yuzu/src/video_core/macro/macro_interpreter.cpp
Kyle Kienapfel 6fa3faec65 Add break for default cases
Visual Studio has an option to search all files in a solution, so I
did a search in there for "default:" looking for any missing break
statements.

I've left out default statements that return something, and that throw
something, even if via ThrowInvalidType. UNREACHABLE leads towards throw

R_THROW macro leads towards a return
2022-11-13 16:30:55 -08:00

363 lines
12 KiB
C++

// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#include <array>
#include <optional>
#include "common/assert.h"
#include "common/logging/log.h"
#include "common/microprofile.h"
#include "video_core/engines/maxwell_3d.h"
#include "video_core/macro/macro_interpreter.h"
MICROPROFILE_DEFINE(MacroInterp, "GPU", "Execute macro interpreter", MP_RGB(128, 128, 192));
namespace Tegra {
namespace {
class MacroInterpreterImpl final : public CachedMacro {
public:
explicit MacroInterpreterImpl(Engines::Maxwell3D& maxwell3d_, const std::vector<u32>& code_)
: maxwell3d{maxwell3d_}, code{code_} {}
void Execute(const std::vector<u32>& params, u32 method) override;
private:
/// Resets the execution engine state, zeroing registers, etc.
void Reset();
/**
* Executes a single macro instruction located at the current program counter. Returns whether
* the interpreter should keep running.
*
* @param is_delay_slot Whether the current step is being executed due to a delay slot in a
* previous instruction.
*/
bool Step(bool is_delay_slot);
/// Calculates the result of an ALU operation. src_a OP src_b;
u32 GetALUResult(Macro::ALUOperation operation, u32 src_a, u32 src_b);
/// Performs the result operation on the input result and stores it in the specified register
/// (if necessary).
void ProcessResult(Macro::ResultOperation operation, u32 reg, u32 result);
/// Evaluates the branch condition and returns whether the branch should be taken or not.
bool EvaluateBranchCondition(Macro::BranchCondition cond, u32 value) const;
/// Reads an opcode at the current program counter location.
Macro::Opcode GetOpcode() const;
/// Returns the specified register's value. Register 0 is hardcoded to always return 0.
u32 GetRegister(u32 register_id) const;
/// Sets the register to the input value.
void SetRegister(u32 register_id, u32 value);
/// Sets the method address to use for the next Send instruction.
void SetMethodAddress(u32 address);
/// Calls a GPU Engine method with the input parameter.
void Send(u32 value);
/// Reads a GPU register located at the method address.
u32 Read(u32 method) const;
/// Returns the next parameter in the parameter queue.
u32 FetchParameter();
Engines::Maxwell3D& maxwell3d;
/// Current program counter
u32 pc{};
/// Program counter to execute at after the delay slot is executed.
std::optional<u32> delayed_pc;
/// General purpose macro registers.
std::array<u32, Macro::NUM_MACRO_REGISTERS> registers = {};
/// Method address to use for the next Send instruction.
Macro::MethodAddress method_address = {};
/// Input parameters of the current macro.
std::unique_ptr<u32[]> parameters;
std::size_t num_parameters = 0;
std::size_t parameters_capacity = 0;
/// Index of the next parameter that will be fetched by the 'parm' instruction.
u32 next_parameter_index = 0;
bool carry_flag = false;
const std::vector<u32>& code;
};
void MacroInterpreterImpl::Execute(const std::vector<u32>& params, u32 method) {
MICROPROFILE_SCOPE(MacroInterp);
Reset();
registers[1] = params[0];
num_parameters = params.size();
if (num_parameters > parameters_capacity) {
parameters_capacity = num_parameters;
parameters = std::make_unique<u32[]>(num_parameters);
}
std::memcpy(parameters.get(), params.data(), num_parameters * sizeof(u32));
// Execute the code until we hit an exit condition.
bool keep_executing = true;
while (keep_executing) {
keep_executing = Step(false);
}
// Assert the the macro used all the input parameters
ASSERT(next_parameter_index == num_parameters);
}
void MacroInterpreterImpl::Reset() {
registers = {};
pc = 0;
delayed_pc = {};
method_address.raw = 0;
num_parameters = 0;
// 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 MacroInterpreterImpl::Step(bool is_delay_slot) {
u32 base_address = pc;
Macro::Opcode opcode = GetOpcode();
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 Macro::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 Macro::Operation::AddImmediate: {
ProcessResult(opcode.result_operation, opcode.dst,
GetRegister(opcode.src_a) + opcode.immediate);
break;
}
