// Copyright 2018 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include "common/assert.h"
#include "common/logging/log.h"
#include "video_core/engines/maxwell_3d.h"
#include "video_core/macro_interpreter.h"
namespace Tegra {
MacroInterpreter::MacroInterpreter(Engines::Maxwell3D& maxwell3d) : maxwell3d(maxwell3d) {}
void MacroInterpreter::Execute(u32 offset, std::vector<u32> parameters) {
Reset();
registers[1] = parameters[0];
this->parameters = std::move(parameters);
// Execute the code until we hit an exit condition.
bool keep_executing = true;
while (keep_executing) {
keep_executing = Step(offset, false);
}
// Assert the the macro used all the input parameters
ASSERT(next_parameter_index == this->parameters.size());
}
void MacroInterpreter::Reset() {
registers = {};
pc = 0;
delayed_pc = {};
method_address.raw = 0;
parameters.clear();
// The next parameter index starts at 1, because $r1 already has the value of the first
// parameter.
next_parameter_index = 1;
carry_flag = false;
}
bool MacroInterpreter::Step(u32 offset, bool is_delay_slot) {
u32 base_address = pc;
Opcode opcode = GetOpcode(offset);
pc += 4;
// Update the program counter if we were delayed
if (delayed_pc) {
ASSERT(is_delay_slot);
pc = *delayed_pc;
delayed_pc = {};
}
switch (opcode.operation) {
case Operation::ALU: {
u32 result = GetALUResult(opcode.alu_operation, GetRegister(opcode.src_a),
GetRegister(opcode.src_b));
ProcessResult(opcode.result_operation, opcode.dst, result);
break;
}
case Operation::AddImmediate: {
ProcessResult(opcode.result_operation, opcode.dst,
GetRegister(opcode.src_a) + opcode.immediate);
break;
}
case Operation::ExtractInsert: {
u32 dst = GetRegister(opcode.src_a);
u32 src = GetRegister(opcode.src_b);
src = (src >> opcode.bf_src_bit) & opcode.GetBitfieldMask();
dst &= ~(opcode.GetBitfieldMask() << opcode.bf_dst_bit);
dst |= src << opcode.bf_dst_bit;
ProcessResult(opcode.result_operation, opcode.dst, dst);
break;
}
case Operation::ExtractShiftLeftImmediate: {
u32 dst = GetRegister(opcode.src_a);
u32 src = GetRegister(opcode.src_b);
u32 result = ((src >> dst) & opcode.GetBitfieldMask()) << opcode.bf_dst_bit;
ProcessResult(opcode.result_operation, opcode.dst, result);
break;
}
case Operation::ExtractShiftLeftRegister: {
u32 dst = GetRegister(opcode.src_a);
u32 src = GetRegister(opcode.src_b);
u32 result = ((src >> opcode.bf_src_bit) & opcode.GetBitfieldMask()) << dst;
ProcessResult(opcode.result_operation, opcode.dst, result);
break;
}
case Operation::Read: {
u32 result = Read(GetRegister(opcode.src_a) + opcode.immediate);
ProcessResult(opcode.result_operation, opcode.dst, result);
break;
}
case Operation::Branch: {
ASSERT_MSG(!is_delay_slot, "Executing a branch in a delay slot is not valid");
u32 value = GetRegister(opcode.src_a);
bool taken = EvaluateBranchCondition(opcode.branch_condition, value);
if (taken) {
// Ignore the delay slot if the branch has the annul bit.
if (opcode.branch_annul) {
pc = base_address + opcode.GetBranchTarget();
return true;
}
delayed_pc = base_address + opcode.GetBranchTarget();
// Execute one more instruction due to the delay slot.
return Step(offset, true);
}
break;
}
default:
UNIMPLEMENTED_MSG("Unimplemented macro operation {}",
static_cast<u32>(opcode.operation.Value()));
}
if (opcode.is_exit) {
// Exit has a delay slot, execute the next instruction
// Note: Executing an exit during a branch delay slot will cause the instruction at the
// branch target to be executed before exiting.
