Mesen-SX/Core/NecDspDisUtils.cpp

#include "stdafx.h"
#include "NecDspDisUtils.h"
#include "DisassemblyInfo.h"
#include "../Utilities/HexUtilities.h"
#include "../Utilities/FastString.h"

void NecDspDisUtils::GetDisassembly(DisassemblyInfo &info, string &out, uint32_t memoryAddr, LabelManager *labelManager)
{
	constexpr const char* aluOperations[16] = { "NOP ", "OR ", "AND ", "XOR ", "SUB ", "ADD ", "SBC ", "ADC ", "DEC" , "INC ", "CMP ", "SHR1 ", "SHL1 ", "SHL2 ", "SHL4 ", "XCHG " };
	constexpr const char* sourceNames[16] = { "TRB", "A", "B", "TR", "DP", "RP", "ROM", "SGN", "DR", "DRNF", "SR", "SIM", "SIL" ,"K", "L", "MEM" };
	constexpr const char* destNames[16] = { "NON", "A", "B", "TR", "DP", "RP", "DR", "SR", "SOL", "SOM", "K", "KLR", "KLM", "L", "TRB", "MEM" };
	constexpr const char* dataPointerOp[4] = { "DPL:NOP", "DPL:INC", "DPL:DEC", "DPL:CLR" };

	FastString str;
	uint32_t opCode = *(uint32_t*)info.GetByteCode();
	uint8_t operationType = (opCode >> 22) & 0x03;

	if(operationType <= 1) {
		//OP or RT
		uint8_t aluOperation = (opCode >> 16) & 0x0F;
		uint8_t source = (opCode >> 4) & 0x0F;
		uint8_t accSelect = (opCode >> 15) & 0x01;
		if(aluOperation) {
			str.Write(aluOperations[aluOperation], " ");

			if(aluOperation <= 7) {
				uint8_t pSelect = (opCode >> 20) & 0x03;

				switch(pSelect) {
					case 0: str.Write("RAM, "); break;
					case 1: str.Write(sourceNames[source], ", "); break;
					case 2: str.Write("M, "); break;
					case 3: str.Write("N, "); break;
				}
			}

			str.Write(accSelect ? "B" : "A");
		}
		
		uint8_t dest = opCode & 0x0F;
		if(dest) {
			str.Delimiter(" | ");
			str.Write("MOV ");
			str.Write(sourceNames[source], ", ");
			str.Write(destNames[dest]);
		}
		
		uint8_t dpLow = (opCode >> 13) & 0x03;
		if(dpLow) {
			str.Delimiter(" | ");
			str.Write(dataPointerOp[dpLow]);
		}

		uint8_t dpHighModify = (opCode >> 9) & 0x0F;
		if(dpHighModify) {
			str.Delimiter(" | ");
			str.Write("DPH:$", HexUtilities::ToHex(dpHighModify));
		}

		uint8_t rpDecrement = (opCode >> 8) & 0x01;
		if(rpDecrement) {
			str.Delimiter(" | ");
			str.Write("RP:DEC");
		}

		if(operationType == 1) {
			str.Delimiter(" | ");
			str.Write("RET");
		}
	} else if(operationType == 2) {
		//Jump
		uint8_t bank = opCode & 0x03; //should be 8 bits?
		uint16_t address = (opCode >> 2) & 0x7FF;
		uint16_t target = (memoryAddr & 0x2000) | (bank << 11) | address;

		switch((opCode >> 13) & 0x1FF) {
			case 0x00: str.Write("JMPSO"); target = 0; break;
			case 0x80: str.Write("JNCA"); break;
			case 0x82: str.Write("JCA"); break;
			case 0x84: str.Write("JNCB"); break;
			case 0x86: str.Write("JCB"); break;
			case 0x88: str.Write("JNZA"); break;
			case 0x8A: str.Write("JZA"); break;
			case 0x8C: str.Write("JNZB"); break;
			case 0x8E: str.Write("JZB"); break;
			case 0x90: str.Write("JNOVA0"); break;
			case 0x92: str.Write("JOVA0"); break;
			case 0x94: str.Write("JNOVB0"); break;
			case 0x96: str.Write("JOVB0"); break;
			case 0x98: str.Write("JNOVA1"); break;
			case 0x9A: str.Write("JOVA1"); break;
			case 0x9C: str.Write("JNOVB1"); break;
			case 0x9E: str.Write("JOVB1"); break;
			case 0xA0: str.Write("JNSA0"); break;
			case 0xA2: str.Write("JSA0"); break;
			case 0xA4: str.Write("JNSB0"); break;
			case 0xA6: str.Write("JSB0"); break;
			case 0xA8: str.Write("JNSA1"); break;
			case 0xAA: str.Write("JSA1"); break;
			case 0xAC: str.Write("JNSB1"); break;
			case 0xAE: str.Write("JSB1"); break;
			case 0xB0: str.Write("JDPL0"); break;
			case 0xB1: str.Write("JDPLN0"); break;
			case 0xB2: str.Write("JDPLF"); break;
			case 0xB3: str.Write("JDPLNF"); break;
			case 0xB4: str.Write("JNSIAK"); break;
			case 0xB6: str.Write("JSIAK"); break;
			case 0xB8: str.Write("JNSOAK"); break;
			case 0xBA: str.Write("JSOAK"); break;
			case 0xBC: str.Write("JNRQM"); break;
			case 0xBE: str.Write("JRQM"); break;
			case 0x100: str.Write("LJMP"); target &= ~0x2000; break;
			case 0x101: str.Write("HJMP"); target |= 0x2000; break;
			case 0x140: str.Write("LCALL"); target &= ~0x2000; break;
			case 0x141: str.Write("HCALL"); target |= 0x2000; break;
			default: str.Write("<unknown jump>"); break;
		}

		str.Write(" $", HexUtilities::ToHex(target));
	} else if(operationType == 3) {
		//Load
		uint16_t value = opCode >> 6;
		uint8_t dest = opCode & 0x0F;

		str.Write("LD ");
		str.Write("$", HexUtilities::ToHex(value), ", ");
		str.Write(destNames[dest]);
	}

	out += str.ToString();
}