case Macro::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 Macro::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 Macro::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 Macro::Operation::Read: {
u32 result = Read(GetRegister(opcode.src_a) + opcode.immediate);
ProcessResult(opcode.result_operation, opcode.dst, result);
break;
}
case Macro::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(true);
}
break;
}
default:
UNIMPLEMENTED_MSG("Unimplemented macro operation {}", opcode.operation.Value());
break;
}
// An instruction with the Exit flag will not actually
// cause an exit if it's executed inside a delay slot.
if (opcode.is_exit && !is_delay_slot) {
// Exit has a delay slot, execute the next instruction
Step(true);
return false;
}
return true;
}
u32 MacroInterpreterImpl::GetALUResult(Macro::ALUOperation operation, u32 src_a, u32 src_b) {
switch (operation) {
case Macro::ALUOperation::Add: {
const u64 result{static_cast<u64>(src_a) + src_b};
carry_flag = result > 0xffffffff;
return static_cast<u32>(result);
}
case Macro::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 Macro::ALUOperation::Subtract: {
const u64 result{static_cast<u64>(src_a) - src_b};
carry_flag = result < 0x100000000;
return static_cast<u32>(result);
}
case Macro::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 Macro::ALUOperation::Xor:
return src_a ^ src_b;
case Macro::ALUOperation::Or:
return src_a | src_b;
case Macro::ALUOperation::And:
return src_a & src_b;
case Macro::ALUOperation::AndNot:
return src_a & ~src_b;
case Macro::ALUOperation::Nand:
return ~(src_a & src_b);
default:
UNIMPLEMENTED_MSG("Unimplemented ALU operation {}", operation);
return 0;
}
}
void MacroInterpreterImpl::ProcessResult(Macro::ResultOperation operation, u32 reg, u32 result) {
switch (operation) {
case Macro::ResultOperation::IgnoreAndFetch:
// Fetch parameter and ignore result.
SetRegister(reg, FetchParameter());
break;
case Macro::ResultOperation::Move:
// Move result.
SetRegister(reg, result);
break;
case Macro::ResultOperation::MoveAndSetMethod:
// Move result and use as Method Address.
SetRegister(reg, result);
SetMethodAddress(result);
break;
case Macro::ResultOperation::FetchAndSend:
// Fetch parameter and send result.
SetRegister(reg, FetchParameter());
Send(result);
break;
case Macro::ResultOperation::MoveAndSend:
// Move and send result.
SetRegister(reg, result);
Send(result);
break;
case Macro::ResultOperation::FetchAndSetMethod:
// Fetch parameter and use result as Method Address.
SetRegister(reg, FetchParameter());
SetMethodAddress(result);
break;
case Macro::ResultOperation::MoveAndSetMethodFetchAndSend:
// Move result and use as Method Address, then fetch and send parameter.
SetRegister(reg, result);
SetMethodAddress(result);
Send(FetchParameter());
break;
case Macro::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 {}", operation);
break;
}
}
bool MacroInterpreterImpl::EvaluateBranchCondition(Macro::BranchCondition cond, u32 value) const {
switch (cond) {
case Macro::BranchCondition::Zero:
return value == 0;
case Macro::BranchCondition::NotZero:
return value != 0;
}
UNREACHABLE();
}
Macro::Opcode MacroInterpreterImpl::GetOpcode() const {
ASSERT((pc % sizeof(u32)) == 0);
ASSERT(pc < code.size() * sizeof(u32));
return {code[pc / sizeof(u32)]};
}
u32 MacroInterpreterImpl::GetRegister(u32 register_id) const {
return registers.at(register_id);
}
void MacroInterpreterImpl::SetRegister(u32 register_id, u32 value) {
// Register 0 is hardwired as the zero register.
// Ensure no writes to it actually occur.
if (register_id == 0) {
return;
}
registers.at(register_id) = value;
}
void MacroInterpreterImpl::SetMethodAddress(u32 address) {
method_address.raw = address;
}
void MacroInterpreterImpl::Send(u32 value) {
maxwell3d.CallMethod(method_address.address, value, true);
// Increment the method address by the method increment.
method_address.address.Assign(method_address.address.Value() +
method_address.increment.Value());
}
u32 MacroInterpreterImpl::Read(u32 method) const {
return maxwell3d.GetRegisterValue(method);
}
u32 MacroInterpreterImpl::FetchParameter() {
ASSERT(next_parameter_index < num_parameters);
return parameters[next_parameter_index++];
}
} // Anonymous namespace
MacroInterpreter::MacroInterpreter(Engines::Maxwell3D& maxwell3d_)
: MacroEngine{maxwell3d_}, maxwell3d{maxwell3d_} {}
std::unique_ptr<CachedMacro> MacroInterpreter::Compile(const std::vector<u32>& code) {
return std::make_unique<MacroInterpreterImpl>(maxwell3d, code);
}
} // namespace Tegra