flycast/core/hw/sh4/dyna/decoder.h

#pragma once
#include "shil.h"
#include "../sh4_if.h"

#define mkbet(c,s,v) ((c<<3)|(s<<1)|v)
#define BET_GET_CLS(x) (x>>3)

enum BlockEndType
{
	BET_CLS_Static=0,
	BET_CLS_Dynamic=1,
	BET_CLS_COND=2,

	BET_SCL_Jump=0,
	BET_SCL_Call=1,
	BET_SCL_Ret=2,
	BET_SCL_Intr=3,
	

	BET_StaticJump=mkbet(BET_CLS_Static,BET_SCL_Jump,0),    //BranchBlock is jump target
	BET_StaticCall=mkbet(BET_CLS_Static,BET_SCL_Call,0),    //BranchBlock is jump target, NextBlock is ret hint
	BET_StaticIntr=mkbet(BET_CLS_Static,BET_SCL_Intr,0),    //(pending inttr!=0) -> Intr else NextBlock

	BET_DynamicJump=mkbet(BET_CLS_Dynamic,BET_SCL_Jump,0),  //pc+2 is jump target
	BET_DynamicCall=mkbet(BET_CLS_Dynamic,BET_SCL_Call,0),  //pc+2 is jump target, NextBlock is ret hint
	BET_DynamicRet=mkbet(BET_CLS_Dynamic,BET_SCL_Ret,0),    //pr is jump target
	BET_DynamicIntr=mkbet(BET_CLS_Dynamic,BET_SCL_Intr,0),  //(pending inttr!=0) -> Intr else Dynamic

	BET_Cond_0=mkbet(BET_CLS_COND,BET_SCL_Jump,0),          //sr.T==0 -> BranchBlock else NextBlock
	BET_Cond_1=mkbet(BET_CLS_COND,BET_SCL_Jump,1),          //sr.T==1 -> BranchBlock else NextBlock
};

enum NextDecoderOperation
{
	NDO_NextOp,     //pc+=2
	NDO_End,        //End the block, Type = BlockEndType
	NDO_Delayslot,  //pc+=2, NextOp=DelayOp
};

struct RuntimeBlockInfo;
bool dec_DecodeBlock(RuntimeBlockInfo* rbi,u32 max_cycles);
void dec_updateBlockCycles(RuntimeBlockInfo *block, u16 op);

struct state_t
{
	NextDecoderOperation NextOp;
	NextDecoderOperation DelayOp;
	u32 JumpAddr;
	u32 NextAddr;
	BlockEndType BlockType;

	struct
	{
		bool FPR64; //64 bit FPU opcodes
		bool FSZ64; //64 bit FPU moves
		bool RoundToZero; //false -> Round to nearest.
		u32 rpc;
		bool is_delayslot;
	} cpu;

	struct
	{
		bool has_readm;
		bool has_writem;
		bool has_fpu;
	} info;
};

const u32 NullAddress = 0xFFFFFFFF;

#define GetN(str) ((str>>8) & 0xf)
#define GetM(str) ((str>>4) & 0xf)
#define GetImm4(str) ((str>>0) & 0xf)
#define GetImm8(str) ((str>>0) & 0xff)
#define GetSImm8(str) ((s8)((str>>0) & 0xff))
#define GetImm12(str) ((str>>0) & 0xfff)
#define GetSImm12(str) (((short)((GetImm12(str))<<4))>>4)