Step(offset, true);
return false;
}
return true;
}
MacroInterpreter::Opcode MacroInterpreter::GetOpcode(u32 offset) const {
const auto& macro_memory{maxwell3d.GetMacroMemory()};
ASSERT((pc % sizeof(u32)) == 0);
ASSERT((pc + offset) < macro_memory.size() * sizeof(u32));
return {macro_memory[offset + pc / sizeof(u32)]};
}
u32 MacroInterpreter::GetALUResult(ALUOperation operation, u32 src_a, u32 src_b) {
switch (operation) {
case ALUOperation::Add: {
const u64 result{static_cast<u64>(src_a) + src_b};
carry_flag = result > 0xffffffff;
return static_cast<u32>(result);
}
case ALUOperation::AddWithCarry: {
const u64 result{static_cast<u64>(src_a) + src_b + (carry_flag ? 1ULL : 0ULL)};
carry_flag = result > 0xffffffff;
return static_cast<u32>(result);
}
case ALUOperation::Subtract: {
const u64 result{static_cast<u64>(src_a) - src_b};
carry_flag = result < 0x100000000;
return static_cast<u32>(result);
}
case ALUOperation::SubtractWithBorrow: {
const u64 result{static_cast<u64>(src_a) - src_b - (carry_flag ? 0ULL : 1ULL)};
carry_flag = result < 0x100000000;
return static_cast<u32>(result);
}
case ALUOperation::Xor:
return src_a ^ src_b;
case ALUOperation::Or:
return src_a | src_b;
case ALUOperation::And:
return src_a & src_b;
case ALUOperation::AndNot:
return src_a & ~src_b;
case ALUOperation::Nand:
return ~(src_a & src_b);
default:
UNIMPLEMENTED_MSG("Unimplemented ALU operation {}", static_cast<u32>(operation));
return 0;
}
}
void MacroInterpreter::ProcessResult(ResultOperation operation, u32 reg, u32 result) {
switch (operation) {
case ResultOperation::IgnoreAndFetch:
// Fetch parameter and ignore result.
SetRegister(reg, FetchParameter());
break;
case ResultOperation::Move:
// Move result.
SetRegister(reg, result);
break;
case ResultOperation::MoveAndSetMethod:
// Move result and use as Method Address.
SetRegister(reg, result);
SetMethodAddress(result);
break;
case ResultOperation::FetchAndSend:
// Fetch parameter and send result.
SetRegister(reg, FetchParameter());
Send(result);
break;
case ResultOperation::MoveAndSend:
// Move and send result.
SetRegister(reg, result);
Send(result);
break;
case ResultOperation::FetchAndSetMethod:
// Fetch parameter and use result as Method Address.
SetRegister(reg, FetchParameter());
SetMethodAddress(result);
break;
case ResultOperation::MoveAndSetMethodFetchAndSend:
// Move result and use as Method Address, then fetch and send parameter.
SetRegister(reg, result);
SetMethodAddress(result);
Send(FetchParameter());
break;
case ResultOperation::MoveAndSetMethodSend:
// Move result and use as Method Address, then send bits 12:17 of result.
SetRegister(reg, result);
SetMethodAddress(result);
Send((result >> 12) & 0b111111);
break;
default:
UNIMPLEMENTED_MSG("Unimplemented result operation {}", static_cast<u32>(operation));
}
}
u32 MacroInterpreter::FetchParameter() {
ASSERT(next_parameter_index < parameters.size());
return parameters[next_parameter_index++];
}
u32 MacroInterpreter::GetRegister(u32 register_id) const {
// Register 0 is supposed to always return 0.
if (register_id == 0)
return 0;
ASSERT(register_id < registers.size());
return registers[register_id];
}
void MacroInterpreter::SetRegister(u32 register_id, u32 value) {
// Register 0 is supposed to always return 0. NOP is implemented as a store to the zero
// register.
if (register_id == 0)
return;
ASSERT(register_id < registers.size());
registers[register_id] = value;
}
void MacroInterpreter::SetMethodAddress(u32 address) {
method_address.raw = address;
}
void MacroInterpreter::Send(u32 value) {
maxwell3d.CallMethod({method_address.address, value});
// Increment the method address by the method increment.
method_address.address.Assign(method_address.address.Value() +
method_address.increment.Value());
}
u32 MacroInterpreter::Read(u32 method) const {
return maxwell3d.GetRegisterValue(method);
}
bool MacroInterpreter::EvaluateBranchCondition(BranchCondition cond, u32 value) const {
switch (cond) {
case BranchCondition::Zero:
return value == 0;
case BranchCondition::NotZero:
return value != 0;
}
UNREACHABLE();
return true;
}
} // namespace Tegra
