dolphin/Source/Core/Common/GekkoDisassembler.h

// Copyright 2014 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

/* $VER: ppc_disasm.h V1.6 (09.12.2011)
 *
 * Disassembler module for the PowerPC microprocessor family
 * Copyright (c) 1998-2001,2009,2011 Frank Wille
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

// Modified for use with Dolphin

#pragma once

#include <cstdint>
#include <string>

#include "Common/CommonTypes.h"
#include "Common/StringUtil.h"

class GekkoDisassembler final
{
public:
	static std::string Disassemble(u32 opcode, u32 current_instruction_address, bool big_endian = true);
	static const char* GetGPRName(u32 index);
	static const char* GetFPRName(u32 index);

private:
	GekkoDisassembler() = delete;

	static void ill(u32 in);
	static std::string imm(u32 in, int uimm, int type, bool hex);

	static std::string ra_rb(u32 in);
	static std::string rd_ra_rb(u32 in, int mask);
	static std::string fd_ra_rb(u32 in, int mask);

	static void trapi(u32 in, unsigned char dmode);
	static void cmpi(u32 in, int uimm);
	static void addi(u32 in, const std::string& ext);
	static size_t branch(u32 in, const char* bname, int aform, int bdisp);
	static void bc(u32 in);
	static void bli(u32 in);
	static void mcrf(u32 in, char c);
	static void crop(u32 in, const char* n1, const char* n2);
	static void nooper(u32 in, const char* name, unsigned char dmode);
	static void rlw(u32 in, const char* name, int i);
	static void ori(u32 in, const char* name);
	static void rld(u32 in, const char* name, int i);
	static void cmp(u32 in);
	static void trap(u32 in, unsigned char dmode);
	static void dab(u32 in, const char* name, int mask, int smode, int chkoe, int chkrc, unsigned char dmode);
	static void rrn(u32 in, const char* name, int smode, int chkoe, int chkrc, unsigned char dmode);
	static void mtcr(u32 in);
	static void msr(u32 in, int smode);
	static void mspr(u32 in, int smode);
	static void mtb(u32 in);
	static void sradi(u32 in);
	static void ldst(u32 in, const char* name, char reg, unsigned char dmode);
	static void fdabc(u32 in, const char* name, int mask, unsigned char dmode);
	static void fmr(u32 in);
	static void fdab(u32 in, const char* name, int mask);
	static void fcmp(u32 in, char c);
	static void mtfsb(u32 in, int n);
	static void ps(u32 inst);
	static void ps_mem(u32 inst);

	static u32* DoDisassembly(bool big_endian);

	static u32 HelperRotateMask(int r, int mb, int me)
	{
		//first make 001111111111111 part
		unsigned int begin = 0xFFFFFFFF >> mb;
		//then make 000000000001111 part, which is used to flip the bits of the first one
		unsigned int end = me < 31 ? (0xFFFFFFFF >> (me + 1)) : 0;
		//do the bitflip
		unsigned int mask = begin ^ end;
		//and invert if backwards
		if (me < mb)
			mask = ~mask;
		//rotate the mask so it can be applied to source reg
		//return _rotl(mask, 32 - r);
		return (mask << (32 - r)) | (mask >> r);
	}

	static std::string ldst_offs(u32 val)
	{
		if (val == 0)
		{
			return "0";
		}
		else
		{
			if (val & 0x8000)
			{
				return StringFromFormat("-0x%.4X", ((~val) & 0xffff) + 1);
			}
			else
			{
				return StringFromFormat("0x%.4X", val);
			}
		}
	}

	static int SEX12(u32 x)
	{
		return x & 0x800 ? (x | 0xFFFFF000) : x;
	}

	enum InstructionType
	{
		PPCINSTR_OTHER  = 0, // No additional info for other instr.
		PPCINSTR_BRANCH = 1, // Branch dest. = PC+displacement
		PPCINSTR_LDST   = 2, // Load/store instruction: displ(sreg)
		PPCINSTR_IMM    = 3, // 16-bit immediate val. in displacement
	};

	enum Flags
	{
		PPCF_ILLEGAL  = (1 << 0), // Illegal PowerPC instruction
		PPCF_UNSIGNED = (1 << 1), // Unsigned immediate instruction
		PPCF_SUPER    = (1 << 2), // Supervisor level instruction
		PPCF_64       = (1 << 3), // 64-bit only instruction
	};

	static u32* m_instr;           // Pointer to instruction to disassemble
	static u32* m_iaddr;           // Instruction.address., usually the same as instr
	static std::string m_opcode;   // Buffer for opcode, min. 10 chars.
	static std::string m_operands; // Operand buffer, min. 24 chars.
	static unsigned char m_type;   // Type of instruction, see below
	static unsigned char m_flags;  // Additional flags
	static unsigned short m_sreg;  // Register in load/store instructions
	static u32 m_displacement;     // Branch- or load/store displacement
};