u32 addr = gprs[instr.rs];
gprs[instr.rd] = core->nextPc;
if (addr & 3) {
#ifndef DONT_CRASH_ON_BAD_JUMP
Helpers::panic("Bad JALR addr\n");
#else
core->exception(CpuCore::Exception::BadFetchAddr, true);
break;
#endif
}
gprs[CpuOpcodes::CpuReg::RA] = core->nextPc;
core->nextPc = addr;
core->branched = true;
break;
Expand Down Expand Up @@ -157,17 +159,29 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
break;
}
case CpuOpcodes::SPECIALOpcode::ADD: {
u32 a = gprs[instr.rs];
u32 b = gprs[instr.rt];
u32 res = a + b;
if (((a >> 31) == (b >> 31)) && ((a >> 31) != (res >> 31))) {
core->exception(CpuCore::Exception::Overflow, true);
break;
}
gprs[instr.rd] = gprs[instr.rs] + gprs[instr.rt];
// TODO: overflow exception
break;
}
case CpuOpcodes::SPECIALOpcode::ADDU: {
gprs[instr.rd] = gprs[instr.rs] + gprs[instr.rt];
break;
}
case CpuOpcodes::SPECIALOpcode::SUB: {
gprs[instr.rd] = gprs[instr.rs] - gprs[instr.rt];
// TODO: overflow exception
u32 a = gprs[instr.rs];
u32 b = gprs[instr.rt];
u32 res = a - b;
if (((a ^ res) & (~b ^ res)) >> 31) {
core->exception(CpuCore::Exception::Overflow, true);
break;
}
gprs[instr.rd] = res;
break;
}
case CpuOpcodes::SPECIALOpcode::SUBU: {
Expand Down Expand Up @@ -204,40 +218,29 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
break;
}
case CpuOpcodes::Opcode::REGIMM: {
switch (instr.regimmOpc & 0x11) {
case CpuOpcodes::REGIMMOpcode::BLTZ: {
if ((s32)gprs[instr.rs] < 0) {
core->nextPc = core->pc + ((u32)(s16)instr.imm << 2);
core->branched = true;
}
break;
}
case CpuOpcodes::REGIMMOpcode::BGEZ: {
if ((s32)gprs[instr.rs] >= 0) {
core->nextPc = core->pc + ((u32)(s16)instr.imm << 2);
core->branched = true;
}
break;
}
case CpuOpcodes::REGIMMOpcode::BLTZAL: {
gprs[CpuOpcodes::CpuReg::RA] = core->nextPc;
if ((s32)gprs[instr.rs] < 0) {
bool ge = (instr.raw >> 16) & 1;
bool link = ((instr.raw >> 17) & 0xf) == 8;

s32 rs = (s32)gprs[instr.rs];

if (link) gprs[CpuReg::RA] = core->nextPc;

if (ge) {
if (rs >= 0) {
core->nextPc = core->pc + ((u32)(s16)instr.imm << 2);
core->branched = true;
}
break;
}
case CpuOpcodes::REGIMMOpcode::BGEZAL: {
gprs[CpuOpcodes::CpuReg::RA] = core->nextPc;
if ((s32)gprs[instr.rs] >= 0) {
else {
if (rs < 0) {
core->nextPc = core->pc + ((u32)(s16)instr.imm << 2);
core->branched = true;
}
break;
}
default:
Helpers::panic("[ FATAL ] Invalid REGIMM instruction 0x%02x (raw: 0x%08x)\n", instr.regimmOpc.Value(), instr.raw);
}

