yuzu/src/video_core/macro_interpreter.h
Subv 8191273a3d MacroInterpreter: Avoid left shifting negative values.
The branch target is signed, so multiply by 4 instead of left shifting by 2
2018-07-30 20:38:24 -05:00

168 lines
5.1 KiB
C++

// Copyright 2018 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <array>
#include <vector>
#include <boost/optional.hpp>
#include "common/bit_field.h"
#include "common/common_types.h"
namespace Tegra {
namespace Engines {
class Maxwell3D;
}
class MacroInterpreter final {
public:
explicit MacroInterpreter(Engines::Maxwell3D& maxwell3d);
/**
* Executes the macro code with the specified input parameters.
* @param code The macro byte code to execute
* @param parameters The parameters of the macro
*/
void Execute(const std::vector<u32>& code, std::vector<u32> parameters);
private:
enum class Operation : u32 {
ALU = 0,
AddImmediate = 1,
ExtractInsert = 2,
ExtractShiftLeftImmediate = 3,
ExtractShiftLeftRegister = 4,
Read = 5,
Unused = 6, // This operation doesn't seem to be a valid encoding.
Branch = 7,
};
enum class ALUOperation : u32 {
Add = 0,
AddWithCarry = 1,
Subtract = 2,
SubtractWithBorrow = 3,
// Operations 4-7 don't seem to be valid encodings.
Xor = 8,
Or = 9,
And = 10,
AndNot = 11,
Nand = 12
};
enum class ResultOperation : u32 {
IgnoreAndFetch = 0,
Move = 1,
MoveAndSetMethod = 2,
FetchAndSend = 3,
MoveAndSend = 4,
FetchAndSetMethod = 5,
MoveAndSetMethodFetchAndSend = 6,
MoveAndSetMethodSend = 7
};
enum class BranchCondition : u32 {
Zero = 0,
NotZero = 1,
};
union Opcode {
u32 raw;
BitField<0, 3, Operation> operation;
BitField<4, 3, ResultOperation> result_operation;
BitField<4, 1, BranchCondition> branch_condition;
BitField<5, 1, u32>
branch_annul; // If set on a branch, then the branch doesn't have a delay slot.
BitField<7, 1, u32> is_exit;
BitField<8, 3, u32> dst;
BitField<11, 3, u32> src_a;
BitField<14, 3, u32> src_b;
// The signed immediate overlaps the second source operand and the alu operation.
BitField<14, 18, s32> immediate;
BitField<17, 5, ALUOperation> alu_operation;
// Bitfield instructions data
BitField<17, 5, u32> bf_src_bit;
BitField<22, 5, u32> bf_size;
BitField<27, 5, u32> bf_dst_bit;
u32 GetBitfieldMask() const {
return (1 << bf_size) - 1;
}
s32 GetBranchTarget() const {
return static_cast<s32>(immediate * sizeof(u32));
}
};
union MethodAddress {
u32 raw;
BitField<0, 12, u32> address;
BitField<12, 6, u32> increment;
};
/// 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 code The macro code to execute.
* @param is_delay_slot Whether the current step is being executed due to a delay slot in a
* previous instruction.
*/
bool Step(const std::vector<u32>& code, bool is_delay_slot);
/// Calculates the result of an ALU operation. src_a OP src_b;
u32 GetALUResult(ALUOperation operation, u32 src_a, u32 src_b) const;
/// Performs the result operation on the input result and stores it in the specified register
/// (if necessary).
void ProcessResult(ResultOperation operation, u32 reg, u32 result);
/// Evaluates the branch condition and returns whether the branch should be taken or not.
bool EvaluateBranchCondition(BranchCondition cond, u32 value) const;
/// Reads an opcode at the current program counter location.
Opcode GetOpcode(const std::vector<u32>& code) 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;
u32 pc; ///< Current program counter
boost::optional<u32>
delayed_pc; ///< Program counter to execute at after the delay slot is executed.
static constexpr size_t NumMacroRegisters = 8;
/// General purpose macro registers.
std::array<u32, NumMacroRegisters> registers = {};
/// Method address to use for the next Send instruction.
MethodAddress method_address = {};
/// Input parameters of the current macro.
std::vector<u32> parameters;
/// Index of the next parameter that will be fetched by the 'parm' instruction.
u32 next_parameter_index = 0;
};
} // namespace Tegra