Helpers::panic("[ FATAL ] Invalid REGIMM instruction 0x%02x (raw: 0x%08x)\n", instr.regimmOpc.Value(), instr.raw);
break;
}
case CpuOpcodes::Opcode::J: {
Expand All @@ -246,7 +249,7 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
break;
}
case CpuOpcodes::Opcode::JAL: {
gprs[CpuOpcodes::CpuReg::RA] = core->nextPc;
gprs[CpuReg::RA] = core->nextPc;
core->nextPc = (core->pc & 0xf0000000) | (instr.jumpImm << 2);
core->branched = true;
break;
Expand Down Expand Up @@ -280,8 +283,14 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
break;
}
case CpuOpcodes::Opcode::ADDI: {
gprs[instr.rt] = gprs[instr.rs] + (u32)(s16)instr.imm;
// TODO: overflow exception
u32 a = gprs[instr.rs];
u32 b = (u32)(s16)instr.imm;
u32 res = a + b;
if (((a >> 31) == (b >> 31)) && ((a >> 31) != (res >> 31))) {
core->exception(CpuCore::Exception::Overflow, true);
break;
}
gprs[instr.rt] = res;
break;
}
case CpuOpcodes::Opcode::ADDIU: {
Expand Down Expand Up @@ -352,6 +361,9 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
if (addr & 1) {
#ifndef DONT_CRASH_ON_BAD_READWRITE
Helpers::panic("Bad lh addr 0x%08x\n", addr);
#else
core->exception(CpuCore::Exception::BadFetchAddr, true);
break;
#endif
}
gprs[instr.rt] = (u32)(s16)mem->read<u16>(addr);
Expand All @@ -361,8 +373,8 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
u32 address = gprs[instr.rs] + (u32)(s16)instr.imm;
const int shift = ((address & 3) ^ 3) * 8;
u32 dataTemp = mem->read<u32>(address & ~3);
u32 rtTemp = gprs[instr.rt] & ~(0xffffffff >> shift);
dataTemp >>= shift;
u32 rtTemp = gprs[instr.rt] & ~(0xffffffff << shift);
dataTemp <<= shift;
gprs[instr.rt] = dataTemp | rtTemp;
break;
}
Expand All @@ -371,6 +383,9 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
if (addr & 3) {
#ifndef DONT_CRASH_ON_BAD_READWRITE
Helpers::panic("Bad lw addr 0x%08x\n", addr);
#else
core->exception(CpuCore::Exception::BadFetchAddr, true);
break;
#endif
}
gprs[instr.rt] = mem->read<u32>(addr);
Expand All @@ -386,6 +401,9 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
if (addr & 1) {
#ifndef DONT_CRASH_ON_BAD_READWRITE
Helpers::panic("Bad lhu addr 0x%08x\n", addr);
#else
core->exception(CpuCore::Exception::BadFetchAddr, true);
break;
#endif
}
gprs[instr.rt] = mem->read<u16>(addr);
Expand All @@ -395,8 +413,8 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
u32 address = gprs[instr.rs] + (u32)(s16)instr.imm;
const int shift = (address & 3) * 8;
u32 dataTemp = mem->read<u32>(address & ~3);
u32 rtTemp = gprs[instr.rt] & ~(0xffffffff << shift);
dataTemp <<= shift;
u32 rtTemp = gprs[instr.rt] & ~(0xffffffff >> shift);
dataTemp >>= shift;
gprs[instr.rt] = dataTemp | rtTemp;
break;
}
Expand All @@ -412,6 +430,9 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
if (addr & 1) {
#ifndef DONT_CRASH_ON_BAD_READWRITE
Helpers::panic("Bad sh addr 0x%08x\n", addr);
#else
core->exception(CpuCore::Exception::BadStoreAddr, true);
break;
#endif
}
mem->write<u16>(addr, gprs[instr.rt]);
Expand All @@ -421,8 +442,8 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
u32 address = gprs[instr.rs] + (u32)(s16)instr.imm;
const int shift = ((address & 3) ^ 3) * 8;
u32 dataTemp = mem->read<u32>(address & ~3);
u32 rtTemp = gprs[instr.rt] << shift;
dataTemp &= ~(0xffffffff << shift);
u32 rtTemp = gprs[instr.rt] >> shift;
dataTemp &= ~(0xffffffff >> shift);
mem->write<u32>(address & ~3, dataTemp | rtTemp);
break;
}
Expand All @@ -432,6 +453,9 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
if (addr & 3) {
#ifndef DONT_CRASH_ON_BAD_READWRITE
Helpers::panic("Bad sw addr 0x%08x\n", addr);
#else
core->exception(CpuCore::Exception::BadStoreAddr, true);
break;
#endif
}
mem->write<u32>(addr, gprs[instr.rt]);
Expand All @@ -441,8 +465,8 @@ void Interpreter::step(CpuCore* core, Memory* mem, Disassembler* disassembler) {
u32 address = gprs[instr.rs] + (u32)(s16)instr.imm;
const int shift = (address & 3) * 8;
u32 dataTemp = mem->read<u32>(address & ~3);
u32 rtTemp = gprs[instr.rt] >> shift;
dataTemp &= ~(0xffffffff >> shift);
u32 rtTemp = gprs[instr.rt] << shift;
dataTemp &= ~(0xffffffff << shift);
mem->write<u32>(address & ~3, dataTemp | rtTemp);
break;
}
Expand Down
8 changes: 5 additions & 3 deletions src/cpu/cpu_core.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -77,7 +77,7 @@ struct COP0 {
case (u32)COP0Reg::BDA: return 0;
case (u32)COP0Reg::JumpDest: return 0;
case (u32)COP0Reg::DCIC: return 0;
case (u32)COP0Reg::BadVAddr: return 0;
case (u32)COP0Reg::BadVAddr: return badVaddr;
case (u32)COP0Reg::BDAM: return 0;
case (u32)COP0Reg::BPCM: return 0;
case (u32)COP0Reg::Status: return status.raw;
Expand Down Expand Up @@ -168,8 +168,8 @@ class CpuCore {
}
};

namespace CpuOpcodes {
enum CpuReg {
namespace CpuReg {
enum {
R0 = 0, AT = 1, V0 = 2, V1 = 3,
A0 = 4, A1 = 5, A2 = 6, A3 = 7,
T0 = 8, T1 = 9, T2 = 10, T3 = 11,
Expand All @@ -180,7 +180,9 @@ enum CpuReg {
GP = 28, SP = 29, S8 = 30, RA = 31,
LO = 32, HI = 33
};
}

namespace CpuOpcodes {
enum Opcode {
SPECIAL = 0x00,
REGIMM = 0x01,
Expand Down

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